The southern Bald Eagle (Haliaeetus leucocephalus leucocephalus) is the subspecies of the southern United States and north-west Mexico.[1] It is the nominate subspecies, and it is smaller than the northern form.[2][3]
Names and classification
This is the nominate subspecies, the one that carries the same name as the species. Linnaeus named the species in 1766 as Falco leucocephalus.[2][4] IOC, ITIS and GBIF agree on the two names.[1][4][2]
Range
The IOC list gives its range as the southern United States and north-west Mexico.[1] Eagles in the south are smaller than those in the north.[3] Where this form meets the northern one is not defined in any source used here. In Mexico, nesting shrank to a remnant at Magdalena Bay in Baja California, where no more than three pairs were found a year in 1983–93.[5]
Classification evidence
Not everyone agrees. A study of enzyme genes found a smooth change from north to south, with no break that matched the northern and southern subspecies.[6] Some authorities therefore treat the Bald Eagle as having no subspecies.[6]
Sources
- IOC World Bird List, version 15.2
- GBIF backbone, Haliaeetus leucocephalus
- U.S. Fish and Wildlife Service, Bald Eagle species page
- ITIS, Haliaeetus leucocephalus (TSN 175420)
- Henny et al. 1993, Journal of Raptor Research 27 (Baja California)
- Morizot et al. 1985, Biochemical Genetics 23: 337–345 (genetic variation)