RESUMO
Most primates experience seasonal fluctuations in the availability of food resources and face the challenge of balancing energy expenditure with energy gain during periods of resource scarcity. This is likely to be particularly challenging in rugged, montane environments, where available energy is relatively low and travel costs are high. Chimpanzees (Pan troglodytes) show extensive behavioral diversity across study sites. Yet, as most research has focused on low- and mid-elevation sites, little is known on how chimpanzees respond to periods of low fruit availability in harsh montane environments. We use focal follow and phenology data to investigate how fruit availability influences daily path length and monthly home range in chimpanzees living in Nyungwe National Park, a montane forest in Rwanda. Nyungwe chimpanzees decreased their daily travel distances during periods of fruit scarcity. However, this decrease in travel effort did not correspond with a decrease in foraging area. Instead, monthly homes ranges shifted location across the study period. Nyungwe chimpanzees occupy a relatively wide altitudinal range and the shifts in monthly home range location may reflect differences in the altitudinal distribution of food resources. Chimpanzee monthly diet was often dominated by one or two species and each of these species were confined to different elevation zones. One important species, Podocarpus latifolius, grew only at high elevations (2,600-2,950 m) and chimpanzees ranged at the altitudinal peak of their range for 2 consecutive months while feeding on this species. Thus, while high elevations are often thought to be harsh environments for primates, they can be an important part of a species' home range when they provide a refugium for densely distributed, important food species.
Assuntos
Comportamento Apetitivo , Frutas , Pan troglodytes/fisiologia , Altitude , Animais , Dieta , Ecossistema , Florestas , Comportamento de Retorno ao Território Vital , Pinales , Ruanda , Estações do AnoRESUMO
Populations of the endangered eastern chimpanzee (Pan troglodytes schweinfurthii) are declining throughout their range. Although Nyungwe National Park (NNP) harbors the largest remaining eastern chimpanzee population in Rwanda, we know little about their space use and dietary patterns. We studied home range, movement, and diet of two communities of chimpanzees in NNP using daily tracking data (6:00 am to 6:00 pm) collected from 2000 to 2015. One community, Mayebe, resided in the forest center, and the other community, Cyamudongo, inhabited a forest fragment located about 10 km from the main forest. Home range estimated with the 95% kernel density estimation (KDE) method was 21 km2 for the Mayebe community and 4 km2 for the Cyamudongo community. Chimpanzee home range sizes were smaller during the dry versus wet season and varied monthly throughout the year. The Mayebe community had an average hourly step length of 75 ± SE 5 m with a daily movement range of 987 ± SE 71 m, while the Cyamudongo community had a shorter hourly step length of 52 ± SE 3 m with a daily movement range of 651 ± SE 71 m. Both chimpanzee communities fed primarily on Ficus spp. Other important dietary items included fruits of Symphonia globulifera, Syzygium guineense, and Chrysophyllum gorungosanum for the Mayebe community and Trilepisium madagascariense for the Cyamudongo community. Food choice varied monthly and seasonally for each chimpanzee community. Our study provides the first estimates of home range size and movement parameters for chimpanzees in Rwanda and documents their food habits and seasonal variations therein. We also identified the 50% core home range for each chimpanzee community and suggest this area as the focus of management actions. These results could help park management reduce threats to chimpanzees and other sympatric species by improving the efficiency of ranger patrols.
Assuntos
Dieta , Preferências Alimentares , Comportamento de Retorno ao Território Vital , Movimento , Pan troglodytes/fisiologia , Animais , Florestas , Parques Recreativos , Ruanda , Estações do AnoRESUMO
Background: For forty years, there has been growing uncertainty about whether Hill's horseshoe bat (Rhinolophushilli) still persists in Nyungwe National Park, Rwanda. Only known from one small area within the National Park, R.hilli is listed as Critically Endangered by the International Union for the Conservation of Nature (IUCN), based on its extremely small geographic range and presumed low number of mature individuals. Here, we present and describe bat species occurrence data contributed to the Global Biodiversity Information Facility (GBIF) that we collected as part of a long-term collaborative project to rediscover this lost species. This data paper describes the survey methods and findings resulting from cave roost surveys, capture surveys, and acoustic sampling of bat echolocation activity in Nyungwe National Park and surrounding areas in south-western Rwanda from 2013-2020 and their conservation relevance. New information: We report the discovery of an extant population of Hill's horseshoe bat (Rhinolophushilli) in Nyungwe National Park, Rwanda, 40 years since the last reported observation of the species in 1981. We also report the first record of Lander's horseshoe bat (Rhinolophuslanderi) in Nyungwe National Park and the first record of the Damara woolly bat (Kerivoulaargentata) in Rwanda. The dataset contributed to GBIF and described in this paper includes 278 occurrence records from 10 bat species of five families detected at 71 locations in or near Nyungwe National Park, Rwanda. We include a description of the morphological descriptions of R.hilli and present the first acoustic echolocation signatures and phylogenetic information for this species.
RESUMO
BACKGROUND: Acute Rheumatic Fever and Rheumatic Heart Disease are the leading cause of acquired heart disease in Low-Income Countries, and a common cause in High-Income Countries. We compared rheumatic carditis, its echocardiographic presentation at diagnosis and its progression in Italy and Rwanda. METHODS: Retrospective study including all consecutive patients diagnosed with rheumatic carditis in an Italian (IT) and two Rwandan Hospitals (RW). Echocardiography was performed at diagnosis and three follow-up visits. Baseline characteristics, history of primary and secondary prophylaxis and cardiovascular complications data were collected. RESULTS: Seventy-nine and 135 patients were enrolled in IT and RW, respectively. Mitral regurgitation was the most common lesion (IT: 70%, RW: 96%) in both cohorts; mixed valve lesions and severe lesions were more prevalent in RW. Age at diagnosis (IT: 8.4 ± 2.9 yrs.; RW: 11.1 ± 2.7 yrs.; P < 0.001), adherence to secondary prophylaxis (IT: 99%; RW: 48%; P < 0.001) and history of primary prophylaxis (IT: 65%; RW: 6%; P < 0.001) were different. During the follow-up, native valve lesions completely resolved in 38% of IT and in 2% of RW patients (P < 0.001). By contrast, cardiac surgery was performed in 31% of RW and 5% of IT patients (P < 0.001). Cardiovascular complications and death were only observed in RW. CONCLUSIONS: The more severe cardiac involvement, the higher rate of valve surgery, CV complications and deaths in RW, could be due to delayed diagnosis and treatment, scarce adherence to secondary prophylaxis and differences in social determinants of health.