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The delta of the Nile as it enters Lake Albert is part of a Ramsar site and supports 35 km2 of papyrus swamp through which run channels of the river. For 12 months in 2017-2018, we made monthly bird counts, each of ten minutes, at 20 points along swamp edges. Overall, 143 species were recorded, of which 13 were particularly common in the papyrus, and a similar number along the channels. Of seven papyrus-restricted species observed, three are globally red-listed notably papyrus gonolek and shoebill. Most species are resident, but white-winged terns and several hirundine species were seasonally common. Our baseline counts should be repeated in future years as well as recording potential threats—climate change, oil and gas operations and other human activities. Most, but not all, of the Ramsar site is within Murchison Falls National Park, which is well-protected; if possible, the protection should be extended to the whole site

As more and more species become threatened, the need to assess population sizes accurately in order to facilitate effective management actions increases. There is an extensive literature on counting birds, but no consensus on the most appropriate units in which to record the results. To stimulate discussion on the use of “number of pairs” for estimating bird population size we review some of the main problems and difficulties. Some counts, especially of seabirds, give total numbers, whereas breeding season counts of songbirds often record territories or, less frequently, numbers of nests. The use of different units complicates comparisons, for example between non-breeding and breeding populations. In many populations there are non-breeding individuals (including immatures, helpers or those who have failed to secure a mate or a territory) that may be hard to distinguish from those that are breeding. Some of the last may even be more conspicuous than paired birds. The proportion of such, for most s...

Biodiversity indicators are essential for monitoring the impacts of pressures on the state of nature, determining the effectiveness of policy responses, and tracking progress towards biodiversity targets and sustainable development goals. Indicators based on trends in the abundance of birds are widely used for these purposes in Europe and have been identified as priorities for development elsewhere. To facilitate this we established bird population monitoring schemes in three African countries, based on citizen science approaches used in Europe, aiming to monitor population trends in common and widespread species. We recorded > 500 bird species from c. 450 2-km transects in Botswana, > 750 species from c. 120 transects in Uganda, and > 630 species from c. 90 transects in Kenya. Provisional Wild Bird Indices indicate a strong increase in bird populations in Botswana and a small decrease in Uganda. We also provide comparisons between trends of habitat generalists and specialists, of birds within and outside protected areas, and between Afro-Palearctic migrants and resident birds. Challenges encountered included recruiting, training and retaining volunteer surveyors, and securing long-term funding. However, we show that with technical support and modest investment (c. USD 30,000 per scheme per year), meaningful biodiversity indicators can be generated and used in African countries. Sustained resourcing for the existing schemes, and replication elsewhere, would be a cost-effective way to improve our understanding of biodiversity trends globally, and measure progress towards environmental goals.

Funding: The cost of fieldwork was generously covered by The Peregrine Fund (USA) and the Royal Society for the Protection of Birds (UK). Globally, conversion of natural habitats to farmland poses the greatest extinction risk to birds, its consequences being especially pervasive in the case of large predators and scavengers, whose declines may trigger extensive cascading effects. Human population growth in sub-Saharan Africa is expected to drive a vast expansion in agricultural land by 2050, largely at the expense of pastoral land and savanna. The greatest expanse of suitable land yet to be converted to agriculture lies in East and Central Africa, including South Sudan, DRC and Tanzania. To gauge the effects of land conversion on raptor populations in this region we used road survey data from neighbouring Uganda, from which we determined linear encounter rates (birds seen 100 km−1; n = 33 species), and species richness (from 53 species). Encounter rates were much lower in pastoral land than in protected savanna (median difference: −41%; 23 species), and lower still in agricultural land (−90%; 24 species). These disparities were influenced by diet and body mass. For large eagles and vultures, encounter rates in agricultural land were 97% lower than in protected savanna (median of 12 species), whereas for smaller raptors they were 30% lower (12 species). Large, apex consumers were thus more vulnerable to farmland expansion, and this was reflected in the mean body mass of species encountered in savanna (1740 g), pastoral (995 g) and agricultural land (856 g). Body mass differences remained significant when vultures were excluded. Since threat status is linked to body mass, encounter rates for globally threatened and near-threatened species likewise showed a more pronounced deficit in farmland than those of least concern. Accordingly, pastoral and agricultural transects were less species-rich (10.6 and 6.7 raptor species 100 km−1, respectively) than savanna transects (13.2 species). Our findings suggest that the expansion of agricultural land in sub-Saharan Africa will reduce raptor populations in pastoral land and savanna by c. 50% and 90%, respectively. We propose that conservation efforts focus on identifying the causes of raptor population deficits in farmland, and on safeguarding tracts of unprotected, intact savanna, together with existing protected areas. Postprint

Impacts of urbanization on biodiversity are commonly studied using urbanization gradients which provide a space-for-time substitution in estimating consequences of urban expansion. Rates of urbanization and human population growth are high in tropical countries of the developing world, which also hold most of the world’s biodiversity hot-spots, yet few studies have considered biodiversity trends along urban gradients in these regions. Bird communities across a gradient of nine sites in Uganda, from the city centre of Kampala to outlying rural locations, were studied over a six year period. These sites were ordered along an urbanization gradient using Principle Components Analysis based on habitat variables estimated at each site. Bird species richness showed a decrease from rural to urban sites, a trend especially evident in forest birds. There was no clear pattern in total abundance, total biomass or biomass per individual along the gradient. However, this latter result was heavily influenced by a colony of Marabou Storks at one site. When this species was omitted, there was evidence of a positive trend with urbanization, showing that as species richness decreased, the bird community was increasingly dominated by larger species with increasing urbanization, which were mainly scavengers able to exploit human refuse. These results provide further support for the negative impacts of urbanization on species richness, but also demonstrate trends in abundance and biomass are variable across different regions. In particular, the increasing dominance of larger species in urban areas may be relevant to certain geographic and/or socioeconomic contexts.

SummaryDuring 1998–2011, in an area of western Cyprus spanning about one-quarter of the global breeding range of the endemic Cyprus Warbler Sylvia melanothorax, the species declined at a rate of c.59% decade-1, suggesting that there is an urgent need to review its global conservation status. This decline has coincided with the recent, rapid colonisation of western Cyprus by the Sardinian Warbler S. melanocephala, whose numbers have increased substantially within the study area, as might be expected of a newly colonising breeding species. To identify possible causes of the Cyprus Warbler’s decline we compared its rate of change with measures of land-cover, vegetation density, altitude, rainfall and the presence of Sardinian Warblers at survey sites. The rate of decline in the Cyprus Warbler’s abundance was strongly correlated with land-cover and with the duration of site occupancy by Sardinian Warbler; Cyprus Warbler abundance had declined more steeply on sites colonised by Sardinian Warblers early in the survey period than on sites colonised later. Furthermore, on sites surveyed by BirdLife Cyprus in 2006–2014, Cyprus Warbler abundance had continued to decline significantly (also by c.59% decade-1) in western Cyprus, while Sardinian Warbler abundance had continued to increase. In contrast, Cyprus Warbler abundance showed no significant change in central and eastern Cyprus, where Sardinian Warblers were sparse or absent during the breeding season. These findings are consistent with at least two contrasting scenarios: that changes have occurred in land-cover or climatic conditions in Cyprus, to the detriment of Cyprus Warbler and to the benefit of Sardinian Warbler; or that in western Cyprus at least, the two species may compete for similar resources, despite a lack of evidence of this in an earlier, more detailed study. In either case, we suggest the need for a thorough, nationwide breeding survey of the two species.

Uganda is one of the most species rich countries in Africa because of the presence of several major biomes. However, it is also a country that has lost much of its natural habitat to agriculture. Uganda is a country that has been better surveyed for its biodiversity than many African countries, but despite this, there has not been a comprehensive analysis of the critical sites that contribute to biodiversity conservation at a global, as well as at a national level. We here present such an assessment using mammals, birds, reptiles, amphibians, and plants as surrogate taxa. We identified 36 terrestrial sites that are of sufficient global importance to qualify as Key Biodiversity Areas (KBAs), using the Global Standard for the Identification of KBAs, which complement an additional nine freshwater sites. National red listing of species and ecosystems was used to identify sites of national importance for conservation. We employ a conservation planning approach using Marxan to identify the minimum set of sites needed to conserve all the globally and nationally threatened species and nationally threatened habitats in Uganda. The findings show that most of the remaining natural habitat in Uganda is important for the conservation of globally and nationally threatened species and threatened habitat. Large areas of irreplaceable habitat occur outside protected areas, although more extensive surveys of these areas would likely reduce the area that is irreplaceable.

Long-term studies of urban birds are relatively scarce, especially in Africa. We analysed trends in species richness and bird species occurrence over a 32-year period in Kampala, Uganda, in order to assess changes in the bird community in a period that has shown rapid expansion of the city’s human population. Given that species may respond to urbanisation according to their diet, we also analysed bird community trends of species groups defined according to predominant diet. There was an overall decline in species richness that was largely driven by declines in insectivores and granivores. General declines were evident also when the trends in the most common individual species in these two groups were considered. The occurrence of the commonest predator and scavenger species tended to increase over the period considered. Insectivorous species are likely to be especially affected by increasing urbanisation due to air pollution. Predators and scavengers are likely to have benefitted from the inability of municipal waste management to keep pace with growth in the human population, hence providing more potential food resources. Both insectivores and predators/scavengers are therefore good candidates for the development of urban indicators.

Vultures provide critical ecosystem services, yet populations of many species have collapsed worldwide. We present the first estimates of a 30-year PanAfrican vulture decline, confirming that declines have occurred on a scale broadly comparable with those seen in Asia, where the ecological, economic, and human costs are already documented. Populations of eight species we assessed had declined by an average of 62%; seven had declined at a rate of 80% or more over three generations. Of these, at least six appear to qualify for uplisting to Critically Endangered. Africa’s vultures are facing a range of specific threats, the most significant of which are poisoning and trade in traditional medicines, which together accounted for 90% of reported deaths. We recommend that national governments urgently enact and enforce legislation to strictly regulate the sale and use of pesticides and poisons, to eliminate the illegal trade in vulture body parts, as food or medicine, and to minimize mortality caused by power lines and wind turbines.

The globally Vulnerable Grey Parrot (Psittacus erithacus) has been seen in Kampala, Uganda’s capital city, in increasing numbers in recent years. This apparently new behaviour of a typically forest species is helped by the presence of many large trees, which provide roosting and nesting sites, and fruiting trees where they feed. Grey Parrots in Kampala potentially come from three sources: escapees, releases of captive birds or wild birds moving into a suburban environment. Birds mostly exhibit behaviours typical of wild birds, but as most, if not all, of the Grey Parrots in captivity are wild-caught and would revert to wild-caught behaviours when released, it is difficult to distinguish them from the wild population. However, we believe that at least some of the birds seen in Kampala are wild.

In recent decades, Marabou Storks Leptoptilos crumeniferus have become common in many urban centres, including Kampala, Uganda, where, as of 2016, they number several thousand birds, with more than 1 200 breeding pairs. Elsewhere in Uganda, the majority of colonies are also in towns and villages. Traditionally, a bird of savannas, breeding in those areas is timed so that the growing young are in the nest during the December to February drier period, when food for scavengers is expected to be more abundant. In southern Uganda, most colonies start each season around November, and this was originally the case in Kampala. However, in recent years, nesting has begun several weeks earlier for the majority of pairs, and up to four months earlier for a smaller group. The main diet of Marabous in Kampala is human refuse, which is available all year round, so in principle they could nest at any time. However, they do not do that. In ‘natural’ ecosystems, breeding at the ‘wrong’ time would probably be disadvantageous, resulting in large young in the nest during rainy periods, a time of food scarcity. Thus, within the traditional nesting season, earlier nesters produce more young. It is not yet clear whether the very early nesters in Kampala also produce more young than the main group. Further understanding of this unusual situation will benefit from continued studies in future years.Keywords: changing breeding season, Leptoptilos crumeniferus, Marabou Stork, urbanisation