Mark Parry | Geology Reports

USGS2025

Statistical review of systematic reconnaissance flight (SRF) surveys (2008-2023) for monitoring American alligator (Alligator mississippiensis) nests in Everglades National Park

We reviewed current (2008-2023) protocols for monitoring American alligator nests in Everglades National Park (ENP) using a qualitative statistical review framework that emphasizes connecting measurable objectives with evaluation of survey design elements. Our review outlined the statistical assumptions that, if severely violated, would prevent defensible inferences from being drawn regarding the three alligator nesting metrics monitored in ENP’s systematic reconnaissance flight (SRF) surveys: nest effort (number of nests), nest distribution, and nest fate. After evaluating the current survey and inference methods, we offer potential adjustments or augmentations to the design and models currently used to better account for potential error sources and align the stated objectives with statistical inferences.

Florida↗

USGS2016

Large reptiles and cold temperatures: Do extreme cold spells set distributional limits for tropical reptiles in Florida?

Distributional limits of many tropical species in Florida are ultimately determined by tolerance to low temperature. An unprecedented cold spell during 2–11 January 2010, in South Florida provided an opportunity to compare the responses of tropical American crocodiles with warm-temperate American alligators and to compare the responses of nonnative Burmese pythons with native warm-temperate snakes exposed to prolonged cold temperatures. After the January 2010 cold spell, a record number of American crocodiles ( n = 151) and Burmese pythons ( n = 36) were found dead. In contrast, no American alligators and no native snakes were found dead. American alligators and American crocodiles behaved differently during the cold spell. American alligators stopped basking and retreated to warmer water. American crocodiles apparently continued to bask during extreme cold temperatures resulting in lethal body temperatures. The mortality of Burmese pythons compared to the absence of mortality for native snakes suggests that the current population of Burmese pythons in the Everglades is less tolerant of cold temperatures than native snakes. Burmese pythons introduced from other parts of their native range may be more tolerant of cold temperatures. We documented the direct effects of cold temperatures on crocodiles and pythons; however, evidence of long-term effects of cold temperature on their populations within their established ranges remains lacking. Mortality of crocodiles and pythons outside of their current established range may be more important in setting distributional limits.

Ecosphere↗