Dispersal of Newly-Emerged
Diamond-backed Terrapin (Malaclemys
terrapin) Hatchlings at Jamaica Bay, NY
Gateway National Recreation Area
Jamaica Bay Wildlife Refuge
Rulers Bar Hassock
Nesting Ecology
TON or TIN
Terrestrial Overwintering Outside the Nest Terrestrial Overwintering Inside the Nest
Terrestrial vs. Aquatic Overwintering
Adaptations for Terrestrial
Overwintering in Northern Latitudes
Freeze tolerance
Supercooling
West facing dune face and wrack line
2009
2010
2011
2012
The facts so far
what we know what we don't know
• Hatchling DBTs
overwinter terrestrially.
- have adapted to freezing
temperatures
• At JBay most appear to
TON.
• Probably overwinter
above the high line.
- need fresh water
•
Is the wrack line utilized
at all as refugia? Do any
overwinter in the wrack
line?
• Where? Habitat type?
Site characteristics?
• How long?
• Where to next?
• ……and so on
Objectives
• 1) identifying characteristics of post-emergent
diamond backed terrapin hatchling
overwintering ecology
• 2) to determine whether diamond-backed
terrapins hatchlings overwintered in the high
tide wrack line, and
• 3) to describe TON microhabitats and
determine what features influence refugia
choice
Passive Integrated Transponder
• Uses a radio signal transmitted from an
electronic device (PIT Tag)
• Activated by an electromagnetic signal from a
reading device / scanner
• Identifies an object
8.5mm x 2.12mm PIT tag
Biomark Portable BP Antennae
FS2001F-ISO Reader
Limitations
• Labor intensive
- Hatchling must be within range of the
scanner
• Read range affected by :
– Antenna power
– Tag orientation
– Interference
Data Collection
2009 -2012
2009-2010
60 Hatchlings tagged from 8 locations (7 protected
nests, wrack line)
2010-2011
36 hatchlings from 9 locations (protected nests)
2011-2012
251 hatchlings from 29 locations (protected nests)
Hatchling Locating
• 347 tagged hatchlings (6 from the wrack line)
• 205 never located again
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142 located at