Conservation and Research
The GNC has undertaken a number of conservation and research projects.
2011 American Eel Study Project
The GNC is partnering with the New York State Department of Environmental Conservation to help study local migratory routes of American eels. GNC staff and volunteers are working on the Saw Mill River in Yonkers to find a location that allows the deployment of an eel fike net. Once the location has been established, the team will routinely monitor the net to determine just how many American eels come into this tributary off the Hudson River. The DEC will then use these counts to track populations of the American eel. This is a great project for students who are interested to get their hands wet and to see real science at work. Many students become invigorated by the project and take a true interest in these slimy eels.
The American Eel is a fascinating and misunderstood creature. Eels are catadromous fish, which means they live in fresh water most their lives but are born, breed and die in salt water. The Hudson River and its tributaries are very special to these fish because the Hudson River Estuary is one of the few places in the world with access to both fresh water and ocean waters. (photo credit above: Chris Bowser, NYSDEC) In the last several decades, the American eel population has dropped worldwide enough to raise concern about the future of eels. Since eels cannot reproduce in captivity, it is extremely important to figure out why populations are dropping and what we can do to help.
Two years ago the DEC partnered with local high schools and adult volunteer groups to begin studies about American Eel migration from the ocean to fresh water tributaries. The American Eel migration takes place from the end of March through the end of May. During this time thousands of tiny. two-inch-size glass eels ride the current from the Sargasso Sea, by the Bermuda Triangle, all the way up into the Hudson River. Eel fike nets are placed in strategic tributaries to catch the nocturnal see-through eels on their night journey. They are counted and weighed daily by high school, youth and adult volunteers and released to continue up river.
Investigating Techniques to Survey Flatworms at the Greenburgh Nature Center
Believe it or not, earthworms are non-native to our forests! Most scientists believe that the glaciers that once covered Greenburgh Nature Center over 15,000 years ago scoured the landscape of any trace of a native earthworm. Those that we see today crawling in our woods and gardens are from Europe and Asia. The problem is that while earthworms are great for the garden – tiling, aerating, and fertilizing the soil - they may pose a threat to many native species of wildflowers and trees.
Native plants are used to forest soils characterized by slow decomposition. This slow process results in the accumulation of a thick leaf layer tied together by the threads of fungi that feed on the decomposing leaves. This leaf layer acts as a forest’s skin, shielding the living soil. Enter the earthworm: They can ramp up decomposition chewing up leaf litter in no time and, in essence, “over-fertilizing” the forest. The impact of earthworms on forests (and which species are most “troublesome”) is only now being understood.
But as nature abhors a vacuum, an exotic predator of earthworms has also moved into our neighborhood, Bipalium adventitium, our only terrestrial flatworm. Very little is known about this flatworm, including where can they be found?! Greenburgh Nature Center is partnering with Dr. Mark Weckel and the Mianus River Gorge Preserve’s High School Wildlife Technician Program on a study investigating a technique for surveying flatworms on our property. The technique being investigated involves placing bricks covered with black plastic in several locations in our forests. If flatworms are in the area, they should be attracted to the moist, warm soil under the brick. This flatworm study is part a larger project to investigate the Asian earthworm distribution in suburban forests in Westchester County. While flatworms will not be a panacea for controlling the impact of earthworms, it is important to learn as much as we can about the delicate ecology of our soil communities to better protect its trees and wildflowers.
Waterfowl Nest Box Project
Since 2008, the GNC, Town of Greenburgh Parks and Recreation, Westchester County Parks and Recreation, Bronx River Parkway Reservation Conservancy and students at Saunders Technical High School have worked in conjunction to install waterfowl nest boxes in Town of Greenburgh and Westchester County Park areas. Designed to attract Wood Ducks and Hooded Mergansers, these nest boxes mimic natural cavities, such as found in dead trees, which these birds require to successfully nest. This conservation project is geared towards increasing breeding sites for these species in local wetland areas and create public awareness about the importance of wetland conservation.
The nest box program not only provides nest sites for local waterfowl, it also provides the opportunity for participants to experience waterfowl conservation. Through nest box placement and the annual recording of nest success data, participants become involved with waterfowl conservation and take part in collecting scientific data.
During the fall, students examined nest boxes and recorded productivity of each nest box. The GNC intends to organize this survey on a yearly basis to determine which nest sites are preferred over time and monitor Wood Duck and Hooded Merganser populations in local areas. This project will be expanded each nesting season and is on track to benefit waterfowl, protect wetlands and provide visual wildlife interactions for visitors to our local parks.
Students, special interest groups and landowners who are interested in participating in the nest box program are encouraged to contact Travis Brady at (914) 813-1830 or firstname.lastname@example.org for further information.
Eastern Bluebird Restoration Project
The GNC is pleased to join the Bronx River-Sound Shore Audubon Society in helping to restore the state bird of New York-the eastern bluebird. During the past 10 years, this Eastern Bluebird Project has helped us go from zero nesting eastern bluebird pairs in the monitored areas, to a record high of 30 nesting pairs in 2008.
With the help of GNC staff and community members, we build and place nest boxes in good bluebird habitat. To date over 200 nest boxes have been built and placed. The boxes are then monitored for bluebird activity. This project is a success in part to all of the additional support from the Girl Scouts, Boy Scouts, seniors, elementary and high school students and many others. Several institutions, private and public, allow us to locate the nest boxes on their land.
Area locations open to the public where you have a good chance to see bluebirds include Harts Brook Park & Preserve, Ferncliff, Mount Hope, Mt. Calvery and Kensico cemeteries, Westchester Community College and Burke Rehabilitation Hospital.
If you are interested in learning more about this project and how you can become involved, please contact Sandy Morrissey at email@example.com.
Population Dynamics of Eastern Screech Owls.
In partnership with the Mianus River Gorge Preserve (http://www.mianus.org/), the GNC property is being used as a research site to study the population dynamics of eastern screech owls living in NYC and southern Westchester to better understand its distribution, breeding and habitat requirements. The GNC location represents an important midpoint within the rural-to-urban landscape spectrum in our region.
In conjunction with GNC staff, Chris Nagy, a PhD candidate from City University of New York, is using call-playback surveys to estimate the habitat use and selection of this species. Analysis of recorded owl vocalizations helps identify and monitor individual owls. Results from the 2009 field season confirmed habitat areas in the vicinity of the Nature Center support breeding pairs of this species of Owl. In the years to come, further research at the GNC will help determine the stability of small Screech Owl populations living in fragmented urban areas.
Owls and other birds of prey, help stabilize biological communities and often can help limit pest populations of rodents. In particular, this species adapts well to human-altered areas, and can fill a predatory role to help develop effective population management of rodents.
Tracking Bird Migration at Night through Urban-Rural Corridors in Westchester County
Many migratory bird species are in serious decline. Understanding how birds assess and utilize urban-rural corridors in Westchester County during migration is essential to their conservation. Migrating birds often use urban habitats as stopover sites while traveling between their wintering and summering grounds. However, little is known about how birds evaluate and navigate the resources available in and obstacles presented by urban areas during migration, which generally occurs at night.
Without such knowledge, managers find themselves without rational approaches to monitoring and improving conditions for birds migrating through urban corridors. The first step to managing or improving urban landscapes is to understand what species are migrating through an area and how such landscapes impact these species.
To facilitate collection of this type of data in the Greenburgh area, GNC staff is assisting Dr. Alan Clark (pictured above) from Fordham University to record vocalizations at night on our property during the spring and fall months. Analysis of these recordings will help determine the diversity and abundance of species migrating through Westchester County. These results will provide important information to wildlife managers and city planners on how to improve conditions for birds migrating through urban landscapes.