Other Research Collaborations
I have been fortunate to work with incredible people on a variety of projects. More info on these projects can be found below!
Diverse aging rates in ectothermic tetrapods provide insights for the evolution of aging and longevity
Project Lead: Beth Reinke, Northeastern Illinois University We present a study of aging rates and longevity across wild tetrapod ectotherms, utilizing data from 107 populations (77 species) of reptiles and amphibians. We test hypotheses of how thermoregulatory mode, temperature, protective phenotypes, and pace of life-history contribute to aging. Controlling for phylogeny and body size, ectotherms display a higher diversity of aging rates than endotherms, and include phylogenetically-widespread evidence of negligible aging. By adding ectothermic tetrapods, our comparative analyses enhance our understanding of the evolution of aging. |
We linked annual variability in climate measures to occurrence dynamics while accounting for observational uncertainty.
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Quantifying climate sensitivity and climate-driven change in North American amphibian communities
Project Lead: David AW Miller, Penn State University Here we show that amphibian communities are responsive to climatic variability, using >500,000 time-series observations for 81 species across 86 North American study areas. The effect of climate on local colonization and persistence probabilities varies among eco-regions and depends on local climate, species life-histories, and taxonomic classification. We found that local species richness is most sensitive to changes in water availability during breeding and changes in winter conditions. |
Relative locations of the local camera trap projects included in a global carnivore analysis.
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Assessing global patterns in mammalian carnivore occupancy and richness by integrating local camera trap surveys
Project Lead: Lindsey Rich, California Department of Fish and Wildlife We gathered camera trap data, totaling > 100,000 trap nights, from across five continents. To analyze local and species-specific responses to anthropogenic and environmental variables, we fitted multispecies occurrence models to each study area. To analyze global-level responses, we then fitted a multispecies, multi-area occurrence model. At the global level, our models revealed that carnivore richness and occupancy within study areas was positively associated with prey availability. Occupancy within study areas also tended to increase with greater protection and greater distances to roads. The strength of these relationships, however, differed among countries. |
Kernel activity density estimates for Collared peccary (solid line) and Whitelipped peccary (dashed line) during a 24 h period.
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Using activity and occupancy to evaluate niche partitioning: the case of two peccary species in the Atlantic Rainforest, Brazil
Project Lead: Atilla Colombo Ferreguetti, Rio de Janeiro State University We aimed to test the hypothesis that the collared and white-lipped peccary avoided each other by some degree of niche partitioning in the Vale Natural Reserve, Espírito Santo state, southeastern Brazil. Species-specific occupancy, detection, and activity patterns were estimated from camera-trap data collected at 39 sample sites over a 1-year period. We found that both peccary species respond to similar habitat covariates (palm density, distance to water resources, poaching intensity). We also quantified the probability of co-occurrence, or the Species Interaction Factor (SIF), using a two-species occupancy modelling approach. We found that the two species avoided each other in space (SIF=0.41), thus providing evidence for niche partitioning. |
Ultrasound images of late development embryos showing a clear cranium (arrow) and vertebral coil (bracket).
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Use of field-portable ultrasonography reveals differences in developmental phenology and maternal egg provisioning in two sympatric viviparous snakes
Project Lead: Amanda Sparkman, Westmont College We used field-portable ultrasonography to investigate embryonic development in two sympatric garter snake species, Thamnophis sirtalis and Thamnophis elegans in the Sierra Nevada mountains of California. This approach allowed us to examine previously hidden reproductive traits including the timing and annual variation in development and differences in parental investment in young. Both species are viviparous, occupy similar ecological niches, and experience the same annual environmental conditions. |