Thursday, December 29, 2011

Lost Puffin in Montreal

We have been talking a lot about alcid species in Connecticut in the past month. Razorbills are being seen on a daily basis in Long Island Sound. It feels like it is almost only a matter of time before someone gets a great look at a Black Guilletmot, a Dovekie, a murre species, or more. Finding an Atlantic Puffin would be incredible, the rarest of the rare, though it is on Connecticut's bird list.

Last week I read this story on a lost Puffin that found itself in the streets of Montreal: http://www.thestar.com/news/article/1104858

Yes, it was literally running down the streets in the city, lucky enough to be found by someone who knew what it was and that it did not belong there. These birds are adept at swimming and flying, not running, so I am sure it would have been an easy catch. Nevertheless, the intrepid rescuer made sure that it found its way to an expert, and it will be returned to the Atlantic as soon as it is well enough. There is a photo of the bird in the full article as well.

If a bird like that can be thrown off course that far then it is entirely conceivable that we could see one in Long Island Sound when so many Razorbills are already joining us. It seems more and more likely, as we watch the Razorbills flying west into the Sound each morning, that they are coming in to feed. Small species of fish are known to be on the rise in recent years, and observations from many people, including my own, suggest that they are landing and then feeding after entering our waters. I have watched them doing this off Stratford Point on multiple occasions during the last couple of weeks. We will keep watching and hoping for an Atlantic Puffin of our own, a healthy and well-fed individual that wants to come have a snack in the Sound.

If you want to come to Stratford Point to see some Razorbills for yourself I would suggest you join us for our walk on January 5.


Scott Kruitbosch
Conservation Techinician

Tuesday, December 27, 2011

Christmas Bird Count 2011 - Stratford-Milford

Yesterday I participated in my second Christmas Bird Count of the season, the Stratford-Milford count. I joined Frank Mantlik for his section of Stratford along with Tina Green, surveying from the Washington Bridge connecting the two towns down the Housatonic all the way to Stratford Point and across to the edge of Long Beach. This count took place on the same day as last year, Boxing Day, though it did not feature a crippling blizzard halfway through the day. It was a chilly start, though quite seasonable on the whole, even with the very powerful winds we felt on the Stratford coast in the mid-morning through the afternoon.

There were many special targets we had in mind for this count. A Snowy Owl had been seen in Stratford the day before. Razorbills had been seen on an almost daily basis for a few weeks now in Long Island Sound, and I had spotted them from our own managed Stratford Point on several occasions, including already in the count week. A Little Blue Heron had been seen infrequently, mostly near the Birdseye boat ramp. However, we went in knowing that many irruptive species might be tough to get this year, including Pine Siskin, Common Redpoll, and Rough-legged Hawk to name a few. Additionally, the constant warmth of the fall season meant that more of the birds could remain inland, from ducks on open ponds to sparrows in fields without any snow cover on them.

With the sizable exception of that Snowy Owl, our targets were reacquired along with some more great finds. After successful stops at the DeLuca field area and Frash Pond, Stratford Point was a haven in the early morning with some fantastic birds one does not see too frequently. While we scoped Long Island Sound I picked up a Northern Gannet to our west. Not long after, Tina found those Razorbills once again, with two flying towards us from the east before landing in a group of American Black Duck and Gadwall. They disappeared underwater rather quickly before I spotted another fly in to the same area. It seemed as if things went quickly- another Gannet, Surf Scoter after many White-winged Scoter, and every duck species you can reasonably expect. A Snow Bunting flew in, a lone bird I had seen on Christmas day as well, only slightly bested by the lone American Pipit on the revetment wall. Frank and Tina picked out a Merlin along with two Northern Harriers hunting in the distance.

The full account of the long and busy day would be an exhaustive read, so I will keep the rest of this summary to some of our better finds. Tina first spotted the only warbler of this count, unlike last weekend's extravaganza, but it was a good one and a different species for the month for me - a Palm Warbler!



It was along Russian Beach, just to the west of Stratford Point, and very camera shy in such an open area. Continued looks at Long Island Sound did not yield much more than we had at the Stratford Point, and a stop at the marina was largely uneventful until suddenly this Greater Yellowlegs appeared in front of us.



It was like magic, not there one moment and then mere feet beyond the three of us on the dock. We have no idea what happened. When searching for the Little Blue Heron in another stop at the boat ramp I had one of those classic birding moments when you find something you aren't looking for because you're so focused on the target in mind. I nearly walked into - literally - three Wilson's Snipe sitting on the side of the parking lot. They flushed and startled me, moving further onto the floating debris that builds up here. I was able to snap some shots of one that stayed in the open.



That Snowy Owl may not have been flying around the Great Meadows Marsh on Monday, but an American Bittern was. Short Beach Park, directly on the east side of Stratford Point, continued the run of presents that this connected shoreline area had already given us. We were treated to a Fox Sparrow that popped up from a bunch of White-throated and Song Sparrows behind the tennis courts and on the edge of the landfill. A Great Egret was tucked away there as well as a single Horned Lark with several Savannah Sparrow on the dunes. We often speak of how important Milford Point and Stratford Point are, but Short Beach Park and Russian Beach are also enormously significant to birds, plant life, and other wildlife. On a non-bird note, I was amazed at how much Prickly Pear Cactus, a state-listed species, was now growing at Russian Beach.

We tallied an astonishing 81 species on the day, finding several of the highlights of the entire circle in the process. The overall total was 102, lower than usual with some silly misses, likely due in part to the warmth. No Chipping or Field Sparrows, Brown Thrasher, Hermit Thrush, and American Kestrel may be because they are still in open inland areas. No Bald Eagle or Wood Duck was probably aided by the abundant unfrozen water here and to our north. At this time of year I could very easily have a Common Grackle or Brown-headed Cowbird at my feeders, but neither were seen as they have been able to feed freely away from our counting eyes.

We have a lot to work on in the next few days to get some of those birds for count week! The weather will not be helping to bring birds south as this warmth looks like it may go on through much of January.


Scott Kruitbosch
Conservation Technician

Saturday, December 24, 2011

Birds crash into parking lots in Utah

Last week I read a remarkable story in USA Today that you can read in full here: http://www.usatoday.com/news/nation/environment/story/2011-12-14/bird-crash-landing-utah/51927250/1

It seems that thousands of migrant grebes somehow mistook parking lots for ponds or lakes, attempting to land in them and instead smashing into the paved surface. The theory put forth is that clouds over the area, and especially over the lights of the parking lots, apparently made it seem as if they were bodies of water, perhaps reflecting the moonlight, waiting for the grebes to land in. No humans were injured and no damage took place other than thousands of birds being killed in these terrible crash landings.

The story takes a more positive turn when it comes to the efforts of wildlife officials and many volunteers. They actually saved thousands of grebes by collecting them from the parking lots the next morning and bringing them back to an actual suitable habitat. While I am guessing some may have been injured and needed some medical attention, many more may have been stunned and simply needed time, like some of the lucky birds that survive window strikes. Others were likely confused and dazed, unable to determine a course of action, and putting them back to where they belong was a huge help.

This tale makes you wonder how often events like this occur without our knowledge. This was a horrible accident brought on by unique conditions - how often do similar situations occur and how can we prevent such events in the future? We likely need to reevaluate leaving lighting such as this on at night as it is often a cause of bird mortality. It would save many birds while also saving everyone some money on the power bill and reducing our usage of fossil fuels, a winning situation for everyone involved.


Scott Kruitbosch
Conservation Technician

Thursday, December 22, 2011

Stratford Point Public Bird Walk - January 5

Connecticut Audubon Society Conservation Biologist Twan Leenders and Conservation Technician Scott Kruitbosch will lead a public bird walk at Stratford Point on January 5th from 9-11AM. We will take a look at what wintering ducks are present and see how many species we can find at the mouth of the Housatonic River. This is a great opportunity to bird one of the prime locations in Connecticut and get a head start on your list for the New Year. We will also discuss the exciting habitat management and conservation projects that will be taking place at Stratford Point in 2012.

The walk will be free and we suggest bringing binoculars and a spotting scope, if you have one. Make sure to dress for the season! It is usually safe to assume that this exposed coastal spot is windier and colder than much of the state. Please meet in the visitor parking lot by the buildings. Stratford Point is located at 1207 Prospect Drive, Stratford. Notification of cancellation will be posted on the CT-BIRDS listserve and the Connecticut Audubon Society website (www.ctaudubon.org). Our tentative back-up date is January 11th. For more information, contact Scott Kruitbosch: skruitbosch@ctaudubon.org

We will definitely be looking for another Snowy Owl and other beautiful rarities! Apart from the Snowy seen at Stratford Point on November 30, another one was reported in the general area in Milford on December 20. There have also been frequent and nearly constant Razorbill sightings across Long Island Sound, so have your scopes ready.


Scott Kruitbosch
Conservation Technician

Tuesday, December 20, 2011

Construction of novel erosion control and habitat restoration project at Stratford Point is making excellent progress!

Hurricane/Tropical Storm Irene left Stratford Point's Long Island Sound-facing shore in shambles and during the month of August the site saw a lot of activity as this damage was repaired. Large trucks and several excavators moved mountains of large boulders into the storm-damaged revetment wall to stabilize and armor the 'high-energy' side of the site. The use of hard structures, such as rock or concrete walls, has traditionally been the method of choice to control erosion in tidal areas. However, in recent years this approach is being revisited and novel, 'soft' erosion control structures are being put to the test in many areas surrounding Connecticut. Connecticut Audubon Society, together with site-owner DuPont and specialized contractor 'All Habitat Services, LLC', is currently in the midst of constructing such a soft erosion control structure along the 'low-energy' north shore of Stratford Point - a novelty in Connecticut.

Contractors evaluate the projected contour of the new dune in an area affected by Hurrican Irene

As their name suggests, these 'soft' structures are relatively flexible and can absorb some of a wave's energy as it crashes onto the structure, rather than deflect it like a hard surface would. The latter scenario often results in undermining of the structure and/or excessive erosion at its base, causing a sea wall to become compromised over time. In areas where wave impact is relatively minor and in areas of sensitive coastal habitat, a soft erosion control structure may be a better fit. The northern cove of Stratford Point fits both descriptions since its orientation protects it from most direct wave impacts while the coastal habitat found on-site is among the most threatened in the state. Once completed, the newly constructed erosion control feature will be contoured, covered with a thick layer of sand and planted with 38,000 dune grass plugs to form an artificial coastal dune system extending the length of the north shore.

The first tube goes in to set the baseline

Historically, the intertidal zone of Stratford Point was densely vegetated with Smooth Cordgrass (Spartina alterniflora), rooted in banks of organic peat. A large-scale remediation in 2000-01 led to the removal of large amounts of lead shot from the site's upland and tidal areas - a remnant of the site's history as a trap and skeet shooting club. However, this environmental clean-up also caused the loss of all peat substrate and associated plant life from the intertidal zone. This loss of vegetation zone has destabilized beach sediment and led to erosion of the site's shoreline due to unabated exposure to wave action. Between 2001 and 2011, over 100 horizontal feet of upland was lost along sections of the north shore of Stratford Point, and erosion continued to be a problem.

Each additional layer of tubes is wrapped in sheets of geotextile and anchored in the
upland, while the entire stack is also tied together by a geotextile covering
    

In 2010, Connecticut Audubon Society's Conservation Biologist, Twan Leenders, carried out a feasibility study to evaluate whether the concept of creating erosion control structures that are integrated in coastal habitat elements was feasible at Stratford Point. Monitoring studies to assess the species of plants and animals currently found along the northern shore of Stratford Point, and additional surveys of nearby high-quality coastal dune habitats to investigate the potential target species composition for the newly created coastal dune were completed this past year. The latter study was carried out by CAS Science & Conservation staff and students from Sacred Heart University, with financial support from The Nature Conservancy. Once all the pieces of the plan were in place, by fall of this year, it was decided to move ahead as soon as possible to stop further erosion of the site's shoreline. The unseasonably warm weather in recent weeks has helped the project tremendously and extended our work window well into December. If this pattern holds, we should see a finished project before the end of the year!

The plantings arrive at Stratford Point: 38,000 beach grass plugs and their private chauffeur.
The plants are temporarily stockpiled here until the dune is ready to be planted. 

The process of constructing the basis for this artificial dune is worth a closer look. Rather than using traditional stone elements for a foundation, the entire structure is built around a series of sediment-filled geotextile tubes. Each tube is filled to capacity with a mixture of sand and organic compost to form a 12-inch diameter 'sausage' that runs the entire 750 foot length of the dune. Individual tubes are arranged in a step-ladder fashion, stacked up to nine tubes high in some places, and held together by sheets of additional geotextile fabric. The sediment-filled tubes are flexible and dynamic and settle snugly around the variable contours of the shoreline. They are placed against the face of the eroding shoreline and the entire structure is engineered to match the height of the existing bluff. Once completed, the tubes will be hidden from view by the sediment and plants that cover the dune, but they will provide stability and bulk to the entire system. The dune grass plantings will gradually be enhanced with a more diverse mixture of vegetation, but initially it is most important that these fast-growing grasses establish an extensive root system to stabilize all the sediment on top of the dune.

The tubes are in and a substantial section of the structure is covered with  sand already.
The new shoreline contour is taking shape...

Apart from the creation of the artificial dune system, the 2010 feasibility study also recommended restoring the historic tidal marsh vegetation lost during the 2000-01 large scale remediation at Stratford Point. Smooth Cordgrass plants growing in the intertidal zone move with the water's tidal motion and absorb energy from waves before they hit the shore. The combination of decreased erosion as a result of lower wave energy and the sand-trapping ability of salt marsh vegetation will promote the growth of a sandy beach habitat. Restoring the salt marsh fringe present at Stratford Point prior to 2001 will help to protect the newly created coastal dune system, while enhancing the tidal marsh habitat at the site. This salt marsh restoration project is next on the docket for 2012.

Beach Grass is being planted in the foreground, while the finishing touches are put on the dune contour
in the back. The end is in sight!   

Stratford Point's new dune system is designed to be dynamic and to allow for deposition and migration of wind-blown sediment. In the long term, the appearance of this coastal dune habitat will be shaped by the prevailing elements and will hopefully become an integral part of the site's coastal landscape. Continued monitoring of the area will tell us not only whether the soft erosion control structure does its job of stabilizing the shoreline, but we are also very interested to see whether plant and animal species that depend on coastal habitats will gradually occupy the newly created habitat. In the next couple of years, Connecticut Audubon Society staff will implement additional novel habitat management and conservation projects at Stratford Point and we will keep you informed on how they turn out. Through a series of creative habitat restoration and management projects we are hoping to see the recovery of local at-risk species while the site transitions from what was once an environmental hazard to a vibrant coastal nature preserve. Come see it for yourself some time!

Twan Leenders, Conservation Biologist
Photos by Twan Leenders

Sunday, December 18, 2011

Christmas Bird Count 2011 - Westport-Fairfield

Today I participated in the Westport-Fairfield Christmas Bird Count as I do annually, joining Charlie Barnard Jr. for his area of the circle. He covers the Fairfield shore, an area with a tremendous variety of habitats, allowing us to take an arduous hike out to the end of Penfield Reef and a walk through the old landfill that is now part of the Pine Creek Open Space, among other stops. Suffice it to say, there is a lot of ground to cover, and often many "good" birds to find. I did not think today's highlight theme, on this naturally frigid December day, would be warblers.

Alex Burdo and James Purcell, two young and very skilled birders, got a head start on things during count week, tallying a bunch of nice birds we hoped to find again today. The highlight of the day for me was relocating a Nashville Warbler along with an Orange-crowned Warbler...and another...and...what...another! Yes, we ended up with three Orange-crowned Warblers along with the Nashville after I initially pish-ed out the first two birds exactly where they were seen the day before. Here are some shots of the Nashville, the bird I focused on getting shots of because of the late date at the expense of photographing the three Orange-crowned Warblers.







The three others eluded my camera as I struggled to focus on them while they moved in and out of bittersweet tangles and other brush, but those on hand had fantastic looks.

This was all after another cool find made all the more special because of the date. They may be common in some parts of the year, but this Common Yellowthroat is anything but that a week before Christmas!




One warbler that we did not record that Alex and James found yesterday was a Yellow-breasted Chat, though I bet it was right there staring at us, hiding from our eager eyes. Earlier in the morning, we had a Yellow-rumped Warbler at Jennings Beach making it a total of six individuals of four warbler species on the day. I hope next week's Stratford-Milford count has just as many unexpected highlights and Stratford Point provides a few of them.


Scott Kruitbosch
Conservation Technician

Saturday, December 17, 2011

Connecticut Audubon Society names new Communications Director

Connecticut Audubon Society has named conservationist and author Tom Andersen as its director of communications and community outreach.

Tom will oversee all of Connecticut Audubon’s communications with members, the general public, and the press, and will also coordinate the organization’s public policy and advocacy work.

“We’re poised to grow and to play a bigger role in conservation issues in Connecticut,” said CAS President Robert Martinez. “Tom knowledge and experience in the not-for-profit world and in conservation will help us focus our message and our work, reach more people, and be even more effective in protecting Connecticut’s critical natural habitats.”

Tom  will oversee Connecticut Audubon’s website and direct communications with members and the general public; social media; and press relations. He will lead a team of Connecticut Audubon staff and board members in identifying, and then formulating positions on, the public policy issues that make up the core of Connecticut Audubon’s advocacy work.

He is the author of This Fine Piece of Water: An Environmental History of Long Island Sound, published by Yale University Press. Tom spent 10 years at Westchester Land Trust, in Bedford Hills, N.Y., as director of communications and special projects and as acting executive director. He helped Westchester Land Trust protect an average of more than 600 acres a year from 2000 through 2010, a decade during which the total amount of land the organization protected rose from 900 acres to more than 7,000 acres.

Previously he worked as a newspaper reporter in Westchester County, mainly writing about environmental issues. A former 15-year Connecticut resident, he now lives in Pound Ridge, N.Y.

He can be reached at tandersen@ctaudubon.org.


Scott Kruitbosch
Conservation Technician

Friday, December 16, 2011

Razorbill flight and a Common Eider

A strange event took place in Long Island Sound yesterday as tens of Razorbills, perhaps more, flew through heading to the west. They were seen throughout the morning and afternoon at several locations on the Connecticut coast. They are almost a regular sight at Hammonasset State Park right now. A flight like this along with increased reports of the species in the past few years leads one to suspect something has changed as they are very rare here otherwise. The most common theory is that they are coming in to the Sound much more often because of an increase in their prey, small fish. Perhaps we will be able to piece it together in coming years.

I had actually seen a single Razorbill flying west from Stratford Point a few weeks ago on November 22. Yesterday, Charlie Barnard found a couple of Razorbills swimming around off Stratford Point early in the morning, though they headed off to the southwest relatively quickly. I spent an hour or so seawatching and tallied six more, all flying right by to the west. While I was scoping the Sound I found another rare bird that is increasingly reported, a Common Eider. This female flew in directly in front of me, just east of the lighthouse, and swam around with a few American Black Ducks for a while.



It seems Stratford Point is only going to be more active for species such as these in the immediate future, so keep them in mind if you visit us, and please tell us if you see them or anything even more rare.


Scott Kruitbosch
Conservation Technician

Wednesday, December 14, 2011

Stratford Point bird walk 12/14 results

A quick but big thanks to everyone who joined us for the bird walk this morning at Stratford Point. We will announce the date of next month's walk soon. The weather was remarkable for December 14 with only a very light wind and above-normal temperatures in the warm sun. The beautiful conditions made it a little quieter than a typical December day for us as ducks are still coming in Long Island Sound from the north, and as Tom wrote about yesterday and we in the conservation department suspect, some may not spend the winter on our shore this year. Nevertheless, we saw 30 species, with some nice looks at the ducks that were present and a very entertaining group of around 75 Snow Buntings that frequently flew right over our heads. Here are all of the species spotted today:

Brant 
Mute Swan 
Gadwall 
American Wigeon
American Black Duck 
Mallard 
Surf Scoter 
White-winged Scoter
Long-tailed Duck 
Common Goldeneye 
Red-breasted Merganser 
Red-throated Loon 
Common Loon 
Great Cormorant 
Northern Harrier 
Black-bellied Plover 
Sanderling 
Ring-billed Gull 
Herring Gull (American) 
Great Black-backed Gull 
Mourning Dove 
American Crow 
Carolina Wren 
Northern Mockingbird 
European Starling 
Snow Bunting 
Savannah Sparrow 
Song Sparrow 
House Finch 
House Sparrow 


Scott Kruitbosch
Conservation Technician

Tuesday, December 13, 2011

Diving Ducks and Oyster Beds

The mouth of the Housatonic River and the stretch of Long Island Sound immediately to the east and west is one of the richest natural spawning areas for oysters not only in the Sound but probably in the northeast.

Oysters that spawn in the Housatonic populate the mouth of the river, and currents sweep oyster larvae around Stratford Point, where they settle out on Bridgeport Natural Bed, a four-square mile area from Point No Point to Black Rock that is so important to the Sound’s oystermen that state regulators allow oyster boats to use hand-powered dredges only, so as not to damage the beds with power dredges.

I visited Stratford Point today to learn about Connecticut Audubon Society’s habitat restoration project there, and in the course of an hour’s conversation with Scott Kruitbosch, Connecticut Audubon’s conservation technician, some interesting speculation about the Housatonic oyster beds emerged.

Last year at this time, Scott told me, there were “massive” numbers of diving ducks on the mouth of the river. Greater and Lesser Scaup. White-winged Scoters and Surf Scoters, maybe Black Scoters, as well as Redheads and King Eider. This year, nothing. The protected cove to the north has plenty of dabblers -- American Wigeon, Black Ducks, Gadwall -- but the diving ducks are not around.

The diet of diving ducks includes small oysters. The speculation by Connecticut Audubon’s conservation staff -- a guess, really -- is that something happened to the oyster beds. And the further speculation is that what happened was Hurricane Irene.

Numerous oystermen reported in September that the storm had damaged their equipment and smothered their oyster beds with sand and mud. Historically, the infamous hurricane of 1938 did so much damage -- wrecking oyster boats and oyster beds -- that it almost wiped out the Sound’s oyster industry. It took two decades for it to recover.

I haven’t seen a full assessment of the damage that Irene did to the Sound’s oysters. But if the lack of diving ducks on the Housatonic is an indication, the damage includes not only the Sound’s oystermen but possibly the wildlife that relies on the Sound’s oysters as well.

You can read more about Stratford Point here and here on Connecticut Audubon's website. -- Tom Andersen

Monday, December 12, 2011

8,041 Broad-winged Hawks

I have greatly enjoyed many of the days spent hawk watching thus far in three seasons at Boothe Memorial Park in Stratford, though I do not think any surpassed the thrill of September 16, 2011, when 8,234 raptors were recorded including 8,041 Broad-winged Hawks. Contrary to the prelude to the day in my last writing on the historic Turkey Vulture flight, I felt extremely certain that we were about to be enthralled by a flight of thousands of Broad-winged Hawks in the week leading up to it. Even a full six days before the flight we were set to receive I was mentioning it to friends and fellow observers, saying in an email that a fast and strong cold front would be “hard to time…exactly a week away but it'll be fun, mega Broad-wing push”. Boothe’s previous Broad-winged Hawk daily record was only 1,884, this was only year three, and I am not a psychic – what made me so confident about that day?

Looks like a good day for hawks! (See the weather vane at the top of the tower in this northwest facing photo by Frank Mantlik)

I went back and examined some of the "mega" flights at various points in Connecticut's history in the year since the conclusion of the 2010 hawk watch season in an effort to determine when one would occur again. Thanks to Neil Currie and so many other vigilant hawk watchers over the last 40 years we have a very strong set of data that can guide you to general flight dates. The late teens of September are a superb time for Broad-winged Hawks to fly, and this has become generally basic knowledge among those invested in the hobby. Knowing when a given species has the itch to get on the move to the south is one very important factor, but what happens if the weather doesn’t cooperate? Some birds, especially the Broad-winged Hawk, would never want to move against a southerly wind or under particularly overcast and rainy skies.


Atmospheric success

I put on my weather hat and dove in to meteorological data, using the dates of some of the biggest flights of Broad-winged Hawks the region had ever seen and examining the weather conditions that made them possible. I looked for patterns in the atmosphere on a large scale – wind speed and direction, the placement of high pressure centers, any blocking weather in the days before, sky conditions, temperatures and precipitation, and more. Some of the major motivating factors fell in line with conventional hawk watch wisdom, namely that raptors often take to the skies after the passage of a fall cold front. However, this is where things get much more complicated as a simple frontal passage is not sufficient for a strong hawk movement, let alone a historic one.

The most important factor, in my eyes, is the recent placement of a strong high pressure center over the vicinity of the Great Lakes region during the daytime hours of a given flight day. Such a perfect placement is seen infrequently with a cold air mass filtering down from Canada in the wake of a low in September. For the most part, the cold front passage has to be swift enough and clean, without any other areas of low pressure remaining nearby, without the presence of residual precipitation via a subsequent shortwave or other means, and sizable enough to encompass at least the entire northeastern United States and southeastern Canada. This seems to be the best conveyor belt for Broad-winged Hawks, pushing them to the south across multiple states, and such a placement puts Connecticut squarely under northwest winds from the anti-cyclonic flow of the high. The timing of the movement of the high is important for the flight but also for the pressure gradient as the winds have to be light to moderate, as a howling wind from the northwest will move some birds, but not allow thousands to stream through.

There are actually many more ways a passing cold front could permit a small or moderate flight, though not a sizable one. Let’s say a cold front passes through with high pressure moving in from the south – this flow will be westerly and ultimately southwesterly, disallowing any substantial movement whatsoever. We could have a weak cold front passing through with showers followed by a lack of any significant air mass, or an upper trough causing completely overcast skies (limiting thermals) and some precipitation on its heels. Sometimes a cold front will pass through only to stall out just to the east or southeast of Connecticut, making it difficult to get raptors moving through our air in any great numbers. Sometimes you do not need a cold front at all, and one of the best periods of movement in 2011 proved that. The departure of a sluggish upper level low spinning over the region in early October was followed by a high that graced us with light northwest winds on October 5 and 6, pushing through 352 and 621 raptors, respectively, with October 6 allowing Boothe to break daily Sharp-shinned Hawk and Bald Eagle records, among others.


September 2011’s weather

The key to a massive Broad-winged Hawk flight is clearly the weather leading up to and on the day in question, and this held true in 2011. Early September was plagued by a nearly constant southerly or southwest flow in the wake of Tropical Storm Irene. The few fronts that passed through Connecticut stalled near or over the region, with one coming through in the first week of September stopping off our coast as Hurricane Katia came north through the Atlantic. Her sizable influence and cyclonic flow actually provided the best hawk watching day for Boothe Park prior to this Broad-winged Hawk flight, with 40 raptors seen under light northwest winds – yes, only forty. It is abundantly clear that the hawks were stopped from any significant movement whatsoever prior to the date of the major flight this September, and it is likely this contributed to the extremely large movement that followed.

Once we were around one week away, I noticed that long-range models indicated the likely possibility of a large and strong cold front stretching from southeast Canada to the Gulf coast pushing through late in the following week, clearing the entire eastern seaboard. A strong high pressure center would move through the northern Great Plains and possibly settle near the Great Lakes or Ohio Valley. This is essentially what occurred with wondrously fortuitous timing as the front cleared well off the Atlantic coast overnight on September 15, allowing for the air mass of the high to take over as it moved in to position near the Great Lakes near sunrise. The distance between pressure centers was enough to keep the winds at a moderate strength, around 8-12 MPH at our site, with occasional gusts lessening in frequency and intensity as the day went along. We were even able to muster up some light cirrus overhead to top off the near-ideal conditions.


Boothe Park’s position

A lot has been said about the position of Boothe Memorial Park in discussions about the high number of raptors occasionally passing over. It is situated approximately three miles off Long Island Sound from its closest point, actually in Milford. Somewhat like Turkey Vultures and some of the other buteo species, huge numbers of Broad-winged Hawks are reluctant to move much closer to the coast than our position, and indeed, many that come over are heading to the west or west southwest rather than south or even southwest. We can have streams of birds in a long train heading west while more are being added to it by incoming kettles from the north. Below is a shot of us on September 16, unfortunately the only photo taken that day during the nonstop action, counting the streams of Broad-wings going to the west southwest.

From left to right, Charlie Barnard, the clipboard on the chair, Scott Kruitbosch, Bill Banks - taken by Frank Mantlik

Once again, like the Turkey Vultures, the key at Boothe Park is to have a light to moderate wind from the north or northwest. Any easterly component pushes birds away from us due to geography, and when it comes to Broad-winged Hawks, they will not take to the sky in nearly the same force. As I discussed in the above section, the winds were mostly light to moderate, with occasionally stronger gusts that wore down as the day progressed. This ensured that the Broad-wings would be pushed from all inland areas down along the coast, but not so much that they were battered in the air, kept from attaining the appropriate altitude, or forced to fly to our south.


Nine exhilarating hours

The count began at 8:00 a.m., with Bill Banks joining me bright and early. We would remain there for the next nine hours, with Charlie Barnard and Frank Mantlik spending significant portions of the heavy afternoon flight there, and Penny Solum joining us for some time in the morning. As most hawk watchers know, it takes some time for raptors to get into the skies mostly because of the fact they are waiting for thermals, rising columns of warm air that help them almost effortlessly glide to the south. This is particularly true at Boothe Park for another reason as it is difficult to see much around ground level because of trees, buildings, and other impediments. The birds have to be relatively high in the sky to see them, and we typically only get early birds either directly over our heads or in gaps to the east and southeast near the Housatonic River.

We tallied a few quick Bald Eagles, Ospreys, Cooper’s Hawks, a bunch of Sharp-shinned Hawks, a Northern Harrier, and an American Kestrel. In the case of Broad-winged Hawks, it takes them an especially long time to wake up and get on the move, and we did not have any of them until 18 passed through between 10:00 and 11:00 a.m. By this point, I was beginning to get a little anxious about my prediction, and whether or not we would be able to pull off a large enough flight in approximately the next four or five hours. Catching even a couple thousand birds in such a time frame seemed like an insurmountable task at the rate we were going, but I kept repeating to myself (in my head and out loud, as others can likely attest to) that this was a perfect setup on a perfect date, and we were going to be paid off soon enough.

I suppose many of the Broad-winged Hawks we saw that day had some distance to cover after taking to the skies, moving to the south from other parts of Connecticut or coming in from nearby areas in the first few hours of the day before reaching us. Not long after 11 a.m. the major flight started, and before the hour was over, we had broken our hourly record of 876 birds (set on 09/20/10 by me, counting alone, from 3:00 to 4:00 p.m. that day) with a strong 892. Even if we maintained this rate we would have a tremendous afternoon, and we thought that if we could get a few more clouds than the 15% cover of cirrus we had that hour, this could be spectacular. Suffice it to say, we did, and it was more than we could have hoped for. We shattered the hourly record and the daily total record between 12:00 and 1:00 p.m. as we tallied 1,278 Broad-winged Hawks, pushing our total over 2,000.

I certainly did not anticipate doubling this over in the next hour, but from 1:00 to 2:00 p.m. we counted a mind-blowing 2,887 passing over our heads. For the most part this took the form of an exceptionally long and seemingly endless river of raptors nearly directly above our position, slightly to the north of straight up from the site. It spanned the sky from the trees and neighborhoods to the west all the way to the horizon over the Housatonic in the east. We craned our necks until we could not bear the physical pain any longer, the four of us trying to somehow keep track of and count every single bird in this enormous river. Part of the problem I recall having was that they flew in a wide track stretching beyond one or even two binocular views, especially tough for my “10s”.

One had to sweep their binoculars back and forth simply to count all the birds in even one small section of the river all while they moved to the west. Bill, Charlie, and Frank were fantastic, calling out the numbers to me as I added them up in my head and occasionally scratched down totals on the data sheet. We all tried to count these overwhelming numbers as best we could while keeping on the conservative side if we ever lost track of a few, being careful not to double count any. Our independent counts of sometimes hundreds of birds were often extremely close to one another. A few times we had to stop and stare in awe, being overwhelmed by the sheer outrageousness and splendor of the sight, unable to think correctly or process it fully. I thought we would be able to cruise past 3,000 in the hour, but they started to slow down from their peak movement before we got to 3 o’clock.

That is not to say the movement was anything but astonishing in the next hour as we totaled more 2,468 Broad-winged Hawks. Our bodies would finally get a respite from constantly staring upwards as the flight rapidly slowed down before 4:00 p.m., and we concluded at 5:00 after a final hour of 175 more. Here are the unreal totals for the raptor migrants tallied during our nine hours of observation:

Osprey - 30
Bald Eagle - 11
Northern Harrier - 5
Sharp-shinned Hawk - 122
Cooper's Hawk - 12
Broad-winged Hawk - 8,041
American Kestrel - 12
Un. Buteo - 1
TOTAL - 8,234


Broad-winged Hawk flight history

I had some idea of the magnitude of our total in that it was of limited historic nature, though that it was nowhere near the top days seen in Connecticut, as some flights have been over 10,000 birds, with Quaker Ridge in Greenwich having a couple of days over 30,000. I surely thought the other coastal sites that day, Quaker or Lighthouse Point in New Haven, would have numbers similar to ours, probably greater at the former and lesser at the latter. However, the conditions I described apparently did play out perfectly for us, as we beat the more-inland Greenwich total of 6,342 raptors, 6,176 being Broad-winged Hawks. Lighthouse Point, being right on the water, had 3,713 raptors with 3,116 Broads, having had more of the other species, also to be expected.

Neil Currie, one of the founders of the NorthEast Hawk Watch and raptor migration expert, has been a force in creating and promoting hawk watching for 40 years. It is because of him and others that we have all of the information on migration that we do now, from prime locations to observe raptors, to the dates of flights, and decades of data. Neil was kind enough to compile and send me information on the largest flights of Broad-winged Hawks ever in Connecticut so that I could get a sense of the significance of this flight and compare it further to when others like it occurred. All of the data discussed below does not yet include the 2011 season.

There have been 456 days in which over 1,000 hawks were observed at a given location in Connecticut, with 2,000+ being seen 192 times, 3,000+ recorded 99 times, 4,000+ tallied 67 times, and a sensational total of 5,000+ on 47 occasions. All of the dates of the sightings of 5,000+ raptors fall between September 12 and 25, with the majority being between the September 14 and 19.  Unsurprisingly, Quaker Ridge leads the pack with 14 of these days, followed by a tie for second of four each for Lighthouse Point and Whippoorwill Hill, out of 20 different sites. In consideration to our total of 8,234 at Boothe Park on September 16, there had been 19 previous counts of 8,000+ hawks in Connecticut history, this being the 20th in the last 40 years.

On the surface, this leads one to think such an event happens every other year, but this is not the case. Some of the mammoth flights have been recorded at multiple locations on the same day at these extreme levels, such as a movement on September 19, 1993 that featured 25,307 raptors at Booth Hill in West Hartland, 23,371 at Woodchuck Lane in Harwinton, and 22,475 at Quaker Ridge in Greenwich. Some have occurred back to back, like a flight of 30,786 raptors at Quaker Ridge followed two days later by a movement of 10,022 more at Greenwich Point. Interestingly, 24 of the flights over 5,000 took place in the 1980s, and 19 took place in the 1990s, with only three being recorded in the first decade of the 21st century.

As far as I can tell, the 8,234 raptors we recorded at Boothe Park on September 16, 2011 was the highest one-day total seen in Connecticut since 11,107 were counted at Booth Hill in West Hartland on September 13, 1998, when I would have been just shy of 13 years-old and quite clueless as to the very existence of such phenomena possibly occurring down the road from me at Boothe Park. That is an extraordinarily remarkable time period, and only makes the observations and memories of that day even more special. Let us hope that more days like this are coming in the future, and the population of Broad-winged Hawks to our north did not peak in the past. I cannot wait to see what September 2012 has in store for us and if we will be able to predict it so accurately once again.

You can see more information, from directions to all of this data, on our HawkCount page here:
http://www.hawkcount.org/siteinfo.php?rsite=703

Scott Kruitbosch
Conservation Technician

Photos © Frank Mantlik

Saturday, December 10, 2011

Migratory bats

I wanted to bring up the subject of bats after some sightings that I have had in the past few weeks. On November 26, I noticed a unique flying creature swirling around through my neighborhood around sunset. It was quickly obvious that it was not a swallow or a swift. I was able to determine that it was a Red Bat (Lasiurus borealis), a species of Special Concern on the Connecticut Endangered Species Act, before it flew off to the south continuing its migration as darkness overtook the area. Red Bats are forest dwellers, and while it was certainly not out of place in my neighborhood, it did seem late in the season for a sighting.

Little is known about the migratory routes and timing of departure from Connecticut or points north for the various bat species we can expect to see in our state, but November and December can be brutally cold months for insectivores. Even October was a perilous month this year. Stratford Point is actually a good place to spot Red Bats in the fall, and we are starting to think the site may be on a migration route with bats following either the Housatonic River to the south or the Long Island Sound coastline to the west. An extreme example occurred on the morning after Tropical Storm Irene. I arrived at Stratford Point well before sunrise, and around 6 a.m. I spotted a Red Bat coming in from Long Island Sound and heading towards our main building, likely roosting there, possibly in the vents along the roof, for the day. I believe it was returning to land after finding itself over water as the sun came up, as many birds do.

Again, the Red Bat is a forest dwelling species, and the mouth of the Housatonic River, sands of Long Island Sound, and Stratford Point's coastal grasslands are well out of place for it. Inclement weather likely pushes some of the others to stay here and hunt the area, once again just like some bird species that are out of habitat on the property do. Another notable sighting was of a bat species flying into the gable vent on the main building of Stratford Point on Tuesday afternoon, December 6, as the rain poured down and fog continued to cover the area. Twan believes what I saw was an Eastern Pipistrelle (Pipistrellus subflavus) as we have already encountered the species on the property in December before, with a single Eastern Pipistrelle seen roosting in a building during an extreme cold snap a couple years ago. We do not know if it was a migrant or a resident.

I also had a recent report via an at-reply to our Twitter account of what an observer believes to be multiple Little Brown Bats every night in their yard. Clearly, there is a lot to learn about bats in Connecticut, and we would always appreciate hearing about any sightings you have, especially during the fall and winter months.


Scott Kruitbosch
Conservation Technician

Wednesday, December 7, 2011

Historic Turkey Vulture Flight

The Boothe Park Hawk Watch has now closed for the 2011 season with a sensational 12,215 raptors counted in only 115.5 hours. This is the first of a series of pieces that I, as the coordinator of the site who spent the vast majority of those hours there, will be writing during the offseason on some of the special sightings and notable numbers we enjoyed this year.

One of the many Turkey Vulture kettles from 10/28/11

On October 28, 2011, the hawk watch at Boothe Memorial Park in Stratford experienced an unprecedented event as those on hand tallied 521 migrant Turkey Vultures in only 7.5 hours of observation, obliterating any known flight record in New England and even some beyond. This astounding total was supplemented by 218 Red-tailed Hawks, a sum not to be relegated to an afterthought. The Red-tail count is believed to be the third highest in New England history, falling short of a Lighthouse Point total of 237 on November 7, 1999, and Boothe’s own total of 249 on November 1, 2010, the current record holder. Not coincidentally and as will be examined, that day held Boothe’s previous Turkey Vulture high count of 190, also one of the best ever in the northeast. In only the third year of opportunistic observation, Boothe has established itself as a regional force to be reckoned with when it comes to buteos and vultures, and a strong site for nearly every other Connecticut migrant raptor species.


Comparisons

It is safe to say that no one could have predicted the enormity of the Turkey Vulture explosion of October 28 as such a sum has traditionally been reserved for an elite group of watch sites with decades of experience. Many of these sites are far to our south, like Kiptopeke in Virginia, or buoyed with supreme geographical aids, as is the case in Cape May each fall or Braddock Bay in the spring. Cape May was one of my first thoughts at the conclusion of the epic day – specifically, had we come even close to touching one of their best flight days for Turkey Vultures? One has to bear in mind that they hold records that the vast majority of count sites can never dream of impinging upon. Seeing 1,023 Osprey or 278 Northern Harrier in one day is laughable for us here in Connecticut, but still not as impossibly insurmountable as daily totals of 7,000 Sharp-shinned Hawk or 1,231 Cooper’s Hawk are. For now, I can only dream that Boothe Park will complete an entire season with those sorts of numbers in the not too distant future.

Cape May’s top three Turkey Vulture flights are “only” 784, 607, and 602, still comfortably beyond the 521 we witnessed on October 28, but not at all embarrassing in comparison to Boothe’s new record. This immediately invigorated me, and I looked at many other sites in New England and the Mid-Atlantic, finding few if any that came even close to this spectacular fall flight. I already knew that Connecticut’s two major sites, Quaker Ridge in Greenwich and Lighthouse Point, in a combined total of over 80 years of observations, were nowhere close to our new record. Their top flights were 192 and 135, respectively. Moving out of state to a couple of other infamous sites, Franklin Mountain in New York topped off at 136 Turkey Vultures and Hawk Mountain Sanctuary in Pennsylvania peaked at 123, and several more locations were around these numbers. I should add one condition to these decades and decades of observations - the Turkey Vulture population is increasing to our north over time, and it must be understood that more migrants will be passing through, generally, every year. Regardless of that fact, Boothe’s total remains almost supreme amongst many similar and strong opponents.


The day’s weather

After that examination, the most obvious question remained: why did such an extremely high number of Turkey Vultures take to the skies to head south on this particular day? October 28 is in a range of time quite conducive to significant flights, though it is still relatively early in the season, with the last Boothe record occurring four days later the previous year, and the instant conclusion being that the date did not act like a late trigger to suddenly spur the birds south. One would presume beforehand that they would have kept migrating in a regular manner for another few weeks at the very least. I have already discussed the lack of totals approaching this one at other sites, thus for the moment making the small sample size of Boothe’s data somewhat less of a confounding variable, and this flight more of an anomaly. For the sake of argument, let us assume it was - that leaves us to wonder what exactly that trigger was and what in the world could have prompted this.

What remains is the weather, the conditions on and around this special day that helped to allow such an event to take place that Friday morning. The Tuesday before, October 25, had actually been a very productive day at Boothe Park with 276 raptors tallied, 76 of them Turkey Vultures, despite crystal clear blue skies. This flight in itself provides evidence that there were not birds being “backed up” by poor conditions for a week or more, and many had been able to move through Connecticut already. If there had been only a few raptors counted in the days before, or a continual southerly flow of some sort, a subsequent record flight might have been more understandable. That Tuesday movement came after a cold front passed through from a low centered well to the north in Canada and on northwest winds from high pressure moving through the Ohio Valley.


Realistic view of streaming Turkey Vultures going behind the clock tower earlier in the week before the historic flight

On that Wednesday and Thursday, October 26 and 27, the northeast region was plagued by a series of lows along a cold front that finally passed through Thursday night. As that front swiftly cleared our area and headed southeast, one of the biggest keys to the event came in the form of a superbly placed high moving in from the Great Lakes towards western New York and Pennsylvania just in time for the daytime hours on Friday. The pressure gradient was not very strong because of the rapid exodus of the front, and the high provided northwest winds of approximately 4-7 MPH for most of the day on Friday, a perfect strength to aid raptors moving south and gently push them to follow the coastline, but not thrust them all the way to the shore. This wind speed and direction has been shown to be optimal for Boothe Park on numerous occasions with it being a few miles off Long Island Sound.


2010 flight conditions

These conditions were, not coincidentally, nearly indistinguishable to the ones that provided the terrific flight at Boothe Park previously mentioned on November 1, 2010. The movement of the cold front, the placement of the high, wind speed and direction were all essentially the same, though there had been no cloud cover whatsoever that day. Turkey Vultures do sometimes fly by Boothe Park at high altitudes, though most go through at a moderate height compared to other species, and nearly all are detectable to the naked eye or binoculars even against the deep blue sky with their dark color and slow drifting style. Even when streaming through they often come in groups, thus the likelihood of missing a significant amount because of a lack of clouds, or finding more because of even partial cloud cover, is negligible.


Typical streaming Turkey Vultures at Boothe Park

Looking past the weather and at the personnel, I was the official counter on both of the record days, and I had either two or three people with me for the most part, with Charlie Barnard joining me both years, Tina Green and Frank Mantlik assisting for parts of the 2010 flight, and Bill Banks on hand for the day in 2011. We actually put in 8.25 hours on November 1 compared to the already stated 7.5 hours on October 28.  Calculating the Red-tailed Hawk average per hour for the November 1 flight yields 30.18, and for the October 28 movement it comes in at 29.07, a minuscule difference. Obviously, the Turkey Vulture rates are much greater, with 23.03 per hour on November 1 and a mind-blowing 69.47 on October 28. Nearly every factor between the two days is identical except for this extremely abnormal Turkey Vulture count.


Snowtober

After examining every detail and nuance of the day of the historic flight and those leading up to it, I was left to scrutinize what came after, and having the very next day go down in New England weather history was a heck of a coincidence. Snowtober became a popular social media name for the devastating classic “winter” nor’easter that struck Connecticut and surrounding states on October 29 and 30, leaving catastrophic damage in its wake and well over a foot of snow in many areas. There are absolutely no comparisons to a storm of this magnitude occurring in October in any year, decade, or century, even apocryphal tales from colonial history. It was undoubtedly a multi-century event that left some birds in desperate straits, having to cope with an early snowfall of such a depth when many of those ill prepared for it had yet to vacate the northeast. 

Frank Mantlik spent 1.25 hours at Boothe after the storm ended on the afternoon of October 30 with brutally strong northwest winds and saw 135 Turkey Vultures go by, as they were evidently still moving in marvelous numbers over the snow-covered landscape. I considered all of this more and more on Halloween, as it was a particularly “birdy” day on the shores of Long Island Sound, with birds like Savannah Sparrow and Eastern Bluebird flying in to Stratford Point in the middle of the day from the north. Stratford Point had no snow left whatsoever already after only a few inches falling that weekend and quickly melting on the comparably warm coastline. Had the Turkey Vultures been able to deduce that such a snowfall was on the way and planned their escape from the north the day before with such favorable conditions? Could they have possibly surmised a nor’easter would bury the ground and make finding carrion all the more difficult?

I readily admit such a suggestion may seem ludicrous, but after investigating all of what I have I am left with little other conclusion beyond tremendous coincidence and sheer luck. One might fall back to the fact we have scant data at Boothe Park in comparison to other sites, and although these sites have not had similar flights, we just be on the premiere Turkey Vulture flight path in the northeast United States. I wholeheartedly embrace such a title and welcome it with open arms, though I do not think we can make our acceptance speech quite yet. One remaining matter needs to be mentioned – what occurred at Lighthouse Point on October 28, 2011.


Will a sight like this from the historic day be common multiple times each year for us?



That other record

While we at Boothe Park were celebrating a wondrously successful day, the observers stationed at Lighthouse Point were shattering the previous record as well, as they tallied an astonishing 371 Turkey Vultures in 8.75 hours. As I mentioned earlier, their previous record, in over 40 years of nearly constant vigilant hawk watching, was only 135. This new total, nearly tripling the historic high count, is a strong piece of evidence in the argument that something was in the air on that day. If Lighthouse Point had totaled say, 150 or so Turkey Vultures, I think it could be seen as a new high count on a terrific day that could be expected as the population has grown to the north in recent years. But to so decimate the record that has been derived from decades of data suggests that this was truly a special event and gives us a hint that maybe, somehow, someway, these birds may have known what was in store for them had they not departed from the region as quickly as possible.

Perhaps results from next year will render all of this moot with an even more stupendous flight, but either way, a vulture’s ability to anticipate poor weather conditions it is something to consider. I cannot wait to see what the 2012 season has in store for us, and though it may be some time away, I invite you all to join us whenever possible as Connecticut Audubon Society increases monitoring efforts at Boothe Memorial Park. Once again, you can see more information, from directions to all of this data, on our HawkCount page here: http://www.hawkcount.org/siteinfo.php?rsite=703 


Scott Kruitbosch
Conservation Technician

Tuesday, December 6, 2011

Winter of 2010-2011's toll on birds in Connecticut

The winter of 2010-2011 was one of the worst Connecticut has ever experienced, with some stations recording the greatest snow depth ever, the snowiest January ever, and one of the highest snowfall totals for an entire season. The Boxing Day Blizzard was only the beginning as the state took major hits several more times before all was said and done with a March 24 light snow event. Such a constant onslaught of snow can spell disaster for a number of bird species who succumb to the frigid conditions or perish when they cannot find sufficient food sources. Carolina Wrens, a resident species, are said to be a great indicator of how conditions impact birds as snow can take a toll on their population, preventing them from feeding on various invertebrates on the snow-covered earth. You may have seen some come to your feeders to eat primarily suet, or perhaps peanuts or peanut butter.

I wanted to see if this assertion was accurate or not, and how much their numbers changed from 2010 to 2011, so I decided to use eBird data to take a look at things. I chose to use data by year primarily because, apart from the blizzard in the last week of 2010, the snow for the season in question was focused all in 2011. I excluded December from the 2011 totals as checklists are still being submitted, and we must bear in mind some may still have yet to come in for other parts of the year as well. However, as of around 9 a.m. today, there have been 16,434 checklists submitted to eBird for Connecticut in 2011, and 14,410 for 2010, so sample size for each year does not appear to be an issue. I do acknowledge that we are dealing with data from hundreds of unknown observers of various skill levels across only two years, and it would be foolhardy to draw any certain conclusions.

Look at frequency first, the percentage of all checklists submitted reporting Carolina Wrens of any number in 2010 and 2011:



Whoa! There is a lot to look at here...
  • In 2010, there is a spike in the spring as breeding season begins, with males singing, territorial disputes, etc.
  • There is also a drop in the middle of breeding season, as parents stay quiet and are busy feeding young, before a return to more constant levels
  • See how fast the percentage falls from the last week of 2010, and the Boxing Day Blizzard, to the first week of January in 2011, though both years have falling numbers as winter approaches
  • Then they plummet during the January bombardment of snow in 2011 compared to more constant numbers in 2010
  • 2011 mimics 2010 in some regards with a slight spike in spring, and a decrease in breeding season
  • The recovery is swift and by late summer and fall the 2010 numbers touch 2010 levels briefly
  • While the current population is certainly less than 2010 at the same date, the breeding season definitely looks to have brought numbers of Carolina Wrens back up to some degree
Let's say the species is recorded on a checklist - how many birds are then seen, on average?

  • Once again, a good correlation between years with similar features
  • Notice how the average number drops quickly in January in both years and spikes around June with pairs feeding young - while the species may be seen less, they are often seen together
  • 2011's average is a bit less than 2010 overall, though not enormously
  • However, the most obvious observation is what the heck is that spike?!
The anomalous increase occurs in the December 15 period in 2010, and it does not appear to be a fluctuation that we can attribute to limited sample size. That number, about 2.5, is the average number of birds seen derived from a total of 71 checklists reporting the species between December 15 and 21 in 2010. That many checklists reporting the species in that period is actually higher than average since Carolina Wrens were seen on approximately 52.7 checklists for each of the 48 periods in 2010. If they had been reported on, say, 15 or 20 checklists, then we might have been able to explain it away by saying the data was lacking. That does not appear to be the case.

Looking back up to the frequency graph, we can also see a spike in the period after a consistent decline in December that went unnoticed when we first looked at it. Did the birds suddenly start showing up at backyard feeders in high numbers that week? Were more tallied during surveys because of sheer luck? Could some have been moving to the south a bit and through Connecticut? They are not said to be migratory. It may simply be a coincidence, but it makes one wonder what happened...and it makes my always suspicious and imaginative mind wonder if the wrens had a hint that we were about to be inundated with snow.

Finally, the total number of birds reported each period, a straight sum...

  • Basically what we expected by now with the spring spike, winter drops, and the anomaly previously discussed
  • There is a nice jump in both Octobers as well, with the highest level in 2011 outside of the rapid January decline
  • Interestingly, the highest frequency in 2011 was also in October, though in another period
  • One would figure this would occur after a successful breeding season, but why October instead of earlier in the fall or late summer?
It seems from this data that yes, Carolina Wrens are indeed quite susceptible to large snowfalls and sizable snow depths, but that they can recover relatively quickly with the right breeding conditions the next season. Numbers are down still right now, but not nearly as far as they were at the end of the brutal winter. That strange jump in numbers last December prior to the week of the Boxing Day Blizzard may still be an anomaly overall despite the fact it was sufficiently reported in the context of the period. I do not like coincidences, though, and for the most part, I do not believe they exist. It feels somewhat ridiculous to even imply that birds can predict a storm days before its formation thousands of miles away, but it makes me wonder what was going on there.

Perhaps if we start seeing a bunch of Carolina Wrens in our yards and at our feeders we will know some snow is on the way...hey, wait, I saw one looking for insects in the wheel of my car yesterday!

Scott Kruitbosch
Conservation Technician

Monday, December 5, 2011

Western Kingbird continues

I surveyed our H. Smith Richardson Wildlife Preserve and Christmas Tree Farm again last week and enjoyed seeing the vagrant Western Kingbird continue to thrive in our field and grasslands habitat. It has been eating a few berries, though it is doing very well hawking insects in this unseasonably warm weather. It is fortunate to have such a pattern in place during a time where every night could easily be well below freezing. Here are a couple more photos and some HD video of it.




 Insect target acquired!




Later this week I believe we will finally begin to see some actual December-like weather, and I hope it chooses to move on back to the south sooner rather than later, as it may have already. I have not heard any reports of it in the last few days. Don't forget to buy a Christmas tree from us if you visit our preserve on Sasco Creek Road in Westport!


Scott Kruitbosch
Conservation Technician

Saturday, December 3, 2011

Connecticut Audubon Society to Develop Conservation & Management Plan for Aspetuck Land Trust’s Trout Brook Valley Preserve

By Twan Leenders
Conservation Biologist
Connecticut Audubon Society

Aspetuck Land Trust (ALT) announced plans in October this year to work with the Connecticut Audubon Society (CAS) to develop an adaptive management and conservation strategy for the Trout Brook Valley Preserve. The objective is to gather information to help ALT maintain Trout Brook Valley in a natural state while simultaneously supporting its public use goal, encouraging passive recreational use and enjoyment of the property. CAS is delighted to partner with ALT in this important project.

Over the course of a year, biologists and staff from the CAS Science and Conservation Office will carry out surveys to detect the presence of threatened, endangered or otherwise at-risk species in the Trout Brook Valley Preserve and to identify sensitive habitat areas contained within the preserve’s forested uplands.

Within the 1,009 acre preserve, spanning Weston and Easton, are vernal pools, shrub swamps, talus slopes, grasslands and other specialized habitats harboring plant and animal species. These species are uniquely dependent on these biological ‘islands’ within an otherwise largely forested area intersected by a 22-mile trail network. The trails were laid out gradually over the past 12 years, often without knowledge of these special microenvironments.


Risks of Disappearing Species

These specialized habitat pockets tend to be the first to disappear or become degraded when environmental pressure increases. The species that rely on them generally disappear simultaneously. Due to their very specific environmental requirements and because of the overall scarcity of the habitats they occupy, these specialized plants and animals tend to be rare and in need of protection.

We already know that the Trout Brook Valley preserve is home to some species included in Connecticut’s Endangered and Threatened Species Act. We believe that there are more to be found.

Across the state, Connecticut forests are gradually becoming more homogeneous with reduced species diversity and an increasing numbers of invasive species. At the same time rarer, more sensitive habitats and species slowly disappear. Highly adaptable plants and animals that can survive in a wide variety of habitats (the kinds of species that one tends to see in yards, parks and other areas associated with development – starlings, pigeons, squirrels, raccoons, coyotes, etc.) are very able to expand their range. Without careful land management, all our natural forests are at risk of becoming impoverished carbon copies of such disturbed habitats.

Importantly, this process takes place while the overall habitat may still look like a forest to the untrained observer. Effectively, more sensitive species are driven to extinction under our very noses! The quality and functionality of an area can be irreversibly damaged if no careful management and conservation strategy is put in place to maintain and protect healthy species and habitat diversity.


Meeting ALT’s Stewardship Goals

A carefully designed management and conservation plan based on relevant survey data will allow ALT to carry out its stewardship goal of maintaining the Trout Brook Valley Preserve in a natural state in a way that balances the need for protection of the area’s resources, plants and animals. Simultaneously, the study findings will help ALT fulfill its commitment to provide open space for passive recreational use and enjoyment of the property. Currently, regulated recreational uses of Trout Brook Valley include hiking, dog walking, hunting, fishing, and horseback riding. Hiking with off leash dogs has been suspended for a year while the CAS study is carried out. 

The surveys carried out in the preserve will span an entire year, starting fall 2011 and concluding by fall 2012 to ensure complete coverage of all seasons (not all plants and animals are visible year-round). This prolonged survey period will also allow Connecticut Audubon Society staff to evaluate a wide variety of factors that could potentially affect the preserve’s future health. These range from the spread of invasive plants, plant diseases and pests, to the location of the existing trails and the management practices used to maintain sections of the property.

Throughout the year there will be opportunities for interested members of the public to directly help us and participate in the surveys. Please stay tuned for more information!

=====================

You may have noticed a taste of the results of our survey work already here in the blog. We are very excited about the data collected so far, and we will keep you up to date from time to time with any particularly noteworthy, intriguing, or just plain cool discoveries during our progress.


Scott Kruitbosch
Conservation Technician