Peregrine Falcons on Coastal Beaches of Washington: Fifteen Years of Banding and Surveys

Varland, Daniel E.; Buchanan, Joseph B.; Fleming, Tracy L.; Loughin, Thomas M.

doi:10.3356/jrr-10-112.1

Cited by 4 publications

(7 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During the fall, a large number of comparatively less-experienced juveniles either migrate through or begin to overwinter at our study area (Varland et al 2012). Moreover, late fall and winter days are shorter and rainfall and winds are more frequent and intense during winter compared with all other seasons in Washington (Mass 2008), thereby possibly reducing opportunities for effective hunting flights.…”

Section: Methodsmentioning

confidence: 96%

“…The 11.8-km-long Grayland Beach study area extended from the Warrenton-Cannery Road beach access north to the Bonge Road beach access. The 39.9-km-long Long Beach study area extended for the length of the Long Beach Peninsula (currently 0.3 km longer than reported in Varland et al (2012), due to sand accretion at the north end of the peninsula), starting at North Head. We frequently excluded the southernmost part of Ocean Shores Beach and both ends of Grayland Beach in our driving surveys (see below), because soft sand precluded safe driving.…”

Section: Study Areamentioning

confidence: 91%

“…Field Procedures. We observed scavenging by Peregrine Falcons during the course of ongoing studies of shorebird abundance (Buchanan 1992), falcon hunting behavior (Buchanan 1996), and long-term raptor banding focused on Peregrine Falcons (Varland et al 2008a(Varland et al , 2008b(Varland et al , 2012. Our observations of scavenging were made while conducting vehicle-based surveys along the three study beaches between January 1983 and May 2015.…”

Section: Methodsmentioning

confidence: 99%

“…Although we also recorded the sex and subspecies of each falcon, herein we report sex and subspecies only for those falcons we were able to capture. For these individuals, we used measurements (e.g., wing chord, culmen, and tail length) to classify individuals by sex and a combination of plumage characteristics, measurements, and photo review by outside experts as described in Varland et al (2012) to classify individuals by subspecies. We captured and banded 192 peregrines from 1995 through May 2015 using capture and color-banding techniques described in Varland et al (2012).…”

Section: Methodsmentioning

confidence: 99%

“…For these individuals, we used measurements (e.g., wing chord, culmen, and tail length) to classify individuals by sex and a combination of plumage characteristics, measurements, and photo review by outside experts as described in Varland et al (2012) to classify individuals by subspecies. We captured and banded 192 peregrines from 1995 through May 2015 using capture and color-banding techniques described in Varland et al (2012). Observers used spotting scopes, cameras with telephoto or zoom lenses, and sometimes binoculars to identify color-banded falcons resighted during the study.…”

Section: Methodsmentioning

confidence: 99%

See 4 more Smart Citations

Scavenging as a Food-Acquisition Strategy by Peregrine Falcons

Varland¹,

Buchanan

Fleming

et al. 2018

Journal of Raptor Research

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Methodsmentioning

confidence: 96%

Section: Study Areamentioning

confidence: 91%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Scavenging as a Food-Acquisition Strategy by Peregrine Falcons

Varland¹,

Buchanan

Fleming

et al. 2018

Journal of Raptor Research

Self Cite

View full text Add to dashboard Cite

show abstract

Seasonal and inter-annual variation in exposure to peregrines (Falco peregrinus) for southbound western sandpipers (Calidris mauri)

Ydenberg

2022

Mov Ecol

View full text Add to dashboard Cite

Background The western sandpiper (Calidris mauri) is an early southbound migrant species in North America. The ‘peregrine avoidance’ hypothesis proposes that this timing evolved to reduce exposure to their main predator, the peregrine (Falco peregrinus), along the Pacific flyway. Methods I evaluate this hypothesis based on 16 years of near-daily (June – October) measures of peregrine presence made on the Fraser River estuary, a major stopover in the Pacific northwest. Results Exposure to peregrines is lowest for the earliest southbound western sandpipers, and rises steeply as peregrines en route from northern breeding areas begin to arrive in late July or August. Peregrine arrival timing varies greatly between years, shifting in step with the onset of spring along coastal Alaska. Peregrine presence on the Fraser estuary on any date is higher in years with earlier spring onset. On the median adult sandpiper passage date (day-of-year 198) this increases 17-fold over the inter-annual range between the earliest and latest peregrine arrival dates. Conclusion The pattern of strong and predictable changes in the seasonal pattern of danger quantified here provides a further test of the hypothesis that danger affects migratory timing. Western sandpipers appear to anticipate the exposure level of southward migration, perhaps because they are able to observe spring onset on their Alaskan breeding grounds. They adjust the duration of parental care and length of the breeding season to keep the date of migratory departure from the Arctic relatively invariant in spite of large interannual variation in spring onset. While underway they also adjust aspects of migratory behavior. These observations support the ‘peregrine avoidance’ hypothesis, and suggest that western sandpipers are able to counter, at least partially, the higher migratory danger of early spring years.

show abstract