Group population and density estimates of pileated gibbons, Hylobates pileatus, in four protected areas in the Northern Plains Landscape, Cambodia

Foraging range and habitat use by Cape Vulture Gyps coprotheres from the Msikaba colony, Eastern Cape province, South Africa

Koedoe ◽

10.4102/koedoe.v57i1.1240 ◽

2015 ◽

Vol 57 (1) ◽

Cited By ~ 14

Author(s):

Morgan B. Pfeiffer ◽

Jan A. Venter ◽

Colleen T. Downs

Keyword(s):

South Africa ◽

Protected Areas ◽

Breeding Season ◽

Movement Ecology ◽

Kernel Density ◽

Eastern Cape Province ◽

Eastern Cape ◽

Convex Polygons ◽

Density Estimates ◽

Kernel Density Estimates

Despite the extent of subsistence farmland in Africa, little is known about endangered species that persist within them. The Cape Vulture (Gyps coprotheres) is regionally endangered in southern Africa and at least 20% of the population breeds in the subsistence farmland area previously known as the Transkei in the Eastern Cape province of South Africa. To understand their movement ecology, adult Cape Vultures (n = 9) were captured and fitted with global positioning system/global system for mobile transmitters. Minimum convex polygons (MCPs),and 99% and 50% kernel density estimates (KDEs) were calculated for the breeding and non breeding seasons of the Cape Vulture. Land use maps were constructed for each 99% KDE and vulture locations were overlaid. During the non-breeding season, ranges were slightly larger(mean [± SE] MCP = 16 887 km2 ± 366 km2) than the breeding season (MCP = 14 707 km2 ± 2155 km2). Breeding and non-breeding season MCPs overlapped by a total of 92%. Kernel density estimates showed seasonal variability. During the breeding season, Cape Vultures used subsistence farmland, natural woodland and protected areas more than expected. In the non-breeding season, vultures used natural woodland and subsistence farmland more than expected, and protected areas less than expected. In both seasons, human-altered landscapes were used less, except for subsistence farmland.Conservation implications: These results highlight the importance of subsistence farm land to the survival of the Cape Vulture. Efforts should be made to minimise potential threats to vultures in the core areas outlined, through outreach programmes and mitigation measures.The conservation buffer of 40 km around Cape Vulture breeding colonies should be increased to 50 km.

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Distribution and population density of the Endangered Cauca Guan Penelope perspicax

Bird Conservation International ◽

10.1017/s0959270906000475 ◽

2006 ◽

Vol 16 (4) ◽

pp. 299-307 ◽

Cited By ~ 4

Author(s):

GUSTAVO H. KATTAN ◽

ADRIANA LEÓN ◽

GERMÁN CORREDOR ◽

WILLIAM BELTRÁN ◽

MÓNICA PARADA

Keyword(s):

Population Density ◽

Protected Areas ◽

Mixed Forest ◽

Forest Reserve ◽

Density Estimates ◽

The Andes ◽

The Pacific ◽

Exotic Tree ◽

Fraxinus Chinensis ◽

Two Populations

The original 24,900 km2 distribution of the Cauca Guan Penelope perspicax is currently reduced to less than 750 km2. In addition, forest within this range is fragmented and populations are isolated. We conducted surveys to determine the presence of the Cauca Guan at several locations within its present range, and mapped all known localities with guan records. Cauca Guan populations are confirmed to occur at only four sites, and the guan is absent from several localities with historic records. Some sites where the Cauca Guan is potentially present are highlighted. In particular, the possible existence of populations on the Pacific slope of the Andes requires confirmation, since a large habitat block is available. Population density estimates were obtained in two protected areas. In Yotoco Forest Reserve (559 ha) we estimated 8.6 guans km−2. At Otún-Quimbaya Flora and Fauna Sanctuary (489 ha), guans fed seasonally on leaves of Chinese ash Fraxinus chinensis, an exotic tree planted in a revegetation programme. Seasonal densities in ash plantations were over 100 guans km−2, whereas in mixed forest, mean density was 41.6 birds km−2. Ash has apparently become a key resource for this population. Although these two populations are within protected areas and have relatively high densities, they are small and isolated and require continued monitoring.

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Density of Pied Crows Corvus albus in two of South Africa's protected areas

10.1101/2021.05.19.444802 ◽

2021 ◽

Author(s):

Thomas Frederick Johnson ◽

Campbell Murn

Keyword(s):

South Africa ◽

Decision Making ◽

Protected Areas ◽

Vegetation Index ◽

Evidence Based ◽

Density Estimates ◽

Ecological Information ◽

Normalised Difference Vegetation Index ◽

Northern Cape ◽

Evidence Based Decision Making

In recent decades, the pied crow Corvus albus population has grown in southern Africa, and this may have had impacts on other species. Conservationists and land managers may question the degree of threat posed by pied crows to other species, but a scarcity of ecological information on pied crows limits evidence-based decision-making. Using a distance density function we provide initial pied crow density estimates of 0.24 crows km-2 (0.12-0.5; 95% CI) and 0.18 crows km-2 (0.07-0.45; 95% CI) in two protected areas in the Northern Cape Province of South Africa. We infer that pied crow density is negatively associated with the normalised difference vegetation index (NVDI).

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