DOI: 10.5061/dryad.sxksn0387
title: Body size measurements and stomach contents of Alligator mississippiensis on Jekyll Island, Georgia

description: Human-driven land use change can fundamentally alter ecological
 communities, especially the diversity and abundance of large-bodied
 predators. Yet despite the important roles large-bodied predators play in
 structuring communities through feeding, there have been only a few
 investigations of how the feeding patterns of large-bodied predators
 change in human-dominated landscapes. One group of large-bodied predators
 that has been largely overlooked in the context of land use change is the
 crocodilians. To help fill these gaps we studied the feeding patterns of
 juvenile American alligators (Alligator mississippiensis) on neighboring
 barrier islands on the southeast coast of Georgia, USA. Jekyll Island has
 multiple golf courses and substantial amounts of human activity, while
 Sapelo Island does not have any golf courses and a much smaller amount of
 human activity. We found that juvenile alligator populations on both
 islands ate the same types of prey but in vastly different quantities.
 Sapelo Island alligators primarily consumed crustaceans while alligators
 that lived on Jekyll Island’s golf courses ate mostly insects/arachnids.
 Furthermore, the Jekyll Island alligators exhibited a much more generalist
 feeding pattern (individuals mostly ate the same types of prey in the same
 quantities) than the more specialized Sapelo Island alligators (diets were
 more varied across individuals). The most likely explanation for our
 results is that alligators living on golf courses have different habitat
 use patterns and have access to different prey communities relative to
 alligators in more natural habitats. Thus, land use change can strongly
 alter the feeding patterns of large-bodied predators and, as a result, may
 affect their body condition, exposure to human-made chemicals, and role
 within ecological communities.
description: We conducted the study on Jekyll Island (31° 3’58” N, 81° 24’52”
 W), a barrier island on the southeast coast of Georgia, USA between March
 and August during 2019 and 2020. We located alligators on golf courses at
 night using handheld spotlights and captured them using a fishing pole and
 line with a modified treble hook attached. We then brought each animal to
 shore and taped its mouth closed before measuring total length (TL) and
 snout-vent length (SVL) dorsally to the nearest 0.1 cm. We determined sex
 via cloacal examination and then used the hose-Heimlich technique to
 collect stomach contents. This technique involves filling each alligator’s
 stomach with water and then applying pressure to the alligator’s flanks
 until the water, and any prey items inside, exit the mouth. We collected
 all water and prey items in a bucket and, following release of each
 alligator at the capture site, we sieved the prey items and stored them in
 jars filled with 95% ethanol. In the laboratory we identified all prey
 items to the lowest possible taxonomic level and weighed each item to the
 nearest 0.1 g (wet weight).
description: # Jekyll Island alligator stomach contents *** We conducted the study on
 Jekyll Island (31° 3’58” N, 81° 24’52” W), a barrier island on the
 southeast coast of Georgia, USA between March and August during 2019 and
 2020. We located alligators on golf courses at night using handheld
 spotlights and captured them using a fishing pole and line with a modified
 treble hook attached. We then brought each animal to shore and taped its
 mouth closed before measuring morphometrics. We determined sex via cloacal
 examination and then used the hose-Heimlich technique to collect stomach
 contents. This technique involves filling each alligator’s stomach with
 water and then applying pressure to the alligator’s flanks until the
 water, and any prey items inside, exit the mouth. We collected all water
 and prey items in a bucket and, following release of each alligator at the
 capture site, we sieved the prey items and stored them in jars filled with
 95% ethanol. In the laboratory we identified all prey items to the lowest
 possible taxonomic level and weighed each item to the nearest 0.1 g (wet
 weight). ## Description of the data and file structure The data are
 arranged in columns, including the date/time each animal was captured,
 each animal's ID (tail notch), total length and snouth-vent length
 and body girth and tail girth and foot length in centimeters, skull length
 and skull width and eyes-to-snout-length and width between eyes in inches,
 weight in kilograms, latitude and longitude of capture location, the
 number of prey collected from each animal that fall into different prey
 categories, and the mass of prey in each category. Cells with NA represent
 measurements that were not collected. ## Sharing/Access information None
 ## Code/Software None