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The Eastern Bronze-naped Pigeon Columba delegorguei satisfies the population size criterion of D1 for regionally Endangered (population size estimated to number less than 250 mature individuals). In addition, the species' EoO is less than 500 km2 and there is a continuing decline in the extent and quality of the habitat in which it occurs.
The species has an extremely fragmented distribution throughout Africa, being restricted to remnant forest patches (Dean 2005). The nominate subspecies occurs to eastern Zimbabwe, central Mozambique and eastern South Africa. Within the region, it is restricted to Mistbelt and Coastal Scarp forests in KwaZulu-Natal and, historically, Eastern Cape. Currently, breeding is thought to be restricted to Ngoye Forest Reserve, Dhlinza Forest Nature Reserve, Entumeni Nature Reserve, Karkloof and Nkandla forests (Nuttall 2000). The combined area of these reserves is 89 km2. As is typical of frugivorous pigeons, the species is nomadic in response to food sources and is likely to move between these and other forests (Dean 2005). Records from Lusikisiki and Port St Johns in Eastern Cape, and iSimangaliso Wetland Park and uMlalazi Nature Reserve in KwaZulu-Natal indicate that individuals do leave their core areas, possibly in search of food (Quickelberge 1989, Nuttall 2000). The species has undergone a considerable contraction in range over the past 70 years (Nuttall 2000). It no longer occurs at Pigeon Valley, Durban, the locality at which the type specimen was collected, nor in the Bulwer, Dargle and Richmond districts of KwaZulu-Natal where it was formerly considered common by Clancey (1964).
The global population has not been quantified (BirdLife International 2014). Although it was described as common throughout its range (Gibbs 2001), Baptista et al. (1997) made mention that it is rare and possibly threatened in South Africa. Nuttall (2000) provided no regional estimate, but mentioned that the population estimate of 400-700 mature individuals derived from Johnson et al. (1998) was possibly too high and should be considered a maximum. The diagnostic calls of displaying males during summer may be suggestive of a greater number of birds than is actually present (Nuttall 2000). In addition, the species occurs at low densities within apparently suitable habitat, which is becoming increasingly limited. Based upon this, as well as anecdotal evidence (HN Chittenden pers. comm.), the regional population is estimated to be between 150-200 mature individuals. Confidence in this regional population estimate is low.
The global population is thought to be stable in absence of any evidence indicating declines (BirdLife International 2014). Little is known of trends affecting the regional population, and therefore a similar assumption is made. Confidence in this regional population trend estimate is low.
The primary threat facing the Eastern Bronze-naped Pigeon is loss of habitat, which has led to fragmentation of forests (Nuttall 2000). Destruction of forests since the 1700s for urban development, commercial plantations and agriculture (Geldenhuys and MacDevette 1989) has resulted in severe fragmentation, creating forest ‘islands' which may threaten the viability of small populations of forest taxa, including forest birds such as Eastern Bronze-naped Pigeon. Increased demand for traditional medicines is also threatening forests, due to debarking and consequent death of certain tree species. Cattle grazing within forests, which ultimately changes the species composition of forests, is considered a threat (Nuttall 2000).
No specific conservation measures are underway. Ngoye, Dhlinza, Entumeni, Karkloof and Nkandla forests, the core of the species' range in the region, are all listed as Provincial Nature Reserves under the administration of Ezemvelo KwaZulu-Natal Wildlife. However, inadequate resources are currently available for the reserve's management.
A Population and Habitat Viability Assessment (PHVA) is recommended, as is a Biodiversity Management Plan, culminating in a National Species Recovery Plan. Annual monitoring of populations at key sites is required. Strict enforcement of conservation regulations in nature reserves needs to be maintained and forest management improved, including an immediate reduction in illegal forest utilisation.
* Accurate estimates of population size, ecological requirements, seasonal movements and possible genetic variation are urgently required.