Parameter Estimation for a Declining, Elusive Species. Scott, C D. Ph.D. Thesis, University of Georgia, Athens, Georgia, USA, 2022. abstract bibtex One of the primary mechanisms to evaluate the population status and determine the effectiveness of management actions is the use of population viability models (PVAs). PVAs depend on the quality of demographic data, which are often not known for focal populations and therefore “borrowed” from other studies or estimated by expert opinion. Recent PVAs to estimate the status and management effects on Diamondback Terrapins, Malaclemys terrapin, in Georgia assume that terrapins nest twice per year and lay approximately 7 eggs per clutch. However, there are anecdotal reports of higher nesting frequency suggest that current PVA estimates are pessimistic. We used 7 years of citizen science data from the Skidaway Audubon Diamondback Terrapin Project of nesting on Skidaway Island to describe the naïve fecundity of the population and reevaluate a previously published PVA. Mean clutch size was 8.5 eggs per clutch, and the mean number of observed nesting events per year per female was 2.1, with 32% of females observed nesting 3 or more times in a single year and a maximum of 6 nesting events in a single season. Persistence probability increased between 32% and 216% for all management scenarios of the PVA. The distribution of days between nesting events showed a strong right skew that indicates a high likelihood that many nesting events are not observed and the true mean nesting frequency is significantly greater than the naïve estimate. These observations indicate that current fecundity estimates for Diamondback Terrapins in Georgia are likely too low and models are underestimating population growth and persistence.
@phdthesis{scott_parameter_2022,
address = {Athens, Georgia, USA},
type = {Senior {Thesis}},
title = {Parameter {Estimation} for a {Declining}, {Elusive} {Species}},
abstract = {One of the primary mechanisms to evaluate the population status and determine the effectiveness of management actions is the use of population viability models (PVAs). PVAs depend on the quality of demographic data, which are often not known for focal populations and therefore “borrowed” from other studies or estimated by expert opinion. Recent PVAs to estimate the status and management effects on Diamondback Terrapins, Malaclemys terrapin, in Georgia assume that terrapins nest twice per year and lay approximately 7 eggs per clutch. However, there are anecdotal reports of higher nesting frequency suggest that current PVA estimates are pessimistic. We used 7 years of citizen science data from the Skidaway Audubon Diamondback Terrapin Project of nesting on Skidaway Island to describe the naïve fecundity of the population and reevaluate a previously published PVA. Mean clutch size was 8.5 eggs per clutch, and the mean number of observed nesting events per year per female was 2.1, with 32\% of females observed nesting 3 or more times in a single year and a maximum of 6 nesting events in a single season. Persistence probability increased between 32\% and 216\% for all management scenarios of the PVA. The distribution of days between nesting events showed a strong right skew that indicates a high likelihood that many nesting events are not observed and the true mean nesting frequency is significantly greater than the naïve estimate. These observations indicate that current fecundity estimates for Diamondback Terrapins in Georgia are likely too low and models are underestimating population growth and persistence.},
language = {en},
school = {University of Georgia},
author = {Scott, C Dare},
year = {2022},
}
Downloads: 0
{"_id":"hqg3eGPR3hCkzPNKT","bibbaseid":"scott-parameterestimationforadecliningelusivespecies-2022","author_short":["Scott, C D."],"bibdata":{"bibtype":"phdthesis","type":"Senior Thesis","address":"Athens, Georgia, USA","title":"Parameter Estimation for a Declining, Elusive Species","abstract":"One of the primary mechanisms to evaluate the population status and determine the effectiveness of management actions is the use of population viability models (PVAs). PVAs depend on the quality of demographic data, which are often not known for focal populations and therefore “borrowed” from other studies or estimated by expert opinion. Recent PVAs to estimate the status and management effects on Diamondback Terrapins, Malaclemys terrapin, in Georgia assume that terrapins nest twice per year and lay approximately 7 eggs per clutch. However, there are anecdotal reports of higher nesting frequency suggest that current PVA estimates are pessimistic. We used 7 years of citizen science data from the Skidaway Audubon Diamondback Terrapin Project of nesting on Skidaway Island to describe the naïve fecundity of the population and reevaluate a previously published PVA. Mean clutch size was 8.5 eggs per clutch, and the mean number of observed nesting events per year per female was 2.1, with 32% of females observed nesting 3 or more times in a single year and a maximum of 6 nesting events in a single season. Persistence probability increased between 32% and 216% for all management scenarios of the PVA. The distribution of days between nesting events showed a strong right skew that indicates a high likelihood that many nesting events are not observed and the true mean nesting frequency is significantly greater than the naïve estimate. These observations indicate that current fecundity estimates for Diamondback Terrapins in Georgia are likely too low and models are underestimating population growth and persistence.","language":"en","school":"University of Georgia","author":[{"propositions":[],"lastnames":["Scott"],"firstnames":["C","Dare"],"suffixes":[]}],"year":"2022","bibtex":"@phdthesis{scott_parameter_2022,\n\taddress = {Athens, Georgia, USA},\n\ttype = {Senior {Thesis}},\n\ttitle = {Parameter {Estimation} for a {Declining}, {Elusive} {Species}},\n\tabstract = {One of the primary mechanisms to evaluate the population status and determine the effectiveness of management actions is the use of population viability models (PVAs). PVAs depend on the quality of demographic data, which are often not known for focal populations and therefore “borrowed” from other studies or estimated by expert opinion. Recent PVAs to estimate the status and management effects on Diamondback Terrapins, Malaclemys terrapin, in Georgia assume that terrapins nest twice per year and lay approximately 7 eggs per clutch. However, there are anecdotal reports of higher nesting frequency suggest that current PVA estimates are pessimistic. We used 7 years of citizen science data from the Skidaway Audubon Diamondback Terrapin Project of nesting on Skidaway Island to describe the naïve fecundity of the population and reevaluate a previously published PVA. Mean clutch size was 8.5 eggs per clutch, and the mean number of observed nesting events per year per female was 2.1, with 32\\% of females observed nesting 3 or more times in a single year and a maximum of 6 nesting events in a single season. Persistence probability increased between 32\\% and 216\\% for all management scenarios of the PVA. The distribution of days between nesting events showed a strong right skew that indicates a high likelihood that many nesting events are not observed and the true mean nesting frequency is significantly greater than the naïve estimate. These observations indicate that current fecundity estimates for Diamondback Terrapins in Georgia are likely too low and models are underestimating population growth and persistence.},\n\tlanguage = {en},\n\tschool = {University of Georgia},\n\tauthor = {Scott, C Dare},\n\tyear = {2022},\n}\n\n\n\n","author_short":["Scott, C D."],"key":"scott_parameter_2022","id":"scott_parameter_2022","bibbaseid":"scott-parameterestimationforadecliningelusivespecies-2022","role":"author","urls":{},"metadata":{"authorlinks":{}},"html":""},"bibtype":"phdthesis","biburl":"https://bibbase.org/zotero-group/jcmaerz/6026148","dataSources":["mCHFziEwJLRwofY4u","cEHounRE4nrKSn63i"],"keywords":[],"search_terms":["parameter","estimation","declining","elusive","species","scott"],"title":"Parameter Estimation for a Declining, Elusive Species","year":2022}