Worrying news on Timneh Parrots from Gola

Posted by Simon Valle & Stuart Marsden

The Timneh Parrot (Psittacus timneh) together with the congeneric Grey Parrot (Psittacus erithacus) has recently been uplisted, to Endangered based on the suspected decline due to habitat loss and trapping for the pet trade (BirdLife International 2018). However, the hard truth is that we have hardly any data on the size and trends of the populations that dwell in the remaining forest patches across its range. As part of a project generously funded by the Parrot Wildlife Foundation, successfully launched inaugurated with a productive workshop at the Gola Rainforest National Park (GRNP), Dr Simon Valle (Bangor University) has spent four weeks surveying in and around GRNP to understand how abundant the species may be. 

Community guide Mohamed Nyallay (left) and porters Mustapha Kanneh (centre) and Keni Desmond on their way to set a base camp in the heart of Gola Rainforest National Park (Photo: S. Valle)

Preliminary results from the surveys have raised some serious concerns for the species in Gola, despite being probably one of the best preserved and managed protected areas in West Africa. Simon and his team often struggled to find any parrots even in the better-preserved forest at the core of the national park. Encounters were rare and far apart and judging from the extremely low encounter rates (0.3 parrots/hour), and, until the analysis is done, we can only assume that Timneh Parrots presumably persist at very low densities in the area as a whole. These figures are alarming if we compare them to those of healthy populations of the congeneric Grey Parrot such as the 30 ± 8 parrots per sq km in Lobéké National Park, Cameroun (Marsden et al. 2015), or the 59 ± 4 parrots  per sq km on the Island of Príncipe, São Tomé & Príncipe (Valle et al. 2017). 

A rare encounter in Gola forest. 
Community Guide Mohamed Mansare` listens to a 
group of Timneh Parrots feeding on a nearby tree.

Most encounters were from the 4-km buffer zone that surrounds the park, where the forest is under continuous threat from inhabitants of the surrounding settlements. The buffer zone holds pockets of reasonably intact forest and hosts some very successful wildlife -friendly cocoa farms managed in partnership with the park authorities. However, in some areas, the buffer zone still bears the clear signs of slash-and-burn farming, selective logging for valuable timber and mining for gold and diamonds. These are the areas where the work of the park authorities is the most difficult and the survival of the remaining forest most fragile.

A team surveys for Timneh Parrots in the 4-km buffer zone around the Gola Rainforest National Park, where large areas are cleared with fire to make space for subsistence farming (Photo: S. Valle)

The data collected in GRNP are an important alarm bell and shows us that a well-protected and carefully managed protected area may not be sufficient to guarantee the recovery of a population to a healthy state, or at least not before many years (Valle et al. 2018). Moreover, these results highlight the importance of performing similar surveys across the range to assess the true conservation status of this species and the need for consistent monitoring of the remaining populations. With this in mind, and following up on the successful training held in GRNP, Simon has delivered a further workshop at the HQ of the National Protected Areas Authority, the government agency which manages all protected areas across the country. Together with Prof Stuart Marsden (Manchester Metropolitan University), Simon will keep on working closely with the NPAA and GRNP to develop a long-term countrywide monitoring scheme for Timneh Parrot, probably the first of its kind in Africa.

References

BirdLife International (2018) Species factsheet: Psittacus timneh. Downloaded from http://www.birdlife.org on 12/05/2018

Marsden, S.J., Loqueh, E., Takuo, J.M., Hart, J.A., Abani, R., Ahon, D.B., Annorbah, N.N.D., Johnson, R., & Valle, S. (2015) Using encounter rates as surrogates for density estimates makes monitoring of the heavily-traded grey parrots achievable across Africa. Oryx 50(4):617-625

Valle, S., Collar, N.J., Harris, E., & Marsden, S.J. (2017) Spatial and seasonal variation in abundance within an insular grey parrot population. African Journal of Ecology 55(4):433-442

Valle, S., Collar, N.J., Harris, E., & Marsden, S.J. (2018) Effects of trapping method and capture rate variability on harvest sustainability in a heavily traded parrot. Biological Conservation 217:428–436

Spotlight on Timneh Parrot

 Posted by Stu, Simon Valle & Amy Marsden

Ever since Simon Valle (now Bangor University) and Nat Annorbah finished their PhDs on Grey Parrots here at MMU, we’ve been itching to start more work on this stunning but troubled taxon. The opportunity arrived in the form of a grant from the newly formed Parrot Wildlife Foundation See their website, a French charity dedicated to parrot welfare and conservation run by Eric Vignot. Stu had spent a very pleasant week in early March with Eric and Irina in Dominican Republic, kicking off Andrea Thomen’s PhD on parrots on that island. Now it was time for something a little tougher.

Above - Simon talking about Timneh's range (Photo: Amy); Below - Stu introducing the science behind the simple encounter rate method (Photo: Simon)

There are two main components to the project – a workshop on Timneh Parrot monitoring and a survey of the parrot across the Gola Rainforest National Park (GRNP). This post describes the former and some thoughts on how Timneh Parrots can be monitored effectively but practically long term across their range. 

Relaxing after practicing fieldwork in Gola

The three-day course took place at GRNP’s research station/guest lodge in Lalehun. The attendees for the workshop represented a number of institutions and organisations working within conservation in Sierra Leone - the Conservation Society of Sierra Leone (CSSL), National Protected Area Authority (NPAA), students and lecturers from Njala University and Eastern Polytechnic, and staff from the Gola Rainforest itself. Mustapha Songe, a tour guide from a community on the border of the National Park, also attended. The aim was to introduce delegates to the ecology and plight of the Timneh, train them in a simple method to monitor parrots that can be done whilst conducting their usual duties, and to discuss ways in which a scheme to monitor Timnehs could possibly be rolled out across Sierra Leone.

Lovely t-shirts and other course materials - thanks to Bearprint Design, TinnedSnail, and Amy Marsden (Photos: Amy)

The method itself centres on a paper we published in Oryx in 2015 – we identified the relationship between grey parrot abundance as estimated using Distance sampling and an ‘on-the-hoof’ encounter rate method (simply the number of parrot groups seen or heard per hour of walking or sitting). The course included plenty of field practice and discussion, especially feedback on how the method could be tailored for the local situation. We were all delighted with both the level of interest and understanding (many participants had little or no biological training), and the enthusiasm for taking forward a countrywide parrot monitoring scheme. Certainly, Timneh Parrot monitoring is on the agenda for Gola, and we hope elsewhere too. Simon will be visiting NPAA in Freetown to discuss possibilities in other protected areas.

The course is only the beginning of our work at Gola. Simon is starting five weeks of fieldwork right across the National Park to estimate abundance and habitat needs of the species. The first step on this exciting journey was to check out reports of a large parrot roost in a community forest close to Gola with Patrick Dauda of the park’s Research & Monitoring Department. We were unable to see parrots at what seems to be a ‘flexible’ roosting area, but hope that Simon and Patrick will be able to return to the site to check on numbers of parrots in the area.

Checking potential roosting tree in one of the community forests on the border of the Nartional Park (Photo: Amy)

We thank: Alusine Kpara, Sheriff Mohamed V, Mustapha Dabenie, Ahmed M Swaray, Amara Aruma, Ibraihim J Kallon (GRNP); Momoh Bai Sesay, Mohamed Sama (CSSL); Osman Deen, Alhassan Khalli Kamara, Abdul Karim Sesay, Wuyatta Kallon (NPAA); Bobson Kobba (Njala University), James Feika (Eastern Polytechnic); and Mustapha Songe (Community tour guide) for interesting discussions during the course. Special thanks go to Benjamin Barca, Brima Sheku Turay, and Patrick Dauda of Gola Rainforest National Park for their amazing support and help with logistics. The project is funded by Parrot Wildlife Foundation.

The trapping of adult grey parrots is ruinous

Posted by Simon Valle & Stu

In a paper just published in Biological Conservation, Simon Valle et al. investigated how different capture methods and other aspects of parrot trade, other than just the actual volume of birds taken from the wild, can affect sustainability of harvest. This is of course important as the ‘currency’ which is generally used by CITES and government agencies to assess the impact of bird trade is usually solely the total number taken from the wild. This paper shows how crucial it is to also consider other facets of the trade – if adults or nestlings are taken, how may fluctuations in annual harvest affect sustainability, and what role may habitat loss or augmentation have in influencing population stability. 

The study was grounded in the building of a population viability model (PVA), a tool often used in conservation biology to see how populations might grow or decline in the future. These models use demographic parameters such as birth rates, mortality of juveniles and adults, longevity, and other life history traits to predict future population trajectories and to identify those aspects of the animals’ lives that are most crucial to safeguard. PVAs are data-hungry, and the lack of real data from wild populations means that, often, parameters have to be taken from other species, from captive birds, or are simply guessed. Our models used some data (e.g. on mortality) from other large parrot species, but Simon’s months of fieldwork on the grey parrot (Psittacus erithacus) population on Príncipe meant that we had a reasonable idea of most of the parameters needed for the running of the models.

Inquisitive subadult grey parrot kept as a pet on the island of Príncipe.This individual would have been originally caught as a chick from the nest, as is common  practice on the island .

Our first important finding was that there was a very fine line between a harvest being sustainable in the long term, and ruinous. A harvest of around 900 individuals per year allowed the population to thrive, but one of 1000 birds almost certainly resulted in extinction of grey parrots on the island. Hence, to keep trade sustainable, we would need to relying on a scientific balancing act, but this is the polar opposite of how grey parrot trade is currently managed – we have little or no confidence that quotas are strictly adhered to, mortality in trade is pitiful and unknown, and often we don’t even know from which country the parrots were even caught.     

Predicted population trajectories in response to no harvest (0% of the initial population); and annual harvests (SD) of 600 (100), i.e. 7.5% of the initial population, 900 (100), and 1200 (100) chicks, i.e. 15% of the initial population. Light grey lines =population trajectories resulting from each simulation; black solid lines = mean trajectory.

Even more disturbing is that the age of birds taken from the wild blows simple numbers of birds taken out of the water in terms of its importance. On Principe, there was a tradition of only taking chicks from nests, and leaving the adults to be. This is likely one of the keys to the species’ survival in large numbers on the island. The figure below shows how disastrous the taking of just a few adults can be. The taking of birds ‘randomly’ from the population, as might be done in places like Cameroon where birds are caught en mass at aggregations, is utterly ruinous.

Difference in predicted 50-year trends when the population is subject to a harvest of 900 ± 100 harvesting chicks only, nest raiding (i.e. one adult is collected with every two chicks) and indiscriminate trapping.

Another interesting finding of the study was that having a ‘steady’ (well-managed and well-policed) harvest of small numbers of birds every year is more likely to be sustainable in the long term than a harvest that is inconsistent across years. The message here is that booms and busts of parrot trapping are not a good thing.  

Predicted population trend and individual simulations in response to harvesting a fixed (left) or variable (right) quota of 900 (top) and of 1000 (bottom) chicks each year

But booms and busts, high and variable mortality and other real uncertainties are exactly the realities that have plagued the trade in grey parrots for the past decades. Effective trade management seems a million miles away from what is happening at present across the species’ range.

On Príncipe grey parrots are commonly raised together with other household pets.

The research on the Grey Parrots in Príncipe was funded by

and supported by

Counting Grey Parrots made easier

Posted by Simon Valle

A new paper to be published in an upcoming issue of Oryx, and now available on their website, looks at encounter rates as a possible simple but effective way of understanding the magnitude of parrot populations without having to employ more time- and resources-consuming methods like distant sampling. The study is the result of a wide collaboration involvng African BirdLife partners surveying grey parrots (Grey Parrot Psittacus erithacus and Timneh Parrot Psittacus timneh) across its vast distribution range in Central and West Africa. The project was funded by CITES through BirdLife International.

Estimating population size and trends in abundance is an essential starting point for the conservation and management of any animal species. Nonetheless, this may often be easier said than done. Species can have huge distributions, be secretive, highly mobile, live in remote areas, or, like parrots, all of the above. Psittaciformes are among the most difficult bird species to survey, and as a result only 25% of species have a reliable population estimate (Marsden and Royle 2015). 

Grey Parrots (Psittacus erithacus), as most Psittaciformes, are canopy dwelling birds often difficult to detect in tropical forest. (Photo: F. Marolla)

Distance sampling is the most used and probably most accurate method for estimating population densities and size of most parrot populations, but the method requires a considerable amount of time, technical skills and economic resources - that often are simply not available. Hence, our goal of finding rapid, simple and economic methods for that can be used as an indication of population sizes for conservation or management purposes, when more precise methods cannot be implemented. 

The ranges of grey Psittacus erithacus and Timneh parrots Psittacus timneh in West and Central Africa.

We carried out independent distance sampling and simple encounter rate surveys for grey parrots at ten sites in five countries (Cameroon, Côte D’Ivoire, DR Congo, Liberia and São Tomé & Príncipe). Whilst the distance sampling surveys strictly followed the rules of the method and accounted only for perched birds (Buckland et al. 2008), in the encounter rate method recorders could spend variable amounts of time walking or standing and records of flying parrots were included in calculations. We found that densities were extremely variable across the range ranging from 0-0.5 individuals per sq km in Côte d’Ivoire and the Central Democratic Republic of the Congo to c. 30 per sq km  in Cameroon and >70 per sq km on the island of Príncipe. Most importantly, we found a significant correlation between the densities estimated with distance sampling and the number of groups encountered per hour.

The relationship between estimates of grey parrot density (± SE) and encounter rates (± SE), with 95 % prediction region (shaded).

This is important link between anecdotal information and actual densities, which can have useful applications for grey parrot monitoring in Africa. Data can be collected by existing monitoring schemes or by anti-poaching patrols without any further investment of time or money, and this can be converted into actual, albeit imprecise, parrot densities. We propose a hierarchical approach to surveying grey parrots, where results from easy and cheap encounter rate surveys may give a first indication as to whether the population is large enough to justify further and more costly distance sampling surveys. Where the latter is recommended for a precise estimate, the former can still be a valid method to monitor effectively the population on a regular basis.

Navigating through tropical forests is an arduous task, which park rangers (here rangers in Gola Forest Transboundary N. P., Liberia) regularly undertake on their patrols. These policing trips could be good opportunities to gather information on grey parrot densities. (Photo: S.Valle)

References

Buckland, ST, Marsden, SJ & Green, RE (2008) Estimating bird abundance: making methods work. Bird Conservation International 18: S91-S108.

Marsden, SJ & Royle, K (2015) Abundance and abundance change in the world's parrots. Ibis 157: 219-229 DOI: 10.1111/ibi.12236.



Acknowledgements

Data from Liberia, Côte d’Ivoire, Cameroon and DRC were collected during the BirdLife International African Grey Parrot Pilot Project funded by the Secretariat of CITES.



The work on the island of Príncipe was funded by Parrots International and HBD kindly provided logistical support. Nat Annorbah's work is funded by Loro Parque Fundacion.

Searching for Grey Parrots in Ghana

Posted by Nathaniel Annorbah & Stuart Marsden

In his study, Nat has to cover a huge study area of
60,000 sq. km across the South West of the country.

The aim of the PhD research is to assess the historic and current distribution, abundance and ecology of the Grey Parrot Psittacus erithacus in Ghana in order to make informed predictions about the sustainability of trade and land-use changes. Relevant data on other frugivorous birds such as hornbills and pigeons are being collected at the same time. Despite its large geographical distribution, the Grey Parrot population is suspected to be suffering a rapid decline because the extent of the annual harvest for international trade, and the high rate of ongoing habitat loss. The species is listed as Vulnerable in the (BirdLife International 2014).

Nat has already conducted surveys for Grey Parrots and other fruit-eating birds between April 2012 and March 2013, and he is now again in Ghana to continue his work on greys. His study area is huge - about 60,000 sq. km, comprising a mosaic of inhabited, cultivated and forested areas in south-western Ghana, the stronghold of grey parrots in the country.

Selective logging in forest reserves takes the largest trees. Logging company staff tell us that the huge trees they harvest often have 'nail ladders' allowing trappers to climb to the parrot nests (Photo: Stuart Marsden).

The study area was partitioned into a grid of 10 x 10 sq. km cells. A random sample of around 50 cells has been selected for surveys. 3-5 days are spent in each cell trying to find evidence for the presence of parrots and other frugivores. These ‘presence’ points will form the basis of a MAXENT analysis of current parrot distribution. Interviews were also conducted in the cells to obtain information about local people’s knowledge of the Grey Parrot, but also to record the socio-economic aspects of the its trade. Particularly important is the information on the historic presence of grey parrots in each cell – these points will form the ‘historic’ presence points for a MAXENT analysis of the past distribution.

Nat interviews local hunter-farmers to better understand the historic range of the Grey Parrot in SW Ghana (Photo: Stuart Marsden)

A great part of fieldwork was to locate roosts of Grey Parrots and to count birds to estimate roost population sizes. G. Dändliker (1992), a CITES consultant, did a survey of parrot roosts in Ghana in the early 1990s – some of these roosts contained hundreds of birds. It is our aim to visit as many of these roosts as possible to see how they have changed over in the subsequent 20 years. Locating roosts needs accurate information provided by trappers or local knowledge in general and a lot of legwork.

Fieldwork conditions: rain can soon transform roads in rivers (Photo: Nat Annorbah).

Fieldwork in Ghana has not been easy. Torrential rain makes ‘road’ conditions atrocious, the 4WD has taken a battering, electricity is scarce, and illnesses such as malaria are a real concern. Even local elections made things difficult in places.




A total of just 101 parrots were encountered during the first year’s survey. Parrots were recorded in just nine of the 31 surveyed sites surveyed  and not one wild grey parrot has so far been recorded in this year’s survey. Grey Parrots were present in only three of twelve roost sites revisited from the 1992 study and all 16 of Dändliker’s roosts visited so far this year have been ‘empty’. We will soon post on what looks like a collapse of the grey parrot population right across the country.

Excessive parrot trade has surely had a big hand in the disappearance of Grey Parrots from Ghana. Despite being incredibly rare in the wild, a few can still be found for sale.

References

BirdLife International. 2014. Species factsheet: Psittacus erithacus. Downloaded from http://www.birdlife.org on 14/02/2014.

Dändliker, G. 1992. The Grey Parrot in Ghana: a population survey, a contribution to the biology of the species, a study of its commercial exploitation and management recommendations. A report on CITES Project S-30.  Unpublished report to CITES.


Nat's PhD is funded by

Eyeing up the age structure of grey parrot populations

Posted by Filippo Marolla and Simon Valle

Filippo Marolla is a biology student from the Sapienza University of Rome. He's working with Simon to test some new methods for estimating densities and age ratio of Grey Parrots in Príncipe.

Among the several objectives we have set for our second fieldwork season in Príncipe, is a test of a non-invasive method for the estimation of the age ratio of the population of Grey Parrots. Determining the proportions of age classes in an animal population is crucial to the understanding of its dynamics and viability. However, this operation can be complicated for species which are hard to age in the field. To date, the only reliable method available to age Grey Parrots is the colour of the iris (Dändliker 1992). 

Downy chick with completely black iris (photo Filippo Marolla)

Captive fully fledged 'grey-eyed' juvenile grey parrot
 on Príncipe (Photo: Filippo Marolla)

When the chicks first open their eyes (about 7-10 days after hatching), the iris is black. During the first year, it slowly turns paler, passing through different shades of grey, and after the first year, it gradually turns bright yellow. Dändliker (1992) reckons that individuals can be aged up to four years of age, but, due to the variability among individuals, the only reliable separation is between first-year birds and others. Using this aging criterion can be quite easy for birds in captivity, but it can be a real nightmare in the wild, as parrots are either very difficult to approach when perched, or they typically fly high and fast in closed canopy forest.









Our objective is to test if photographs especially taken from strategic lookouts can be used as a method of estimating juvenile/non-juvenile ratio in Príncipe. We will take high-definition pictures of as many parrot individuals as we can, whether they are flying or foraging, using a Canon Eos 700D camera with a Zoom Lens EF 100-400mm (f/4.5-5.6). We are currently carrying out a training period in order to identify logistic problems and to improve our skills in taking good photos as quickly as needed. So far results are encouraging and, despite many ups and downs, the number of usable photos (i.e. where the iris colour is clearly recognizable) increases from session to session.

Three parrots flying over São Joaquim are readily identifiable as adults 

(Photo: Filippo Marolla)

Parrots often use preferential flyways to move daily in small flocks from foraging areas to roosting sites. We are focusing our efforts on some open areas located along these flight paths. Oque Daniel and El Miradouro are two elevated lookout points, located respectively in the North-West and in the East side of Príncipe, from where it's easy to spot parrots flying over, often right above your head. Other observation points, e.g. the surroundings of São Joaquim, are located in feeding sites such as flat areas with high densities of oil palms Elaeis guineensis, which give us the chance of taking pictures of perched birds. A typical working session consists in two hours of photo-catching during the time of the day in which parrots are most active, i.e. between 6 and 8 AM or between 4 PM and the sunset at 6 PM. 

View from El Miradouro, one of the strategic lookouts from which photos of flying grey parrots are taken in Príncipe (Photo: Simon Valle)

After some weeks of work, we are now able to provide some figures about how things are going.  In the best session in El Miradouro, we photo-catched 71 flying individual parrots on about 150 sighted, among which 25 have clearly recognizable iris colour, i.e. an aging success rate of 17.5%.

A grey parrot flying over shows the bright yellow eye typical of an adult
 (Photo: Filippo Marolla)

In the best session in São Joaquim, we photo-caught 22 perched individual parrots on about 43 sighted, with 10 individuals with clearly recognizable iris colour, i.e. an ageing success rate of 23%. Considering the practical difficulties associated with the method, we can be satisfied with the ageing rate we reached so far. 

 A perched adult feasting on the pollen from on Erythrina variegata  flowers 

 (Photo: Filippo Marolla) 

The first results are encouraging, suggesting that this kind of ‘photo-trapping’ might be useful for the study of grey parrot populations elsewhere in their vast range. Our next step is to see if we can detect changes in population structure across months using repeat photographic surveys. We expect the juvenile/non juvenile ratio to be at its maximum in March-April – when juveniles have just fledged – and at its minimum in August-September – when juvenile mortality has taken its toll. 

Two adults flying in a oil palm plantation in São Joaquim (Photo: Filippo Marolla)

This distant bird flying away is still readily identifiable as an adult 
(Photo: Stuart Marsden)

References

Dändliker, G. (1992). The Grey Parrot in Ghana: A population survey, a contribution to the biology of the species, a study of its commercial exploitation and management recommendations. A report on CITES Project S-30. Unpublished report to CITES.


The research on the Grey Parrots in Príncipe is funded by 



and supported by