Illuminating the Mysteries of the Smallest Birds: Hummingbird Population Health, Disease Ecology, and Genomics.

Hummingbirds share biologically distinctive traits: sustained hovering flight, the smallest bird body size, and high metabolic rates fueled partially by nectar feeding that provides pollination to plant species. Being insectivorous and sometimes serving as prey to larger birds, they fulfill additional important ecological roles. Hummingbird species evolved and radiated into nearly every habitat in the Americas, with a core of species diversity in South America.

Ecology and Chronic Wasting Disease Epidemiology Shape Prion Protein Gene Variation in Rocky Mountain Elk (Cervus elaphus nelsoni).

As chronic wasting disease (CWD) continues to spread across North America, the relationship between CWD and host genetics has become of interest. In Rocky Mountain elk (Cervus elaphus nelsoni), one or two copies of a leucine allele at codon 132 of the prion protein gene (132L*) has been shown to prolong the incubation period of CWD. Our study examined the relationship between CWD epidemiology and codon 132 evolution in elk from Wyoming, USA, from 2011 to 2018.

Multi-population puma connectivity could restore genomic diversity to at-risk coastal populations in California.

Urbanization is decreasing wildlife habitat and connectivity worldwide, including for apex predators, such as the puma (). Puma populations along California's central and southern coastal habitats have experienced rapid fragmentation from development, leading to calls for demographic and genetic management. To address urgent conservation genomic concerns, we used double-digest restriction-site associated DNA (ddRAD) sequencing to analyze 16,285 genome-wide single-nucleotide polymorphisms (SNPs) from 401 pumas sampled broadly across the state.

Prevalence and diversity of haemosporidians in a migratory high-elevation hummingbird in North America.

Hummingbirds (Trochilidae) are sensitive to environmental changes because of their extraordinary ecology, metabolism, and the highest red blood cell counts found in any vertebrate. These physiological attributes may render hummingbirds particularly susceptible to the effects of haemosporidian (blood parasite) infections. Much of the research on haemosporidians in hummingbirds has been conducted in South America; less is known about haemosporidian diversity and prevalence in North America.

INVESTIGATING ASSOCIATIONS AMONG RELATEDNESS, GENETIC DIVERSITY, AND CAUSES OF MORTALITY IN SOUTHERN SEA OTTERS (ENHYDRA LUTRIS NEREIS).

Southern sea otter (Enhydra lutris nereis) population recovery is influenced by a variety of factors, including predation, biotoxin exposure, infectious disease, oil spills, habitat degradation, and resource limitation. This population has also experienced a significant genetic bottleneck, resulting in low genetic diversity. We investigated how two metrics, familial relatedness and genetic diversity, are correlated with common causes of mortality in southern sea otters, including cardiomyopathy, acanthocephalan (Profilicollis spp.

Spatio-temporal analyses reveal infectious disease-driven selection in a free-ranging ungulate.

Infectious diseases play an important role in wildlife population dynamics by altering individual fitness, but detecting disease-driven natural selection in free-ranging populations is difficult due to complex disease-host relationships. Chronic wasting disease (CWD) is a fatal infectious prion disease in cervids for which mutations in a single gene have been mechanistically linked to disease outcomes, providing a rare opportunity to study disease-driven selection in wildlife. In Wyoming, USA, CWD has gradually spread across mule deer () populations, producing natural variation in disease history to evaluate selection pressure.

Host relatedness and landscape connectivity shape pathogen spread in the puma, a large secretive carnivore.

Urban expansion can fundamentally alter wildlife movement and gene flow, but how urbanization alters pathogen spread is poorly understood. Here, we combine high resolution host and viral genomic data with landscape variables to examine the context of viral spread in puma (Puma concolor) from two contrasting regions: one bounded by the wildland urban interface (WUI) and one unbounded with minimal anthropogenic development (UB). We found landscape variables and host gene flow explained significant amounts of variation of feline immunodeficiency virus (FIV) spread in the WUI, but not in the unbounded region.

Pronghorn population genomics show connectivity in the core of their range.

Preserving connectivity in the core of a species' range is crucial for long-term persistence. However, a combination of ecological characteristics, social behavior, and landscape features can reduce connectivity among wildlife populations and lead to genetic structure. Pronghorn (), for example, exhibit fluctuating herd dynamics and variable seasonal migration strategies, but GPS tracking studies show that landscape features such as highways impede their movements, leading to conflicting hypotheses about expected levels of genetic structure.

Minimum habitat thresholds required for conserving mountain lion genetic diversity.

Jointly considering the ecology (e.g., habitat use) and genetics (e.

Urbanization impacts apex predator gene flow but not genetic diversity across an urban-rural divide.

Apex predators are important indicators of intact natural ecosystems. They are also sensitive to urbanization because they require broad home ranges and extensive contiguous habitat to support their prey base. Pumas (Puma concolor) can persist near human developed areas, but urbanization may be detrimental to their movement ecology, population structure, and genetic diversity.

Analysis of insecticide exposure in California hummingbirds using liquid chromatography-mass spectrometry.

External feather rinses and homogenized whole-carcass tissue matrix from two hummingbird species found in California (Calypte anna and Archilochus alexandri) were analyzed for the presence of nine insecticides commonly used in urban settings. Using a liquid chromatography-high-resolution mass spectrometry (LC-HRMS) analytical method, samples were quantitatively tested for the following neonicotinoids: dinotefuran, nitenpyram, thiamethoxam, acetamiprid, thiacloprid, clothianidin, imidacloprid, and sulfoxaflor. This analytical method was also used to qualitatively screen for the presence of approximately 150 other pesticides, drugs, and natural products.

Extinction vortex dynamics of top predators isolated by urbanization.

Extinction risk is elevated in small, isolated populations due to demographic and genetic interactions. Therefore, it is critical to model these processes realistically in population viability analyses (PVA) to inform local management and contribute to a greater understanding of mechanisms within the extinction vortex. We conducted PVA's for two small mountain lion populations isolated by urbanization in southern California to predict population growth, extinction probability, and loss of genetic diversity with empirical data.

GENETIC DIVERSITY OF YELLOW-BILLED MAGPIES ( PICA NUTALLI) BEFORE AND AFTER A WEST NILE VIRUS EPIDEMIC.

The appearance of West Nile virus (WNV) coincided with declines in California, US bird populations beginning in 2004, and particularly affected corvid populations, including Yellow-billed Magpies ( Pica nutalli), an endemic species to California. Our objective was to determine if the timing of the WNV epidemic correlated with changes in the genetic diversity or population structure of magpies. We hypothesized the declines in magpie abundance from WNV would lead to genetic bottlenecks and reduced genetic diversity, but not to changes in population genetic structure.

Measures of effective population size in sea otters reveal special considerations for wide-ranging species.

Conservation genetic techniques and considerations of the evolutionary potential of a species are increasingly being applied to species conservation. For example, effective population size ( ) estimates are useful for determining the conservation status of species, yet accurate estimates of current remain difficult to obtain. The effective population size can contribute to setting federal delisting criteria, as was done for the southern sea otter ().

Pathogens in space: Advancing understanding of pathogen dynamics and disease ecology through landscape genetics.

Landscape genetics has provided many insights into how heterogeneous landscape features drive processes influencing spatial genetic variation in free-living organisms. This rapidly developing field has focused heavily on vertebrates, and expansion of this scope to the study of infectious diseases holds great potential for landscape geneticists and disease ecologists alike. The potential application of landscape genetics to infectious agents has garnered attention at formative stages in the development of landscape genetics, but systematic examination is lacking.

Founder events, isolation, and inbreeding: Intercontinental genetic structure of the domestic ferret.

Domestication and breeding for human-desired morphological traits can reduce population genetic diversity via founder events and artificial selection, resulting in inbreeding depression and genetic disorders. The ferret () was domesticated from European polecats (), transported to multiple continents, and has been artificially selected for several traits. The ferret is now a common pet, a laboratory model organism, and feral ferrets can impact native biodiversity.

Leukocyte Reference Intervals for Free-Ranging Hummingbirds in Northern California, USA.

Hummingbirds are specialized nectarivores and important ecological pollinators that are the focus of conservation efforts as well as scientific investigations of metabolism and flight dynamics. Despite their importance, basic information is lacking about hummingbird blood cells. We aimed to establish reference intervals for total and differential leukocyte counts from healthy free-ranging hummingbirds in northern California.

Multi-level, multi-scale resource selection functions and resistance surfaces for conservation planning: Pumas as a case study.

The importance of examining multiple hierarchical levels when modeling resource use for wildlife has been acknowledged for decades. Multi-level resource selection functions have recently been promoted as a method to synthesize resource use across nested organizational levels into a single predictive surface. Analyzing multiple scales of selection within each hierarchical level further strengthens multi-level resource selection functions.

Mitogenomes and relatedness do not predict frequency of tool-use by sea otters.

Many ecological aspects of tool-use in sea otters are similar to those in Indo-Pacific bottlenose dolphins. Within an area, most tool-using dolphins share a single mitochondrial haplotype and are more related to each other than to the population as a whole. We asked whether sea otters in California showed similar genetic patterns by sequencing mitogenomes of 43 otters and genotyping 154 otters at 38 microsatellite loci.