Grey parrots are endangered and their populations are collapsing across Africa — except for one small oceanic island. Why?

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According to a number of recent studies (for example, this one), the world’s wild parrots are on a fast track towards extinction, and it’s all out fault. According to that study, we are not setting aside enough protected spaces to protect parrots, few of these protected spaces are located where wild parrots actually live, and fewer still are large enough for wild parrots to actually comfortably live within.

Now that we have a good idea of what we should do to help all wild parrots, what might we learn if we carefully examine how might these proposed recommendations affect one particularly heavily traded species of parrot? Take Africa’s grey parrots, Psittacus erithacus, for example. On one hand, their situation looks quite desperate because wild populations of the grey parrot (also known in the pet trade as the Congo African grey parrot) are collapsing, thanks to runaway trapping to meet the demands of the multi-million dollar international pet trade (ref), for eating, and for use in traditional ‘medicines’ (ref). In addition to outsized trapping pressures, this parrot’s forest home is being rapidly destroyed.

All of these pressures led to grey parrots being listed as Endangered in 2016 by the International Union for Conservation of Nature (IUCN; ref). Additionally, the grey parrot does not live in any protected areas nor does it live in any parrot conservation hotspots identified by the previously mentioned study (more here). Instead, they occupy a huge range that extends across the forest belt of western and central equatorial Africa.

Despite the serious decline in the numbers of wild grey parrots, a closer look reveals a peculiar conundrum in this parrot’s troubling, albeit all too familiar, story: this parrot’s population decline is not uniform. For example, a collection of recent studies have found wild grey parrots are still ‘reasonably common’ in some parts of Cameroon (ref), whereas the species is in steep decline throughout the Democratic Republic of Congo (DRC; ref) and Côte d’Ivoire (ref), and is (almost?) extinct in Ghana (ref) and Nigeria (ref).

And yet, there is one tiny bright spot where wild grey parrots are still exceptionally common: Príncipe Island (see map). This small volcanic island, located in the Gulf of Guinea, is home to a remarkably high average density of 53 — give or take 6 — grey parrots per square kilometer, which is slightly more than half a square mile (ref). That’s a lot of parrots. How are grey parrots maintaining such remarkable population densities on this tiny oceanic island whilst its continental populations are crashing? Was trapping ever a big threat to grey parrots living on Príncipe Island? What can we learn about parrot conservation from the grey parrots of Príncipe Island?

First, removing grey parrots from the wild was stopped on Príncipe Island ten years before this parrot was listed as endangered.

“In 2006, a ban on all trapping and trade was put in place by the regional government of the island of Príncipe. This stopped the large scale trade that was going on on the island,” conservation biologist Simon Valle said in email. Dr Valle, whose dissertation focused on the grey parrots of Príncipe, is a lecturer in Conservation Science at Bangor University and director for its undergraduate conservation degrees, as well as a Fellow of the Higher Education Academy (FHEA), a UK funding scheme designed to encourage excellence in teaching.

“However, given the low levels of enforcement, it is possible that a few individuals are still being harvested illegally for the local market,” Dr Valle explained in email. “This, though, is a negligible volume if compared to the heavy trade that was going on before, with up to 1,500 chicks exported annually.”

And yet, despite its history of heavy trade in grey parrots, Príncipe has always been home to large numbers of grey parrots. Why?

According to Dr Valle’s study, there are several reasons for this. First, this could be due to differences in how the birds were captured and removed from the wild. Trappers on Príncipe traditionally climbed grey parrot nest trees located in traditional trapping sites and removed individual chicks rather than indiscriminately capturing large flocks of adult parrots congregating at feeding sites or by destroying the entire nest tree — both practices that are typical on the African continent.

Second, even before the local government stepped in to stop trapping, Príncipe itself effectively protected its wild parrots: at least 45% of the island is covered by rugged primary and secondary lowland forests that are, for all practical purposes, inaccessible. Thus, Príncipe’s wild grey parrots have an abundance of healthy large trees that are suitable for nesting, and a nearly all of these trees are situated beyond the grabby hands of poachers where their remoteness insulates them from direct human interference as other forms of disturbance.

Dr Valle’s studies of the grey parrots of Príncipe suggest they are free of many of the constraints that negatively impact populations of wild grey parrots living on the African continent — and by extension, all large parrot species living elsewhere — that include: adequate numbers of appropriately-sized nest cavities in large trees; sufficient densities of large trees, and of course, plentiful numbers of adult parrots themselves. Dr Valle and his collaborators propose that most large wild parrots can be better conserved by meeting these three requirements:

  1. protect nest cavities from poachers, as well as from nest predators and competitors (both native and introduced), to ensure that wild parrots successfully raise enough chicks to take their place as breeding adults in the wild population
  2. adjust current forestry practices to safeguard individual large trees, especially those known to have nest holes, so wild parrots (and other cavity-nesting species) have adequate places to breed
  3. fine-tune international bans on parrot trapping to prioritize interventions against indiscriminate trapping of adult birds away from their nests. For example, adult grey parrots have pale straw-colored eyes whilst juveniles have dark eyes, so recording the eye color of all grey parrots in confiscated shipments can be used to identify and locate indiscriminate trapping and to deal with those situations separately

“Grey Parrots are a charismatic and endangered species of which we still know far too little,” Dr Valle said in email. “However, our research in Príncipe has allowed us to identify three key practical steps for the conservation of this species (and possibly other large parrots too).”

Nevertheless, instead of focusing on everything that we do not know, we must instead focus on what we do know to save wild parrots, and we do know that deforestation, agriculture and poaching are destroying these remarkable birds, and that we must act quickly and decisively if wild parrots are to have a future at all.

Source:

Simon Valle, Nigel J. Collar, Martim Melo and Stuart J. Marsden (2021). What can the abundance of Grey Parrots on Príncipe Island tell us about large parrot conservation? Journal of Tropical Ecology, published online on 8 April 2021 ahead of print | doi:10.1017/S0266467421000031

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