Changes in Population Structure of Diamondback Terrapins (Malaclemys terrapin terrapin) in a Previously Surveyed Creek in Southern New Jersey

Avissar, Naomi

doi:10.2744/1071-8443(2006)5[154:cipsod]2.0.co;2

Cited by 7 publications

(6 citation statements)

References 9 publications

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“…Currently, the overall status and trends of terrapin populations remain uncertain because few researchers have established estimates of population sizes (Bishop, 1983;Tucker et al, 2001;Mitro, 2003;Avissar, 2006). Consistent, long-term monitoring is needed to detect temporal changes in population sizes (Avissar, 2006), but using intensive present-day methods requires too much time, money, and sampling effort. Based on our results, we therefore recommend the development of an alternative monitoring program that relies on systematic head-count surveys to evaluate diamondback terrapin population trends over time.…”

Section: Discussionmentioning

confidence: 99%

Development of a rapid-assessment technique for diamondback terrapin (Malaclemys terrapin) populations using head-count surveys

et al. 2009

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Although diamondback terrapins appear to be declining throughout much of their geographic range, more information is required to evaluate population trends. Unfortunately, sampling terrapin populations is both time and labor intensive. We initiated studies to examine the efficacy of using head counts in tidal creeks as a rapid-assessment technique for monitoring terrapin populations. From 2005 to 2007, we conducted headcount surveys in conjunction with regular aquatic sampling. Head-count surveys consisted of recording the number of terrapins we observed from a boat going up (run 1) and down (run 2) tidal creeks. These surveys were conducted before aquatic sampling (i.e., low tide) as well as other times (e.g., high tide). We found the strongest positive relationship between the number of terrapins observed in run 1 combined with run 2 and the number of terrapins captured (R 2 = 0.538). We examined the effects of variables such as day of year, time of day, cloud cover, and creek location on the number of heads seen. Such models will allow effective monitoring of terrapin population trends and improve implementation of appropriate conservation measures. We recommend a refinement of head-count surveys and the involvement of citizen scientists to aid in the establishment of a range-wide monitoring program that will greatly increase survey effort while saving time and money.

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Section: Discussionmentioning

confidence: 99%

Development of a rapid-assessment technique for diamondback terrapin (Malaclemys terrapin) populations using head-count surveys

et al. 2009

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“…Identifying and modeling environmental factors that influence spatiotemporal abundance patterns are key for more informative and useful estimates of population size, yet these factors are largely absent from DBT population studies. Population estimates of DBT are typically generated using capture–recapture methods (Avissar, 2006; Baxter et al, 2016; Butler, 2002; King & Ludlam, 2014). These methods generate valuable information on abundance, survivorship, and demography, but require substantial effort that often restricts sampling to only a few areas within the population region (Hart & McIvor, 2008; King & Ludlam, 2014).…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Factors affecting spatiotemporal patterns of nest site selection and abundance in diamondback terrapins

Levasseur

Prescott

Faherty

et al. 2023

Ecology and Evolution

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“…Terrapin populations have not fully recovered and are possibly declining because of continued harvest, incidental trapping, vehicle and boat strikes, predation, habitat loss, coastal development, and pollution [8,9]. The current status of terrapin populations is difficult to assess because there are few published studies containing terrapin population sizes [10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Poor Correlation between Diamondback Terrapin Population Estimates Using Two New Estimation Methods

Prowant

Burke

2020

Diversity

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Reliable estimates of animal and plant population sizes are necessary to track trends in populations through time. Diamondback terrapins are an ecologically unique keystone species that are globally declining. Conservation efforts for this species rely on accurate estimates of population sizes; however, diamondback terrapin population size estimates are difficult to measure with precision or accuracy. Terrapin collection methods are often labor-, time-, and cost-intensive. The present study compares two recently developed rapid assessment methods for measuring diamondback terrapin abundances. Since mark–recapture or similar data were unavailable, we could not test the accuracy of either method directly; instead, we compared the two methods. If the methods produce similar estimates of terrapin population size, this would increase confidence in these methods. We measured the abundance of diamondback terrapins at 77 sites in Long Island, New York, using headcount surveys and surveys of parasitic trematodes that can be used as a proxy for terrapin abundance. We used random forest analyses to test whether the variation in diamondback terrapin abundance measured using headcount surveys could be explained by either the prevalence or the abundance of trematode parasites. The most variation explained by any of the models was 7.77%, indicating that trematode prevalence and abundance could not explain the variation in terrapin abundance measured using headcounts. This poor correlation between terrapin census methods indicates that one, or both, of the census measures are inaccurate, at least in the habitats found across Long Island, NY. A technique that accurately estimates the abundance of diamondback terrapin populations is critical to understanding their population fluctuations and trends. The only way to evaluate the status of the species is to have information on population numbers and trends across the species’ range, which might not be possible without a more accessible survey method.

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Changes in Population Structure of Diamondback Terrapins (Malaclemys terrapin terrapin) in a Previously Surveyed Creek in Southern New Jersey

Cited by 7 publications

References 9 publications

Development of a rapid-assessment technique for diamondback terrapin (Malaclemys terrapin) populations using head-count surveys

Development of a rapid-assessment technique for diamondback terrapin (Malaclemys terrapin) populations using head-count surveys

Factors affecting spatiotemporal patterns of nest site selection and abundance in diamondback terrapins

Poor Correlation between Diamondback Terrapin Population Estimates Using Two New Estimation Methods

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