Tag Archives: SUNY-ESF

Hailing More Snails

When ten endangered Chittenango Ovate Amber snails (COAS), located in only one known location in the world: Chittenango Falls State Park, were brought into an SUNY College of Environmental Science and Forestry (ESF) lab for captive breeding and did not reproduce over the summer of 2014, graduate student Cody Gilbertson and advisor Rebecca Rundell knew they had to adjust something. Eventually the ten COAS were released, but as luck would have it, during the trial, a stowaway baby COAS came in on vegetation that was offered to COAS adults.  The tiny snail on the plant was placed in an enclosure to monitor closely. This was the beginning of a rapid learning curve for Gilbertson on the food preferences of COAS. New York State Department of Environmental Conservation (in charge of endangered species permitting) granted permission for them to keep the one snail over winter and raise it alone in the lab. From this blessing in disguise, Gilbertson was able to figure out the specific species of leaves this one snail she named “Hatch” preferred to eat – dead cherry leaves! Cherry leaves collected in the spring were consumed regularly and “Hatch” began to grow rapidly. Gilbertson knew it was risky keeping a small hatchling snail because in the past, 80% of hatchlings would die within the first two weeks of life in captivity. She thought it was unlikely “Hatch” would live, but this one snail persisted and survived in the lab showing her what it most preferred to eat, and she watched closely. It turns out this was a very practical way of finding out what COAS needs without harming individuals.

When Gilbertson brought two more COAS in from the wild during summer 2015, adults flourished on the improved diet and reproduction occurred resulting in over 600 baby COAS in just two months! The two snails mated with each other and about seven days after mating, egg masses were laid.  A total of about six egg masses were laid by each snail with about 33 eggs in each egg mass. About 270 of these snails were released back to their wild habitat to help expand the wild population of COAS. The other 300+ snails are still in our lab and are thriving. Over 130 snails have reached maturity (over 14mm in shell length) and over 30 egg masses from the captive born snails have been produced so far.

This research, supported by United States Fish and Wildlife Service, has pushed the recovery of COAS species forward with some very large steps:

1) Researchers have performed a first ever release of captive snails back to the wild

2) Scientists now have information about what COAS eat and what they may need to survive in the wild and in captivity

3) Over 300 snails remain in captivity for assisting in securing this species existence.

However, there is still much to learn about this unique and rare species in our upstate NY backyard. Scientists will need to monitor and care for both the wild and captive populations over time for us to tell if this work is successful long term. But they have certainly put their best foot forward!

Gilbertson with 'Hatch'
Gilbertson with “Hatch,” photo by Cody Gilbertson

Post and photos by Cody Gilbertson, graduate student SUNY College of Environmental Science and Forestry

From glass eels to silver eels and everything in between The life stages of the American Eel

Imagine yourself hiking next to a babbling creek.  You come to a small waterfall surrounded by rocks.  The rocks glisten from the spray of the falls.  You walk closer and see dozens of small snake like creatures slithering over the wet rocks.  You watch them move from the top of the rock pile to the bottom.  Then they slide back into the creek.

You saw the American eel utilizing one of its unique adaptations.  Their bodies are coated in a mucus layer, providing protection and a way to absorb oxygen through their skin.  This mucus, in combination with their muscular bodies, allows them to move out of water and across land to avoid barriers.  This, and other adaptations, makes the American eel able to live in more diverse habitats compared to most other fish species.

American eels are fish, despite their snake like appearance, and the only species of eel that live in North America.  They are catadromous, migrating from the saltwater of the Sargasso Sea to the freshwater of streams and lakes.  The Sargasso Sea spans a part of the Atlantic Ocean between Bermuda and Puerto Rico.  Once they reach maturity, they journey back there to spawn.

The vastness of the Sargasso Sea makes it tough for researchers to locate and observe eels spawning in the wild.  At this point, observations of spawning eels remain to be made, although one silver eel was tracked to the Sargasso Sea. Researchers believe the eels die right after spawning.  Some mystery surrounds the final life stages of the American eel.

What happens as they grow?

Let us review the known information about the life stages of the eel.  The eel’s life begins in the Sargasso Sea.  First, they resemble a willow leaf.   These small, oblong, transparent fish, called leptocephali, lack the snake like form of adult eels.  They are about one inch long and rely on the ocean currents to bring them to the east coast.  This journey takes about one year.

Lept
The beginning life stage of the American Eel is called a leptocephalus and these leptocephali use the current to travel to the East Coast. Kils at the English language Wikipedia [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)%5D, via Wikimedia Commons
Now they resemble vermicelli or rice noodles.  At two inches long and still transparent, they are called glass eels.  They make their way into estuaries which connect saltwater to freshwater.  Many of them find themselves in water bodies of local New York State parks along the Hudson River.  Once in freshwater, they develop a brown coloration.  This signifies the shift to their next life stage as elvers.

Glass
The American eel in their glass eel life stage as they arrive to the coast. Chris Bowser

As the elvers grow longer over the next few years, they enter their yellow eel stage.  They live in this stage right before they reach full maturity.  Their size varies based on sex.  Males can grow to two feet long whereas females can reach sizes of four feet.  Their size in each life stage is based on their surrounding environment.  They become silver eels when they reach full maturity to start their migration.

This silver eel stage happens to be the most understudied of all the life stages.  There is no set age that eels are known to reach full maturity and age cannot be determined from external characteristics. Researchers look to study silver eels right before they begin their migration.

What kind of research?

Sarah’s motivation to study silver eels stemmed from her previous experiences working with them in their other life stages.  Her work with eels started with a summer project at Bard College, eight years ago.  After graduation she continued to work with glass eels, elvers, and yellow eels as a Student Conservation Association (SCA) intern at the Hudson River National Estuarine Research Reserve and Estuary Program.  Studying silver eels seemed like the next logical and exciting step for her. Sarah Mount at the SUNY College of Environmental Science and Forestry conducted research on yellow and silver eels.  Her research led to a model that sorts yellow and silver eels into different maturity classes.  The model relies on external characteristics such as the length, weight, eye diameter, pectoral fin length, head length, head width, and body depth of the eels to differentiate maturity classes. This means that future researchers can utilize this model to study the relative age of eels with a capture and release method that does not harm the fish.

With the guidance of Karin Limburg at SUNY College of Environmental Science and Forestry, she developed her research ideas into a master’s level study.  With the help of colleagues at the Hudson River Research Reserve, she spent two summers and two autumns collecting yellow and silver eels from the streams of the Hudson River estuary.

Interns
SCA interns at the Hudson River Research Reserve help Sarah set up a silver eel fyke net. Chris Bowser

Silver eels migrate at night during rain events in the autumn.  To catch them, Sarah set up a fyke net the day before a predicted rain storm.  This v-shaped net spanned the width of the stream and was removed the next morning.

The final life stages of the American eel still remain a mystery.  Sarah Mount’s research begins to solve it both for future research and for herself.  Her model will help future researchers understand when eels reach their full maturity to begin their migration.  When asked about her next steps she said, “Now the only missing piece left is the ocean, I’ve got to get out to the Sargasso Sea sometime.”

Post by Brianna Rosamilia,  Master of Science candidate in Environmental Interpretation at SUNY College of Environmental Science and Forestry

 

Tracking The Elusive New England Cottontail

New England Cottontail
New York’s rarest native rabbit, the New England Cottontail, photo by Amanda Cheeseman

 

It is a typical morning at the Taconic Outdoor Education Center (TOEC) in Fahnestock State Park. The sunshine beams through the forest, a chorus of song birds are greeting the day, and 60 elementary school students are making their way to breakfast to fuel up for an active day of learning in the outdoors. Meanwhile, a familiar truck and crew rolls in to begin their workday visiting several small animal traps set in specific locations in hopes that at least one will contain a rabbit, particularly a New England Cottontail.

The State University of New York College of Environmental Science and Forestry (SUNY ESF) is collaborating with State Parks, and the Department of Environmental Conservation to conduct important research about the population decline of native New England Cottontail. Over the past decade, studies have indicated that their numbers have decreased about 50%. The two major factors contributing to the population decrease are loss of suitable habitat, and the expanding range of the Eastern Cottontail. The only native rabbit species east of the Hudson River is the New England Cottontail; however the range of the Eastern Cottontail has been expanding and now overlaps this territory which causes competition for resources. Predation is also playing a role in the decreasing population; part of this research project is keeping an eye on who’s eating New England Cottontails by using trail cameras. These cameras placed in baited locations and use a motion sensor to take pictures when an animal walks by. Different predators are “captured” in a photo as they come to investigate the bait, which shows the species that a present in the rabbit survey area.

Back at the TOEC, the students are gathering to meet with their instructors for their morning lesson, the phone suddenly rings. “We have a rabbit” says the voice on the other end. Flexibility is part of the job description of an outdoor educator, and no one passes up an opportunity to enjoy a teachable moment, especially when it involves a live animal. All plans are dropped for the moment and after a short walk the students quietly approach the researchers who are preparing to identify, collect data, and radio tag the small mammal.

Juvenile
Measuring a juvenile New England Cottontail, photo by Amanda Cheeseman

Many of students who visit the TOEC are from the New York City area and rarely get to experience being this close to a truly wild animal, and they have a lot of questions such as: “Why is it in a pillowcase?”, “How long are its feet?”, “Is that a baby?” and “What’s That!?”. Their sense of wonder is contagious and the SUNY ESF researchers return the enthusiasm by answering the barrage of questions being hurled at them, while also safely collecting data on their captive rabbit. Measurements are taken, and the data is recorded onto forms and will go into a large database to allow for comparison across the entire northeast. The final step is to attach a small antenna to the rabbit’s back so that the researchers will be able to locate the individual rabbit again through radio telemetry. Now comes the exciting part! The rabbit is released, and in a flash it darts away, immediately out-of-sight, camouflaged amongst the underbrush.

Camouflage
A well camouflaged New England Cottontail. Can you see the antennae? photo by Amanda Cheeseman

Upon reflection, many students will say seeing the rabbit was their favorite part of the week, and they walk away with the feeling of being included in something important. Nothing teaches better than experience; giving students the chance to interact with a living, breathing part of the ecosystem around them. It sure makes for a pretty great day.

Post by Dana Mark, environmental educator at TOEC

Hail the Snails!

Need to slow down your fast-paced life?

The Chit in its natural habitat, by C. Gilbertson
The chits are well camouflaged for living in the leaf litter, by C. Gilbertson

Try watching a snail! No seriously, it’s quite calming. They glide along and seemingly know exactly where they are going. They are curious, and if you listen really carefully, you may hear them munching away when they eat!

Cody Gilbertson, a Master’s student of conservation biology at SUNY-ESF, has been working with and watching snails since 2010. On top of that, the species she works with is a small land snail that is also one of the most endangered species of New York. This little snail is quite famous because it is only found at one location in the entire world!

Not a bad field site! By P. Harper
Not a bad field site! By P. Harper

The Chittenango Ovate amber snail resides at Chittenango Falls State Park. At the base of a waterfall 167 feet in height, this unique species goes about its business amongst rocky ledges and lush vegetation. This summer, teams of volunteers signed up to help Gilbertson assess the size of the snail population and contribute data for her research.

In these snail surveys, volunteers survey small plots of snail habitat for a set amount of time, capturing small snails in tupperware containers as they go. After the collection, all the captured snails are sorted an identified, so we can figure out which are Chittenango Ovate Amber Snails (affectionately called “Chits”) and which are other snail species. After the count, the Chits are released back where they were found and the other snails are removed.

The team scrambles over rocks! By P. Harper
The team scrambles over rocks! By P. Harper

The data from these surveys is part of Gilbertson’s greater study on the life cycle of this rare snail and figuring out what is necessary for their survival. What do they eat? What conditions do they need to survive? How the heck do they live through upstate New York winters? She is looking for new methods to increase this snail’s overall numbers with a goal to help stabilize their population and create a template for other conservation efforts for land snail species.

Captive COAS_Cody Gilbertson_SUNYESF
This baby snail was born in captivity, and may provide clues to how we can protect the endangered chits. By C. Gilbertson

Another important aspect of the project is captive breeding. So far, Gilbertson has successfully bred a biologically similar snail species and yielded roughly 3000 hatchlings. She is also looking at how many other snail species live in isolated populations within New York State to find out if isolated populations are common or rare in this family of snails.

Not many people slow down to examine the small beings on earth. Some animals may almost be invisible, but they all play a big part in ecosystems and the small size of the animal does not make them less important. So next time you’re feeling rushed in life, take a moment to watch a snail, you’d be amazed at the calm steady creature before you!

Featured image is of Chittenango Falls at Chittenango Falls State Park, by Paris Harper.

Post by Cody Gilbertson and Paris Harper

Predator Study At State Parks

A research study out of the State University of New York College of Environmental Science and Forestry (SUNY-ESF) is collaborating with Fahnstock State Park and Wonder Lake State Park in Putnam County to look at predator populations as part of an ongoing study of the declining population of New England cottontails (NEC), Sylvilagus transitionalis. NEC is a rabbit native to the northeastern U.S., but studies indicate that in the past decade, the population of NEC has decreased by as much as 50%. Some populations of the cottontails are in New York State Parks, and learning more about best management practices is critical to protecting this species.

As the New England cottontail (NEC) is a declining species being considered for listing on the federal Endangered Species Act, there are a lot of ongoing efforts to create habitat for these rabbits in the Northeast. The hope is these efforts will preemptively restore populations of NEC in the region, making it unnecessary to list the species as endangered.

The two greatest contributing factors to the decline of NECs are loss of habitat and the introduction of the Eastern cottontail, Sylvilagus floridanus. While the two cottontail species are almost identical in appearance, the Eastern Cottontail generally outcompetes NECs for food and habitat, edging the native species out of its former range. While loss of habitat and the introduction of the Eastern cottontail are both factors contributing to the decline of New England Cottontail, this study looks at predation in conjunction with other management practices.

Predation accounts for almost all natural mortality in NECs. As such, increases or decreases in the predator community would have serious consequences for the cottontail population. Most management projects have focused on enhancing habitat for NECs, but this study considers whether those projects might have the unintended consequence of altering the predator communities in such a way that cottontail survival is reduced. If that’s the case, then it will be necessary to consider predator management strategies when managing habitat for NEC. Results from this study will help inform habitat managers and recover NEC populations.

The project, led by PhD student Amanda Cheeseman and Dr. Jonathan Cohen, both from SUNY-ESF, together with Scott Silver of the Wildlife Conservation Society and Putnam Highlands Audubon, uses trail cameras targeting mammal predators, in combination with visual and auditory surveys for hawks, owls, and eagles, to examine predator communities in areas where different ways of controlling and managing NEC habitat are already being practiced. The project is taking place across multiple sites in Putnam and Dutchess counties. The pictures above were taken in Fahnstock State ParkThe information from the predator study will be compared to data from radio-collared cottontails in order to get a complete picture of the predator-prey relationships in New England Cottontail habitats.

featured image is of the New England Cottontail, Sylvilagus transitionalis, by Michael Merchand, NYNHP