VU
Yellow-casqued Hornbill Ceratogymna elata



Justification

Justification of Red List category
This species has been uplisted to Vulnerable because observations regarding threats and the disappearance of the species from many areas strongly imply that it is undergoing a rapid population decline owing to on-going and unsustainable hunting pressure, habitat loss and fragmentation.

Population justification
Recent calculations put the species's area of suitable habitat at 35,808 km2, and mean population density at 0.35 birds/km2. This gives an estimated population size of 12,533 individuals (H. Rainey in litt. 2007), here rounded to 12,500 individuals. This roughly equates to 8,000-9,000 mature individuals.

Trend justification
Observations on the prevalence of high hunting pressure and habitat loss, and the apparent disappearance of the species from some areas, strongly suggest that it is experiencing a rapid population decline.

Distribution and population

Ceratogymna elata is widespread in West Africa from Senegal (very small range [Morel and Morel 1990]), Mali (although its presence is disputed [Dowsett-Lemaire and Dowsett 2005]), Guinea (c.419 individuals), Guinea-Bissau, Sierra Leone (c.624 individuals), Liberia (c.2,385 individuals), Côte d'Ivoire (c.3,871 individuals), Ghana (c.817 individuals; it still occurs in the east, albeit in very small numbers [Dowsett-Lemaire and Dowsett 2009b], which may not represent a viable population [Dowsett-Lemaire and Dowsett 2009a]) and it is likely on its way out in the east (Dowsett-Lemaire and Dowsett 2014), Togo (few records [Cheke and Walsh 1996]), Benin (although its presence is disputed [Dowsett and Dowsett-Lemaire 2011]), Nigeria (c.1,625 individuals) and Cameroon (c.2,791 individuals) (Fry et al. 1988, H. Rainey in litt. 2007). It still appears to be locally common in forested areas of Sierra Leone, south-west Ivory Coast and Liberia (H. Rainey in litt. 2007). Additionally, in parts of Cameroon and south-west Nigeria it may also still be abundant, but there are indications that it is declining in many places (Elgood et al. 1994, P. Hall in litt. 1999, Jam 2006, H. Rainey in litt. 2007, 2011, F. Dowsett-Lemaire in litt. 2012). Much of Liberia has been deforested in recent years, so it is possible that while its population is still stable where forest remains, the overall area of occupancy may have declined with loss or degradation of habitat. Recent observations suggest that the species is in rapid decline in Ghana. It appears to have been extirpated from many areas, including Bia National Park (NP), where there have been no records since 1991 (Dowsett-Lemaire and Dowsett 2011a, F. Dowsett-Lemaire in litt. 2012). It has not been recorded at Atewa Range FR since 2005 at least, with perhaps the last confirmed record in May 2002 (per Dowsett-Lemaire and Dowsett 2011b). During a survey of three forest reserves in Ghana (Draw River, Bio-Tano and Krokosua) in October-November 2003, only one large hornbill was recorded in high quality habitat, at a time when such species should have been present, probably indicative of local declines (H. Rainey in litt. 2011). In Togo, it has probably been extirpated from Assoukoko forest, which is the largest area of forest remaining in the country (F. Dowsett-Lemaire in litt. 2012). Overall, the population is suspected to be in rapid decline.




Ecology

It is a bird of lowland primary forest but also occurs in logged and secondary forest, riverine forest and oil-palm plantations (Fry et al. 1988, Holbech 1992, 1996). It has also been recorded in predominantly agricultural landscapes, for example in areas near Gola Forest, Sierra Leone (J. Lindsell in litt. 2012). The species undergoes local movements in response to fruit availability.

Threats

Hunting is likely to be a major threat throughout its range (H. Rainey in litt. 1999) and, in Ghana, over-hunting is probably causing a serious decline (Holbech 1992, 1996, Dowsett-Lemaire and Dowsett 2014). Logging is probably only a threat to the species in small forests where hunting is rampant (Holbech 1992, 1996), but destruction of forest throughout its range is causing habitat fragmentation, resulting in the increasing isolation of large fragments, which may inhibit movement between seasonal food sources and lead to a reduction in its population (Elgood et al. 1994, H. Rainey in litt. 2011). Deforestation is on-going and affecting protected areas; for example forest at Déré Foret Classée (Guinea) has been mostly cleared (H. Rainey in litt. 2012). Since this is a long lived and mobile species there is also the concern that populations, particularly in degraded areas, may seem healthier than they really are - birds may persist, although breeding may be disrupted causing populations to crash when these adult birds die (H. Rainey in litt. 2007). Hornbills in general are thought to have been extirpated from some of the more isolated forest fragments (H. Rainey in litt. 2011). The species is on the way out in eastern Ghana, and it is likely extinct in Togo (F. Dowsett-Lemaire in litt. 2016). Its disappearance from Bia NP, where there have been no records since 1991 (Dowsett-Lemaire and Dowsett 2011a), is probably related to uncontrolled hunting and the logging of the southern section in the 1990s. The species's fate in south-western Ghana is very unfavourable, with most habitat expected to be lost to timber extraction and agricultural encroachment, and habitat in reserves expected to be lost by the early 2030s (Dowsett-Lemaire and Dowsett 2014). This species may, additionally, be impacted by climate change (Baker and Willis 2014).

Conservation actions

Conservation Actions Underway
It occurs in many protected areas across its range, but is effectively protected and secure in only a fraction of these, having already disappeared from numerous reserves owing to hunting and habitat loss (H. Rainey in litt. 2011, 2012; F. Dowsett-Lemaire and Dowsett 2014). The species is abundant and well protected in Gola Forest (Sierra Leone and Liberia) (J. Lindsell in litt. 2012, F. Dowsett-Lemaire in litt. 2012).

Conservation Actions Proposed
Regularly monitor the species at selected sites across its range to determine trends. Research the extent and nature of the threat caused by hunting. Conduct awareness programmes to discourage hunting. Protect significant areas of forest at key sites, in both strictly protected areas and community-led multiple use areas. Improve the management of existing protected areas to ensure de facto protection.

Identification

60-70 cm. Large hornbill, with blackish upperparts and lower underparts, black crest, brown and white checkered sides of head, black bill with pale yellow casque, and bright blue wattle and skin around eye. Female has much smaller, brownish bill with reduced casque, and brown crest.

Acknowledgements

Text account compilers
Mahood, S., O'Brien, A., Pilgrim, J., Robertson, P., Shutes, S., Starkey, M., Taylor, J., Westrip, J.

Contributors
Rainey, H., Barlow, C., Dowsett-Lemaire, F., Lindsell, J., Dowsett, R.J., Hall, P.


Recommended citation
BirdLife International (2024) Species factsheet: Yellow-casqued Hornbill Ceratogymna elata. Downloaded from https://datazone.birdlife.org/species/factsheet/yellow-casqued-hornbill-ceratogymna-elata on 13/12/2024.
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 13/12/2024.