Slowing the loss of biodiversity amidst the sixth mass extinction is a core tenet of the field of wildlife conservation, and it is propelled by legal and regulatory frameworks that emphasize intervention for species-at-risk. The overwhelming focus on species extinctions, however, has de-emphasized the extent and consequences of the loss of abundance of still-common wild animals. Working agricultural lands comprise up to 40% of the Earth’s ice-free terrestrial land surface, and habitat conversion to agriculture is a leading cause of both global defaunation and greenhouse gas emissions. In this presentation, I argue that more wildlife work should focus on keeping common animals common, particularly in working landscapes where people work, grow food, and live in co-existence with wild animals.

Changes in habitat and vegetation in space and time can strongly affect the behavior of both prey and their predators, thus shaping the outcomes of predator-prey interactions. In managed agroecosystems, these changes could mediate the capacity for natural enemies to reduce economically damaging pests. Farmers in Napa Valley, CA install nest boxes to attract American barn owls (Tyto furcata) to their winegrape vineyards for rodent pest control. However, vineyards exhibit marked spatial and temporal variation in habitat structure due to viticultural practices (i.e., mowing cover crops, trellis systems, and pruning). How the owls respond to this habitat heterogeneity remains unresolved. During the spring and summer of 2024, we deployed GPS tags fitted with accelerometers on adult breeding barn owls in Napa Valley to track their hunting behavior. These data will be used in integrated step-selection function and resource selection function analyses to reveal how changes in vegetation structure affect hunting strike location distributions. By leveraging improved GPS tracking technology, a heterogeneous landscape, and predictable and abrupt changes in vegetation caused by viticultural practices, this research will investigate questions fundamental to understanding predator-prey interactions while also shedding light on how owls contribute to rodent pest management in this agricultural ecosystem.

Agricultural expansion threatens biodiversity, but promoting native species like insectivorous birds in agricultural landscapes could benefit both biodiversity and farm productivity alike. Recently, some California winegrape growers have used nest boxes to promote biodiversity and attract insectivorous birds in an effort to help control insects. While early findings suggested nest boxes have a positive impact on bird functional richness and abundance, later research found no significant effect on avian community composition or pest control. This project addresses research needs using a before-after-control-impact experiment involving winegrape vineyards in Napa Valley, California. The objectives of this study are to (i) examine how habitat and landscape composition influence bird communities and (ii) how the addition of nest boxes affects insectivore abundance. Avian point counts were conducted for two seasons on 20 vineyards, 10 with existing nest boxes and 10 with nest boxes added between field seasons. We hypothesize that the addition of songbird nest boxes to winegrape vineyards attracts insect-eating birds, and these effects are mediated by local and landscape level characteristics. We also hypothesize that the beneficial effects of within-farm habitat complexity on bird abundance and diversity are mediated by the composition of the surrounding landscape.

Avian biodiversity is declining across the country, and conservation lands alone will likely not be able to support vibrant avian communities long-term. Agricultural expansion contributes to this bird population decline, but the integration of bird friendly practices into agricultural land, such as vineyards, could support many birds that have lost habitat to development. We assessed how different habitat characteristics of existing vineyards in San Luis Obispo County, California, including percent grassland, shrubland, vineyard, agriculture, and canopy cover, as well as structural complexity, influence taxonomic and functional avian community structure as well as individual species occupancy. Variation in canopy cover and shrubland cover appeared to have the greatest influence on community composition in and around the vineyards. Whereas canopy cover, structural complexity, and proximity to streams influenced many species’ occupancy. Vineyard modifications such as adding small amounts of canopy and preserving existing natural habitat could have large impacts on bird communities in vineyards.  This analysis will help guide local bird friendly vineyard management to help increase the abundance and diversity of birds that can utilize these modified lands for foraging, shelter, and to connect larger areas of protected land.

Habitat selection in birds holds important implications for fitness and conservation practices. Social information, in tandem with habitat cues, may provide an efficient way for an individual to assess future breeding site quality. We investigated the hypothesis that prospecting Western Bluebirds use post-breeding social information to select nest sites the following year across winegrape vineyards in Napa Valley. In late summer of 2023, 10 vineyards without a history of nest boxes received 20 boxes each (n=200). On five vineyards, 12 boxes received a three-day experimental treatment using playback and an old nest to simulate reproductive success (n=60). We filmed experimental boxes during the treatment period, as well as nearby boxes within range of the vocalizations (near-treatment, n=30), and boxes located on the 5 vineyards with no treatment at all (control, n=30). Boxes were re-visited during the summer of 2024 to determine timing of use and occupying species, and to collect local habitat data. We found that Western Bluebirds preferred boxes near isolated tree patches, and the effectiveness of social information on nest selection was mediated by habitat. Video analysis will determine whether prospecting visitation rates influence probability of future nest box use.

Invasive wild ungulates pose significant global concerns due to their impact on ecosystem functions and competition with native species. Many island systems lack large native predators to control wild ungulate populations, which intensifies these adverse effects, particularly on agricultural land. Across Hawaiʻi, approximately one million acres of ranchland are dedicated to beef production. However, the overabundance of axis deer, mouflon sheep, and feral goats has resulted in overgrazing of some areas, which increases sediment runoff, promotes spread of invasive plants, decreases ecosystem health, and threatens the livelihood of generational ranchers. This study examines the relationship between invasive ungulate abundance and changes in plant biomass on ranchlands in Maui and Hawaiʻi Island. We utilized game cameras, grazing exclusion cages, and line-transect sampling to quantify wild ungulate detections, vegetation loss, and plant community composition. Higher detections of wild ungulates were positively associated with reduced plant biomass but were not statistically significant (p= 0.26). Wild ungulates were found across all types of plant community composition, indicating that the expansion of wild ungulates is widespread on ranchlands. Our findings underscore the widespread expansion of ungulates across the landscape and highlight the necessity of collaborative management between agricultural and conservation land managers for sustainable land use.