Biology subjects

Sullivan, J.

Publications and source records attributed to Sullivan, J..

21 records · Page 2Linked to original sources

bioRxiv2020

Calories delivered by nonhuman primate foraging enrichment: Data and methods to inform decisions concerning the dietary consequences of enrichment

Foraging opportunities are a key component of enrichment in captive nonhuman primates providing manipulative opportunities in which animals can engage in species-typical behaviors. Recent studies suggest captive NHP populations have increased body weight over time leading to negative health outcomes. Increasing food foraging opportunities provides added calories that can be estimated but often are not directly measured. We assessed 10 commonly used foraging puzzles for the amount of foraging material they held; evaluated the range of caloric content delivered; and determine the labor and usage cost of each. Five preparation areas were sampled. The amount of foraging material contained in each prepared puzzle was calculated by subtracting the average empty puzzle weight from the loaded puzzle weight. A detailed description of food content was used to illustrate caloric content. Larger prepared puzzles held more food (M=104.9 g) as compared to small volumes puzzles (M=59.8 g). Analysis of the weight of food applied and caloric content suggest larger puzzles do have the potential to provide increased caloric load; however, the added food from large foraging puzzles constitutes only 5%-10% of the daily k/cal dietary requirement. The study illustrates the importance of considering puzzle characteristics when selecting foraging toys and discusses the considerations of cost of puzzle deployment, maintenance and interactive benefit. The broad significance of our assessment suggests that calories from foraging opportunities are not excessive and can be managed by adopting standard serving sizes and scheduling intermitted presentation of non-nutritive enrichment options.

animal behavior and cognition↗

bioRxiv2018

Impending regeneration failure of the IUCN Vulnerable Borneo ironwood (Eusideroxylon zwageri)

The regeneration of many climax species in tropical forest critically depends on adequate seed dispersal and seedling establishment. Here we report the decreased abundance and increased spatial aggregation of younger trees of the Borneo ironwood (Eusideroxylon zwageri) in a protected forest in Sabah Malaysia. We observed a high level of seedling herbivory with strong density dependence, likely exacerbated by local aggregation and contributing to the progressively shrinking size-distribution. We also note the largely undocumented selective herbivory by sambar deer on E. zwageri seedlings. This study highlights the combined impact of altered megafauna community on a tree population through interlinked ecological processes and the need for targeted conservation intervention for this iconic tropical tree species.

ecology↗

bioRxiv2018

The choice of tree prior and molecular clock does not substantially affect phylogenetic inferences of diversification rates

Comparative methods allow researchers to make inferences about evolutionary processes and patterns from phylogenetic trees. In Bayesian phylogenetics, estimating a phylogeny requires specifying priors on parameters characterizing the branching process and rates of substitution among lineages, in addition to others. However, the effect that the selection of these priors has on the inference of comparative parameters has not been thoroughly investigated. Such uncertainty may systematically bias phylogenetic reconstruction and, subsequently, parameter estimation. Here, we focus on the impact of priors in Bayesian phylogenetic inference and evaluate how they affect the estimation of parameters in macroevolutionary models of lineage diversification. Specifically, we use BEAST to simulate trees under combinations of tree priors and molecular clocks, simulate sequence data, estimate trees, and estimate diversification parameters (e.g., speciation rates and extinction rates) from these trees. When substitution rate heterogeneity is large, parameter estimates deviate substantially from those estimated under the simulation conditions when not captured by an appropriate choice of relaxed molecular clock. However, in general, we find that the choice of tree prior and molecular clock has relatively little impact on the estimation of diversification rates insofar as the sequence data are sufficiently informative and substitution rate heterogeneity among lineages is low-to-moderate.

evolutionary biology↗