Geology topics

Peter M. Sanzenbacher

Publications and source records attributed to Peter M. Sanzenbacher.

8 recordsLinked to original sources

USGS2024

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.

Conservation Biology↗

USGS2023

Utilizing high-resolution genetic markers to track population-level exposure of migratory birds to renewable energy development

With new motivation to increase the proportion of energy demands met by zero-carbon sources, there is a greater focus on efforts to assess and mitigate the impacts of renewable energy development on sensitive ecosystems and wildlife, of which birds are of particular interest. One challenge for researchers, due in part to a lack of appropriate tools, has been estimating the effects from such development on individual breeding populations of migratory birds. To help address this, we utilize a newly developed, high-resolution genetic tagging method to rapidly identify the breeding population of origin of carcasses recovered from renewable energy facilities and combine them with maps of genetic variation across geographic space (called ‘genoscapes’) for five species of migratory birds known to be exposed to energy development, to assess the extent of population-level effects on migratory birds. We demonstrate that most avian remains collected were from the largest populations of a given species. In contrast, those remains from smaller, declining populations made up a smaller percentage of the total number of birds assayed. Results suggest that application of this genetic tagging method can successfully define population-level exposure to renewable energy development and may be a powerful tool to inform future siting and mitigation activities associated with renewable energy programs.

PLOS Sustainability and Transformation↗

USGS2022

Vulnerability of avian populations to renewable energy production

Renewable energy production can kill individual birds, but little is known about how it affects avian populations. We assessed the vulnerability of populations for 23 priority bird species killed at wind and solar facilities in California, USA. Bayesian hierarchical models suggested that 48% of these species were vulnerable to population-level effects from added fatalities caused by renewables and other sources. Effects of renewables extended far beyond the location of energy production to impact bird populations in distant regions across continental migration networks. Populations of species associated with grasslands where turbines were located were most vulnerable to wind. Populations of nocturnal migrant species were most vulnerable to solar, despite not typically being associated with deserts where the solar facilities we evaluated were located. Our findings indicate that addressing declines of North American bird populations requires consideration of the effects of renewables and other anthropogenic threats on both nearby and distant populations of vulnerable species.

California↗

USGS2002

Residency and movement patterns of wintering dunlin in the Willamette Valley of Oregon

In the winters of 1998–1999 and 1999–2000, we tracked 67 radio-marked Dunlin ( Calidris alpina ) throughout the complex agricultural landscape of the Willamette Valley of Oregon. Individual birds were tracked across 8-week sampling periods and indicated a high degree of regional fidelity throughout the three winter sampling periods. Birds exhibited varied degrees of fidelity to specific wetland sites and were detected at an average of nine different sites. Distances traveled within the region were extensive and greatest during late winter. Females ranged farther from capture sites than males, and movement from capture sites for all birds was greatest during late winter. Mean home-range size (95% minimum convex polygons) of birds was 258.2 ± 44.8 km 2 (SE) and was greatest during late winter. Diurnal roosts were identified as centers of activities and daily movements were most pronounced during crepuscular periods. These data represent the most extensive documentation of winter movements for a shorebird at an inland site. Findings indicate Dunlin were winter residents, and extensive local movements suggest a high degree of functional connectivity of habitats.

Oregon↗

USGS2002

Space use, migratory connectivity, and population segregation among Willets breeding in the western Great Basin

Western Willets ( Catoptrophorus semipalmatus inornatus ) were banded (n = 146 breeding adults and chicks) and radio-marked (n = 68 adults) at three western Great Basin wetland complexes to determine inter- and intraseasonal space use and movement patterns (primarily in 1998 and 1999). Birds were then tracked to overwintering sites where migratory connectivity and local movements were documented. Willets arrived synchronously at breeding sites during mid-April and spent less than 12 weeks in the Great Basin. There were no movements to other sites in the Great Basin during the breeding or postbreeding season. However, most breeding birds moved locally on a daily basis from upland nest sites to wetland foraging sites. The mean distance breeding birds were detected from nests did not differ between sexes or between members of a pair, although these distances were greater among postbreeding than breeding birds. Home-range estimates did not differ significantly between paired males and females during breeding or postbreeding. However, female home ranges were larger following breeding than during breeding. Shortly after chicks fledged, adult Willets left the Great Basin for locations primarily at coastal and estuarine sites in the San Francisco Bay area. Limited data revealed little among-site movements once Willets arrived at the coast, and birds appeared to be site faithful in subsequent winters. Winter sites of western Great Basin Willets differed from those used by birds from other areas in the subspecies' range, suggesting another subspecies or distinct population segment may exist. This study illustrates the importance of understanding movements and space use throughout the annual cycle in conservation planning.

California, Oregon↗

USGS2002

Regional fidelity and movement patterns of wintering killdeer in an agricultural landscape

Killdeer ( Charadrius vociferus ) is a common and widespread North American species for which there are few studies of residency patterns and movements. We quantified fidelity and movement patterns of 24 radio-tagged Killdeer in the Willamette Valley of Oregon during the winter of 1999-2000. Results from telemetry surveys and census efforts revealed that the group monitored was composed of winter residents (63%), winter transients (26%), and year-round residents (11%). Movements were localized with birds detected at an average distance of 5.15 ± 0.91 (SE) km from the site of capture. Mean home range size (95% kernel) was 7.73 ± 3.19 km 2 . However, results also indicated periodic exploratory movements, with some birds detected up to 30 km from marking sites. Overall, individuals exhibited a low degree of fidelity to specific sites and were detected at an average of 11.9 ± 1.1 sites. No differences were found in monthly movement patterns. In almost all cases, year-round residents were more sedentary than winter residents and winter transients. Results indicate a complex regional population structure and highlight the need to consider both migrant and resident birds, as well as seasonal differences in habitat needs and space use requirements, in future conservation planning efforts.

Oregon↗

USGS2001

Killdeer population trends in North America

Killdeers (Charadrius vociferus) are considered a common species that inhabits a wide range of wetland and upland habitats throughout much of North America, yet recent information suggests that they may be declining regionally, if not throughout much of their range. To address this issue, we examined population trends of this species at multiple spatial and temporal scales using data from two major avian survey efforts, the Breeding Bird Survey (BBS) and Christmas Bird Count (CBC). A summary of BBS trends indicates significant long-term (1966a??1996) declines in breeding populations across North America. Geographic regions driving this decline were Canada, western survey regions of the continent, and select southeastern states. In contrast, over the same time period, Killdeer populations increased in some midwestern states, particularly those in the Great Lakes region. Recent BBS trends (1986a??1996) indicate highly significant declines across most areas of North America surveyed. Trends from CBC data (1959a??1988) indicate declines at a smaller spatial scale. While the ability of current major avian survey efforts to detect population trends for Killdeer and other shorebird species warrants further examination, significant negative trends in Killdeer populations indicates the need to further investigate the status of this species.

Journal of Field Ornithology↗

USGS2000

Application of a modified harness design for attachment of radio transmitters to shorebirds

Radio transmitter attachment methodology is important to the design of radio telemetry studies. In 1998, we attached 5 transmitters to a captive population of Western Sandpipers ( Calidris mauri ) and 7 transmitters to wild Killdeer ( Charadriusv ociferus ) using a modified version of the Rappole and Tipton (1991) figure-8 leg-loop harness. Captive birds fitted with harnesses did not exhibit quantifiable differences in behavior relative to control birds. Based on initial success in using the leg-loop harnesses, we used harnesses to attach transmitters in the wild to 30 Killdeer and 49 Dunlin ( Calidris alpina ) during the winters of 1998-1999 and 1999-2000. This was part of a study on movements of wintering shorebirds in the Willamette Valley of Oregon, USA. Wild birds showed no adverse effects of the harnesses.Thus, the described harness is a practical method for attachment of transmitters to shorebirds. Advantages of this harness method include a reduction in handling time at capture, elimination of the need to clip feathers for attachment, and increased transmitter retention time.

Oregon↗