Spatial Patterns of Diamondback Terrapin (Malaclemys terrapin) Nest Mortality in Relation to Vegetation Management: Implications for Persistence of a Managed. Smith, K. J. Ph.D. Thesis, University of Georgia, Athens, Georgia, USA, 2017. abstract bibtex Nesting is an important component in animal life cycles, and many species incur significant costs associated with nesting. Human activities can often interrupt nesting behavior and lead to degradation of nesting habitats. For turtles, altering vegetation structure can lead to reduced nesting success by increasing predation rates. The diamondback terrapin (Malaclemys terrapin) occupies salt marshes and female terrapins undergo terrestrial excursions to nest on sparsely vegetated areas above the high tide. Terrapin females show high nest location fidelity and natal philopatry, and therefore, may continue to nest in areas where human activities have degraded local conditions. The objectives of my research are to: (1) evaluate whether the creation and maintenance of shrub habitat increases predation rates on terrapin nests; (2) determine whether spatial patterns of vegetation-driven predation on nests are contributing to a terrapin population decline; and (3) evaluate whether vegetation management will improve terrapin nest survival. Building off of a long-term study of terrapins on the Jekyll Island Causeway (JIC) and a recent dieback of Northern raccoon (Procyon lotor), the primary predator of terrapin nests, I used artificial nests to measure predation rates in areas of hedgerow, recently cleared hedgerow, and open, sparse vegetation. Using the results of my experiment, I modeled spatial patterns of nest mortality along the entire JIC and integrated that into a population viability analysis (PVA) to estimate the effects of vegetation-driven nest predation on terrapin population persistence. I found that predation rates on nests in hedgerows (62.5% of nests) was 100% greater compared to the predation rate on nests in open sites (31.7%). However, nest predation rates in areas of recent shrub removal remained high (71.5%). Nest predation was 39% lower in 2016 (45.7% of nests) compared to a previous study in 2013 at the same locations (75.4%), which was consistent with the recent die back of the local raccoon population. I found that the top model for estimating depredation of nests at our study site included location and vegetation within a 25-m buffer. The primary driver behind nest depredation rates is the location of the nest and vegetation had a much lower impact than previously thought. Despite the strong effect of vegetation on nest predation, my results suggest that vegetation removal does not immediately reduce predation rates. However, with new estimates of nest depredation, terrapins have a much higher probability of persistence. In the future, management plans should account for the spatial depredation rates in addition to vegetation depredation rates.
@phdthesis{smith_spatial_2017,
address = {Athens, Georgia, USA},
type = {Senior {Thesis}},
title = {Spatial {Patterns} of {Diamondback} {Terrapin} ({Malaclemys} terrapin) {Nest} {Mortality} in {Relation} to {Vegetation} {Management}: {Implications} for {Persistence} of a {Managed}},
abstract = {Nesting is an important component in animal life cycles, and many species incur significant costs associated with nesting. Human activities can often interrupt nesting behavior and lead to degradation of nesting habitats. For turtles, altering vegetation structure can lead to reduced nesting success by increasing predation rates. The diamondback terrapin (Malaclemys terrapin) occupies salt marshes and female terrapins undergo terrestrial excursions to nest on sparsely vegetated areas above the high tide. Terrapin females show high nest location fidelity and natal philopatry, and therefore, may continue to nest in areas where human activities have degraded local conditions. The objectives of my research are to: (1) evaluate whether the creation and maintenance of shrub habitat increases predation rates on terrapin nests; (2) determine whether spatial patterns of vegetation-driven predation on nests are contributing to a terrapin population decline; and (3) evaluate whether vegetation management will improve terrapin nest survival. Building off of a long-term study of terrapins on the Jekyll Island Causeway (JIC) and a recent dieback of Northern raccoon (Procyon lotor), the primary predator of terrapin nests, I used artificial nests to measure predation rates in areas of hedgerow, recently cleared hedgerow, and open, sparse vegetation. Using the results of my experiment, I modeled spatial patterns of nest mortality along the entire JIC and integrated that into a population viability analysis (PVA) to estimate the effects of vegetation-driven nest predation on terrapin population persistence. I found that predation rates on nests in hedgerows (62.5\% of nests) was 100\% greater compared to the predation rate on nests in open sites (31.7\%). However, nest predation rates in areas of recent shrub removal remained high (71.5\%). Nest predation was 39\% lower in 2016 (45.7\% of nests) compared to a previous study in 2013 at the same locations (75.4\%), which was consistent with the recent die back of the local raccoon population. I found that the top model for estimating depredation of nests at our study site included location and vegetation within a 25-m buffer. The primary driver behind nest depredation rates is the location of the nest and vegetation had a much lower impact than previously thought. Despite the strong effect of vegetation on nest predation, my results suggest that vegetation removal does not immediately reduce predation rates. However, with new estimates of nest depredation, terrapins have a much higher probability of persistence. In the future, management plans should account for the spatial depredation rates in addition to vegetation depredation rates.},
language = {en},
school = {University of Georgia},
author = {Smith, Kayla Jordan},
year = {2017},
}
Downloads: 0
{"_id":"xc7rJzSnK5EJZ2y8J","bibbaseid":"smith-spatialpatternsofdiamondbackterrapinmalaclemysterrapinnestmortalityinrelationtovegetationmanagementimplicationsforpersistenceofamanaged-2017","author_short":["Smith, K. J."],"bibdata":{"bibtype":"phdthesis","type":"Senior Thesis","address":"Athens, Georgia, USA","title":"Spatial Patterns of Diamondback Terrapin (Malaclemys terrapin) Nest Mortality in Relation to Vegetation Management: Implications for Persistence of a Managed","abstract":"Nesting is an important component in animal life cycles, and many species incur significant costs associated with nesting. Human activities can often interrupt nesting behavior and lead to degradation of nesting habitats. For turtles, altering vegetation structure can lead to reduced nesting success by increasing predation rates. The diamondback terrapin (Malaclemys terrapin) occupies salt marshes and female terrapins undergo terrestrial excursions to nest on sparsely vegetated areas above the high tide. Terrapin females show high nest location fidelity and natal philopatry, and therefore, may continue to nest in areas where human activities have degraded local conditions. The objectives of my research are to: (1) evaluate whether the creation and maintenance of shrub habitat increases predation rates on terrapin nests; (2) determine whether spatial patterns of vegetation-driven predation on nests are contributing to a terrapin population decline; and (3) evaluate whether vegetation management will improve terrapin nest survival. Building off of a long-term study of terrapins on the Jekyll Island Causeway (JIC) and a recent dieback of Northern raccoon (Procyon lotor), the primary predator of terrapin nests, I used artificial nests to measure predation rates in areas of hedgerow, recently cleared hedgerow, and open, sparse vegetation. Using the results of my experiment, I modeled spatial patterns of nest mortality along the entire JIC and integrated that into a population viability analysis (PVA) to estimate the effects of vegetation-driven nest predation on terrapin population persistence. I found that predation rates on nests in hedgerows (62.5% of nests) was 100% greater compared to the predation rate on nests in open sites (31.7%). However, nest predation rates in areas of recent shrub removal remained high (71.5%). Nest predation was 39% lower in 2016 (45.7% of nests) compared to a previous study in 2013 at the same locations (75.4%), which was consistent with the recent die back of the local raccoon population. I found that the top model for estimating depredation of nests at our study site included location and vegetation within a 25-m buffer. The primary driver behind nest depredation rates is the location of the nest and vegetation had a much lower impact than previously thought. Despite the strong effect of vegetation on nest predation, my results suggest that vegetation removal does not immediately reduce predation rates. However, with new estimates of nest depredation, terrapins have a much higher probability of persistence. In the future, management plans should account for the spatial depredation rates in addition to vegetation depredation rates.","language":"en","school":"University of Georgia","author":[{"propositions":[],"lastnames":["Smith"],"firstnames":["Kayla","Jordan"],"suffixes":[]}],"year":"2017","bibtex":"@phdthesis{smith_spatial_2017,\n\taddress = {Athens, Georgia, USA},\n\ttype = {Senior {Thesis}},\n\ttitle = {Spatial {Patterns} of {Diamondback} {Terrapin} ({Malaclemys} terrapin) {Nest} {Mortality} in {Relation} to {Vegetation} {Management}: {Implications} for {Persistence} of a {Managed}},\n\tabstract = {Nesting is an important component in animal life cycles, and many species incur significant costs associated with nesting. Human activities can often interrupt nesting behavior and lead to degradation of nesting habitats. For turtles, altering vegetation structure can lead to reduced nesting success by increasing predation rates. The diamondback terrapin (Malaclemys terrapin) occupies salt marshes and female terrapins undergo terrestrial excursions to nest on sparsely vegetated areas above the high tide. Terrapin females show high nest location fidelity and natal philopatry, and therefore, may continue to nest in areas where human activities have degraded local conditions. The objectives of my research are to: (1) evaluate whether the creation and maintenance of shrub habitat increases predation rates on terrapin nests; (2) determine whether spatial patterns of vegetation-driven predation on nests are contributing to a terrapin population decline; and (3) evaluate whether vegetation management will improve terrapin nest survival. Building off of a long-term study of terrapins on the Jekyll Island Causeway (JIC) and a recent dieback of Northern raccoon (Procyon lotor), the primary predator of terrapin nests, I used artificial nests to measure predation rates in areas of hedgerow, recently cleared hedgerow, and open, sparse vegetation. Using the results of my experiment, I modeled spatial patterns of nest mortality along the entire JIC and integrated that into a population viability analysis (PVA) to estimate the effects of vegetation-driven nest predation on terrapin population persistence. I found that predation rates on nests in hedgerows (62.5\\% of nests) was 100\\% greater compared to the predation rate on nests in open sites (31.7\\%). However, nest predation rates in areas of recent shrub removal remained high (71.5\\%). Nest predation was 39\\% lower in 2016 (45.7\\% of nests) compared to a previous study in 2013 at the same locations (75.4\\%), which was consistent with the recent die back of the local raccoon population. I found that the top model for estimating depredation of nests at our study site included location and vegetation within a 25-m buffer. The primary driver behind nest depredation rates is the location of the nest and vegetation had a much lower impact than previously thought. Despite the strong effect of vegetation on nest predation, my results suggest that vegetation removal does not immediately reduce predation rates. However, with new estimates of nest depredation, terrapins have a much higher probability of persistence. In the future, management plans should account for the spatial depredation rates in addition to vegetation depredation rates.},\n\tlanguage = {en},\n\tschool = {University of Georgia},\n\tauthor = {Smith, Kayla Jordan},\n\tyear = {2017},\n}\n\n\n\n","author_short":["Smith, K. J."],"key":"smith_spatial_2017","id":"smith_spatial_2017","bibbaseid":"smith-spatialpatternsofdiamondbackterrapinmalaclemysterrapinnestmortalityinrelationtovegetationmanagementimplicationsforpersistenceofamanaged-2017","role":"author","urls":{},"metadata":{"authorlinks":{}},"html":""},"bibtype":"phdthesis","biburl":"https://bibbase.org/zotero-group/jcmaerz/6026148","dataSources":["cEHounRE4nrKSn63i","jCzfhtqfYxC5Tyadj"],"keywords":[],"search_terms":["spatial","patterns","diamondback","terrapin","malaclemys","terrapin","nest","mortality","relation","vegetation","management","implications","persistence","managed","smith"],"title":"Spatial Patterns of Diamondback Terrapin (Malaclemys terrapin) Nest Mortality in Relation to Vegetation Management: Implications for Persistence of a Managed","year":2017}