The Grey Parrot Psittacus erithacus
and its recently separated sister species Timneh Parrot P. Timneh
―both listed as Vulnerable on the IUCN Red List―do not have the usual very colourful and attractive plumage colours as found in many other parrots, with the exception of the bright red tail (dark maroon coloured tail in Timneh). However, they have great popularity, which can be attributed to their remarkable abilities to copy the human voice and indeed to interact meaningfully with their owners. Unfortunately, this popularity has been more or less a “curse” for the species, and places them among the most heavily traded of all parrots. The impact of the excessive trade in the species is further confounded by habitat loss and degradation.
The Grey Parrot has a huge range of nearly three million square kilometres (sq. km) over much of West and Central Africa, inhabiting the Guinean forests of the region. In Ghana, the species’ range covers some 75,000 sq. km.
In close collaboration with our colleague at BirdLife International http://people.ds.cam.ac.uk/cns26/njc/publications.html
, our recent study here at Manchester Metropolitan University, shows that Ghana’s Grey Parrot population has declined drastically (90-99%) over the last two decades, and the future looks very uncertain for the species if the situation is not urgently addressed. We reviewed the species’ historical abundance across Ghana, and undertook targeted searches during 3- to 5-day visits to 42 different 100 sq. km study plots across the country's forest zone. We also surveyed 42 roost areas, including repeated counts at 22 parrot roosts first performed two decades ago. Finally, we assessed around 900 people's perceptions of the population decline and its causes.
We did not find any roosts in current use, and only 18 individual Grey Parrots were recorded in three roost areas that each harboured up to 1,200 birds two decades ago. Encounter rates averaged around 15 times lower than those recorded in the early 1990s. The findings of our study, which was funded by Loro Parque Fundación http://www.loroparque-fundacion.org/en/
, pointed to the excessive capture of Grey Parrots for the pet trade as well as habitat loss and modification―mainly the felling of large trees with cavities where parrots nest―to be the major causes of the catastrophic population decline recorded in Ghana. Over 67,000 Grey Parrots were officially exported from Ghana between 1976 and 1990; this figure does not include numbers for the rampant illegal trade and does not account for the 50% average mortality from capture to market. To compound the problem, Ghana lost about a third of its forest cover between 1990 and 2010, with an associated decline in quality of the remaining habitats. The large-scale commercial trade in the West African country seems to have gradually collapsed in the mid- to late 1990s as it became unprofitable owing to increasing difficulty in finding large numbers of birds.
With the exception of a few places, there is no evidence that, population declines are less severe anywhere else within the West African range of Grey Parrot, or across the entire range of the Timneh Parrot. The current situation means that no legal trade should be allowed from West Africa, and raises major concerns over continued trade in much of mainland Central Africa. The IUCN Red List classification of both Grey Parrot and especially the much smaller-ranged Timneh Parrot clearly requires re-evaluation.
There is an enormous lack of knowledge about various aspects of the ecology of Grey and Timneh parrots in the wild. These knowledge gaps persist regardless of the advances made in behavioural studies (ethology) on these species as well as the increasing evidence of their current and worsening threat status and their causal factors. Scientific research is therefore needed urgently in the range states to inform conservation action as follows: 1. Estimation of population sizes and structure, 2. Monitoring to decipher population trends in areas with baseline data, and 3. Studies on reproductive ecology. Such studies will also provide much needed insight into how trade and habitat loss and/or degradation contribute to population declines over time.
Further reading: Annorbah, N. N. D., Collar, N. J., and Marsden, S. J. (2016). Trade and habitat change virtually eliminate the Grey Parrot Psittacus erithacus from Ghana. Ibis 158: 82–91. http://onlinelibrary.wiley.com/doi/10.1111/ibi.12332/full