MOVEMENT ECOLOGY OF THE MEXICAN FISH-EATING BAT, MYOTIS VIVESI

Foraging behavior is influenced by the distribution of prey in time and space and the presence of conspecifics. Echolocating bats, which advertise their behavior while vocalizing, provide a unique opportunity for understanding how an organism interacts with conspecifics and the environment to find food. Here I use GPS tracking combined with on-board recording to investigate the foraging movements of lactating Mexican fish-eating bats, Myotis vivesi, in the Gulf of California, Mexico, over a 5-year period. In Chapter 1, I assessed five alternative methods for behavioral state segmentation of GPS tracked foraging paths using on-board audio for validation. While most methods perform well, hidden-Markov model segmentation showed the highest accuracy at predicting foraging movement. In Chapter 2, I evaluated habitat selection across multiple scales for fish-eating bats foraging in the Midriff Islands Region in the Gulf of California. Foraging site use at large scales is most predictive and is associated with dynamic (chlorophyll concentration) and static variables (ocean depth, sea floor slope) consistent with known tidal upwelling regions. In Chapter 3, I examine the function of in-flight social calls recorded from roughly half of all tagged individuals during their foraging flights. Calls contained spectral differences among individuals, were associated with the ends of flights as bats return to their roost, and increased in occurrence with pup age, consistent with directive calls used to communicate with mobile pups. In Chapter 4, I explore how prey distribution impacts social behavior and foraging movements. On-board audio reveals that conspecifics are present during commuting and foraging and playback experiments demonstrate an attraction to foraging call sequences. In collaboration with several colleagues I combined these findings with data from four other bat species ranging in diet and habitat type. Taken together, bat species that frequently encounter conspecifics, such as Myotis vivesi, have ephemeral prey and variable flights (e.g. duration and foraging site location), whereas bats that forage solitarily have predictable or non-shareable prey, such as a congener Myotis myotis, show less variability in their flights. Overall, these results provide new insights into the foraging dynamics and social behavior of bats

DNA methylation predicts age and provides insight into exceptional longevity of bats

This work was supported by a Paul G. Allen Frontiers Group grant to S.H., the University of Maryland, College of Computer, Mathematical and Natural Sciences to G.S.W., an Irish Research Council Consolidator Laureate Award to E.C.T., a UKRI Future Leaders Fellowship (MR/T021985/1) to S.C.V. and a Discovery Grant from the Natural Sciences and Engineering Research Council (NSERC) of Canada to P.A.F. S.C.V. and P.D. were supported by a Max Planck Research Group awarded to S.C.V. by the Max Planck Gesellschaft, and S.C.V. and E.Z.L. were supported by a Human Frontiers Science Program Grant (RGP0058/2016) awarded to S.C.V. L.J.G. was supported by an NSERC PGS-D scholarship.Exceptionally long-lived species, including many bats, rarely show overt signs of aging, making it difficult to determine why species differ in lifespan. Here, we use DNA methylation (DNAm) profiles from 712 known-age bats, representing 26 species, to identify epigenetic changes associated with age and longevity. We demonstrate that DNAm accurately predicts chronological age. Across species, longevity is negatively associated with the rate of DNAm change at age-associated sites. Furthermore, analysis of several bat genomes reveals that hypermethylated age- and longevity-associated sites are disproportionately located in promoter regions of key transcription factors (TF) and enriched for histone and chromatin features associated with transcriptional regulation. Predicted TF binding site motifs and enrichment analyses indicate that age-related methylation change is influenced by developmental processes, while longevity-related DNAm change is associated with innate immunity or tumorigenesis genes, suggesting that bat longevity results from augmented immune response and cancer suppression.Publisher PDFPeer reviewe

Moving in the anthropocene: global reductions in terrestrial mammalian movements

Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission

Biological Earth observation with animal sensors

Space-based tracking technology using low-cost miniature tags is now delivering data on fine-scale animal movement at near-global scale. Linked with remotely sensed environmental data, this offers a biological lens on habitat integrity and connectivity for conservation and human health; a global network of animal sentinels of environmen-tal change

An Annotated Bibliography on the Biological Effects of Constructing Channels, Jetties, and Other Coastal Structures

Source: https://erdc-library.erdc.dren.mil/jspui/This bibliography includes 199 historic and recently published research reports for use in evaluating the biological effects of constructing channels, jetties, and other coastal structures on fish and shellfish migration

Sampling Macroinvertebrates on High-Energy Sand Beaches

Source: https://erdc-library.erdc.dren.mil/jspui/This report summarizes the most practical and cost-effective techniques developed from CERC-sponsored research and the literature for quantitatively sampling high-energy sand beach macroinvertebrates. The general habitat, the field crew's qualifications and duties, and the materials and equipment are described. A general approach to planning the fieldwork, timing the trips, and developing a sampling plan is given. Methods for taking, transferring, and preserving samples for laboratory analysis are described. Sample treatment, population analysis, cost and manpower requirements are discussed

An Annotated Bibliography of CERC Coastal Ecology Research

Source: https://erdc-library.erdc.dren.mil/jspui/This bibliography identifies the research work that was either funded by or published by the CERC Coastal Ecology Branch from 1967 to March 1978