scholarly journals Predatory blue crabs induce stronger nonconsumptive effects in eastern oystersCrassostrea virginicathan scavenging blue crabs

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3042 ◽  
Author(s):  
Avery E. Scherer ◽  
Miranda M. Garcia ◽  
Delbert L. Smee
Keyword(s):  
Habitat Selection ◽  
Food Webs ◽  
Crassostrea Virginica ◽  
Prey Availability ◽  
Oyster Tissue ◽  
Alarm Cues ◽  
Blue Crabs ◽  
Nonconsumptive Effects ◽  
Diet Cues ◽  
Reduced Risk

By influencing critical prey traits such as foraging or habitat selection, predators can affect entire ecosystems, but the nature of cues that trigger prey reactions to predators are not well understood. Predators may scavenge to supplement their energetic needs and scavenging frequency may vary among individuals within a species due to preferences and prey availability. Yet prey reactions to consumers that are primarily scavengers versus those that are active foragers have not been investigated, even though variation in prey reactions to scavengers or predators might influence cascading nonconsumptive effects in food webs. OystersCrassostrea virginicareact to crab predators by growing stronger shells. We exposed oysters to exudates from crabs fed live oysters or fed aged oyster tissue to simulate scavenging, and to controls without crab cues. Oysters grew stronger shells when exposed to either crab exudate, but their shells were significantly stronger when crabs were fed live oysters. The stronger response to predators than scavengers could be due to inherent differences in diet cues representative of reduced risk in the presence of scavengers or to degradation of conspecific alarm cues in aged treatments, which may mask risk from potential predators subsisting by scavenging.

Analysis of tributyltin in estuarine sediments and oyster tissue,Crassostrea virginica

1987 ◽  
Vol 1 (6) ◽  
pp. 541-544 ◽  
Author(s):  
C D Rice ◽  
F A Espourteille ◽  
R J Huggett
Keyword(s):  
Crassostrea Virginica ◽  
Estuarine Sediments ◽  
Oyster Tissue

Summer rest site selection by Appalachian eastern spotted skunks

2019 ◽  
Vol 100 (4) ◽  
pp. 1295-1304 ◽  
Author(s):  
Robin Y Y Eng ◽  
David S Jachowski
Keyword(s):  
South Carolina ◽  
Habitat Selection ◽  
Site Selection ◽  
Prey Availability ◽  
Woody Debris ◽  
Relative Probability ◽  
Modeling Framework ◽  
Drainage Channels ◽  
Unit Increase ◽  
Rest Sites

AbstractEastern spotted skunks (Spilogale putorius) have suffered a dramatic range-wide decline leading to concern that the species is likely vulnerable to extinction, but were recently discovered to persist in a portion of the southern Appalachian Mountains (United States). For 2 years we investigated habitat selection by eastern spotted skunks to develop an understanding of their habitat and conservation needs in northwestern South Carolina. We used a discrete choice modeling framework to evaluate vegetative and topographic features that we predicted would influence rest site selection by male and female spotted skunks. Using VHF telemetry, we tracked 15 spotted skunks (10 males and 5 females) to 215 day-time rest sites between the months of April and August. Spotted skunks selected rest sites in close proximity to drainage channels, where the relative probability of selection decreased 18% and 50% with every 20-m increase in distance to a drainage channel for males and females, respectively. Relative probability of selection by female spotted skunks increased 30% for every one-unit increase in coarse woody debris (CWD), and relative probability of selection by male spotted skunks increased 25% for every 10% increase in understory cover. These results are consistent with previous studies that have identified cover as important for protection from predators; however, we additionally identified CWD and drainage channels as important to habitat selection by spotted skunks. These latter attributes are likely selected based on prey availability, but alternate ecological functions of these features warrant further investigation. Preservation of understory vegetation and CWD within drainage networks might benefit conservation of eastern spotted skunks in the southern Appalachians.

Phages Infecting Vibrio vulnificus Are Abundant and Diverse in Oysters (Crassostrea virginica) Collected from the Gulf of Mexico

1998 ◽  
Vol 64 (1) ◽  
pp. 346-351 ◽  
Author(s):  
Angelo DePaola ◽  
Miles L. Motes ◽  
Amy M. Chan ◽  
Curtis A. Suttle
Keyword(s):  
Gulf Of Mexico ◽  
Crassostrea Virginica ◽  
Vibrio Vulnificus ◽  
Gulf Coast ◽  
Morphological Evidence ◽  
Broad Host Range ◽  
Oyster Tissue ◽  
Mobile Bay ◽  
Apalachicola Bay ◽  
Transmission Electron

ABSTRACT Phages infecting Vibrio vulnificus were abundant (>104 phages g of oyster tissue−1) throughout the year in oysters (Crassostrea virginica) collected from estuaries adjacent to the Gulf of Mexico (Apalachicola Bay, Fla.; Mobile Bay, Ala.; and Black Bay, La.). Estimates of abundance ranged from 101 to 105 phages g of oyster tissue−1 and were dependent on the bacterial strain used to assay the sample. V. vulnificus was near or below detection limits (<0.3 cell g−1) from January through March and was most abundant (103 to 104 cells g−1) during the summer and fall, when phage abundances also tended to be greatest. The phages isolated were specific to strains of V. vulnificus, except for one isolate that caused lysis in a few strains of V. parahaemolyticus. Based on morphological evidence obtained by transmission electron microscopy, the isolates belonged to the Podoviridae,Styloviridae, and Myoviridae, three families of double-stranded DNA phages. One newly described morphotype belonging to the Podoviridae appears to be ubiquitous in Gulf Coast oysters. Isolates of this morphotype have an elongated capsid (mean, 258 nm; standard deviation, 4 nm; n = 35), with some isolates having a relatively broad host range among strains of V. vulnificus. Results from this study indicate that a morphologically diverse group of phages which infect V. vulnificus is abundant and widely distributed in oysters from estuaries bordering the northeastern Gulf of Mexico.

scholarly journals Prey-Driven Behavioral Habitat Use in a Low-Energy Ambush Predator

2020 ◽  
Author(s):  
Annalee M. Tutterow ◽  
Andrew S. Hoffman ◽  
John L. Buffington ◽  
Zachary T. Truelock ◽  
William E. Peterman
Keyword(s):  
Spatial Distribution ◽  
Habitat Selection ◽  
Small Mammal ◽  
Optimal Foraging ◽  
Prey Availability ◽  
Low Energy ◽  
List Type ◽  
Fine Scale ◽  
Timber Rattlesnake ◽  
Ambush Predator

AbstractFood acquisition is an important modulator of animal behavior and habitat selection that can affect fitness. Optimal foraging theory predicts that predators should select habitat patches to maximize their foraging success and net energy gain, which predators can achieve by targeting spaces with high prey availability. However, it is debated whether prey availability drives fine-scale habitat selection for predators.We assessed whether an ambush predator, the timber rattlesnake (Crotalus horridus), exhibits optimal foraging site selection based on the spatial distribution and availability of prey.We evaluated the spatial concordance of radio-telemetered timber rattlesnake foraging locations and passive infrared game camera trap detections of potential small mammal prey (Peromyscus spp., Tamias striatus, and Sciurus spp.) in a mixed-use forest in southeastern Ohio from 2016–2019. We replicated a characteristic timber rattlesnake ambush position by focusing cameras over logs and modeled small mammal encounters across the landscape in relation to remotely-sensed forest and landscape structural features. To determine whether snakes selectively forage in areas with higher prey availability, we projected the estimated prey spatial relationships across the landscape and modeled their overlap of occurrence with observed timber rattlesnake foraging locations.We broadly predicted that prey availability was greatest in mature deciduous forests, but T. striatus and Sciurus spp. exhibited greater spatial heterogeneity compared to Peromyscus spp. We also combined predicted species encounter rates to encompass a body size gradient in potential prey. The spatial distribution of cumulative small mammal encounters (i.e. overall prey availability), rather than the distribution of any one species, was highly predictive of snake foraging.Timber rattlesnakes appear to select foraging locations where the probability of encountering prey is greatest. Our study provides evidence for fine-scale optimal foraging in a low-energy, ambush predator and offers new insights into drivers of snake foraging and habitat selection.

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