Several graduate students from the raptor biology and biology graduate programs presented papers and posters at Idaho Chapter of the Wildlife Society annual meeting March 5-8 at the Owyhee Plaza Hotel in Boise.
They include:
Neil Paprocki: Wintering Raptor Population Trends in Idaho and the Morley Nelson Snake River Birds of Prey National Conservation Area
A majority of raptor studies focus on surveys during the breeding and fall migration seasons. However, breeding populations of birds may be partly limited to winter mortality and habitat conditions, which are poorly represented in the scientific literature. The goal of this research was to monitor how wintering raptor populations in Idaho and the Morley Nelson Snake River Birds of Prey National Conservation Area (NCA) have changed over the last 20 years. The main factor driving increased abundance for many species appears to be climate change as winters in the NCA are becoming significantly warmer, less severe, with less snow cover.
Allison Korte: Urbanization and Avian Species Richness and Abundance Along the Boise River Corridor
Riparian corridors provide valuable habitat for breeding, migration and dispersal activities of birds. However, these ecosystems are popular targets for urban development as they bring wildlife closer to city and residential buildings. More than 80 species were identified during the surveys. They were separated into nesting and foraging guilds to show effects of human disturbances on species composition. Researchers analyzed the data using Akaike Information Criterion Corrected modeling. For example, the presence of birds in the cavity-nesting guild was best described by the presence of live grass, suggesting a need to preserve open habitat. They also analyzed several individual species. For instance, the top model for the Yellow Warbler was characterized by the presence of riparian habitat and the presence of people, suggesting that this species is tolerant of people, as long as riparian habitat is maintained. This study improves the basic understanding of the effects of urban development on avian species along riparian corridors.
Michelle Laskowski: Prevalence of haemosporidian parasites in migrating Idaho raptors
Many studies have examined blood parasites in raptors during the breeding season but few have examined raptor blood parasites during migration. Migration is energetically demanding, even in healthy birds, and parasitic infections can be a serious threat, especially to young, inexperienced birds. Researchers tested four species of diurnal raptors during their fall migration from 2010 – 2011 for haemosporidian blood parasites. Lymphocytes were the most abundant white blood cell type, with higher numbers in infected than in non-infected individuals, with variations in individuals with multiple infections. These results link pressures of migration with blood parasite prevalence, intensities and the immune cost associated with multiple infections.
Rob Miller: Northern Goshawk breeding and productivity relative to prey abundance within the Sawtooth National Forest.
The health of an ecosystem is dependent upon the interactions within and among species. Predator-prey interactions often have a disproportionately larger influence on ecosystem health and ecosystem functions than other interactions. It follows that predator-prey interactions must be understood and evaluated as part of any ecosystem health monitoring program. As a top predator within the South Hills of Sawtooth National Forest, the Northern Goshawk provides an ideal model for studying predator-prey interactions in a unique setting. Researchers found that avian prey abundance, but not mammalian prey abundance, was a significant predictor of goshawk breeding status even though their breeding season diet was dominated by mammals. The study provides novel data on Northern Goshawk prey consumption and the relationship of consumption to prey abundance, forest structure and forest health, factors important to our understanding of goshawks and their role in the ecosystem.
Patrick Kolar: Impacts of wind turbines on Buteo hawk fledgling mortality in the Columbia Plateau Ecoregion
Production of energy from wind power has expanded throughout the Columbia Plateau Ecoregion (CPE) in recent years. Despite this rapid development, little data has been published that pertains to the response of breeding raptors or their young to wind turbines. The study shows that juveniles are less vulnerable to collisions during the relatively short period prior to initiation of natal dispersal compared to other age classes; this could be primarily due to low activity, limited natal range, and the relatively short duration of exposure to wind turbines.
Jamie Utz: Understanding the trade-off between safety and food quality in pygmy rabbits
Conserving a sensitive animal species requires understanding the simultaneous tradeoffs between food and shelter within a landscape. Most management approaches only consider singular factors like percent cover at landscape spatial scales. Quantifying the synergy between food and cover quality at a scale relevant to a foraging animal could better reveal the forces that shape habitat use. To better understand habitat use components, researchers investigated tradeoffs between predation risk and diet quality in a sagebrush endemic, the pygmy rabbit