Osprey Pandion haliaetus

  • Order: Accipitriformes
  • Family: Pandionidae
  • Polytypic: 4 subspecies
  • Authors: Alan F. Poole
Sections

Conservation

Conservation Status

U.S. and Canadian populations stable or increasing, following drastic pesticides-induced reductions in breeding numbers along the Northeast coast (Maine to Chesapeake Bay) and the Great Lakes during the 1950s and 1960s.  Most U.S. breeding populations now at or above pre-pesticides numbers.

Status of Ospreys breeding in northwestern Mexico (coastal Baja California, islands in the Gulf of California, and coastal Sonora and Sinaloa) over 3 decades (1977 - 2006) well summarized by Henny et al. 2008:

"Minimum population estimate for the area surveyed in 2006 was 1343 nesting pairs, an 81% increase since 1977, but only a 3% increase since 1992/1993. On the Gulf side of Baja California the population generally remained stable; on the Midriff Islands (Gulf of California) roughly similar numbers from 1992/1993 (308 pairs) to 2006 (289 pairs); on the Sonora mainland the population decreased from 214 pairs in 1993 to 158 pairs in 2006. In contrast, the population in coastal Sinaloa, which had increased by 150% between 1977 and 1993, grew again by 58% between 1993 and 2006, from 180 to 285 pairs. The surveys confirmed previously described patterns of rapid population changes at a local level, coupled with apparent shifts in spatial distribution. The large ground-nesting population that until recently nested on two islands in San Ignacio Lagoon (Pacific Ocean side, Baja California) was no longer present on the islands in 2006, but an equivalent number of pairs were found to the north and south of the lagoon, nesting in small towns and along adjoining overhead electric lines, with no overall change in population size for that general area. Use of artificial nesting structures was 4.3% in 1977 and 6.2% in 1992/1993, but jumped to 26.4% in 2006. Use of poles that support overhead electric lines poses a risk of electrocution to Ospreys and also causes power outages and fires. We recommend modification of these poles to safely accommodate Osprey nests, as has been successfully accomplished in many countries."

Outside of northwestern Mexico, Neotropical Osprey breeding numbers are known much less well. For Cuba, virtually no data exist, although nesting concentrations may occur, especially along the north coast and on Isle of Pines (Juvenal). In the Bahamas, anecdotal observations suggest Ospreys are very rare and local as breeders, with virtually no hard data on numbers, distribution, or breeding success. Sprunt's (1977) surveys in the 1970s found few nesting pairs (40-50, maximum) along coastal Belize, Yucatan, and eastern Mexico, in stark contrast to northwestern Mexico. In short, studies of Caribbean Ospreys are urgently needed, especially given how well this species responds to management (protection, nesting poles).

Effects of human activity on populations

In general, Ospreys are surprisingly tolerant of human disturbance, nesting successfully in urban and suburban habitats in the United States and Canada.  That said, habituation is key; pairs not habituated to human traffic may desert nests if disturbance appears suddenly and for extended periods.

Ospreys historically affected by shooting in North America, although less so than other diurnal raptors. U.S. banding data 1972–1984 (Poole and Agler 1987) showed 30% of 451 birds recovered were shot, with 93% from wintering grounds in Central or South America. In Brazil 1937-2006 (Mestre and Bierregaard 2009), 65 of 90 Ospreys recovered were shot; no significant change in shooting rates during the period.  Young Ospreys (1st migration) appear especially vulnerable to shooting, as well as all Ospreys in and around fish farms.  Curbing the shooting of birds at fish farms in the Neotropics remains a key conservation challenge for the years ahead.  Work by Bechard and Marquez-Reyes (2003) provides a model for collaborative efforts on this issue.

Recommended Citation

Poole, A. F. (2009). Osprey (Pandion haliaetus), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/nb.osprey.01