Journal of Raptor Research
Volume 32, Issue 2, 1998, Pages 120-125

Size variation of migrant bald eagles at Glacier National Park, Montana (Article)

Mcclelland B.R. , Shea D.S. , Mcclelland P.T. , Patterson D.A.
  • a School of Forestry, University of Montana, Missoula, MT 59812, United States, Box 366, West Glacier, MT 59936, United States
  • b School of Forestry, University of Montana, Missoula, MT 59812, United States, Box 90, Babb, MT 59411, United States
  • c School of Forestry, University of Montana, Missoula, MT 59812, United States, Box 366, West Glacier, MT 59936, United States
  • d Department of Mathematics, University of Montana, Missoula, MT 59812, United States

Abstract

We measured morphological variables on 303 migrating Bald Eagles (Haliaeetus leucocephalus) at Glacier National Park, Montana (GNP), during 1977-88. Based on results of a concurrent migration study, most of the eagles we measured were from summering areas in the Northwest Territories, Canada. Eagles were classified by plumage as juvenile, subadult, or adult. Feather lengths differed among plumage classes in all variables, but only the eighth and ninth primaries and tail differed (decreased with age) among all three plumage classes in both sexes. We found no differences in beak depth among the three plumage classes of either sex. Masses did not differ among age classes of either sex of eagles with empty crops. The length of the exposed culmen did not differ between adult eagles at GNP and a southern Colorado wintering area. Culmen length, beak depth, and length of hallux did not differ between adult eagles at GNP and museum study skins from Canada, Alaska, and the northern US.

Author Keywords

[No Keywords available]

Index Keywords

morphometry bald eagle Ciconiiformes USA, Montana, Glacier National Park body size Haliaeetus leucocephalus Falconiformes
Link
https://www.scopus.com/inward/record.uri?eid=2-s2.0-0031659115&partnerID=40&md5=f0515f0237a63fcab029a1ba48eb6a4d
ISSN: 08921016
Cited by: 1
Original Language: English