|Red List Category & Criteria:
||Butchart, S. & Symes, A.
||Gorresen, M., Klavitter, J., Nelson, J. & Pratt, T.
||Benstead, P., Capper, D., Sharpe, C J, Stuart, T., Taylor, J.
This species is classified as Near Threatened because it has a very small population and a small range, for which there is currently no evidence of a decline. If the population was found to be declining, it would warrant uplisting to a higher threat category.
|Previously published Red List assessments:|
- 2008 – Near Threatened (NT) –
- 2004 – Near Threatened (NT) –
- 2000 – Lower Risk/near threatened (LR/nt) –
- 1994 – Lower Risk/near threatened (LR/nt) –
- 1988 – Threatened (T) –
|Range Description:||Buteo solitarius breeds on Hawai`i in the Hawaiian Islands (USA), with vagrants recorded on Maui, O'ahu and Kaua'i. The population is thought to be fairly stable (J. Nelson in litt. 2007), and estimates range from 1,457 (Klavitter et al. 2003) and 1,600 (1,120 adults) to 2,700 birds (Hall et al 1997, Griffin et al. 1998). The lack of information on historical numbers makes an assessment of this species difficult, and the underlying trend may be of gradual decline as nesting habitat disappears (J. Klavitter in litt. 1999). The rapid occupation of abandoned breeding territories suggests that the species may now be at or near the carrying capacity of remaining habitat (J. Nelson in litt. 2007). |
United States (Hawaiian Is.)
|♦ Continuing decline in area of occupancy (AOO):||Unknown|
|♦ Extreme fluctuations in area of occupancy (AOO):||No||♦ Estimated extent of occurrence (EOO) - km2:||7000|
|♦ Continuing decline in extent of occurrence (EOO):||Unknown||♦ Extreme fluctuations in extent of occurrence (EOO):||No|
|♦ Continuing decline in number of locations:||Unknown|
|♦ Extreme fluctuations in the number of locations:||No|
|♦ Upper elevation limit (metres):||2700|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Using a mean density of 0.004 birds/ha observed in 1993, and an estimate of 400,000 ha of suitable habitat on Hawai`i, an estimate of 1,600 birds, including 1,120 adults (560 pairs), was calculated by Hall et al. (1997). A similar estimate of 1,457 individuals was obtained from surveys in 1998-1999. The breeding population calculated by Hall et al. (1997) is rounded to 1,100 mature individuals.|
Trend Justification: The population is thought to be fairly stable and may be at or near the carrying capacity of remaining habitat (J. Nelson in litt. 2007).
|Current Population Trend:||Stable|
|♦ Number of mature individuals:||1100||♦ Continuing decline of mature individuals:||Unknown|
|♦ Extreme fluctuations:||No||♦ Population severely fragmented:||No|
|♦ Continuing decline in subpopulations:||Unknown|
|♦ Extreme fluctuations in subpopulations:||No||♦ All individuals in one subpopulation:||No|