Data Zone
Justification of Red List category
There is contradictory evidence as to whether this species is in decline (there is evidence to suggest that its range may have decreased) or increasing (it is suggested that the spread of plantations and the afforestation of grasslands increase available habitat). The global population size has been estimated to be small, but there is uncertainty over the appropriate population size range. Thus the species has been assessed as Near Threatened, but targeted surveys to generate better population size and trend estimates are highly encouraged.
Population justification
The population is estimated to number 1,000-10,000 individuals, roughly equating to 670-6,700 mature individuals. However, a more precise estimate of the population size is urgently required.
Trend justification
There is uncertainty over the population trend. Using data from the first and second South African Bird Atlas Project (SABAP; SABAP1 1987-1992; SABAP2 2007-2014), Cooper et al. (2017) found that there was an 8% contraction in range. Lee et al. (2017) suggest a range decline of 14% with a core range decline of 3% between the SABAP recording periods. Additionally, data from Global Forest Watch suggest that over the past 21 years (three generations), there has been negligible forest loss in the species' range (Global Forest Watch 2021).
However, the spread of plantations within its range is potentially beneficial for the species, with the afforestation of grasslands increasing the potential habitat (see e.g., Allan et al. 1997; Cooper 2015). Such spread of plantations led Ferguson-Lees and Christie (2001) to suggest that the species may in fact be increasing. There are reports that forest buzzards use Eucaplyptus species as nesting sites (Hirsch et al. 2020).
Given the uncertainty over the trend it is tentatively assessed as stable, but further work is urgently required to assess whether the species may in fact be in decline.
Buteo trizonatus is endemic to South Africa, breeding only in the Western Cape and Eastern Cape Provinces (del Hoyo et al. 2020). Records from Mpumalanga, Limpopo and KwaZulu-Natal all appear to be of non-breeders (Taylor et al. 2015).
This species inhabits native temperate forests from sea level up to 1,000 m, and rarely to 1,500 m (Ferguson-Lees and Christie 2001). It can also be found in plantations, though usually near to areas of native forest (Ferguson-Lees and Christie 2001). The breeding season is September to January, with breeding confined to the Western Cape and Eastern Cape Provinces (Ferguson-Lees and Christie 2001; del Hoyo et al. 2020).
Deforestation has lead to estimated range contraction; Cooper et al. (2017) estimates an 8% contraction, and Lee et al. (2017) a contraction of 14%, with a core range decline of 3% between Southern African Bird Atlas Project recording periods. The expansion of plantations may be beneficial, but the logging of areas will likely affect the species, with nests potentially being lost (Ferguson-Lees and Christie 2001). However, there is evidence that the species is nesting in eucalyptus plantations (Hirsch et al. 2020).
Farm reservoirs may prove to be a threat to this species as large raptors are known to drown in them (Anderson et al. 1999).
Conservation Actions Underway
CITES Appendix II. CMS Appendix II. Raptor MOU Category 3. Found in at least eighteen Important Bird and Biodiversity Areas (IBAs) in South Africa, of which fourteen have some degree of legal protection (Taylor and Peacock 2018). The species is also included in the South African Bird Atlas Project.
Conservation Actions Needed
Conduct thorough re-examination of the conservation outlook of the species (Taylor et al. 2015), including surveys to better estimate population size and trends. Assess the taxonomic status of the all-dark ‘mystery buzzards’ in the Western Cape (Taylor et al. 2015).
Text account compilers
Murray-Watson, R.
Contributors
Butchart, S.H.M., Ekstrom, J., Harding, M., Symes, A., Taylor, J. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Forest Buzzard Buteo trizonatus. Downloaded from
https://datazone.birdlife.org/species/factsheet/forest-buzzard-buteo-trizonatus on 23/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 23/11/2024.