Decoupling of bird migration from the changing phenology of spring green-up.

The green-up of vegetation in spring brings a pulse of food resources that many animals track during migration. However, green-up phenology is changing with climate change, posing an immense challenge for species that time their migrations to coincide with these resource pulses. We evaluated changes in green-up phenology from 2002 to 2021 in relation to the migrations of 150 Western-Hemisphere bird species using eBird citizen science data. We found that green-up phenology has changed within bird migration routes, and yet the migrations of most species align more closely with long-term averages of green-up than with current conditions. Changing green-up strongly influenced phenological mismatches, especially for longer-distance migrants. These results reveal that bird migration may have limited flexibility to adjust to changing vegetation phenology and emphasize the mounting challenge migratory animals face in following en route resources in a changing climate.

Climate change causes declines and greater extremes in wetland inundation in a region important for wetland birds.

Wetland ecosystems are vital for maintaining global biodiversity, as they provide important stopover sites for many species of migrating wetland-associated birds. However, because weather determines their hydrologic cycles, wetlands are highly vulnerable to effects of climate change. Although changes in temperature and precipitation resulting from climate change are expected to reduce inundation of wetlands, few efforts have been made to quantify how these changes will influence the availability of stopover sites for migratory wetland birds. Additionally, few studies have evaluated how climate change will influence interannual variability or the frequency of extremes in wetland availability. For spring and fall bird migration in seven ecoregions in the south-central Great Plains of North America, we developed predictive models associating abundance of inundated wetlands with a suite of weather and land cover variables. We then used these models to generate predictions of wetland inundation at the end of the century (2069-2099) under future climate change scenarios. Climate models predicted the average number of inundated wetlands will likely decline during both spring and fall migration periods, with declines being greatest in the eastern ecoregions of the southern Great Plains. However, the magnitude of predicted declines varied considerably across climate models and ecoregions, with uncertainty among climate models being greatest in the High Plains ecoregion. Most ecoregions also were predicted to experience more-frequent extremely dry years (i.e., years with extremely low wetland abundances), but the projected change in interannual variability of wetland inundation was relatively small and varied across ecoregions and seasons. Because the south-central Great Plains represents an important link along the migratory routes of many wetland-dependent avian species, future declines in wetland inundation and more frequent periods of only a few wetlands being inundated will result in an uncertain future for migratory birds as they experience reduced availability of wetland stopover habitat across their migration pathways.

The geographic extent of bird populations affected by renewable-energy development.

Bird populations are declining globally. Wind and solar energy can reduce emissions of fossil fuels that drive anthropogenic climate change, yet renewable-energy production represents a potential threat to bird species. Surveys to assess potential effects at renewable-energy facilities are exclusively local, and the geographic extent encompassed by birds killed at these facilities is largely unknown, which creates challenges for minimizing and mitigating the population-level and cumulative effects of these fatalities. We performed geospatial analyses of stable hydrogen isotope data obtained from feathers of 871 individuals of 24 bird species found dead at solar- and wind-energy facilities in California (USA). Most species had individuals with a mix of origins, ranging from 23% to 98% nonlocal. Mean minimum distances to areas of likely origin for nonlocal individuals were as close as 97 to >1250 km, and these minimum distances were larger for species found at solar-energy facilities in deserts than at wind-energy facilities in grasslands (Cohen's d = 6.5). Fatalities were drawn from an estimated 30-100% of species' desingated ranges, and this percentage was significantly smaller for species with large ranges found at wind facilities (Pearson's r = -0.67). Temporal patterns in the geographic origin of fatalities suggested that migratory movements and nonmigratory movements, such as dispersal and nomadism, influence exposure to fatality risk for these birds. Our results illustrate the power of using stable isotope data to assess the geographic extent of renewable-energy fatalities on birds. As the buildout of renewable-energy facilities continues, accurate assessment of the geographic footprint of wildlife fatalities can be used to inform compensatory mitigation for their population-level and cumulative effects.

Extensión geográfica de las poblaciones de aves afectadas por desarrollos de energía renovable Resumen Las poblaciones mundiales de aves están en declive. Las energías solar y eólica pueden reducir las emisiones de combustibles fósiles que causan el cambio climático, aunque la producción de energías renovables representa una amenaza potencial para las aves. Los censos para evaluar los efectos potenciales en los centros de energía renovable son exclusivamente locales y se sabe poco sobre la extensión geográfica representada por las aves que mueren en estas instalaciones, lo que plantea obstáculos para mitigar los efectos acumulativos y de nivel poblacional de estas muertes. Realizamos análisis geoespaciales con datos del isótopo de hidrógeno estable obtenido de las plumas de 871 ejemplares de 24 especies de aves que fueron hallados muertos en los centros de energía solar y eólica en California, EE.UU. La mayoría de las especies contó con ejemplares de orígenes mixtos, con un rango del 23% al 98% no local. La media de la distancia mínima a las áreas de probable origen de los ejemplares no locales varía entre los 97 hasta > 1,250 km. Estas distancias mínimas fueron mayores para las especies encontradas en los centros de energía solar situadas en desiertos que para las especies encontradas en los centros de energía eólica localizadas en pastizales (d de Cohen = 6.5). Las muertes representan un 30­100% de la extensión de las especies. Este porcentaje fue significativamente menor para las especies con extensiones amplias encontradas en instalaciones eólicas (r de Pearson = ­0.67). Los patrones temporales en el origen geográfico de las muertes sugieren que los movimientos migratorios y no migratorios, como la dispersión y el nomadismo, influyen en la exposición de estas aves al riesgo de muerte. Nuestros resultados demuestran la utilidad de los isótopos estables para evaluar el alcance geográfico de las muertes de aves asociadas a energías renovables. Con el progresivo aumento de instalaciones de energía renovable, una evaluación precisa de la huella geográfica de la mortandad de fauna salvaje podrá guiar la mitigación compensatoria de sus efectos acumulativos y de nivel poblacional.

Climate Change and Wetlands in the Southern Great Plains: How Are Managers Dealing with an Uncertain Future?

Little guidance is available to assist wetland managers in developing climate adaptation plans. To facilitate development of recommendations for adaptation strategies, it is essential to first determine if or how wetland managers are addressing these challenges. We used an online survey to solicit feedback from wetland managers and biologists in the Southern Great Plains of North America to gain information on perceptions of wetland managers regarding climate change; assess how the effects of climate change are being addressed through management; and identify barriers to implementing climate change adaptation. The majority of wetland managers (63%) agreed they are currently experiencing effects of climate change in wetlands, and most respondents (76%) reported that changes in the timing of water availability throughout the year was the most likely impact. Managers reported using a diversity of approaches in managing for changing precipitation, with management of native and invasive plant species being the two most common practices. Lack of funding and personnel were the most commonly identified factors limiting manager's response to changing precipitation patterns. In addition, >50% of managers indicated uncertainty about the effects of climate change on wetlands as a barrier to management, which may relate to limited access to peer-reviewed science. While most of the management practices reported were short-term measures and may not reflect long-term adaptation for climate change, the fact that many managers are considering climate change in their management suggests that there is considerable opportunities to continue developing capacity for climate change adaptation in the region.

Fire management alters the thermal landscape and provides multi-scale thermal options for a terrestrial turtle facing a changing climate.

As effects of climate change intensify, there is a growing need to understand the thermal properties of landscapes and their influence on wildlife. A key thermal property of landscapes is vegetation structure and composition. Management approaches can alter vegetation and consequently the thermal landscape, potentially resulting in underappreciated consequences for wildlife thermoregulation. Consideration of spatial scale can clarify how management overlaid onto existing vegetation patterns affects thermal properties of landscapes relevant to wildlife. We examined effects of temperature, fire management, and vegetation structure on multi-scale habitat selection of an ectothermic vertebrate (the turtle Terrapene carolina triunguis) in the Great Plains of the central United States by linking time-since-fire data from 18 experimental burn plots to turtle telemetry locations and thermal and vegetation height data. Within three 60-ha experimental landscapes, each containing six 10-ha sub-blocks that are periodically burned, we found that turtles select time-since-fire gradients differently depending on maximum daily ambient temperature. At moderate temperatures, turtles selected sub-blocks with recent (<1 year) time-since-fire, but during relatively hot and cool conditions, they selected sub-blocks with later (2-3 year) time-since-fire that provided thermal buffering compared with recently burned sub-blocks. Within 10-ha sub-blocks, turtles selected locations with taller vegetation during warmer conditions that provided thermal buffering. Thermal performance curves revealed that turtle activity declined as temperatures exceeded ~24-29°C, and on "heat days" (≥29°C) 73% of turtles were inactive compared with 37% on non-heat days, emphasizing that thermal extremes may lead to opportunity costs (i.e., foregone benefits turtles could otherwise accrue if active). Our results indicate that management approaches that promote a mosaic of vegetation heights, like spatiotemporally dynamic fire, can provide thermal refuges at multiple spatial scales and thus be an actionable way to provide wildlife with multiple thermal options in the context of ongoing and future climate change.

Review and synthesis of the global literature on domestic cat impacts on wildlife.

A vast global literature documents that free-roaming domestic cats (Felis catus) have substantial negative effects on wildlife, including through predation, fear, disease and competition-related impacts that have contributed to numerous wildlife extinctions and population declines worldwide. However, no study has synthesized this literature on cat impacts on wildlife to evaluate its overarching biases and major gaps. To direct future research and conservation related to cat impacts on wildlife, we conducted a global literature review that entailed evaluation and synthesis of patterns and gaps in the literature related to the geographic context, methods and types of impacts studied. Our systematic literature search compiled 2245 publications. We extracted information from 332 of these meeting inclusion criteria designed to ensure the relevance of studies analysed. This synthesis of research on cat impacts on wildlife highlights a focus on oceanic islands, Australia, Europe, and North America, and on rural areas, predation, impacts of unowned cats, and impacts at population and species levels. Key research advances needed to better understand and manage cat impacts include more studies in underrepresented, highly biodiverse regions (Africa, Asia, and South America), on cat impacts other than predation, and on methods designed to reduce impacts on wildlife. The identified areas of needed research into cat impacts on wildlife will be critical to further clarifying the role of cats in global wildlife declines and to implementing science-driven policy and management that benefit conservation efforts.

Field-testing effectiveness of window markers in reducing bird-window collisions.

Bird-window collisions are a major source of human-caused mortality for which there are multiple mitigation and prevention options available. Despite growing availability of products designed to reduce collisions (e.g., glass with etched patterns or markers and films adhered over existing glass), few replicated field tests have been conducted to assess their effectiveness after installation on glass. We conducted a field study to evaluate the effectiveness of a commercially marketed product (Feather Friendly® markers) in reducing bird-window collisions at glass-walled bus shelters in Stillwater, Oklahoma, USA. This study included a before-after control-impact (BACI) analysis comparing numbers of collisions at 18 bus shelters in both pre-treatment (2016) and post-treatment (2020) periods, and an analysis comparing 18 treated and 18 untreated shelters during 2020. For the BACI analysis, collisions were significantly reduced between 2016 and 2020 at shelters treated with the Feather Friendly® markers even though collisions increased at shelters that remained untreated. For the 2020 analysis, there were significantly fewer collisions at treated than untreated shelters. Relative to a baseline study in 2016, we estimated that treating half of Stillwater's bus shelters resulted in a 64% reduction in total annual bird collisions. Together, these analyses provide a rigorous field test of the effectiveness of this treatment option in reducing bird-window collisions. Our research provides a model for similar studies at both bus shelters and buildings to evaluate and compare products designed to reduce bird-window collisions, and therefore, contribute to reducing this major mortality source affecting bird populations. Supplementary Information: The online version contains supplementary material available at 10.1007/s11252-022-01304-w.

Limitations, lack of standardization, and recommended best practices in studies of renewable energy effects on birds and bats.

Increasing global energy demand is fostering the development of renewable energy as an alternative to fossil fuels. However, renewable energy facilities may adversely affect wildlife. Facility siting guidelines recommend or require project developers complete pre- and postconstruction wildlife surveys to predict risk and estimate effects of proposed projects. Despite this, there are no published studies that have quantified the types of surveys used or how survey types are standardized within and across facilities. We evaluated 628 peer-reviewed publications, unpublished reports, and citations, and we analyzed data from 525 of these sources (203 facilities: 193 wind and 10 solar) in the United States and Canada to determine the frequency of pre- and postconstruction surveys and whether that frequency changed over time; frequency of studies explicitly designed to allow before-after or impact-control analyses; and what types of survey data were collected during pre- and postconstruction periods and how those data types were standardized across periods and among facilities. Within our data set, postconstruction monitoring for wildlife fatalities and habitat use was a standard practice (n = 446 reports), but preconstruction estimation of baseline wildlife habitat use and mortality was less frequently reported (n = 84). Only 22% (n = 45) of the 203 facilities provided data from both pre- and postconstruction, and 29% (n = 59) had experimental study designs. Of 108 facilities at which habitat-use surveys were conducted, only 3% estimated of detection probability. Thus, the available data generally preclude comparison of biological data across construction periods and among facilities. Use of experimental study designs and following similar field protocols would improve the knowledge of how renewable energy affects wildlife. Article Impact Statement Many surveys at wind and solar facilities provide limited information on wildlife use and fatality rates.

Limitaciones, Falta de Estandarización y las Mejores Prácticas Recomendadas en Estudios de los Efectos de las Energías Renovables sobre las Aves y los Murciélagos Resumen La creciente demanda global por energía está fomentando el desarrollo de energías renovables como una alternativa a los combustibles fósiles. Sin embargo, las instalaciones de energías renovables pueden afectar de manera adversa a la fauna. Las pautas para la ubicación de dichas instalaciones recomiendan o requieren que los desarrolladores de los proyectos realicen censos previa y posteriormente a la construcción de las instalaciones para pronosticar el riesgo y estimar los efectos de los proyectos propuestos. A pesar de esto, no existen estudios publicados que hayan cuantificado los tipos de censo usados o cómo los tipos de censo están estandarizados para las instalaciones en específico y en general. Evaluamos 628 publicaciones revisadas por pares, reportes sin publicar y referencias y analizamos los datos de 525 de estas fuentes (203 instalaciones: 193 de energía eólica y 10 de energía solar) en los Estados Unidos y Canadá para determinar la frecuencia de los censos previos y posteriores a la construcción y si dicha frecuencia cambió con el tiempo; para determinar la frecuencia de los estudios diseñados explícitamente para permitir los análisis antes-y-después o de control-impacto; y para determinar cuáles tipos de datos fueron recolectados previa y posteriormente a la construcción y cómo aquellos tipos de datos estuvieron estandarizados a través de los periodos y entre las instalaciones. Dentro de nuestro conjunto de datos, el monitoreo posterior a la construcción de las fatalidades faunísticas y el uso de hábitat fue una práctica común (n = 446 reportes), pero la estimación previa a la construcción de la línea base del uso de hábitat por la fauna y la mortalidad estuvo reportada con menor frecuencia (n = 84). Sólo el 22% (n = 45) de las 203 instalaciones proporcionaron datos de los censos previos y posteriores a la construcción y el 29% (n = 59) contó con diseño de estudios experimentales. De las 108 instalaciones en las que se realizaron censos de uso de hábitat, sólo el 3% incluyó la estimación de la probabilidad de detección. Por lo tanto, los datos disponibles generalmente impiden la comparación de los datos biológicos durante los periodos de construcción y entre las instalaciones. El uso del diseño de estudios experimentales y el seguimiento de protocolos de campo similares mejoraría el conocimiento sobre cómo las energías renovables afectan a la fauna.

Rickettsia parkeri and Candidatus Rickettsia andeanae in Amblyomma maculatum Group Ticks.

We determined prevalence of Rickettsia spp. in 172 ticks of the Amblyomma maculatum group collected from 16 urban sites in Oklahoma City, Oklahoma, USA, during 2017 and 2018. Most ticks (59.3%) were collected from 1 site; 4 (2.3%) were infected with Rickettsia parkeri and 118 (68.6%) with Candidatus Rickettsia andeanae.

Species-specific and temporal scale-dependent responses of birds to drought.

Global climate change is increasing the frequency and intensity of weather extremes, including severe droughts in many regions. Drought can impact organisms by inhibiting reproduction, reducing survival and abundance, and forcing range shifts. For birds, considering temporal scale by averaging drought-related variables over different time lengths (i.e., temporal grains) captures different hydrologic attributes which may uniquely influence food supplies, vegetation greenness/structure, and other factors affecting populations. However, studies examining drought impacts on birds often assess a single temporal grain without considering that different species have different life histories that likely determine the temporal grain of their drought response. Furthermore, while drought is known to influence bird abundance and drive between-year range shifts, less understood is whether it causes within-range changes in species distributions. Our objectives were to (a) determine which temporal grain of drought (if any) is most related to bird presence/absence and whether this response is species specific; and (b) assess whether drought alters bird distributions by quantifying probability of local colonization and extinction as a function of drought intensity. We used North American Breeding Bird Survey data collected over 16 years, generalized linear mixed models, and dynamic occupancy models to meet these objectives. Different bird species responded to drought at different temporal grains, with most showing the strongest signal at annual or near-annual grains. For all drought-responsive species, increased drought intensity at any temporal grain always correlated with decreased occupancy. Additionally, colonization/extinction analyses indicated that one species, the dickcissel (Spiza americana), is more likely to colonize novel areas within the southern/core portion of its range during drought. Considering drought at different temporal grains, along with hydrologic attributes captured by each grain, may better reveal mechanisms behind drought impacts on birds and other organisms, and therefore improve understanding of how global climate change impacts species and the landscapes they inhabit.

Side-swiped: Ecological cascades emanating from earthworm invasion.

Non-native, invasive earthworms are altering soils throughout the world. Ecological cascades emanating from these changes stem from earthworm-caused changes in detritus processing occurring at a mid-point in the trophic pyramid, rather than the more familiar bottom-up or top-down cascades. They include fundamental changes (microcascades) in soil morphology, bulk density, nutrient leaching, and a shift to warmer, drier soil surfaces with loss of organic horizons. In North American temperate and boreal forests, microcascades cause effects of concern to society (macrocascades), including changes in CO2 sequestration, disturbance regimes, soil quality, water quality, forest productivity, plant communities, and wildlife habitat, and facilitation of other invasive species. Interactions among these changes create cascade complexes that interact with climate change and other environmental changes. The diversity of cascade effects, combined with the vast area invaded by earthworms, lead to regionally important changes in ecological functioning.

Variation and drivers of airflow patterns associated with olfactory concealment and habitat selection.

Many terrestrial predators rely on olfaction to detect prey; therefore, prey should select habitat to reduce detectability of their odor cues. One way prey can potentially conceal their odor is by selecting locations with high turbulence and/or updrafts, conditions that disperse odor plumes and make odor sources difficult to locate. However, it is unclear how these conditions vary among vegetation cover types and which vegetative features drive them. We assessed variation and drivers of variables hypothesized to influence olfactory concealment (turbulence intensity and airflow slope) and experimentally evaluated whether these variables indeed influence predator detection of simulated prey. Specifically, we compared vegetation patch-scale values of turbulence intensity and airflow slope among grassland, shrubland, and forest and assessed relationships among these airflow variables and local-scale vegetative features within each vegetation type. Additionally, we experimentally investigated the importance of turbulence intensity, airflow slope, and visual concealment for predicting predator detection of scented quail eggs. In all vegetation types, we documented high variability in airflow conditions. At the patch scale, turbulence intensity was greater in shrubland and grassland than in forest, and updrafts were most common in shrubland whereas downdrafts were most common in grassland. Grassland was the only vegetation type with strong relationships among turbulence intensity and local vegetation features; both visual concealment and vegetation height were positively related to turbulence intensity. Additionally, persistence of scented quail eggs in grassland was best predicted by turbulence intensity; egg persistence increased with turbulence intensity. Our characterization of differences in olfactory variables among vegetation types provides an important step towards building a clearer understanding of olfactory landscapes. Further, our observation of both patch- and local-scale variation in olfactory variables suggests that prey can potentially select for olfactory concealment at multiple scales. We hypothesize that olfactory concealment provided by high levels of turbulence intensity is an important component of cover in grassland, and that in grassland/shrubland landscapes, prey selection of shrubland patches reduces odor detectability. Our finding of a positive relationship between turbulence intensity and visual concealment also suggests that olfactory concealment may be a previously underappreciated confounding factor in studies of habitat selection.

Factors influencing experimental estimation of scavenger removal and observer detection in bird-window collision surveys.

Wildlife collisions with human-built structures are a major source of direct anthropogenic mortality. Understanding and mitigating the impact of anthropogenic collisions on wildlife populations require unbiased mortality estimates. However, counts of collision fatalities are underestimated due to several bias sources, including scavenger removal of carcasses between fatality surveys and imperfect detection of carcasses present during surveys. These biases remain particularly understudied for bird-window collisions, the largest source of avian collision mortality. In Stillwater, Oklahoma, USA, we used bird carcasses collected during window collision monitoring to experimentally assess factors influencing scavenging and observer detection, and we employed trail cameras to characterize the scavenger community and timing of scavenging. We recorded nine scavenger species, but the domestic cat and Virginia opossum were responsible for 73% of known-species scavenging events. The most frequent scavenger species were primarily nocturnal, and 68% of scavenging events occurred at night. Scavenger species best predicted time to first scavenging event, season best predicted carcass persistence time, and both season and carcass size predicted whether any carcass remains persisted after scavenging. Our results also suggest that observer detection was influenced by substrate, with greater detection of carcasses on artificial substrates. Our findings related to scavenging timing have important implications for the unbiased estimation of collision mortality because the timing of peak scavenging relative to timing of peak mortality can substantially influence accuracy of adjusted mortality estimates. Further, the differences in correlates for time to first scavenging and time to carcass removal (i.e., persistence time) illustrate the importance of explicitly measuring these often-independent events that are frequently conflated in the anthropogenic mortality literature.

The unseen invaders: introduced earthworms as drivers of change in plant communities in North American forests (a meta-analysis).

Globally, biological invasions can have strong impacts on biodiversity as well as ecosystem functioning. While less conspicuous than introduced aboveground organisms, introduced belowground organisms may have similarly strong effects. Here, we synthesize for the first time the impacts of introduced earthworms on plant diversity and community composition in North American forests. We conducted a meta-analysis using a total of 645 observations to quantify mean effect sizes of associations between introduced earthworm communities and plant diversity, cover of plant functional groups, and cover of native and non-native plants. We found that plant diversity significantly declined with increasing richness of introduced earthworm ecological groups. While plant species richness or evenness did not change with earthworm invasion, our results indicate clear changes in plant community composition: cover of graminoids and non-native plant species significantly increased, and cover of native plant species (of all functional groups) tended to decrease, with increasing earthworm biomass. Overall, these findings support the hypothesis that introduced earthworms facilitate particular plant species adapted to the abiotic conditions of earthworm-invaded forests. Further, our study provides evidence that introduced earthworms are associated with declines in plant diversity in North American forests. Changing plant functional composition in these forests may have long-lasting effects on ecosystem functioning.

Factors associated with bat mortality at wind energy facilities in the United States.

Hundreds of thousands of bats are killed annually by colliding with wind turbines in the U.S., yet little is known about factors causing variation in mortality across wind energy facilities. We conducted a quantitative synthesis of bat collision mortality with wind turbines by reviewing 218 North American studies representing 100 wind energy facilities. This data set, the largest compiled for bats to date, provides further support that collision mortality is greatest for migratory tree-roosting species (Hoary Bat [Lasiurus cinereus], Eastern Red Bat [Lasiurus borealis], Silver-haired Bat [Lasionycteris noctivagans]) and from July to October. Based on 40 U.S. studies meeting inclusion criteria and analyzed under a common statistical framework to account for methodological variation, we found support for an inverse relationship between bat mortality and percent grassland cover surrounding wind energy facilities. At a national scale, grassland cover may best reflect openness of the landscape, a factor generally associated with reduced bat activity and abundance that may also reduce turbine collisions. Further representative sampling of wind energy facilities is required to validate this broad pattern. Ecologically informed decisions regarding placement of wind energy facilities involves multiple considerations, including not only factors associated with bat mortality, but also factors associated with bird collision mortality, indirect habitat-related impacts to all species, and overall ecosystem impacts.

A quantitative synthesis of the role of birds in carrying ticks and tick-borne pathogens in North America.

Birds play a central role in the ecology of tick-borne pathogens. They expand tick populations and pathogens across vast distances and serve as reservoirs that maintain and amplify transmission locally. Research into the role of birds for supporting ticks and tick-borne pathogens has largely been descriptive and focused in small areas. To expand inference beyond these studies, we conducted a quantitative review at the scale of North America to identify avian life history correlates of tick infestation and pathogen prevalence, calculate species-level indices of importance for carrying ticks, and identify research gaps limiting understanding of tick-borne pathogen transmission. Across studies, 78 of 162 bird species harbored ticks, yielding an infestation prevalence of 1981 of 38,929 birds (5.1 %). Avian foraging and migratory strategies interacted to influence infestation. Ground-foraging species, especially non-migratory ground foragers, were disproportionately likely to have high prevalence and intensity of tick infestation. Studies largely focused on Borrelia burgdorferi, the agent of Lyme disease, and non-migratory ground foragers were especially likely to carry B. burgdorferi-infected ticks, a finding that highlights the potential importance of resident birds in local pathogen transmission. Based on infestation indices, all "super-carrier" bird species were passerines. Vast interior areas of North America, many bird and tick species, and most tick-borne pathogens, remain understudied, and research is needed to address these gaps. More studies are needed that quantify tick host preferences, host competence, and spatiotemporal variation in pathogen prevalence and vector and host abundance. This information is crucial for predicting pathogen transmission dynamics under future global change.

A call for full annual cycle research in animal ecology.

For vertebrates, annual cycles are organized into a series of breeding and non-breeding periods that vary in duration and location but are inextricably linked biologically. Here, we show that our understanding of the fundamental ecology of four vertebrate classes has been limited by a severe breeding season research bias and that studies of individual and population-level responses to natural and anthropogenic change would benefit from a full annual cycle perspective. Recent emergence of new analytical and technological tools for studying individual and population-level animal movement could help reverse this bias. To improve understanding of species biology and reverse the population declines of many vertebrate species, a concerted effort to move beyond single season research is vital.

Factors influencing abundance of 3 tick species across a gradient of urban development intensity in the US Great Plains.

Urbanization alters abiotic conditions, vegetation, and wildlife populations in ways that affect tick abundance and tick-borne disease prevalence. Likely due to such changes, tick abundance has increased in many US urban areas. Despite growing public health importance of tick-borne diseases, little is known about how ticks are influenced by urbanization in North America, especially in the central United States where several pathogens occur at or near their highest incidences. To identify factors influencing tick abundance across a gradient of urbanization intensity, we used CO2 traps and flagging to sample ticks at 16 parks across Oklahoma City, Oklahoma, USA over 2 yr, conducted vegetation surveys, and used trail cameras to estimate a deer abundance index. Our results indicate there is a risk of encountering ticks across the entire urbanization gradient from exurban areas to the urban core, although some species (Dermacentor variabilis (Say)) appear less-common in heavily-urbanized areas. Vegetation variables were also associated with tick abundance. For example, Amblyomma maculatum Koch decreased with increasing woody plant and leaf litter cover, and there was a weak positive relationship between D. variabilis abundance and cover of understory eastern redcedar (Juniperus virginiana L.), indicating this native encroaching tree may increase tick populations in urban areas of the Great Plains. The deer abundance index was positively correlated with A. maculatum and D. variabilis abundance but unrelated to A. americanum (L.) abundance. Public health officials and land managers can use such information about parks/greenspaces and their surroundings to focus public education and land management efforts designed to reduce tick-borne disease prevalence.

Wild birds and urban ecology of ticks and tick-borne pathogens, Chicago, Illinois, USA, 2005-2010.

Bird-facilitated introduction of ticks and associated pathogens is postulated to promote invasion of tick-borne zoonotic diseases into urban areas. Results of a longitudinal study conducted in suburban Chicago, Illinois, USA, during 2005-2010 show that 1.6% of 6,180 wild birds captured in mist nets harbored ticks. Tick species in order of abundance were Haemaphysalis leporispalustris, Ixodes dentatus, and I. scapularis, but 2 neotropical tick species of the genus Amblyomma were sampled during the spring migration. I. scapularis ticks were absent at the beginning of the study but constituted the majority of ticks by study end and were found predominantly on birds captured in areas designated as urban green spaces. Of 120 ticks, 5 were infected with Borrelia burgdorferi, spanning 3 ribotypes, but none were infected with Anaplasma phagocytophilum. Results allow inferences about propagule pressure for introduction of tick-borne diseases and emphasize the large sample sizes required to estimate this pressure.