Fluctuating water depths affect American alligator (Alligator mississippiensis) body condition in the Everglades, Florida, USA

Abstract

Successful restoration of wetland ecosystems requires knowledge of wetland hydrologic patterns and an understanding of how those patterns affect wetland plant and animal populations. Within the Everglades, Florida, USA restoration, an applied science strategy including conceptual ecological models linking drivers to indicators is being used to organize current scientific understanding to support restoration efforts. A key driver of the ecosystem affecting the distribution and abundance of organisms is the timing, distribution, and volume of water flows that result in water depth patterns across the landscape. American alligators (Alligator mississippiensis) are one of the ecological indicators being used to assess Everglades restoration

The metabolic cost of nesting: body condition and blood parameters of Caiman crocodilus and Melanosuchus niger in Central Amazonia

“…Other aspects not addressed in this study such as female body condition prior to nesting (Brandt et al 2016 ) and reproductive allometry also need to be taken into account. Associations between female body size and clutch characteristics have been reported in several crocodilians (Thorbjarnarson 1996 ), including C. crocodilus and C. yacare (Campos et al 2008 ).…”

Public preferences for ecological indicators used in Everglades restoration

“…A set of potential attributes for the choice experiment were chosen based on a comprehensive literature review [13,15,[17][18][19][20][24][25][26][27][28][29][30][31][32][33][34][35][36] and informal interviews with several hydrologists and ecologists familiar with the Everglades ecosystem who are engaged in research and/or management regarding this restoration effort. Attributes were evaluated based on their connection to CERP approved indicators, whether there were existing research or models published in the peer-reviewed literature that could be used to quantify how the attributes would respond to various restoration scenarios, and whether they could be easily understood by Florida residents.…”

“…Increased alligator populations are considered to be a system-wide performance metric for restoration of the hydrology in critical areas of the Everglades ecosystem [36]. Habitat suitability models for the American alligator-Alligator mississippiensis have been developed over the past several decades [20,26,28,29,31]. Wading birds are considered a performance metric for the resumption of the flow of fresh water through the southern Everglades [33].…”

“…If the error terms in the above equations are independently and identically distributed and have a type I extreme value distribution, Eq (2) can be estimated using a conditional logit function [26,41]:…”

A Body Condition Score for Crocodilians

“…In general, crocodile studies are based on the paradigm that BC can be measured through the result of a mathematical function between weight and length, from which the amount of energy reserves of an individual can be deduced (Mazzotti et al, 2012;Zweig et al, 2014). This value allows us to relate several factors such as diet (Delany et al, 1999;Shirley et al, 2016), growth (Saalfeld et al, 2008), reproduction (Barão-Nóbrega et al, 2017), season (Hutton 1987; Barr, 1997), temperature (Brandt, 1991), and water level (Fujisaki et al, 2009;Brandt et al, 2016) to the health, quality, and vigor of individuals and populations (Stevenson and Woods, 2006;Peig and Green, 2009). BC has proven to be of such utility and importance that management programs have used it to evaluate the results of ecological restoration (Mazzotti et al, 2009).…”