196,079 research outputs found
Habitat preferences of the secretive forest buffalo (Syncerus caffer nanus) in Central Africa
No full textThe forest buffalo Syncerus caffer nanus is one of the three subspecies of African buffalo inhabiting the rainforests of Western and Central Africa. Because of its secretive behaviour and main habitat (dense rainforests), there is little quantitative information on the habitat preferences of this buffalo. We present here the first data on the frequencies of this species along a habitat gradient ranging from clearings and rivers to forests, as well as the characteristics of the buffalo's resting places. We recorded information from a buffalo herd during the period January 2002-January 2004 in the Bai-Hokou area (Dzanga-Ndoki National Park, Central African Republic). Resting places were firstly compared with available habitat (i.e. resting vs. random sites) and, successively, comparisons were made between diurnal versus nocturnal and wet versus dry season resting places. Forest buffalos were found to be highly dependent on clearings, as well as on the more open forest stands, characterized by large trees and open canopy. Such preferences could be due to the tendency of the buffalos to rest all together; open patches are likely to facilitate social interactions between the members of the herd
The reproductive strategy in temporary ponds: a study case with the Italian endemic Apennine yellow-bellied toad (Bombina pachypus)
No full textAmphibians are declining worldwide and many species are threatened for unknown reasons. In fact, information
on ecology of several species are not available due to the lack of studies. The Apennine yellow-bellied toad (Bombina
pachypus) is an Italian endemic species in progressive decline in many areas, often for unclear reasons. A two-year study
of 116 temporary ponds in a grazing area of the Majella National Park (central Italy) from 2001 to 2002 revealed that:
(a) Apennine yellow-bellied toads reproduced in small ponds characterized by high desiccation risk; (b) breeding activity
occurred for a prolonged period (at least from May to the beginning of August), during which females spawned clutches of very few eggs in several, successive events; (c) the reproductive success was very low especially because of high egg mortality; and (d) the main cause of mortality was the desiccation of ponds. Consequently, the characteristics of breeding
areas (i.e., small, ephemeral ponds) are the most important feature influencing the reproduction. The safeguard of temporary
ponds is crucial for the conservation of this amphibian and could preserve also the other species using these pools
Spatial properties of a forest buffalo herd and individual positioning as a response to environmental cues and social behaviour
No full textMany animals aggregate into organized temporary or stable groups under the influence of biotic and abiotic factors, and some studies have shown the influence of habitat features on animal aggregation. This study, conducted from 2002 to 2004 in the Dzanga-Ndoki National Park, Central African Republic, studied a herd of forest buffaloes (Syncerus caffer nanus) to determine whether spatial aggregation patterns varied by season and habitat. Our results show that both habitat structure and season influenced spatial aggregation patterns. In particular, in open habitats such as clearings, the group covered a larger area when resting and was more rounded in shape compared to group properties noted in forest during the wet season. Moreover, forest buffaloes had a more aggregated spatial distribution when resting in clearings than when in the forest, and individual positions within the herd in the clearing habitat varied with age and sex. In the clearings, the adult male (n = 24) was generally, on most occasions, located in the centre of the herd (n = 20), and he was observed at the border only four times. In contrast, females (n = 80) occupied intermediate (n = 57), peripheral (n = 14) and central positions (n = 9) within the group. Juveniles (n = 77) also occurred in intermediate (n = 64) and peripheral positions (n = 13). Based on these results, we concluded that habitat characteristics and social behaviour can have relevant effects on the spatial distribution of animals within a group
Bears in Human-Modified Landscapes: The Case Studies of the Cantabrian, Apennine, and Pindos Mountains
No full textBrown bears Ursus arctos were historically persecuted and almost eradicated from Southern Europe in the 20th century as a result of hunting and direct persecution (Zedrosser et al. 2011; Martínez Cano et al. 2016). The effects of human induced mortality were exacerbated by other threats, such as habitat loss and fragmentation, due to the expansion of human populations (Swenson et al.
2000). As a result, nowadays there are only small fragmented populations of bears in Southern Europe, where brown bears frequently inhabit human modified landscapes. These areas are characterised by the widespread presence of people and infrastructures, which potentially have ecological impacts on bears. The close coexistence of brown bears and humans generates multiple human-driven disturbances (Ordiz et al. 2017) and causes bear mortality (Bischof et al. 2009), affecting the distribution, demography, behaviour and
viability of bear populations (Penteriani et al. 2018a; Zarzo-Arias et al. 2018). Brown bears in the Cantabrian (north-western Spain), Apennine (central Italy) and Pindos (north-western Greece) mountains (Figure 19.1) represent three examples of small and threatened bear populations in human-modified landscapes (Figure 19.2). Most of their range is characterised by high human densities, widespread agricultural activities, livestock raising and urban development, connected by dense networks of transport infrastructures
(Penteriani et al. submitted; Mateo-Sánchez et al. 2016). This has resulted in a reduction of continuous habitat suitable for the species (Martínez Cano et al. 2016). Here, we summarise the past and present histories and fates of these three populations as examples on how the coexistence of bears and people in human-modified landscapes can take different turns depending on human
attitudes
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
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