1,721,102 research outputs found
Feeding height stratification among African browsing ruminants
No full textThis study investigated the hypothesis that the use of different feeding levels in the vegetation promotes resource partitioning among browsing ungulate species in African savannas. Focal animal feeding observations, recorded on a real-time basis using a computerized data-capture system, were conducted on giraffe (Giraffa camelopardalis Linnaeus), kudu (Trageluphus strepsiceros Pallas), impala (Aepyceros melampus Lichtenstein) and steenbok (Raphicerus campestris Thunberg) in the central region of the Kruger National Park, South Africa. Although there was clear stratification in mean feeding heights among the four species throughout the seasonal cycle, there was considerable overlap in the feeding-height ranges of kudu, impala and steenbok. Hence, feeding-height stratification probably only separates giraffe from the other species. Giraffe bulls fed at a higher level in the vegetation than cows, often with head and neck extended vertically. It is suggested that bulls benefit in this by gaining access to nutritious new shoots in the upper canopy, but may suffer an increased predation cost due to reduced vigilance when in this posture
Standardizing the data on vehicle-wildlife collisions
Full text linkThere are few more dramatic manifestations of human– wildlife conflict than squealing brakes, a sickening crunch, flying gravel, and then silence except for the weakly spasmodic scrabbling of a semipulverized deer as it lies dying on the side of a highway. The scientific analysis of wildlife–vehicle collisions is an applied science of increasing importance throughout the industrialized world, but it is yet woefully deficient in theoretical underpinnings and standardized methodology. The overarching discipline of road ecology has only recently gained formal recognition through the publication of the first definitive book on this topic by Forman et al. (2003). And until now, there has not been a target journal in which research on the problem of wildlife– vehicle collisions can be highlighted and developed within a focused readership
Home range - body mass relations: a field study on African browsing ruminants
No full textHome range data were collected concurrently from four syntopic browsing ruminant species in a conserved savanna ecosystem. Mean home range areas were: giraffe (Giraffa camelopardalis) 282 km2; kudu (Tragelaphus strepsiceros) 21.9 km2; impala (Aepyceros melampus) 5.82 km2; steenbok (Raphicerus campestris) 0.62 km2. Home range area (A hr) scaled on body mass (M) as: A hr=0.024 M 1.38 (r 2=0.99)
Standardizing the data on wildlife–vehicle collisions
Full text linkThere are few more dramatic manifestations of human– wildlife conflict than squealing brakes, a sickening crunch, flying gravel, and then silence except for the weakly spasmodic scrabbling of a semipulverized deer as it lies dying on the side of a highway. The scientific analysis of wildlife–vehicle collisions is an applied science of increasing importance throughout the industrialized world, but it is yet woefully deficient in theoretical underpinnings and standardized methodology. The overarching discipline of road ecology has only recently gained formal recognition through the publication of the first definitive book on this topic by Forman et al. (2003). And until now, there has not been a target journal in which research on the problem of wildlife– vehicle collisions can be highlighted and developed within a focused readership
Why this journal was created
Full text linkThe publication of this second issue of Human–Wildlife Conflicts is something of a triumph, not only because it reflects the continued support of the journal by contributing authors, but also because it confirms the journal’s ability to survive through lean times. The Jack H. Berryman Institute is dependent on Congressionally directed federal funding passed through USDA/ APHIS/Wildlife Services, but that was disrupted by the power shift that occurred in the U.S. Congress in January. The resolution of Congress to withhold approval of most spending bills until presentation of the fiscal 2008 budget later this year meant that the Berryman Institute’s fiscal 2007 budget did not get passed through to us. That crisis forced our 2 units (BI-West at Utah State University and BI-East at Mississippi State University) to effectively shut down until an interim plan could be made. Thankfully, we have strongly supportive colleagues in Wildlife Services who “passed around the hat” within their own agency and whittled from their own budgets to provide us with the baseline funding we need for the bare essentials, such as the publication of this issue. Our deep appreciation goes to Bill Clay and everyone else in Wildlife Services for their impressive display of support for the Jack H. Berryman Institute
Sex differences in the foraging ecology of large herbivores
No full textAdult males and females of many animal species differ in terms of the taxonomic range of food types they use, and/or the physical and chemical properties of the meals they ingest. Surprisingly, however, recognition and understanding of these differences has advanced slowly. For example, practitioners of wildlife production and conservation typically use total animal numbers for setting stocking rates, estimating area requirements, monitoring plant–animal interactions, etc., with no consideration of sex differences in feeding ecology. Yet the reason why textbooks on wildlife ecology and management (e.g. Caughley & Sinclair, 1994) seldom address sex differences is more the lack of conclusive published information than simple oversight. Hence, my purpose in writing this chapter will be served if it stimulates further research on this ecologically important topic
Large herbivores and savanna heterogeneity
No full textIn taxonomic terms, the large herbivores (\u3e5 kg) of Kruger represent some 30 species drawn from three orders (Artiodactyla, Perissodactyla, Proboscidea) and seven families (Bovidae, Elephantidae, Equidae, Giraffidae, Hippopotamidae, Rhinocerotidae, Suidae). In functional terms there are two guilds: grazers (14 species), which feed mostly on monocots, and browsers (11 species), which feed mostly on dicots. An additional few switch back and forth between guilds (five species) depending on the quantity and quality of plant types available to them for food. A distinctive feature of each guild is that syntopic species tend to vary in body size (Owen-Smith 1985; McNaughton and Georgiadis 1986). For example, in any one part of Kruger during the dry season the browsing guild may include the world\u27s heaviest and tallest extant land animals (elephant [Loxodonta africana] and giraffe [Giraffa camelopardalis], respectively), together with a size-graded variety of others that would include some of the smallest ruminants (steenbok [Raphicerus campestris] and grysbok [R. melanotis]). Such an assemblage typically would represent a body mass range (in kilograms) spanning three orders of magnitude. Although this species richness is impressive in comparison with that of large herbivore assemblages in other biomes and on other continents, it is a typical (and indeed definitive) feature of the African savanna biome (Huntley 1982; Scholes and Walker 1993). Inevitably, questions about why so many large herbi-vore species evolved and how the extant ones coexist have formed a long-standing theme of inquiry in African savanna ecology (Lamprey 1963; Owen-Smith 1985; McNaughton and Georgiadis 1986; Vrba 1992). Here I extend that theme, drawing on research results from Kruger to explore how ungulate guild structure is influenced by savanna heterogeneity at multiple spatial and temporal scales
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