Thursday, 31 October 2013

Welcome to Danny Alder

Welcome to  Danny Alder a new PhD researcher who has just joined our Conservation Research Group.

He will be  looking into the Responses of woodland birds to modified stand structures, with particular attention to ecological patterns and acoustic detections across an ancient woodland matrix. The project is funded by Dorset County CouncilForestry CommissionDorset Environmental Records Centre and the Golden Bottle Trust.

The aim of this PhD is to identify the fine scale features of a large ancient woodland matrix, which determine the distribution and abundance of key woodland bird species. Novel acoustic methods will be tested to measure occupancy rates and detection probabilities of several bird species.

The objectives are:

1. To identify the habitat features which most strongly influence variation in the richness, distribution and abundance of the woodland bird community.

2. To ascertain threshold values for different bird species in patches across the woodland matrix.  This is especially important to understand the influence of novel silvicultural applications being undertaken in the study area.

3. To explore microhabitat characteristics and heterogeneity across the stands using selected woodland birds.

4. To compare manual bird counts with acoustic measures derived from automated recording.

Worked birch coppice, within a ca. 1ha coup showing the dense thicket stage of growth. The produce is used to supply horse racing venues with hurdles.


Sampling using circular plots will be carried out in a minimum number of points representative of the woodland stand management types found within this 800ha ancient semi-natural woodland on the Dorset/Wiltshire border. Bird and habitat measures will be derived to identify the community composition and influence of the structural gradients across the woodland mosaic.

Spotted flycatcher nestlings. This species benefits from 
more open structure woodland and has declined 
significantly in recent decades in the UK.
Measures of relative distribution and abundance of moth taxa will be collected by lepidopterist’s and related to the bird and habitat measures. An ordination analysis e.g. CANOCO will be used to indicate the strength of the relationships between these variables.

Acoustic sampling will be used to provide bird detection measures to model habitat occupancy. Surveys will be undertaken in both winter and summer and abundance estimates calculated using point counts derived from acoustic sampling. Analysis of manual and automated acoustic methods will be carried out using similarity and diversity indices and comparison between detection probabilities will be explored.

Selected specialist birds e.g. marsh tit Poecile palustris and nuthatch Sitta europaea will be studied within a sub-sample of stands. These species maintain year round territories but respond to changes in habitat quality. Automated acoustic detection will be used to identify patch selection within the matrix by these birds through analysis of their contact calls produced when foraging. Multivariate models will be made to predict the likelihood of a species being present based upon the detailed habitat and stand characteristics.

Irregular stand within an ancient woodland showing varied age classes of trees and multiple structured understorey.

A non-intervention stand, formerly coppice with an open lower tier structure.

Danny Alder is funded by‎ 

Wednesday, 30 October 2013

Timneh Parrots in Gola

Posted by Nathaniel Annorbah 

During our recent field trip to Gola Transboundary Park in Liberia, I was fortunate enough to locate a flock of over 70 Timneh Parrots Psittacus timneh feeding in an abdandoned oil palm plantation deep within the forest after a night’s camping at ‘Thomas Camp’. This campsite, an abandoned former diamond mining camp, was reachable within a day’s trekking from our base camp. 

The birds arrived to feed in the morning in groups of 2-16 – they were nervous as they started to gather on the oil palm. As well as counting the birds, I managed to take some decent photos – these appear to be some of the first photos of the species taken in the wild. By 11 am, the parrots were starting to disperse, flying back towards the Sierra Leone border. 

This large group was unusual for the area. Six days of surveying by three teams produced only four other records. Groups of two birds and a singleton were seen flying over our base Camp Alpha, and two records each of two birds recorded along our Distance sampling line transects. One of these pairs were seen eating the fruits known locally as ‘Akusia’. I will be calculating a density estimate for the Gola area, which will be included in my PhD (funded by Loro Parque Fundacion). This estimate is likely to be very low, despite the large group seen at Thomas Camp.

Timneh Parrot eating Oil palm fruit

Nauclea diderrichii, locally known as  'Kusia', a fruit eaten by Timneh Parrot

Nathaniel Annorbah is funded by   

Thursday, 10 October 2013

Liberia Grey Parrot workshop and Gola Forest

Posted by Stuart Marsden

From 21st to 30th September, Nat Annorbah, Simon Valle and I visited Liberia on grey parrot business. Primarily, we were attending and presenting at the CITES/BirdLife International African Grey Parrot monitoring workshop in Monrovia. This workshop was attended by delegates of the five African countries (Cote d’Ivoire, Sierra Leone, Cameroon, DRC, and Liberia itself) participating in the monitoring pilot scheme. I was reporting to CITES and the African CITES authorities on a survey method which has potential right across the huge range of grey parrots. The method is based on the relationship between population density estimates and simple encounter rates – in effect, national park staff or visiting birdwatchers/tourists could report simply the number of parrot groups recorded in a day – and we would be able to convert this to a ball-park density estimate for the area.

Parrot survey training in Gola

Then it was onwards along atrocious roads to the Liberian side of the Gola Transboundary Park. We were joined by Emmanuel Loqueh from the Liberian BirdLife partner SCNL Liberia, and Rowan Martin, a parrot ecologist from UK. We had two aims for the five day visit. First, to assess the status of Timneh parrot Psittacus timneh, the recently split western form of grey parrot. Parrots were rare in the park but we managed to gather data to allow a density estimate and Nat was fortunate to see a flock of around 70 birds feeding on oil palm (as they do) inside the park. Our second aim was to train the park rangers and Site Support Group in parrot, hornbill and turaco monitoring methods. This went well and we thank John Konie and his staff for making us so welcome and for looking after us in the forest.

Nat Annorbah discussing parrot conservation with national park staff

We had generally high encounter rates of birds and primates in the park – much higher than Nat reports from similar Ghanaian forests. Hornbills (including both dwarf hornbills) and Great Blue Turaco were particularly common, while interesting species such as White-breasted Guineafowl, Crimson Seedcracker, and the desirable Gola Malimbe were also seen.