Monday, April 30, 2012

Falkner Island volunteers needed ASAP

Wildlife Biologist Kristina Vagos of the U.S. Fish & Wildlife Service asked me to send out a request for volunteers for Falkner Island this week - either Wednesday (May 2nd) or Thursday (May 3rd) - to finish building their productivity plots and do some other work. She would love to have 2-3 volunteers come out with her and thought our readers and volunteers may be interested.

Here are some details:

  •     Volunteer must be able to navigate tricky surfaces as much of the island is rocky (very rocky) and be physically able to get onto a boat, walk long distances, and work outdoors doing manual labor - digging, moving things, lifting buckets of gravel.
  •     Work will happen from 9am until about 3pm.
  •     Volunteers must bring lunch, water, wear sturdy boots, and be willing to work in an environment where they might encounter poison ivy (more often than not).

This is a great opportunity to see Falkner Island and visit the second oldest lighthouse in Connecticut. She will bring the lighthouse keys so that volunteers can climb to the top. The group will be leaving from Guilford, CT.

Anyone who is interested should contact Kris at (860)399-2513 or by email at by Tuesday (May 1st) at 4pm.

Scott Kruitbosch
Conservation Technician

Saturday, April 28, 2012

April Stratford Point bird walk results

I pushed back the April bird walk at Stratford Point one week because of the anticipated foggy conditions for the 21st. It turned out that yes, the fog did roll in right when the bird walk would have been happening, and we would not have been able to see much that was not right in front of us. I did not expect that we would still be dealing with cooler than average weather after a wet week right now.

Even more strange was the fact that the coast has been without many migrant birds whatsoever due to the weather conditions keeping nocturnal migration to a minimum. Birds have been evenly distributed across the landscape and not in any "hotspots", making some trips through extensive forest productive with low numbers of a variety of species, but any visits to smaller locations that typically have budding trees dripping with warblers and vireos rather quiet.

Despite that, here is what the visitors and I were able to come up with at Stratford Point today.

Canada Goose 
Mute Swan 
American Black Duck 
Red-breasted Merganser 
Common Loon 
Double-crested Cormorant 
Great Egret 
Black-bellied Plover 
American Oystercatcher
Laughing Gull 
Ring-billed Gull 
Herring Gull
Great Black-backed Gull 
Mourning Dove 
Northern Flicker 
Blue Jay  
American Crow 
Fish Crow 
Northern Rough-winged Swallow 
Barn Swallow 
American Robin  
Northern Mockingbird 
Brown Thrasher 
European Starling 
Chipping Sparrow 
Savannah Sparrow 
Song Sparrow 
Northern Cardinal 
Red-winged Blackbird 
Common Grackle 
Brown-headed Cowbird 
House Finch 
American Goldfinch 
House Sparrow 

By Tuesday morning we should have more normal conditions with birds covering all of the expected areas en masse after being held back actually beyond their typical return dates. We are all prey to the weather at this point of the year. Look for more bird walks coming up very soon.

Scott Kruitbosch
Conservation Technician

Friday, April 27, 2012

Chimney Swift decline and possible answers

The Chimney Swift is declining throughout its range in North America, as are many of our aerial insectivores, for reasons that are not entirely clear. Certainly, habitat loss in terms of breeding and migration enters into the equation in many cases, but this is not the complete answer for why the drop has been so precipitous. This article discusses a fascinating find that may help answer some of the reason why this particular species is in trouble:

In 2009, while searching for ways to help endangered birds, research technician Chris Grooms heard that a chimney on his university campus used to host a migratory species known as the chimney swift. When he investigated, he found a pile of bird excrement 2 meters deep. The poop lay at the bottom of a five-story-high chimney and had been deposited over 48 years by the birds, which had roosted there until the top was capped in 1992.

This was actually a treasure trove of information! All of that waste is a pile of insect remains that could be shifted through to see what the birds had eaten over time, possibly providing clues as to what may have changed to accelerate their significant decline.

As DDE increased through the lower layers of the deposit, beetles showed up less often in the birds' diets and true bugs became more common, the researchers report online today in the Proceedings of the Royal Society B. This result agrees with other reports that DDT is hard on beetles, while true bugs can evolve resistance quickly. The change in diet may also help explain why chimney swifts have declined so precipitously, Nocera says.
Canadian surveys have found that the number of chimney swifts dropped 95% between 1968 and 2005. Some researchers have suggested that part of the reason is that chimneys like this one, swifts' preferred habitat, have been capped or redesigned, making it harder for birds to get in. But the new work suggests that the decline may be diet related. Beetles generally contain more calories than do true bugs. Swifts need a ton of energy—they spend a lot of time on the wing, looking for food. A change in their diet, like substituting less-nutritious true bugs, could have a big impact. DDT was banned in the 1970s, but the beetles never seem to have gotten back their original place in the food web, Nocera says.
Nocera thinks DDT and other pesticides may have effects far beyond their well-known impacts on the eggshells of large birds, such as taking away the foods that chimney swifts, barn swallows, flycatchers, and other insect-eating birds relied on.

That is a lot to consider and takes a couple liberties, but it makes a great deal of sense. While more research is definitely needed in this area perhaps there will be more discoveries of such, well, chimney piles that can yield similar results. At some point, a large effort for bird conservation may end up involving the restoration of the natural chain of insect life on the continent, a monumental task. We may have stopped putting DDT and some similar chemicals into the environment (certainly not all like we should) but remediation may be necessary to undo all of the damage it caused.

Scott Kruitbosch
Conservation Technician

Thursday, April 26, 2012

Name this April migrant

Take a look at the bird in the photo below - hey, can you name this April migrant?

The bird was seen at Stratford Point on April 25. It is only seen there in migration. It is a species that anyone should be able to see any given spring in Connecticut. Take a look at the bird, the position it is in, where it is placed in the tree, and consider the date. That should be plenty of information for you to work from. The answer will be coming to you in a few days.

Scott Kruitbosch
Conservation Technician

All photos © Scott Kruitbosch and not to be reproduced without explicit permission

Tuesday, April 24, 2012

Young Researchers Explore Costa Rican Rainforest - Part II: From Frogs to Birds

This is the second half of a report on the recent research trip to the Costa Rican rain forest by students from three Litchfield high schools, supervised by staff from these schools and Connecticut Audubon Society. You can find part I of this report here

Two remaining student research teams focus on different groups of vertebrate animals: amphibians, reptiles and birds. The primary focus of the amphibian and reptile team is monitoring local amphibian populations that had declined dramatically in the late 1980s as the result of an outbreak of a deadly fungal pathogen. Previous years' teams had focused on investigating the spread of the fungus throughout the relatively undisturbed rainforest habitat of the two preserves we work in: Selvatica and Rara Avis. It has become clear that the fungus persists in the habitat and is found in local tadpoles, but the encouraging news is that several species of amphibians that were absent from the preserves for more than 10 years in some cases are slowly starting to show signs of recovery.          

Local streams still host the deadly amphibian pathogen Batrachochytrium dendrobatidis, a fungus that has killed off many amphibian populations worldwide.
The students on this team spend a lot of time surveying suitable habitat and trying to locate the salamanders, frogs, lizard, turtles and snakes that are hidden in the green maze of a rainforest habitat.

Fast-moving streams become difficult to cross during rain storms
Giant aroid plants called 'elephant ears' (Xanthosoma sp.) lend some marshes a fairytale-like atmosphere
Only when you see some students wading through the marsh does their size become apparent
Hundreds of amphibians and reptiles were observed during the two week stay, representing 60 different species.


 Representatives of each species were captured and brought back to our base camp to collect valuable data and to obtain measurements on these poorly known animals
After only a few days in the rainforest students become very skilled at properly handling the animals they work with 
The reptile and amphibian team hard at work measuring the snout-vent length of a harmless Green Keelback (Chironius exoletus), a fast-moving racer-like snake.    

Data sheets are filled out for each observation and captured animal
 Below is a sample of some of the 60 species observed during the trip: 

Strawberry Poison-dart Frogs (Oophaga pumilio) are common in the lowland sections of the preserve
The Ghost Glass Frog (Sachatamia ilex) is one of the target species of the project. Once exceedingly rare in the preserve, it is now reliably found in many streams and its population is recovering rapidly.
Red-eyed Leaf Frogs (Agalychnis callidryas) require standing water to breed in. Because of the heavy rainfall this year we observed several individuals at night near large rain pools.
This rare Crowned Tree Frog (Anotheca spinosa) was first found in Rara Avis four years ago, in spite of intensive searches in the 15 years leading up to it. The discovery of four individuals on this trip could indicate a recent population increase - a very encouraging find!     

During last year's trip we discovered a species of salamander that turned out to be a new species to science  (read all about that here). Unfortunately, since we could not obtain the required permits in time, the animal was released back into the rainforest and could not be taken to a natural history museum to be described as a new species. This year we made arrangements with the Costa Rican government beforehand and of course tried hard to find another individual of this new species. We did not find one, but did end up with a related but already known species instead. Even though it was not a new species to science, it did end up being one that had not been confirmed in the preserve yet so it was still a very exciting find. This little Worm Salamander (named after its worm-like appearance - it has only miniscule limbs) turned out to be the 128th species of amphibian and reptile occurring in the SelvaTica and Rara Avis preserves, a combined area of less than 5 square miles. Quite amazing when compared with for example Connecticut, which measures over 5,500 square miles and harbors 22 amphibian and 24 reptile species.
This Worm Salamander (Oedipina pseudouniformis) is a new addition to the local herpetofauna!  
Ridge-headed Salamander (Bolitoglossa colonnea) an arboreal lungless salamander
Juvenile Turnip-tail gecko (Thecadactylus rapicauda)
Young Brown Vine Snake (Oxybelis aeneus) blending in nicely with its environment.
The defensive posture of this Bronze-backed Parrot Snake (Leptophis nebulosus) is quite impressive!
Other snakes, like this harmless Shovel-toothed Snake (Scaphiodontophis annulatus) may benefit from their resemblance to venomous coral snakes living in the same area. 
The venomous Hognosed Pitviper (Porthidium nasutum) is nearly invisible when it coils up in the leaf litter on the forest floor. 
Its arboreal counterpart, the Eyelash Pitviper (Bothriechis schlegelii) is equally well camouflaged on the moss-covered vegetation in Rara Avis
 As you can tell from the image below, the lush tropical habitat in the study area is quite suitable to hide many more biological surprises!

Of course, the main driving force behind the prolific growth of the vegetation here is sunlight, warmth and LOTS of rain. Although of obvious benefit to the habitat, the latter factor can also make research quite challenging at times. This year's bird team struggled with the prevailing weather pattern for quite a while since their main tool, mist net arrays, can not be kept open during rainy spells. As a result it made it tough for them to catch the migratory birds they were hoping for. Additional projects, such as a study of feeding preferences for local hummingbirds, were also hindered by the weather.    

Experimental set-up with hummingbird feeders sitting idle during yet another tropical down pour
Nevertheless, whenever the weather broke for a little while all the birds would start moving around to forage right away again. All in all, the bird team managed to catch an impressive variety of birds and they even banded several Neotropical migrants that winter in Costa Rica.

Keel-billed Toucan (Rhamphostos sulfuratus) in a Cecropia tree taking advantage of a break in the rain...
Frank Gallo and his bird team head out to open their nets again 
Orange Parrot-beak Flowers (Centropogon sp.) stand out against the green background of the rainforest. This is a good area to find the rare White-tipped Sicklebill (Eutoxeres aquila), a large hummingbird that lives in close association with these flowers. 

White-tipped Sicklebill (Eutoxeres aquila) feeding on Centropogon nectar
Note the strongly decurved bill that is especially adapted t reach deep into tubular flowers 
A spectacular Broad-billed Motmot (Electron platyrhynchum)
Silver-throated Tanager (Tangara icterocephala)
Scale-crested Pygmy-tyrant (Lophotriccus pileatus) a small flycatcher

One of the Neotropical migrants caught and banded by the team: a Wilson's Warbler (Wilsonia pusilla)
CAS master bander and Director of the Coastal Center, Frank Gallo, taught his team many things about birds, bird banding and the importance of conserving habitat along the entire migration corridor. Some of the birds banded in Costa Rica in March may actually show up on our doorstep just about now... Let's hope that our banded birds will get recaptured somewhere along their route so that we can learn more about their biology and improve conservation measures that can benefit these species. One of the birds captured this year was one banded by a previous year's team, indicating that it spends its entire winter in the preserve...

Frank demonstrating the vice-grip like bite of a female Black-throated Trogon (Trogon rufus)
All captured birds are weighed, measured and released on the spot 
A matching pair of White-ruffed Manakins (Corapipo altera). This locally common species is the subject of a PhD project by a local researcher. The bird team members helped this study by recording specific data and color banding these Manakins.  
The 2012 Rainforest Project team returned home with a large amount of data that will require much more time still to process and analyze. This year marked the 20th anniversary of the project and this year's dissertation day will be a special one with many alumni returning to see how the project has grown over the years. If you would like to be part of this public event, please join us on Friday April 27 at 9AM at the Forman School, 12 Norfolk Road, Litchfield.  

The 2012 Rainforest Project students and staff

Twan Leenders
Conservation Biologist

All photos © Twan Leenders and not to be reproduced without explicit permission

Monday, April 23, 2012

Young Researchers Explore Costa Rican Rainforest - Part I: Invertebrate Bonanza

During the first two weeks of March students and staff from Forman School, Wamogo Regional High School and Litchfield High School, accompanied by CAS staff members Frank Gallo and Twan Leenders, headed to the Costa Rican rain forest again. For the 20th year in a row students got their chance to put the skills they learned in class in action and to test the research hypotheses they'd developed in class before traveling to the tropics. With guidance from their experienced project leaders these students studied the strength of local spider silk, recorded katydid calls, banded birds that winter in the rainforest but breed in temperate regions, tracked the recovery of several endangered frog species, documented the local moth diversity and much more. Below is a brief overview of some of the work these young scientists did, focusing on the three invertebrate-centered projects. Part 2 of this narrative will be posted on this blog tomorrow. If you would like to hear the whole story first-hand from the students themselves, they will be presenting their findings during the 20th anniversary Rainforest Project Dissertation Day on Friday April 27th starting at 9AM at the Forman School, 12 Norfolk Road, Litchfield. Everyone is welcome!

The Rainforest Project takes place in Selvatica and Rara Avis Rainforest Preserves, located in the buffer zone of the Braulio Carrillo National Park complex in northeastern Costa Rica. This park complex covers over 475 square kilometers (117,500 acres) of protected land ranging from near sea level to almost 3,000 m (9,850 ft) in elevation and contains several dormant volcanoes. On the way into our study area the group stopped briefly on one of those: Poas Volcano. 

Clouds cover the rim of Poas Volcano's main crater which still bears the signs of its most recent eruption. 
The clouds blow out for a few minutes exposing the main crater. It measures 1,320m in diameter and is some 300m deep with a green lake at the bottom. The crater lake's average temperature is around 110 degrees F and fumaroles spew sulphuric gasses constantly, making conditions in the crater pretty inhospitable for living creatures.    

A nearby old and inactive crater in the side of the mountain has meanwhile returned to cloud forest habitat

The Rainforest Project starts its research at the relatively low elevation Selvatica Preserve, at about 550 m above sea level. The research station is a converted penal colony that was operational in the 1960s and 70s but is now run by an international conservation organization.  
The main building at SelvaTica Preserve is called 'El Plastico' and is the administration building of an old prison colony. Convicts were forced to sleep outside under plastic tarps - hence the name. 
Upon arrival in the rainforest students set up their lab spaces and familiarize themselves with the overwhelming green-ness of the lowland rainforest habitat. No matter how much time they spent preparing for their individual projects and mentally trying to figure out where and how to find their study organisms, actually doing so in the forest is a whole different ballgame....

The Lowland Rain Forest in the preserve is overwhelmingly dense and lush.
However, students team up with their project leaders and head out into the jungle to set up their study plots and to collect data right away. 

The mountainous terrain in the area is full of rivers and streams. Navigating the slippery rocks and muddy streams can be challenging at times.

Every step of the way the view is worthy of a picture and the diversity of plant and animal life is truly mind-boggling

Students learn all sorts of new skills early on. Apart from their respective research subjects they learn how to read maps and navigate the extensive trail system, photograph and otherwise document their research and experiences for presentation during dissertation day and in their research papers to fine-tuning their observation skills. There is something to be seen every step of the way, and some of those things need to be seen in time - spines and thorns on plants, biting ants and spiky caterpillars and there is always the chance of running into a venomous snake...       
Mammal tracks and scat are often seen in the trails and tell us a lot about the local species and their habits. Wendy Welshans, director of the program, demonstrates the finer art of analyzing large cat scat. These fresh Jaguar or Puma droppings contained Peccary fur and bone fragments. 

Another good rainforest skill that students learned quickly is to read the weather patterns - especially useful if you want to dry your laundry....

One of the program's research projects focuses on investigating the potential use of spider silk in the pharmaceutical industry. Silk from the Golden Orb Weaver  (Nephila clavipes) is famously break-resistant and pound-for-pound can be considered stronger than steel. In addition it is lighter in weight and more elastic than any inorganic fiber equivalent. The project has been intent on developing a sustainable way to extract enough high-quality silk as to make this a viable home-industry that would revolve around the need to protect the spider's natural habitat. A type of 'spider-farming' set up in a way not unlike silk-worm farms, that can provide an alternative to destructive cattle ranching that locally takes a heavy toll on the forest.         

A female Agrioppe savignyi, an orb-weaving spider with a distinctive web design.

Students set up experiments with Golden-orb Weaver spiders (Nephila clavipes) moved into a small shed to simulate a farming setup.
A specially designed collection device is used to collect the spider silk from a Golden-orb Weaver
The amount of silk extracted from each spider, coloration of the silk and several other variables are carefully recorded
 A new project this year studies Orthoptera (grasshoppers, katydids and crickets) and Odonata (damselflies and dragonflies). Students working on this project study the diversity of these large groups in the local rainforest and also focus on bioacoustics: the characteristics and functions of the cricket and katydid calls that are a big part of the night sounds in the area.

A dazzling variety of orthopterans is found in the study area.
The variety of dragonflies and damselflies is equally stunning. 
 Since the animals in the target  groups are poorly known and no easy field guides for their identification exist, all sorts of measurements, photographs and drawings are collected for each individual that is found. Data will be shared with expert entomologists in hopes that we can help expand the knowledge of these animals.  
Each cricket, dragonfly and grasshopper collected is carefully documented and released back into its natural habitat. 
The students on this project developed a small, portable sound studio that can be wired with a microphone to record cricket and katydid calls onto a laptop computer. Several frustrating nights were spent waiting for a stubborn subject to start calling - something that did not always work. Luckily patience and some tweaks to the recording method paid off in the long run and the calls of several species could be reliably documented.  
Sound recordings were stored and edited on a laptop computer. The white box in the background is a make-shift sound recording studio.

When seen up-close, the subjects of this project display an amazing variety of shapes, colors and adaptations.

Artistic skills were a 'must' for these students since every new species found had to be documented with drawings illustrating the animal's diagnostic features.  
The project's resident artist hard at work
The following images show some of the animals encountered during our forays in the rainforest...
Immature praying mantis

A very well camouflaged stick insect seemingly covered in moss

Leaf-mimicking praying mantis (Choeradodis rhombicollis)
A large Cone-headed Katydid (Copiphora sp.)

A third project focusing on invertebrates is the moth project which has been documenting species diversity in the preserve for the past couple of years. Due to the full moon and heavy rainfall this year (both factors that keep the moth diversity and density down at night), the team was also looking into some other lepidoteran diversity: caterpillars found during the day.   
Home-made insect traps with a built-in UV 'black' light were placed in different locations in the rainforest or hoisted into trees at night to sample local moth populations  
On a good night the traps and sheets are full of moths and other insects, but this year those nights did not happen very often...

A canopy trap is lowered from the treetops and its contents examined

In addition to the traps, sheets with black lights are set up in strategic locations as well to attract moths

On busy nights the sheer number of insects present can be quite overwhelming!
Species not previously recorded in the area are carefully preserved and documented

 Here is a small sampling of some of the animals found:

Some moths are as colorful as their diurnal butterfly relatives.
Even the seemingly less colorful ones have beautiful subtle markings when viewed up-close, such as the metallic gold highlights on this small moth.
It is no surprise that very few moths are seen during the day, given their amazing camouflage patterns!
Other unusual visitors attracted to the black lights included this small yellow Dobson Fly.
And a large yellow flower-beetle

When moth activity was slow at times, the team shifted its focus to species that could be found during the day. Diurnal butterflies are fairly well-known in the area and the team decided to focus instead on their lesser-known larval stages - some of which are quite amazing!
A large sphingid moth larva with an intimidating spike on its back...
Many of these spiny caterpillars have to be handled with great care since they are often equipped with chemical defenses that can result in very painful stings! 

You really don't want to touch these!

Other species try to escape predation by disguising themselves as something as unappealing as a bird-dropping.
Although not a caterpillar, the bright coloration of this flatworm is probably advertising some unpleasant experience for any predator careless enough to eat it
A large Malachite Butterfly (Siproeta stelenes) hides from the rain

  Check back here tomorrow for part II of the Rainforest Project narrative describing the two remaining projects, studying migratory birds and rare amphibians and reptiles.

Twan Leenders
Conservation Biologist

All photos © Twan Leenders and not to be reproduced without explicit permission