Scavenging birds of Kampala: 1973–2009

Scavenging birds are very conspicuous in Kampala and a number of counts have been made of their numbers since the 1970s. Between the 1970s and mid- 2000s the breeding population of Marabou Storks Leptoptilos crumeniferus increased from about 100 pairs to nearly a thousand, whilst roost counts of Black Kites Milvus migrans also showed large increases. Numbers of Pied Crows Corvus albus and Hooded Vultures Necrosyrtes monachus, also counted as they came into communal roosts, showed lower rates of increase; from mid to late 2000s however, Hooded Vultures seem to be decreasing. These increases perhaps reflect the four-fold increase in the human population over the same period, considerably adding to the refuse upon which these birds mainly feed. In view of alarming declines of scavengers elsewhere, especially vultures, we plan to continue monitoring these Kampala bird

Is the Hamerkop Scopus umbretta a neocolonist or an opportunist nester?

We report two cases of large aggregations of Hamerkop Scopus umbretta nests in relatively small areas; the first had a maximum of 639 nests in 2004, all within an area of about 8 km2 near to Entebbe, Uganda. However, in recent years there were far fewer nests, with less than a hundred in 2012. The reasons for this decline are unclear. The second site, in Queen Elizabeth National Park, had 56 nests in 2004. There are very few previous records of such gregarious behaviour in this species. Even though a pair may build more than one nest, it implies the presence of a large concentration of birds, which must therefore require rich food sources

Asymmetric response of forest and grassy biomes to climate variability across the African Humid Period : influenced by anthropogenic disturbance?

A comprehensive understanding of the relationship between land cover, climate change and disturbance dynamics is needed to inform scenarios of vegetation change on the African continent. Although significant advances have been made, large uncertainties exist in projections of future biodiversity and ecosystem change for the world's largest tropical landmass. To better illustrate the effects of climate–disturbance–ecosystem interactions on continental‐scale vegetation change, we apply a novel statistical multivariate envelope approach to subfossil pollen data and climate model outputs (TraCE‐21ka). We target paleoenvironmental records across continental Africa, from the African Humid Period (AHP: ca 14 700–5500 yr BP) – an interval of spatially and temporally variable hydroclimatic conditions – until recent times, to improve our understanding of overarching vegetation trends and to compare changes between forest and grassy biomes (savanna and grassland). Our results suggest that although climate variability was the dominant driver of change, forest and grassy biomes responded asymmetrically: 1) the climatic envelope of grassy biomes expanded, or persisted in increasingly diverse climatic conditions, during the second half of the AHP whilst that of forest did not; 2) forest retreat occurred much more slowly during the mid to late Holocene compared to the early AHP forest expansion; and 3) as forest and grassy biomes diverged during the second half of the AHP, their ecological relationship (envelope overlap) fundamentally changed. Based on these asymmetries and associated changes in human land use, we propose and discuss three hypotheses about the influence of anthropogenic disturbance on continental‐scale vegetation change

Collaborative Forest Management in Uganda - Recommendations for CSOs

As part of a multi-country review of community forest rights, Ecological Trends Alliance set out to assess the outcomes of the Collaborative Forest Management model in Uganda; identify factors that influence its success; and discuss strategies that can be undertaken by CSOs to improve the outcomes of CFM. In this policy brief we summarize some of the main outcomes of the review, and the consequent recommendations for CSOs

Impacts and implications of oil palm in Uganda’s Lake Victoria Islands - The case of Kalangala district

This synthesis paper brings together numerous studies on the impacts of oil palm plantations established in Kalangala district since 2002. It highlights the lessons, and presents recommen¬dations for reviewing the Kalangala oil palm model in the light of the evidence presented

Oil palm development in Buvuma - Learning from previous experiences and recommendations for future developments

This synthesis paper informs the planned oil palm expansion in Buvuma. It draws on documented experiences from Uganda and especially Kalangala district, and highlighting the possible threats, pressures and impacts in Buvuma, and offering strategies and recommendations to mitigate these

Using playback of vocalisations to survey the Nahan’s francolin, a threatened African forest galliform

Methods using playback of vocalisations have been widely used to survey elusive birds. Most of these methods suffer from the drawback that movement of birds is often elicited by the sound stimulus used, violating assumptions of distance sampling and generating unknown biases in resulting density estimates. Using playback survey data for a globally threatened forest galliform bird in Uganda, we found evidence of strong movement of birds toward the sound stimulus during playback surveys, and demonstrate that this caused a significant overestimation of bird density. We present a simple regression-based method for identifying and correcting this bias that is statistically robust and practical to implement for those surveying elusive forest birds. Based on our adjusted survey data, we estimate that about 40 000 Nahan’s Francolins remain in Uganda.OSTRICH 2012, 83(1): 1–

Using playback of vocalisations to survey the Nahan's francolin, a threatened African forest galliform

Methods using playback of vocalisations have been widely used to survey elusive birds. Most of these methods suffer from the drawback that movement of birds is often elicited by the sound stimulus used, violating assumptions of distance sampling and generating unknown biases in resulting density estimates. Using playback survey data for a globally threatened forest galliform bird in Uganda, we found evidence of strong movement of birds toward the sound stimulus during playback surveys, and demonstrate that this caused a significant overestimation of bird density. We present a simple regression-based method for identifying and correcting this bias that is statistically robust and practical to implement for those surveying elusive forest birds. Based on our adjusted survey data, we estimate that about 40 000 Nahan’s Francolins remain in Uganda