The IUCN now recognizes the savannah Loxodonta africana and forest Loxodonta cyclotis elephants to be separate species. Despite ecological, behavioural and morphological differences, and different habitat ranges, genetic studies confirm that the two species and hybrids coexist in forest–savannah ecotones. However, the hybrid phenotypes have not yet been described. In this survey we examined whether the phenotypes of the two species and of hybrids can be distinguished. In the first step, we used a machine learning algorithm (K-nearest neighbours) to compare 296 reference images of African elephants from five forest areas and six savannah areas where hybrids have not been recorded, confirming that six morphological criteria can be used to distinguish the species with more than 90% confidence. In the second step, we analysed 1,408 videos of elephants from 14 camera traps in Sebitoli, in Kibale National Park, Uganda, part of the main hybridization area. We used a multiple correspondence analysis and a species assignment key, highlighting the presence of three categories of phenotypes. Compared to the savannah and forest phenotypes (36.8 and 12.1%, respectively), the intermediate phenotypes, which could include hybrids, were more frequent (51.1%). Further studies combining morphology and genetics of the same individuals will be necessary to refine this species assignment key to characterize phenotypes confidently. This non-invasive, fast and inexpensive phenotypical-based method could be a valuable tool for conservation programmes.

Megaherbivores play a central role in the evolution and functioning of ecosystems. In tropical forests elephant species are some of the few remaining megaherbivores. Through elephant foraging, nutrients that would be locked in leaves and stems, taking months or years to decay, are quickly liberated for use. In 10 experimental sites in Kibale National Park, Uganda, we set up 10 pairs of plots (4 × 4 m), each pair involved one treatment, elephant dung addition, and one control. After 1 y, we quantified growth (height and leaf number) and survival of young light-demanding (12) and shade-tolerant (19) plant species (439 stems in total). In general, the addition of elephant dung did not increase seedling growth, and it only increased the number of leaves in shade-tolerant plants with a large initial number of leaves. Researchers have speculated that the loss of elephants would shift the composition of African forests to slow-growing tree species. However, this is not supported by our finding that shows some slow-growing shade-tolerant plants grew more new leaves with additional nutrient input from elephant dung, a condition that would occur if elephant numbers increase.

Increasing anthropogenic disturbance in tropical rainforests is a major challenge to biodiversity conservation. The responses of herbivorous insect communities to habitat changes are not well understood. In this study, we investigated the resilience of galling insect communities associated with Neoboutonia macrocalyx (Euphorbiaceae) trees to logging in Kibale National Park, Uganda. Resilience was measured by comparing the species density, abundance and community structure of gallers in nine differently aged successional forests with those in adjacent primary forests. Insect galls were sampled from the canopy of 10 randomly selected trees in each successional stage, five times in a 10-month period. A total of 7219 individuals representing five galler species were recorded. No significant differences were found in the species density and overall density of gallers between the regenerating and primary forests. The mean tree height was positively correlated with the overall density of gallers. The community structure of gallers differed significantly among the successional stages, but exhibited no clear directional recovery trend. In addition, remarkable seasonal variations were observed in galler communities, with peak abundance being found in the wettest months. The results of the preset study indicate that specialist galling insects whose hosts are pioneer trees can recolonize successional sites rapidly and are resilient to the effects of selective and clear-cut logging in case primary or secondary forests with an established population of Neoboutonia host trees (source populations) are close by. Thus, recovering tropical forests can provide important habitats for galling insect biodiversity, highlighting the need to include them in management and conservation priority plans.

Habitat disturbance often results in alterations in community structure of small mammals. Additionally, the parasites harboured by these small mammals may be impacted by environmental changes or indirectly affected by changes in available hosts. To improve our understanding of this interplay, we examined the patterns of parasitism in small mammal communities from a variety of habitats in forested Uganda. Small mammals were collected from areas experiencing variable habitat disturbance, host density and species richness. The analysis focused on 3 most abundant rodent species, Lophuromys aquilus, Praomys jacksoni and Hylomyscus stella, and a diverse group of parasites they harbour. The impact of various habitat and host community factors on parasite prevalence was examined using linear regression and Spearman's rank-order correlation. We further investigated the parasite communities associated with each individual using correspondence analysis. We determined that, parasite prevalence and richness may be occasionally influenced by community and habitat factors, but taxonomy is a driving force in influencing the parasite community harboured by an individual host. Ultimately, applying general principles across a broad range of disturbance levels and diverse host communities needs to be approached with caution in complex communities.

Impoverished communities often turn to illegal extraction of resources from protected areas to alleviate economic pressures or to make monetary gains. Such practices can cause ecological damage and threaten animal populations. These communities also often face a high disease burden and typically do not have access to affordable health care. Here we argue that these two seemingly separate challenges may have a common solution. In particular, providing health care to communities adjacent to protected areas may be an efficient and effective way to reduce the disease burden while also improving local perceptions about protected areas, potentially reducing illegal extraction. We present a case study of a health centre on the edge of Kibale National Park, Uganda. The centre has provided care to c. 7,200 people since 2008 and its outreach programme extends to c. 4,500 schoolchildren each year. Contrasting the provision of health care to other means of improving community perceptions of protected areas suggests that health clinics have potential as a conservation tool in some situations and should be considered in future efforts to manage protected areas.

Traditionally, conservation programmes assume that local peoples’ support for parks depends on receiving material benefits from foreign exchange, tourism, development and employment. However, in the case of forest parks in Africa, where annual visitation can be small, local support may instead result from ecosystem services. Kibale National Park, a forest park in Uganda, demonstrates that people appreciate parks in ways that are seldom cited nor explored. Public perceptions of benefits accrued from Kibale were explored using two different sampling techniques: a community census and a geographic sample. In both surveys, over 50% of respondents perceived benefits provided by Kibale National Park, and over 90% of those who perceived benefits identified ecosystem services, whereas material benefits were cited less frequently. Multimodel selection on a suite of general linear models for the two different sampling methods provided a comparison of factors influencing perceptions of ecosystem services. Perceptions of Park benefits were influenced by geography, household and respondent characteristics, and perception of negative impacts from the Park. Perceived ecosystem benefits played an important role in the way the Park was viewed and valued locally. Parks have considerable impacts on neighbouring communities, and their long-term political and economic sustainability depends on managing these relationships well. Since local people have the most to gain or lose by conserving neighbouring parks, analyses that incorporate the perceptions of local people are essential to management and sustainability of park landscapes.

Spatial and temporal variation of tropical insect communities has rarely been studied, although such variation influences estimates of global species richness. Therefore, we compared spatial and temporal variation of herbivorous insect communities on Neoboutonia macrocalyx trees among seven sites over 1 y in a primary tropical rain forest in Kibale National Park, Uganda. The distance between the study sites varied from 4.8 to 31.2 km and altitudinal differences ranged from 20 to 242 m. Permutational multivariate analysis of variance (PERMANOVA) revealed significant spatial changes in community composition of the herbivorous insects and study sites differed also in insect abundance (6.9–26.2 individuals m−2 of leaf area). This is likely to be caused by differences in vegetation, altitude and microclimate among the study sites. The similarity of insect species composition was negatively correlated with geographic and altitudinal distances among sites and positively correlated with the similarity of tree community composition. Species richness varied significantly between sampling dates, ranging from 33 to 41 species. Also community compositions changed between sampling dates, which likely follows from marked seasonal changes in climate and the phenology of other host plants used by the generalist insect species also living on Neoboutonia macrocalyx. In general our study supports the idea of high variability of herbivorous insect communities in primary rain forests even at a small spatial scale. This should be considered when estimations of insect biodiversity are made.

Illegal extraction from protected areas is often shaped by the surrounding socio-economic landscape. We coupled village-scale socio-economic parameters collected using household surveys with measured levels of illegal resource extraction proximate to study villages to investigate the socio-economic drivers of illegal extraction from Kibale National Park, Uganda. The level of illegal tree harvesting and the number of illegal entry trails into the Park were driven by subsistence demand from villages adjacent to the Park and by for-profit extraction to supply local urban markets, whereas grazing in the Park was linked to high livestock ownership. Capital asset wealth, excluding livestock, was found to mitigate illegal resource extraction from the Park. We also found high human population density to coincide spatially with park-based tourism, research and carbon sequestration employment opportunities. Conservation strategies should be integrated with national policy to meet the needs of local communities and to manage urban demand to reduce illegal extraction from protected areas.

Most research on attitudes to parks in sub-Saharan Africa has been in savannah regions and areas of low population density. Expulsion, exclusion and the imposition of external control are dominant themes, resulting in negative responses to parks, particularly those that represent hard-edged so-called fortress conservation. Our research in the densely populated area around a mid altitude forest park in western Uganda found an alternate narrative in which, despite its hard-edged fortress features, most people view Kibale National Park favourably. Based on a geographically random sample in two agricultural areas neighbouring the Park, our results indicate that most households felt they benefit from the Park and only a small proportion cited negative impacts. Rather than direct economic returns, the benefits most commonly noted by respondents can be characterized as ecosystem services. Most individual respondents and a large majority of the local political leaders said that the Park should continue to exist. Crop raiding by animals from the Park is a problem in some locations but resource restrictions and expulsion were not widely cited by our respondents. The fact that the large majority of residents migrated to the area after the Park was established may be an important explanatory factor for these responses, and this is also likely to be the case for many other mid altitude tropical forest parks, the demographic and land-use histories of which differ from those around many savannah parks.

The relationship between seedling recruitment (under and away from parent trees) and the behaviour of seed dispersers and predators, was explored in a three-year study in Kibale National Park, Uganda. On the basis of 1261 hours of observation, the foraging activity of the diurnal frugivores which fed on fruit from six tree species was quantified. The fate of dispersed and non-dispersed seeds and seedlings was examined experimentally. The findings suggest that a trade-off exists between factors that promote seedling growth in areas with high seedling density and factors that promote dispersal by frugivores. For example, dispersal of Mimusops bagshawei increases both seed and seedling survival; seeds placed away from adult conspecifics had a 8% lower probability of disappearing than seeds placed under adults and seedlings away from adults had a 30% greater probability of surviving than seedlings grown under adults. In contrast, for Uvariopsis congensis, dispersed seeds had a 56% greater probability of disappearing than seeds directly under a parent tree, while the survival of dispersed and non-dispersed seedlings was similar. Non-dispersed seed and seedling disappearance were correlated with the percentage of the fruit crop removed from focal trees, suggesting that the ability to survive under an adult maybe related to other aspects of the tree's life history.

Within the last decade the study of phenology has taken on new importance because of its contribution to climate-change research. However, phenology data sets spanning many years are rare in the tropics, making it difficult to evaluate possible responses of tropical communities to climate change. Here we use two data sets (1970–1983 and 1990–2002) to describe the fruiting patterns of the tropical tree community in Kibale National Park, Uganda. To address variation in spatial patterns, we describe fruiting over 2–3 y among four sites each separated by 12–15 km. Presently, the Kibale region is receiving c. 300 mm more rain than it did at the start of the century, droughts are less frequent, the onset of the rainy season is earlier, and the average maximum monthly temperature is 3.5 °C hotter than it was 25 y ago. The 1990–2002 phenology data illustrated high temporal variability in the proportion of the populations fruiting. Interannual variation in community-wide fruit availability was also high; however, the proportion of trees that fruited has increased over the past 12+y. At the species level a variety of patterns were exhibited; however, a number of the most common species currently rarely fruit, and when they do, typically <4% of the individuals take part in fruiting events. Combining the data set from 1990 to 2002 with that from 1970 to 1983 for specific species again reveals an increase in the proportion of trees fruiting between 1990 and 2002; however, the proportion of the populations fruiting decreased during the earlier period. When one examines particular species over this whole period a variety of patterns are evident. For example, Pouteria altissima exhibited a relatively regular pattern of fruiting during the 1970s; however, it rarely fruited in the 1990s. Contrasting phenological patterns at four sites revealed that at the community level the fruiting patterns of only one of the six pair-wise site combinations were correlated. Relationships between rainfall and fruiting were variable among sites. Contrasting changes in fruiting patterns over the 30 y with differences among the four sites varying in rainfall, suggests that the changes observed in fruiting may be due to climate change. Responses to this climate change are likely complex and will vary among species. However, for some species, current conditions appear unsuitable for fruiting.

This study demonstrates that elephant seed-dispersal is vital for Balanites wilsoniana (Zygophyllaceae), a forest canopy tree with no other effective dispersers. Non-dispersed seeds suffered high mortality (84%) and low germination (3%). Elephants were reliable at visiting fruiting trees (46%), ingesting available seeds (55%) and dispersing the fruit crop (26%). Compared with unpassed seeds, seeds passed through an elephant's gut had improved germination (54.9% vs. 2.9%) and reduced time to germination (82 vs. 132 d). Given predation rates under parent trees, elephant gut passage is expected to improve absolute germination by 66%. When this change in germination is divided by germination of unpassed seeds, elephant gut passage is expect to improve relative germination by as much as 4000%. Although post-dispersal predation occurred in dung containing B. wilsoniana seeds, dispersed seedlings were abundant. Compared with seedlings under parent trees, dispersed seedlings had greater survival and height. Dispersed seedlings survived in a diversity of environments, thrived under high-light conditions, and were negligibly affected by post-dispersal density. Although elephants are not essential for B. wilsoniana germination, their actions greatly increase seedling establishment and move a large proportion of seeds. This high degree of effectiveness, together with very low non-dispersed seed survival, provides strong evidence that B. wilsoniana is dependent on elephants for its long-term persistence.

Kibale National Park (KNP), Uganda, has a number of chimpanzees habituated for tourism. The close genetic relationship between humans and chimpanzees means that there is the potential for disease transmission between the two. The aim of this study was to establish the diseases to which chimpanzees may be exposed by surveying the medical histories of humans in contact with the chimpanzees of KNP. Medical questionnaires were given to tourists visiting KNP and to the population of a village close to the park. The 62 tourist surveys returned indicated a high prevalence of disease symptoms, in particular diarrhoea, as well as ongoing infectious diseases and a lack of current vaccinations. The 50 local surveys returned also indicated a high prevalence of disease symptoms, in particular respiratory disease, along with a low rate of vaccination and a high frequency of visual contact with the chimpanzees both within and outside KNP. This study indicates that humans are a potential source of infection for chimpanzees. The results, which have been communicated to the appropriate authorities, will assist in the devising of proper tourist viewing regulations and provide local health authorities with the information necessary to improve both public health and chimpanzee health. Further recommendations include education of tourists regarding appropriate vaccinations, hand washing prior to the visit, the use of facemasks during the visit, and the provision of latrines. Chimpanzee ecotourism is becoming increasingly popular and protecting the chimpanzees' health will help to ensure that ecotourism is a sustainable activity.

Examination of phenological patterns of tropical trees at different temporal and spatial scales can elucidate biotic and abiotic factors that correlate with fruiting, flowering and/or leaf set patterns. In this study, 3793 trees from 104 species in Kibale National Park, Uganda were monitored. The trees were selected from two sites (Kanyawara and Ngogo) separated by 10 km. Trees were monitored monthly to document community-wide and population-level fruiting and flowering patterns for a maximum of 76 mo. Analysis of two sites over a number of years permitted examination of generalities of patterns found on smaller spatial and temporal scales. Spectral analysis indicated that community-level flowering and fruiting at Kanyawara exhibited regular annual peaks, although the flowering peaks were of shorter duration. At Ngogo, community-level flowering also displayed regular annual peaks, but fruiting had an irregular pattern with no distinct peaks. The abundance of fruiting trees at Kanyawara was negatively related to the minimum temperature in the previous season (3–7 mo prior). Since fruiting tended to peak when the first wet season of the year was ending and the dry season was beginning, this suggests that the minimum temperature in the previous dry season is important in determining how many individuals fruit. Flowering at Kanyawara peaked immediately after the maximum annual period of high irradiance. Within-species synchronization was evident in the flowering for all species examined at Ngogo and for 64% of those at Kanyawara. Fruiting was synchronous within species for 64% of the species at both sites. Despite this general community-level synchronization, the months of peak fruiting and flowering for some species varied markedly among years. Furthermore, for a number of species the timing of fruiting or flowering events differed between Kanyawara and Ngogo. For some species, trends that were suggested from one year of data were not supported when additional years were considered. Although these two sites are close together, share many of the same species, and experience similar climatic regimes, many phenological patterns were site-dependent.

Patterns of buttress formation in tropical trees vary greatly within and among species. In Kibale National Park, Uganda, some form of a buttres was found on 23% of the 78 species (1785 trees) sampled from a variety of distantly related families. Large differences in buttress formation were documented within a single family and even within the same genus. Previous studies have suggested that buttresses are mechanical adaptations to counter asymmetric loads experienced during brief critical phases in a tree’s development and these persist after the need for a mechanical support has disappeared. As a tree grows from the understorey, up to the canopy, or emerges from the canopy, the potential number of occasions that a tree will experience directional stress increases. Many canopy level trees will probably have been in the vicinity of a treefall gap during their development, while emergent trees may experience gap exposure in addition to wind stresses associated with canopy emergence. Therefore, it is predicted that understorey trees should have fewer and less developed buttresses (after correcting for overall tree size) than canopy trees, which should have fewer and less developed buttresses than emergent trees. Detailed measurements of buttresses from 194 trees of eight species support this prediction. There was no evidence that trees thought to have experienced directional stress associated with selective logging almost 30 y ago had increased the number or size of existing buttresses. The pattern of buttressing in Kibale generally supports the idea that buttresses are mechanical adaptations to counter episodic asymmetric loads, and that buttresses persist after the need for a mechanical support has disappeared.

Dispersal of seeds away from the parent plant may facilitate escape from density-dependent seed mortality. However, many post-dispersal events can have a profound influence on the survival of dispersed seeds. By incorporating seeds in the dung that dung beetles process for consumption and oviposition, dung beetles could enhance seed survival if they remove seeds from areas of high predation risk and place them in locations that avoid subsequent predation and that are suitable for germination. The role of dung beetles in seed survival was investigated over 15 mo in Kibale National Park, Uganda. Depths of seeds buried by beetles, levels of predation on buried and unburied seeds, and germination success of seeds buried to different depths were examined. Results suggest that by burying seeds dung beetles increase the probability that seeds will escape predation and germinate. Of seeds placed in dungpiles, 69% remained at the surface, while 25% were buried from 1–3 cm in depth. Larger seeds were buried more shallowly than smaller seeds. Buried seeds were less likely to be removed by predators than seeds at the surface. Germination of seeds buried at 1- and 3-cm depths was significantly higher than seeds buried at 10 cm. For the species tested, many seeds were buried by dung beetles between 1 and 3 cm and at this depth there was a high probability of escaping predators and germinating. This demonstrates the potential ecological importance of dung beetles in facilitating seed survival and provides data to consider the role of dung beetles in the evolution of seed attributes.