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My
Research |
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have three main ongoing research projects and several smaller
projects: |
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Ecology, conservation, and sex determination of diamondback terrapins
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Ecology, conservation, and sex determination of wood turtles, spotted turtles, and bog turtles in northern NJ
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Impact of raccoons on terrapins and terrestrial ecosystems at Jamaica Bay Wildlife Refuge
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Ecology of the introduced wall lizards on Long Island
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Ecology
of the introduced Wall Lizards (Podarcis sicula), on
Long Island.
This species was introduced from its native Italy about 30 years
ago and seems to have adapted well to New York. It is common
in urban areas, easily observed and easily collected in the
field, and lots of fun to work with. It was the main source
of data for my undergraduate research students until recently,
because we're wrapping up work on this species. |
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| For example, my students have studied the freeze tolerance of this species, male reproductive cycles, female reproductive cycles, food habits, and phenology. Currently we are wrapping up some of this work for publication, and starting in some new directions: parasitology genetic variation between populations, and growth rates. Click here to see abstracts of our work on this species, and click here for some of the published work. |
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We
began a long term research program investigating the ecology
and conservation of diamondback terrapins (Malaclemys
terrapin) at Gateway National Recreational Area in 1998.
So far this work has focused on the Jamaica Bay Wildlife Refuge
unit of GNRA. Over 2000 nests/year are laid at JBWR, and nest
mortality has risen to over 90% since raccoons were introduced
onto the main island of JBWR. This project involves most of
my graduate students, undergraduate students, high school students,
and volunteers. Click here for
a more general discussion of terrapins and our research.
We are always interested in folks that might
be interested in volunteering to help. Click here
to learn a little more. Click here
for descriptions of my students' research on terrapins, and
click here for some of the published work. |
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| Raccoons
are also now preying on adult terrapins. It is unclear
whether this has had an impact on terrapin populations, in part
because we are just beginning to examine nesting and predation
on the numerous smaller islands in Jamaica Bay. We are attempting
to estimate the size of the terrapin population so we can detect
trends. We are also beginning a movement study using sonic transmitters,
along with a tag-reward system, that we hope will reveal short
term and long term movements, with a focus on the Hudson River.
Finally, we have begun a study of raccoon behavior that we hope
will lead to management options to reduce their predation on
terrapins. We are always interested in folks that might
be interested in volunteering to help—click here to learn a little more. |
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| Raccoons
are a fairly new source of mortality of terrapin eggs. It is
unclear how much of an impact this has had on terrapin populations,
because we don't know much about hatchling and subadult survivorship
yet. We have studied the population size and movements of the
raccoons. We plan two new projects with the raccoons: taste
aversion training, and population reduction through chemical
contraception. We hope our results will lead to management options
to reduce their predation on terrapins |
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Since
1996 I have been studying the demography and reproduction of
both wild and captive wood turtles, spotted turtles, and bog
turtles, the three eastern members of the genus Clemmys.
My goal is two fold: to gain information useful to the conservation of these species, and to test some of the most important theories of genetic and environmental sex determination. These are ideal species for this kind of work because wood turtles have genotypic sex determination (GSD), spotted turtles have temperature sex determination (TSD), and bog turtles are unknown.
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These are difficult animals to study, which is why little detailed information is known about their behavior in the wild. Fortunately, lots of other people are working on them now too and some great stuff is coming out. My field site has lots of wood turtles, and I've been radio tracking them and focusing on their nesting ecology and have a few years of hatchling sex ratio data. I've been struck by their interesting interactions with beaver. Lately I have been collaborating with Dr. Mike Sebetich of William Patterson University, along with his students. I am particularly interested in long-term data on offspring sex ratio, addressing questions such as:
1. Do individual mothers have consistent offspring sex ratios over multiple years?
2. Do the reproducing females in a population shift offspring sex ratios as a group, or do they vary independently?
3. How biased are the offspring sex ratios of genotypic species?
4. What environmental factors might influence the offspring sex ratios produced by GSD and TSD species?
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