Comparison of movements, body weight, and habitat selection between translocated and resident gopher tortoises

Abstract

Gopher tortoises (Gopherus polyphemus) are among the most frequently translocated herpetofauna; yet, determining translocation success is difficult because tortoises are slow‐growing, long‐lived organisms with low reproductive potential. Comparing behavioral traits of translocated individuals with those of sympatric or nearby resident individuals can provide an ecologically relevant baseline to determine if translocated individuals show behavioral traits consistent with those of long‐term residents. We used radio telemetry to concurrently monitor 21 translocated and 15 resident gopher tortoises across 2 sites in southern Georgia and compared movement patterns, body weights, and multi‐scale habitat selection between treatments. Translocated tortoises moved farther and had larger home ranges than resident tortoises but showed similar patterns of site fidelity. We observed no differences in body weight change between treatments. Patterns of habitat selection were similar between treatments in that tortoises selected structurally open habitats at all scales. Our study suggests that more extensive post‐release movements compared to resident individuals may not necessarily lead to lower site fidelity in translocated individuals. We suspect that the presence of structurally suitable habitat within the release area and retaining translocated individuals within a pre‐release enclosure for 10 months contributed to high site fidelity. Although comparing translocated and resident individuals can help inform translocation efforts, we caution that using resident individuals from ecological sinks may lead to misleading results. © 2014 The Wildlife Society.

Epidemiological Investigation of a Mortality Event in a Translocated Gopher Tortoise (Gopherus polyphemus) Population in Northwest Florida

“…(23). However, our recommended density is higher than documented in many wild populations (0.02-3.08 tortoises/ha; all size classes) of gopher tortoises (61,62,(70)(71)(72). The penning density we recommend may need to be reduced further pending additional research into the effects of translocation on social networks and effects of density on the health and behavior of translocated gopher tortoises.…”

“…Although we did not detect a pathogen responsible for the mortalities, holding animals at higher densities increases the probability of pathogen transmission and disease, which can be exacerbated in highly social species with complex social structures, such as the gopher tortoise (59,60). Gopher tortoise movement and behavior patterns are affected by density, and translocated individuals also tend to have increased movements and home ranges (23,61,62). The increased movement exhibited by translocated tortoises also leads to increased contact opportunities for transmission of potential pathogens (21).…”

An empirical test of the role of learning in translocation

“…Thus, while the prospects of additional learning opportunities might be sufficient in some systems (e.g. Bauder et al, 2014;Knox & Monks, 2014;Sullivan, Nowak & Kwiatkowski, 2015), without the proper consideration of the complex nature of how animals learn, researchers might be prone to make the same assumptions we did herein. Based on our findings, we emphasize the importance of understanding the nature of the processes that facilitate learning, especially in those conservation projects that involve translocations and reintroductions.…”

High-voltage power lines near wild reindeer calving areas

“…RSFs are defined as any function proportional to the probability of use of a resource unit area by an individual and have been widely used across a range of taxa including mammals (Godvik et al 2009;Peters et al 2015), birds (Miller et al 2014), and reptiles (Bauder et al 2014). The response variable was binomial (used/available) and consisted of reindeer GPS locations (taken with 3 h intervals; 10,909 locations in both areas) and an equal amount of randomly sampled positions within the merged 99 % BBMM home range for all animals all years for each area (excluding the one individual that remained at one site closer to the power line for more than a month in 2007, 2008, and 2010), representing available area.…”