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Geology topics

B.A. Millsap

Publications and source records attributed to B.A. Millsap.

5 recordsLinked to original sources
USGS2009

Unusual raptor nests around the world

From surveys in many countries, we report raptors using unusual nesting materials (e.g., paper money, rags, metal, antlers, and large bones) and unusual nesting situations. For example, we documented nests of Steppe Eagles Aquila nipalensis and Upland Buzzards Buteo hemilasius on the ground beside well-traveled roads, Saker Falcon Falco cherrug eyries in attics and a cistern, and Osprey Pandion haliaetus nests on the masts of boats and on a suspended automobile. Other records include a Golden Eagle A. chrysaetos nest 7.0 m in height, believed to be the tallest nest ever described, and, for the same species, we report nesting in rudimentary nests. Some nest sites are within a few meters of known predators or competitors. These unusual observations may be important in revealing the plasticity of a species' behavioral repertoire. ?? 2009 The Raptor Research Foundation, Inc.

Journal of Raptor Research↗
USGS2008

Migration of Florida sub-adult Bald Eagles

We used satellite telemetry locations accurate within 1 km to identify migration routes and stopover sites of 54 migratory sub-adult Bald Eagles (Haliaeetus leucocephalus) hatched in Florida from 1997 to 2001. We measured number of days traveled during migration, path of migration, stopover time and locations, and distance traveled to and from winter and summer areas for each eagle (1?5 years old). Eagles used both Coastal Plain (n = 24) and Appalachian Mountain (n = 26) routes on their first migration north. Mountain migrants traveled farther (X = 2,112 km; 95% CI: 1,815-2,410) than coastal migrants (X = 1,397 km; 95% CI: 1,087?1,706). Eagles changed between migration routes less often on northbound and southbound movements as they matured (X2 = 13.22, df = 2, P < 0.001). One-year-old eagles changed routes between yearly spring and fall migrations 57% of the time, 2-year-olds 30%, and 3-5-year-olds changed only 17% of the time. About half (n = 25, 46%) used stopovers during migration and stayed 6-31 days (X = 14.8 days; 95% CI: 12.8-16.8). We recommend that migratory stopover site locations be added to GIS data bases for improving conservation of Bald Eagles in the eastern United States.

Wilson Journal of Ornithology↗
USGS2002

Prey of the Peregrine Falcon (Falco peregrinus cassini) in Southern Argentina and Chile

The Peregrine Falcon (Falco peregrinus cassini) in Patagonia attracted wide interest two decades ago when there was a focus on determining the taxonomic position of the Pallid Falcon (also called Kleinschmidt's falcon and Tierra del Fuego falcon; formerly named Falco kreyenborgi). In 1981, however, the pallid falcon was confirmed to be a pale color morph of the peregrine, and since that time, little work has been conducted on this color morph. Continent-wide research has continued and has yielded a fair understanding of the breeding distribution of the Peregrine Falcon in South America. Also, two preliminary food habits studies on the peregrine have been completed in Patagonia. Together those papers provided a list of 23 species observed as prey, and McNutt listed another eight species seen pursued (but not captured) by peregrines. The purpose of this paper is to assemble all that has been published on peregrine food habits for Patagonia and Tierra del Fuego and to add to that list from our 1980 and 1981 expeditions.

Journal of Raptor Research↗
USGS1990

Owls

Eight species of owls regularly occur and may breed in one or more of the southeastern states. Several additional northern or western species appear irregularly as accidentals or during years of southward incursions. In the Southeast, the most common and wide- spread owls are the common barn-owl, eastern screech-owl, great horned owl and barred owl; the most restricted is the burrowing owl. The long-eared, short-eared, and northern saw-whet owls are primarily winter visitors in this region, although small and very localized nesting populations of short-eared owls may occur in Virginia. Long-eared owls and northern saw-whet owls may occur in West Virginia and northern saw-whet owls may occur in the highlands of Tennessee and North Carolina. Several owls of the Southeast are Blue-listed as threatened, endangered, or of local concern, including the common barn-owl, eastern screech-owl, burrow'ing owl and short-eared owl. The nesting status of the long-eared owl and northern saw-whet owl are still poorly known. These two owls should be included on stat and regional lists of species of special concern. Important limiting factors for all owls of the Southeast include habitat loss and human related mortality. Management issues center on obtaining a data base useful in predicting the effects of current forest management practices on owl populations and encouraging use of forestry techniques that least impact owls. Research needs include initiating studies of all aspects of the life history and habitat relationships of each owl species.

Book chapter↗