Congo Grey ParrotPsittacus erithacusdensities in oil palm plantation, agroforestry mosaic and protected forest in Southwest Cameroon*

Abstract

SummaryThe Congo Grey Parrot Psittacus erithacus has experienced a severe population breakdown in recent decades. The rainforests of the Korup region in Southwest Cameroon may harbour a large population of this species, but density and population estimates from this area remain controversial. Before the 2016 breeding season, we surveyed Grey Parrots along transects (621.1 km survey effort) in three adjacent landscape types: primary forest in Korup National Park (KNP), smallholder agroforestry matrix (AFM), and industrial oil palm plantation (OPP). We also collected information on the trees used for nesting, feeding and roosting. Using Distance analysis, we estimated relatively low densities of stationary flocks, ranging from 0.30 ind./km2 in KNP, over 0.82 ind./km2 in OPP to 2.70 ind./km2 in the AFM. Parrots were observed feeding or roosting in 17 tree species, of which 15 were located in AFM alone. Feeding was most often observed on cultivated Elaeis guineensis and Dacryodes edulis, but never in maize. The detected parrot densities probably reflect declines within the period 2008–2016, suggesting that the species’ recent IUCN uplisting to ‘Endangered’ and transfer to CITES Appendix I was indeed justified. Our results also suggest that traditional smallholder agroforestry may play a role in habitat conservation strategies, since these forms of cultivation may maintain important breeding and feeding opportunities for Congo Grey Parrots.

Confirmation of strong declines of grey parrots in the Korup region, Cameroon, between 2002 and 2016

“…Our current results confirm those from TA B L E 1 Survey effort L, number of observations of grey parrot clusters n, encounter rate n/L and mean cluster size CS with coefficient of variation (CV) from line transect surveys in the Korup region, Cameroon, for 2001-2002. Values represent untruncated data for both periods and also included encounters of overflying flocks Düker et al, 2020;Tamungang et al, 2016), but which were stemming from differing survey methodologies (Tamungang et al, 2016).…”

“…The parrot declines can be concluded from both, overall encounter rates and density estimates for stationary flocks. We can Düker et al, 2020).…”

“…Between 1975 and 2018, more than 1.4 Mio individuals of wild grey parrots (grey parrot Psittacus erithacus and the former subspecies timneh parrot (now Psittacus timneh ) were reported as having been exported from range states (UNEP World Conservation Monitoring Centre, 2020), with actual offtake being much higher due to pre‐export mortality (CITES, 2016; Fotso, 1998a, 1998b; McGowan, 2001) and nondocumented illegal harvest (Martin, Perrin, et al., 2014). Another threat mentioned has been overall habitat loss and removal of important breeding trees (Annorbah et al., 2016; Martin, Perrin, et al., 2014), but there is also evidence that traditional agricultural landscapes and even towns can be suitable for feeding and breeding (Düker et al., 2020). The impact of the occasional use of grey parrots as bushmeat or for ceremonial and medical purposes is less clear (Düker et al., 2020; Fa et al., 2006).…”

“…Another threat mentioned has been overall habitat loss and removal of important breeding trees (Annorbah et al., 2016; Martin, Perrin, et al., 2014), but there is also evidence that traditional agricultural landscapes and even towns can be suitable for feeding and breeding (Düker et al., 2020). The impact of the occasional use of grey parrots as bushmeat or for ceremonial and medical purposes is less clear (Düker et al., 2020; Fa et al., 2006).…”

“…The Korup area in Southwest Cameroon with its largely unfragmented forests and traditional smallholder mosaic landscapes still provide important habitat for grey parrot populations (Düker et al., 2020; Kupsch et al., 2019). Density estimates from south of Korup National Park for 2016 suggest a strong decline in a period of 6–8 years (Düker et al., 2020; Tamungang et al., 2016). However, the methods used to calculate population densities in these surveys differed, thus preventing strong conclusions about population trends in the region.…”