View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Bangor University Research Portal Low abundance of the Endangered timneh parrot Psittacus timneh in one ANGOR UNIVERSITY of its presumed strongholds Valle, Simon; Collar, Nigel; Barca, Benjamin; Dauda, Patrick; Marsden, Stuart Oryx DOI: 10.1017/S0030605319000802 PRIFYSGOL BANGOR / B Published: 01/01/2020 Peer reviewed version Cyswllt i'r cyhoeddiad / Link to publication Dyfyniad o'r fersiwn a gyhoeddwyd / Citation for published version (APA): Valle, S., Collar, N., Barca, B., Dauda, P., & Marsden, S. (2020). Low abundance of the Endangered timneh parrot Psittacus timneh in one of its presumed strongholds. 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Oct. 2020 Low abundance of the Endangered timneh parrot Psittacus timneh in one of its presumed strongholds S IMON V ALLE,NIGEL J. COLLAR,BENJAMIN B ARCA P ATRICK D AUDA and S TUART J. MARSDEN Abstract Although both the grey parrot Psittacus erithacus most of its range (Clemmons, ; Martin et al., ), and the recently recognized timneh parrot Psittacus timneh but a handful of stronghold areas, such as the Bijagós are categorized as Endangered because of harvest for the pet Archipelago in Guinea-Bissau (Lopes et al., a, b) and trade and loss of habitat, the latter has a much smaller range Sapo National Park in Liberia (Freeman et al., ), may and may be largely restricted to a few stronghold areas. In retain fairly healthy populations of the species (Dändliker, March–April we surveyed for a total of hours in ; Clemmons, ; Lopes et al., b). Recent surveys and around one of these presumed strongholds, the large in Côte d’Ivoire, however, have indicated dramatic declines and well-protected Gola Rainforest National Park, the across the country, including in the most important forest Sierra Leonean portion of the Gola Transboundary Peace protected area, Taï National Park (Marsden et al., ; Park. Timneh parrots were encountered at a rate of . Martin et al., ). groups/h in the National Park and . in the buffer zone, sug- The Gola Rainforest National Park is the Sierra Leonean gesting densities of – individuals per km . These figures are portion of the , km Gola Transboundary Peace Park similar to recent density estimates from the Liberian side of shared with Liberia. Since the s the National Park has the peace park, suggesting that the transboundary population been managed by the national government in partnership amounts to c. , individuals inside the Park and an un- with the UK Royal Society for the Protection of Birds, and known number in the surrounding areas. Densities of the in became West Africa’s first verified REDD+ project timneh parrot may be generally low even in strongholds, its (Barca et al., b). As such, it constitutes one of the largest numbers may be declining steeply, and the global population and best-managed remnants of the Upper Guinean forest in size is probably lower than previously believed. West Africa. Because of the Park’s size and management, and because it lies at the heart of the range of P. timneh,it Keywords Conservation, encounter rate, Gola Rainforest was believed to host a significant proportion of the species’ National Park, grey parrot, Psittacus timneh, Sierra Leone, global population (BirdLife International, b). West Africa, wildlife trade Gola Rainforest National Park (Fig. ) is dominated by lowland moist evergreen high forest, with an annual rainfall he timneh parrot Psittacus timneh, formerly considered of c. , mm, mostly falling in a single wet season from conspecific with the grey parrot Psittacus erithacus,is May to October (Lindsell et al., ). The Park currently T endemic to five countries in the western Upper Guinea consists of two main forest blocks (Gola South, c. km , forests of Africa: from Guinea-Bissau and Guinea through and Gola Central, c. km ) and a smaller sector (Gola Sierra Leone and Liberia to western Côte d’Ivoire (del North, c. km ), surrounded by a -km buffer zone Hoyo & Collar, ). Trapping for the caged bird trade, (c. km ). Formal agreements with most of the local combined with high rates of forest loss, has caused a chiefdoms in the buffer zone support small-scale agricul- major decline of the species across its range (Martin et al., ture, agroforestry and other local livelihood activities ). Although both Psittacus species have recently aimed at reducing intensive exploitation of the forest. been recategorized as Endangered on the IUCN Red List However, illegal gold and diamond prospecting, plus poten- (BirdLife International, b), P. timneh has the smaller tial concessions to oil palm companies, are an ongoing range and population. It has probably disappeared from threat (BirdLife International, a). From March to April , SV spent hours across days surveying for P. timneh in and around Gola SIMON VALLE (Corresponding author, orcid.org/0000-0001-9402-1360) Rainforest National Park, including the two main blocks, School of Natural Sciences, Bangor University, Bangor, Gwynedd, LL57 2UW, with . hours (across days) inside the Park and . UK. E-mail [email protected] hours (across days) in the buffer zone. Walking surveys NIGEL J. COLLAR BirdLife International, Cambridge, UK occupied %( hours) of this time and observations BENJAMIN BARCA and PATRICK DAUDA Royal Society for the Protection of Birds/ from fixed points %( hours). Only one site, Gola Gola Rainforest National Park, Kenema, Sierra Leone South, was surveyed twice from the Sileti guest house, for STUART J. MARSDEN School of Science & the Environment, Manchester Metropolitan University, Manchester, UK minutes each time. As dense vegetation prevented safe access and because of time constraints, surveys were con- Received March . Revision requested May . Accepted June . ducted only along forest trails (% of survey hours) or Oryx, Page 1 of 3 © 2019 Fauna & Flora International doi:10.1017/S0030605319000802 2 S. Valle et al. Fig. 1 - B/W online, B/W in print FIG. 1 Gola Rainforest National Park with its -km buffer zone and the locations of the transects surveyed for the timneh parrot Psittacus timneh. transects cut for a previous study of primates (% of survey TABLE 1 Summary of encounters of the parrot Psittacus timneh hours). Surveys were at all hours of the day from morning to within Gola Rainforest National Park and its buffer zone during dusk (but were suspended during rain or strong winds), and March‒April . all P. timneh heard and seen were counted. Encounter rates Survey Survey No. of No. of (groups/h) were subsequently computed for both the hours days encounters individuals National Park and its buffer zone, and from these numbers Gola Rainforest National Park density was inferred using the calibration in Marsden et al. Gola Central 29.6 5 3 6 (). A number of factors (e.g. detectability, observer skill, Gola South 41.3 7 5 10 seasonal variation in group size, local variability in bird mo- Buffer zone bility) may affect the precision of estimates calculated with Lalehun 15.0 7 1 2 this method, resulting in progressively larger confidence in- Nyayema 5.6 1 1 2 tervals at higher densities. Community Forest Nomo Faama 22.6 5 10 18 During surveys P. timneh was encountered times (on Chiefdom of days; eight times in Gola Rainforest National Park, Total 114.1 25 20 38 times in the buffer zone), with a total of individuals re- corded ( in the National Park, in the buffer zone); the Nomo Faama Chiefdom, in the buffer zone, accounted considered a probable stronghold of the species and has for most encounters and individuals (Table ). Parrots were enjoyed long-term, effective conservation management, only recorded in small groups (mean . ± SD .). Overall en- as manifest by its extensive well-preserved forest and counter rate was . groups/h (. in the National Park, . healthy populations of frugivore species such as the in the buffer zone), which approximates to individual per Vulnerable yellow-casqued hornbill Ceratogymna elata km (%CI–) in the National Park, and per km (% (Valle et al., ) and Endangered Upper Guinea red colo- CI –) in the buffer zone. bus Piliocolobus badius (Barca et al., a). We do not This study, although brief, is the most extensive survey know whether P. timneh has always had a low density in of P. timneh conducted in and around Gola Rainforest the National Park or has suffered recent declines, but the National Park. We found densities much lower than sparse evidence points to the latter. Anecdotal reports of those of reasonably healthy populations of the congeneric large numbers of birds formerly roosting in the Nomo grey parrot (Marsden et al., ), although they were simi- Faama Chiefdom (PD, pers. obs.) and of previous heavy lar to the . individuals per km found in the Liberian trapping suggest that harvest for the pet trade may have portion of the Transboundary Peace Park where, however, played a major role in reducing the area’s population. We aflockof birds was seen on one occasion (Marsden found no indication that parrots are currently trapped et al., , ).
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