Open AccessJournal Article
Resource partitioning by the estuarine turtle malaclemys terrapin: trophic, spatial, and temporal foraging constraints
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Divergent foraging strategies for terrapins of different head widths may result in habitat partitioning, and food accessibility rather than food abundance may be a limiting factor for Terrapins in areas of high tidal variability.Abstract:
We investigated the foraging ecology of the diamondback terrapin (Malaclemys terrapin) in South Carolina by examining fecal samples for evidence of resource partitioning. From 76-79% of the dietary volume was the salt marsh periwinkle (Littorina irrorata); crabs (Uca pugnax, Sesarma reticulatum, and Callinectes sapidus), barnacles (Balanus), and clams (Polynesoda car- oliniana) constituted the remainder. Dietary partitioning is related to the ontogenetic niche of terrapins. Sexual dimorphism occurs in terrapins with females having larger heads and bodies than males. Terrapins with large head widths ingest significantly larger periwinkles and a wider diversity of prey than terrapins with small head widths. Dietary overlap between males and females is greatest when females are small and decreases as females develop larger enlarged heads. Sexual dimorphism in terrapin trophic structures appears to be partially driven by ecological divergence through resource partitioning. High tides permit terrapins to forage aquatically in upper reaches of the salt marsh. Prey size and distribution are variable and changing tidal heights affect the spatiotemporal availability of prey to foraging terrapins. Divergent foraging strategies for terrapins of different head widths may result in habitat partitioning. Food accessibility rather than food abundance may be a limiting factor for terrapins in areas of high tidal variability. Terrapins are clearly prominent but unrec- ognized macroconsumers in salt marsh ecosystems.read more
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From macroplastic to microplastic: Degradation of high‐density polyethylene, polypropylene, and polystyrene in a salt marsh habitat
TL;DR: It is suggested that the degradation of plastic debris proceeds relatively quickly in salt marshes and that surface delamination is the primary mechanism by which microplastic particles are produced in the early stages of degradation.
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Top‐down control of spartina alterniflora production by periwinkle grazing in a virginia salt marsh
Brian R. Silliman,Jay C. Zieman +1 more
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A trophic cascade triggers collapse of a salt-marsh ecosystem with intensive recreational fishing
Andrew H. Altieri,Mark D. Bertness,Tyler C. Coverdale,Nicholas C. Herrmann,Christine Angelini +4 more
TL;DR: It is found that the localized depletion of top predators at sites accessible to recreational anglers has triggered the proliferation of herbivorous crabs, which in turn results in runaway consumption of marsh vegetation, suggesting that overfishing may be a general mechanism underlying the consumer-driven die-off of salt marshes spreading throughout the western Atlantic.
Journal Article
Demographic and ecological factors affecting conservation and management of the diamondback terrapin (Malaclemys terrapin) in South Carolina
TL;DR: A 16-year population study of diamondback terrapins in a South Carolina, USA, salt marsh found that adult females were significantly larger but less numerous than adult males and most of the terrapin captured in the tidal creeks were sexually mature.
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Crab trapping causes population decline and demographic changes in diamondback terrapins over two decades
TL;DR: The changes in demography and sex ratio observed suggest that this terrapin population has declined as a result of selective mortality of smaller individuals in crab traps, and current models are too large to prevent mortality of males and many females in this population.
References
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Book
Ecological Diversity and its Measurement
TL;DR: In this paper, the authors define definitions of diversity and apply them to the problem of measuring species diversity, choosing an index and interpreting diversity measures, and applying them to structural and structural diversity.
Journal ArticleDOI
The ontogenetic niche and species interactions in size-structured populations
Earl E. Werner,James F. Gilliam +1 more
TL;DR: The body size is one of the most important attributes of an organism from an ecological and evolutionary point of view as mentioned in this paper, and it has a predominant influence on an animal's energetic requirements, its potential for resource exploitation, and its susceptibility to natural enemies.
Journal ArticleDOI
On the Measurement of Niche Breadth and Overlap
TL;DR: It is proposed that the species composition of communities utilizing different resource states may be used to develop weighting factors with which each state may be weighted in proportion to its degree of distinctness.
Journal ArticleDOI
Ecological Causes for the Evolution of Sexual Dimorphism: A Review of the Evidence
TL;DR: If ecological causation for dimorphism can be demonstrated in so many cases, despite the inadequacies of the available criteria, the degree of sexual sizeDimorphism in many other animal species may well also have been influenced by ecological factors, and it may be premature of dismiss this hypothesis.
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Ecological causes of sexual dimorphism.
TL;DR: The heritabilities of the traits in males and females are given by the assumption that within each sex the trait is normally distributed with means, m and f, and variances Vm and V.