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Haman K.H.,University of Georgia | Haman K.H.,Tufts University | Norton T.M.,Georgia Sea Turtle Center | Thomas A.C.,University of British Columbia | And 2 more authors.
Journal of Wildlife Diseases | Year: 2012

Sharks are of commercial, research, conservation, and exhibition importance but we know little regarding health parameters and population status for many species. Here we present health indicators and species comparisons for adults of three common wild-caught species: 30 Atlantic sharpnose sharks (Rhizoprionodon terraenovae) and 31 bonnethead sharks (Sphyrna tiburo) from the western Atlantic, and 30 spiny dogfish sharks (Squalus acanthias) from the eastern Pacific. All animals were captured during June-July 2009 and 2010. Median values and preliminary reference intervals were calculated for hematology, plasma biochemistry, trace nutrients, and vitamin A, E, and D concentrations. Significant differences, attributable to physiologic differences among the species, were found in the basic hematologic and plasma biochemistry variables. Significant species differences in arsenic and selenium plasma concentrations were found and appear to coincide with diet and habitat variability among these three species. Vitamin E was significantly higher in the bonnethead shark, again related to the foraging ecology and ingestion of plant material by this species. The Atlantic sharpnose had significantly higher vitamin A concentrations, supported by the higher proportion of teleosts in the diet. Vitamin D was below the limit of quantification in all three species. These preliminary reference intervals for health variables can be used to assess and monitor the population health and serve as indicators of nutritional status in these populations of wild elasmobranchs. © Wildlife Disease Association 2012.


Tuberville T.D.,Savannah River Ecology Laboratory | Norton T.M.,St Catherines Island Wildlife Survival Center | Norton T.M.,Georgia Sea Turtle Center | Waffa B.J.,Sewanee: The University of the South | And 4 more authors.
Biological Conservation | Year: 2011

Population manipulations such as translocation are becoming increasingly important tools in the management of rare and declining species. Evaluating the effectiveness of such manipulations requires comprehensive monitoring of population processes, including dispersal, survivorship, and reproduction. We investigated the mating system of a translocated population of gopher tortoises (Gopherus polyphemus) established through multiple releases, which occurred primarily during 1987-1994. During 2006-2007, we sampled and genotyped 27 candidate males (candidate sires), 34 candidate females (candidate dams), and 121 offspring from 19 clutches at five polymorphic microsatellite loci to determine the relative frequency of multiple paternity and to estimate individual reproductive success. Multiple paternity was detected in 57% of clutches genotyped, and females of single-sire clutches and females of multiple-sire clutches were of similar size. Reproductive success varied among male tortoises, and successful sires were significantly larger than males to which no offspring were attributed. Among successful sires, previously established males sired a disproportionate number of the offspring sampled, despite being significantly smaller than subsequently released males. The high variance in individual reproductive success and the apparent reproductive advantage associated with prior residence observed in this gopher tortoise population has important implications for the design of future translocation projects. © 2010 Elsevier Ltd.


Crawford B.A.,University of Georgia | Maerz J.C.,University of Georgia | Nibbelink N.P.,University of Georgia | Buhlmann K.A.,Savannah River Ecology Laboratory | Norton T.M.,Georgia Sea Turtle Center
Journal of Applied Ecology | Year: 2014

Summary: Roads are pervasive fixtures on most landscapes but are typically among many factors contributing to wildlife population declines. Addressing road mortality as part of larger conservation efforts is challenging because it can be difficult to measure per capita mortality from roads and other concurrent threats. We used 4 years of mark-recapture-recovery data for diamondback terrapins Malaclemys terrapin on a causeway in Georgia, USA, to directly estimate threats of adult road mortality and nest predation, contrast the consequences to population growth using stage-based matrix models and make management recommendations to stabilize the population. Mean estimated annual adult road mortality was 11·1% (range = 4·4-16·4%). Estimated annual nest predation was 61·9%. We estimated that the population was declining (λ < 0·98) in all scenarios where both threats were included. Variation in adult survival was the most influential (highest elasticity) contributor to population growth relative to other demographic rates; however, λ would remain below 1 with any nest predation rate exceeding our estimate even if actions to mitigate road mortality were 100% effective. Synthesis and applications. Our study provides some of the first direct estimates of vehicle mortality rates and shows that mortality can remain sufficiently high among years to cause population declines. We also demonstrate that management actions focused on singular threats are inadequate for recovering populations. We conclude that integrated road and predator management is necessary to conserve turtle populations, and we suggest alternative strategies to compensate for some vehicle mortality and nest depredation. Our study provides some of the first direct estimates of vehicle mortality rates and shows that mortality can remain sufficiently high among years to cause population declines. We also demonstrate that management actions focused on singular threats are inadequate for recovering populations. We conclude that integrated road and predator management is necessary to conserve turtle populations, and we suggest alternative strategies to compensate for some vehicle mortality and nest depredation. © 2013 British Ecological Society.


Crawford B.A.,University of Georgia | Maerz J.C.,University of Georgia | Nibbelink N.P.,University of Georgia | Buhlmann K.A.,Savannah River Ecology Laboratory | And 2 more authors.
Journal of Applied Ecology | Year: 2014

Summary: Road mortality is a major component of human impacts on wildlife populations, and the pervasiveness of roads on the landscape presents a substantial challenge for managing those impacts. The feasibility of methods to reduce road mortality depends on the degree to which this threat is spatially or temporally concentrated, which can be based on habitat, human activities or species' ecology. Diamondback terrapins Malaclemys terrapin are a species of conservation concern across their range, and road mortality is a major threat contributing to local population declines. We used intensive road surveys of the 8·7-km Downing-Musgrove Causeway to Jekyll Island, Georgia, USA, over 2 years to determine whether road activity and mortality was diffused or concentrated spatially (hot spots) or temporally (hot moments) in order to guide efficient management. In 2009 and 2010, we documented 636 terrapin crossings that were temporally and spatially condensed. Temporally, there was a 70-80% chance of a terrapin occurring on the road within a 3-h period around the diurnal high tide and within the first 30 days of the ̃75 day nesting season. Over the two nesting seasons, 52% of terrapin occurrences on the road occurred within the 3-h period around high tide. Spatially, 30% of terrapins were observed crossing in three hot spots that composed less than 10% of the length of the entire causeway, and the percentage of unvegetated high marsh was negatively associated with the number of terrapins that occurred on a section of road. Synthesis and applications. Our results demonstrate that hot spots and hot moments can be identified for species at finer scales than those found by other studies and are related, strongly or weakly, to specific temporal processes or habitat features. We found patterns of road mortality, like most threats, can be diffused or concentrated; therefore, complementary management tools that focus on hot spots or moments and also address the more diffused component of road mortality will be required to reduce this threat for at-risk wildlife. Our results demonstrate that hot spots and hot moments can be identified for species at finer scales than those found by other studies and are related, strongly or weakly, to specific temporal processes or habitat features. We found patterns of road mortality, like most threats, can be diffused or concentrated; therefore, complementary management tools that focus on hot spots or moments and also address the more diffused component of road mortality will be required to reduce this threat for at-risk wildlife. © 2013 British Ecological Society.


Sim R.R.,Maryland Zoo in Baltimore | Norton T.M.,Georgia Sea Turtle Center | Bronson E.,Maryland Zoo in Baltimore | Allender M.C.,University of Illinois at Urbana - Champaign | And 3 more authors.
Veterinary Microbiology | Year: 2015

Herpesvirus infection was identified in two populations of captive Eastern box turtles (Terrapene carolina carolina) using histopathology and polymerase chain reaction (PCR) with DNA sequencing. Necrotizing lesions with eosinophilic to amphophilic intranuclear inclusion bodies were identified in the tissues of one hatch-year individual in January 2013, which was herpesvirus positive by PCR. A separate captive group of adults had an observed herpesvirus prevalence of 58% using PCR in July 2011. In these cases, a novel herpesvirus, Terrapene herpesvirus 1 (TerHV1), was identified and serves as the first herpesvirus sequenced in the genus Terrapene. Similar to the other herpesviruses of the Order Testudines, TerHV1 clusters with the genus Scutavirus of the subfamily Alphaherpesvirinae. © 2014 Elsevier B.V.

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