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1.
Zoology (Jena) ; 142: 125819, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32750648

RESUMEN

Fossorial mammals are supposed to face hypoxic and hypercapnic conditions, but such conditions have been rarely encountered in their natural burrow systems. Gas composition in burrows after heavy rains, deeper burrows and especially nest chambers, where animals usually spend most of the day, could be even more challenging than in shallow burrows. Such situations, however, have been rarely surveyed in the wild. In our study, we determined concentrations of O2, CO2 and CH4 in active burrows and nests of the giant root-rat Tachyoryctes macrocephalus, a large fossorial rodent endemic to the Afroalpine zone of the Bale Mountains in Ethiopia. We were able to determine the precise location of nests by tracking individuals equipped with radio-collars. To the best of our knowledge, this is the first study that analyses air samples taken directly from the nests of actually occupied burrow systems in any free-living fossorial mammal. We found no evidence for environmental hypoxia in the examined burrows and nests (range 19.7-21.6% O2). Concentrations of CO2 in the burrows increased after the burrows were plugged in the evening, but did not reach physiologically problematic levels. The highest CO2 concentrations in burrows were detected in the evening during a wet period (up to 0.44%). In root-rat nest chambers, the highest (but still harmless) CO2 concentrations (up to 1.31%) were detected in the morning (measured in the late dry season only) together with an elevated concentration (up to 13.5ppm) of CH4. Regular surface activity of giant root-rats, combined with the relatively large dimensions of their nest chambers and tunnels, and the absence of heavy soils, may contribute to harmless atmospheres within their burrow systems.


Asunto(s)
Dióxido de Carbono , Comportamiento de Nidificación , Oxígeno , Roedores/fisiología , Animales , Microclima , Suelo
3.
R Soc Open Sci ; 6(9): 190772, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31598305

RESUMEN

African wolves (AWs) are sympatric with endangered Ethiopian wolves (EWs) in parts of their range. Scat analyses have suggested a dietary overlap between AWs and EWs, raising the potential for exploitative competition, and a possible conservation threat to EWs. However, in contrast to that of the well-studied EW, the foraging ecology of AWs remains poorly characterized. Accordingly, we studied the foraging ecology of radio-collared AWs (n = 11 individuals) at two localities with varying levels of anthropogenic disturbance in the Ethiopian Highlands, the Guassa-Menz Community Conservation Area (GMCCA) and Borena-Saynt National Park (BSNP), accumulating 845 h of focal observation across 2952 feeding events. We also monitored rodent abundance and rodent trapping activity by local farmers who experience conflict with AWs. The AW diet consisted largely of rodents (22.0%), insects (24.8%), and goats and sheep (24.3%). Of the total rodents captured by farmers using local traps during peak barley production (July to November) in GMCCA, averaging 24.7 ± 8.5 rodents/hectare/day, 81% (N = 3009) were scavenged by AWs. Further, of all the rodents consumed by AWs, most (74%) were carcasses. These results reveal complex interactions between AWs and local farmers, and highlight the scavenging niche occupied by AWs in anthropogenically altered landscapes in contrast to the active hunting exhibited by EWs in more intact habitats. While AWs cause economic damage to local farmers through livestock predation, they appear to play an important role in scavenging pest rodents among farmlands, a pattern of behaviour which likely mitigates direct and indirect competition with EWs. We suggest two routes to promote the coexistence of AWs and EWs in the Ethiopian highlands: local education efforts highlighting the complex role AWs play in highland ecosystems to reduce their persecution, and enforced protection of intact habitats to preserve habitat preferred by EWs.

4.
BMC Ecol ; 18(1): 40, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-30285707

RESUMEN

BACKGROUND: Understanding the relationship between great apes and their habitat is essential for the development of successful conservation strategies. The chimpanzee Pan troglodytes ellioti is endemic to Nigeria and Cameroon, and occupies an ecologically diverse range of habitats from forests to forest-savannah mosaic in Mbam-Djerem National Park (MDNP) in Cameroon. The habitat variation in chimpanzees is poorly understood in MDNP which provides an excellent opportunity to assess ecological factors that shape the abundance and distribution patterns of P. t. ellioti over a small geographic scale. RESULTS: We counted 249 nests along 132 km of transects in total. Of these, 119 nests along 68 km occurred in dense forest and 130 nests along 64 km in forest-savannah mosaic. Chimpanzee density was 0.88 [95% CI (0.55-1.41)] individuals/km2 in the dense forest and 0.59 [95% CI (0.19-1.76)] in the forest-savannah mosaic. Nest abundance varied with vegetation type and was higher in areas with dense canopy cover, steeper slopes and relatively higher altitudes. CONCLUSIONS: Our estimates of chimpanzee densities were lower than reported in other studied populations in the range of the Nigeria-Cameroon chimpanzee. However, we found that habitat features, slope and altitude likely play a role in shaping patterns of chimpanzee nesting ecology. Further studies need to be focused on nest decay rates and phenology of useful plants in order to model chimpanzee abundance and distribution in Mbam-Djerem National Park.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Pan troglodytes , Animales , Camerún , Parques Recreativos , Densidad de Población
6.
PLoS One ; 11(9): e0162035, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27631976

RESUMEN

Research on the spatial patterns of human-wildlife conflict is fundamental to understanding the mechanisms underlying it and to identifying opportunities for mitigation. In the state of Xishuangbanna, containing China's largest tropical forest, an imbalance between nature conservation and economic development has led to increasing conflicts between humans and Asian elephants (Elephas maximus), as both elephant numbers and conversion of habitable land to rubber plantations have increased over the last several decades. We analyzed government data on the compensation costs of elephant-caused damage in Xishuangbanna between 2008 and 2012 to understand the spatial and temporal patterns of conflict, in terms of their occurrence, frequency and distribution. More than 18,261 incidents were reported, including episodes involving damage to rubber trees (n = 10,999), damage to crops such as paddy, upland rice, corn, bananas and sugarcane (n = 11,020), property loss (n = 689) and attacks on humans (n = 19). The conflict data reconfirmed the presence of elephants in areas which have lacked records since the late 1990s. Zero Altered Negative Binomial models revealed that the risk of damage to crops and plantations increased with proximity to protected areas, increasing distance from roads, and lower settlement density. The patterns were constant across seasons and types of crop damaged. Damage to rubber trees was essentially incidental as elephants searched for crops to eat. A predictive map of risks revealed hotspots of conflict within and around protected areas, the last refuges for elephants in the region, and along habitat corridors connecting them. Additionally, we analyzed how mitigation efforts can best diminish the risk of conflict while minimizing financial costs and adverse biological impacts. Our analytical approach can be adopted, adjusted and expanded to other areas with historical records of human-wildlife conflict.


Asunto(s)
Conservación de los Recursos Naturales , Elefantes , Animales , China , Productos Agrícolas , Bosques , Humanos
7.
Vaccine ; 34(40): 4792-8, 2016 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-27543453

RESUMEN

Diseases are a major cause of population declines in endangered populations of several canid species. Parenteral vaccination efforts to protect Ethiopian wolves (Canis simensis) from rabies have targeted the domestic dog reservoir, or the wolves themselves in response to confirmed outbreaks. Oral vaccination offers a more cost-efficient, safe and proactive approach to protect Ethiopian wolves and other threatened canids from rabies. Field trials of the oral vaccine Rabigen® SAG2Dog were undertaken in the Bale Mountains of southeastern Ethiopia. Four different bait types and three delivery methods were tested in twelve Ethiopian wolf packs, and the oral vaccine (using the preferred bait) was trialled in three packs. Vaccine uptake and immunization rates were measured through direct observations and in live-trapped animals through the assessment of biomarker levels and serological status. Commercial baits were never taken by wolves; goat meat baits had the highest uptake, compared to rodent and intestine baits. Targeted delivery from horseback and nocturnal delivery within a pack's territory performed favourably compared to random bait distribution. Bait uptake by non-target species was lowest during the nocturnal blind distribution. Of 21 wolves trapped after vaccination, 14 were positive for the biomarker iophenoxic acid (i.e. ingested the bait and most likely pierced the sachet with the vaccine). Of these, 86% (n=12/14) had levels considered sufficient to provide protective immunity to wildlife (⩾0.20IU/ml), and 50% (n=7/14) demonstrated antibody titres above the universally recognised threshold (⩾0.5IU/ml) -the baseline average was 0.09IU/ml (n=12 wolves). All but one of the wolves vaccinated in 2014 were alive 14months later. Our trials confirm the potential for SAG2, delivered in a goat meat bait, to effectively protect Ethiopian wolves against rabies, supporting the initiative for a more efficient and proactive approach to manage and eventually eliminate rabies in Ethiopian wolf populations.


Asunto(s)
Vacunas Antirrábicas/administración & dosificación , Rabia/prevención & control , Vacunación/veterinaria , Lobos , Administración Oral , Animales , Animales Salvajes , Especies en Peligro de Extinción , Etiopía , Vacunas Antirrábicas/uso terapéutico , Vacunación/métodos
8.
Environ Manage ; 56(3): 684-94, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25971736

RESUMEN

People who perceive economic benefits and enjoy unrestricted access to natural resources tend to support ecosystem conservation efforts. Our study explores whether this remains true in remnant patches of Afroalpine ecosystem in North Ethiopia, where communal land provides valuable natural resources for the local communities and also sustain small populations of the endangered Ethiopian wolf (Canis simensis). Questionnaires were designed to assess ecological and socio-economic characteristics of the livelihoods of the Amhara people living in Mount Abune Yosef and their attitudes toward Afroalpine and Ethiopian wolf conservation. Of the 120 households interviewed, selected randomly from across eight villages, 80 % benefited from natural resources by grazing their livestock and harvesting firewood and grasses. The majority (90 %) also suffered from livestock predation by Ethiopian wolves and common jackals (Canis aureus) and crop raiding by geladas (Theropithecus gelada), birds, and rodents, yet more than half reported a positive attitudes toward Ethiopian wolves (66 %). People with positive attitudes tended to live close to the communal land, to own more livestock, and to be unaffected by conflict. Many also recognized the need to protect the Afroalpine habitats of Abune Yosef (71 %), and this attitude predominated among the literate, households that owned land, had smaller herds and were further away. We discussed how people's attitudes were modulated by human-wildlife conflicts and by the benefits derived from the access to natural resources in communal land, and the implications for the conservation of Afroalpine ecosystem and the flagship Ethiopian wolf.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Ecosistema , Opinión Pública , Lobos/crecimiento & desarrollo , Animales , Actitud , Conservación de los Recursos Naturales/estadística & datos numéricos , Etiopía , Humanos , Ganado , Poaceae , Dinámica Poblacional , Conducta Predatoria , Encuestas y Cuestionarios
9.
Emerg Infect Dis ; 21(5): 824-32, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25898177

RESUMEN

The Ethiopian wolf (Canis simensis) is the world's rarest canid; ≈500 wolves remain. The largest population is found within the Bale Mountains National Park (BMNP) in southeastern Ethiopia, where conservation efforts have demonstrated the negative effect of rabies virus on wolf populations. We describe previously unreported infections with canine distemper virus (CDV) among these wolves during 2005-2006 and 2010. Death rates ranged from 43% to 68% in affected subpopulations and were higher for subadult than adult wolves (83%-87% vs. 34%-39%). The 2010 CDV outbreak started 20 months after a rabies outbreak, before the population had fully recovered, and led to the eradication of several focal packs in BMNP's Web Valley. The combined effect of rabies and CDV increases the chance of pack extinction, exacerbating the typically slow recovery of wolf populations, and represents a key extinction threat to populations of this highly endangered carnivore.


Asunto(s)
Virus del Moquillo Canino , Moquillo/epidemiología , Especies en Peligro de Extinción , Lobos/virología , Animales , Brotes de Enfermedades , Moquillo/diagnóstico , Virus del Moquillo Canino/clasificación , Virus del Moquillo Canino/genética , Perros , Etiopía/epidemiología , Femenino , Genes Virales , Geografía , Masculino , Filogenia , Densidad de Población , Dinámica Poblacional
10.
Mol Ecol ; 13(8): 2275-86, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15245401

RESUMEN

During the last glacial age, Afro-alpine habitats were widespread across the highlands of Ethiopia. A wolf-like canid ancestor is thought to have colonized this expanding habitat and given rise to a new species that was remarkably well adapted to the high altitude environment: the Ethiopian wolf Canis simensis. Here, we address the timing of genetic divergence and examine population genetic history and structure by investigating the distribution of mitochondrial DNA (mtDNA) sequence variation. The pattern of mtDNA variation and geographical distribution indicate an initial population expansion, probably immediately after divergence from the wolf-like ancestor, around 100,000 years ago. The partition of mtDNA haplotypes that followed was most likely the result of habitat reduction and fragmentation at the onset of deglaciation approximately 15,000 years ago. Phylogenetic and geographical associations suggest that the most likely genetic partitioning corresponds to three mountain areas, Arsi/Bale, Wollo/Shoa and Simien/Mt. Guna. Although there is a degree of clustering of haplotypes from both sides of the Rift Valley, the lack of reciprocal monophyly does not support the taxonomic classification of two subspecies. This study highlights the importance of populations north of the Rift Valley for the maintenance of genetic variability within the species and has consequent implications for conservation.


Asunto(s)
Clima , Ambiente , Genética de Población , Filogenia , Lobos/genética , Análisis de Varianza , Animales , Secuencia de Bases , Conservación de los Recursos Naturales , Cartilla de ADN , ADN Mitocondrial/genética , Etiopía , Variación Genética , Geografía , Haplotipos/genética , Datos de Secuencia Molecular , Dinámica Poblacional , Análisis de Secuencia de ADN , Especificidad de la Especie
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