Open Access. Powered by Scholars. Published by Universities.®
- Institution
Articles 1 - 6 of 6
Full-Text Articles in Life Sciences
Predators As Agents Of Selection And Diversification, Jerald B. Johnson, Mark C. Belk
Predators As Agents Of Selection And Diversification, Jerald B. Johnson, Mark C. Belk
Faculty Publications
Predation is ubiquitous in nature and can be an important component of both ecological and evolutionary interactions. One of the most striking features of predators is how often they cause evolutionary diversification in natural systems. Here, we review several ways that this can occur, exploring empirical evidence and suggesting promising areas for future work. We also introduce several papers recently accepted in Diversity that demonstrate just how important and varied predation can be as an agent of natural selection. We conclude that there is still much to be done in this field, especially in areas where multiple predator species prey …
Morphological Convergence During Pregnancy Among Predator And Nonpredator Populations Of The Livebearing Fish Brachyrhaphis Rhabdophora (Teleostei: Poeciliidae), Jeff S. Wesner, Eric J. Billman, Adam Meier, Mark C. Belk
Morphological Convergence During Pregnancy Among Predator And Nonpredator Populations Of The Livebearing Fish Brachyrhaphis Rhabdophora (Teleostei: Poeciliidae), Jeff S. Wesner, Eric J. Billman, Adam Meier, Mark C. Belk
Faculty Publications
Predation can drive morphological divergence in prey populations, although examples of divergent selection are typically limited to nonreproductive individuals. In livebearing females, shape often changes drastically during pregnancy, reducing speed and mobility and enhancing susceptibility to predation. In the present study, we document morphological divergence among populations of nonreproductive female livebearing fish (Brachyrhaphis rhabdophora) in predator and nonpredator environments. We then test the hypothesis that shape differences among nonreproductive females are maintained among reproductive females between predator and nonpredator environments. Nonreproductive females in predator environments had larger caudal regions and more fusiform bodies than females in nonpredator environments; …
Differential Mortality Drives Life-History Evolution And Population Dynamics In The Fish Brachyrhaphis Rhabdophora, Jerald B. Johnson, J. Jaime Zuniga-Vega
Differential Mortality Drives Life-History Evolution And Population Dynamics In The Fish Brachyrhaphis Rhabdophora, Jerald B. Johnson, J. Jaime Zuniga-Vega
Faculty Publications
Life-history theory predicts that populations experiencing different levels of extrinsic mortality will evolve divergent reproductive strategies. Previous work in the live bearing fish Brachyrhaphis rhabdophora shows that individuals from populations that occur with piscivorous fish mature earlier and at smaller sizes and have more and smaller offspring than fish from populations without predators. However, until now, there have been no data to demonstrate that differences in mortality rates actually exist between predator and predator free sites. Here we present the results of a serial mark-recapture field study designed to estimate mortality rates in natural populations of B. rhabodophora from Costa …
Prey Handling And Diet Of Louisiana Pine Snakes (Pituophis Ruthveni) And Black Pine Snakes (P. Melanoleucus Lodingi), With Comparisons To Other Selected Colubrid Snakes, D. Craig Rudolph, Shirley J. Burgdorf, Richard N. Conner, Christopher S. Collins, Daniel Saenz, Richard R. Schaefer, Toni Trees, C. Michael Duran, Marc Ealy, John G. Himes
Prey Handling And Diet Of Louisiana Pine Snakes (Pituophis Ruthveni) And Black Pine Snakes (P. Melanoleucus Lodingi), With Comparisons To Other Selected Colubrid Snakes, D. Craig Rudolph, Shirley J. Burgdorf, Richard N. Conner, Christopher S. Collins, Daniel Saenz, Richard R. Schaefer, Toni Trees, C. Michael Duran, Marc Ealy, John G. Himes
Faculty Publications
Diet and prey handling behavior were determined for Louisiana pine snakes (Pituophis ruthveni) and black pine snakes (P. melanoleucus lodingi). Louisiana pine snakes prey heavily on Baird's pocket gophers (Geomys breviceps), with which they are sympatric, and exhibit specialized behaviors that facilitate handling this prey species within the confines of burrow systems. Black pine snakes, which are not sympatric with pocket gophers, did not exhibit these specialized behaviors. For comparative purposes, prey handling of P. sayi sayi and Elaphe obsoleta lindheimeri was also examined.
Modeling Interactions Of Browsing Predation, Infaunal Activity And Recruitment In Marine Soft-Sediment Habitats, Sara M. Lindsay, David S. Wethey, Sarah A. Woodin
Modeling Interactions Of Browsing Predation, Infaunal Activity And Recruitment In Marine Soft-Sediment Habitats, Sara M. Lindsay, David S. Wethey, Sarah A. Woodin
Faculty Publications
In marine soft-sediment habitats, the sediment surface is altered by activities of sediment dwellers (infauna). Such biogenic disturbance can influence recruitment success if settling larvae and juveniles avoid disturbed sites or if juveniles die as a result of disturbance after settling. Because infauna commonly lose exposed body parts to browsing predators and disturb less sediment as a result, we developed a simulation model to examine the interactions between browsing predation, infaunal adult activity, and recruitment. Sediment disturbance in the model was based on data for the polychaete Abarenicola pacifica. We simulated the activity of two general types of predators: prey …
Pelage Coloration In Oldfield Mice (Peromyscus Polionotus): Antipredator Adaptation?, Mark C. Belk, Michael H. Smith
Pelage Coloration In Oldfield Mice (Peromyscus Polionotus): Antipredator Adaptation?, Mark C. Belk, Michael H. Smith
Faculty Publications
Reflectance spectra (in full light and moonlight) of dorsal pelage of 469 adult oldfield mice (Peromyscus polionotus) comprising nine regional samples were compared to reflectance spectra of corresponding surface and subsurface soil samples to test for a selective effect of predation on color of pelage. Mice were slightly more reddish in hue, generally had more chroma, and were less reflective than soil at all locations. Color of pelage within locations was not significantly correlated with color of soil. Among all locations, brightness of pelage and soil were significantly positively correlated. Among mainland locations, there was a significant positive …