scholarly journals Toward reliable population density estimates of partially marked populations using spatially explicit mark-resight methods

2019 ◽  
Vol 9 (4) ◽  
pp. 2131-2141 ◽  
Author(s):  
Andrew Carter ◽  
Joanne M. Potts ◽  
David A. Roshier
Keyword(s):  
Population Density ◽  
Spatially Explicit ◽  
Density Estimates

Density and activity patterns of ocelot populations in Yasuní National Park, Ecuador

Mammalia ◽  
2016 ◽  
Vol 80 (4) ◽  
Author(s):  
Julia Salvador ◽  
Santiago Espinosa
Keyword(s):  
Population Density ◽  
Habitat Loss ◽  
National Park ◽  
Conservation Status ◽  
Activity Patterns ◽  
Camera Trap ◽  
Oil Extraction ◽  
Density Estimates ◽  
Yasuni National Park ◽  
Ecuadorian Amazon

AbstractOcelots were historically hunted for their skins but habitat loss is now their most serious threat, causing rapid declines in populations throughout their range. Ocelot abundance has been estimated for various locations across the Neotropics, but we still lack this information from some countries, including Ecuador. Knowing whether ocelot abundance is increasing or decreasing is important to assess the conservation status of this species and the conditions of its habitats in the Ecuadorian Amazon and in the region. To determine whether ocelot abundance and its behavior are affected by human-related activities, camera-trap surveys were carried out in two localities of Yasuní National Park (YNP), one that has experienced hunting, oil extraction, and roads (Maxus Road) and one that is largely unaffected by these activities (Lorocachi). During the survey, 35 and 36 individual ocelots were photographed in Maxus Road and Lorocachi, respectively. Population density estimates were similar for both localities, ranging from 0.31 (SE±6) to 0.85 (SE±17) ocelots/km

The influence of various factors on some methods of estimating fibre and follicle population density in the skin of Merino sheep. I. Methods of delineating area of natural skin

1958 ◽  
Vol 9 (2) ◽  
pp. 237 ◽  
Author(s):  
HB Carter ◽  
HN Turner ◽  
MH Hardy
Keyword(s):  
Population Density ◽  
Body Region ◽  
Skin Area ◽  
Sampling Errors ◽  
Density Estimates ◽  
Merino Sheep ◽  
Coefficients Of Variation ◽  
Biopsy Punch ◽  
The Mean ◽  
Influence Measurement

Many factors may influence measurement of skin area for estimation of fibre or follicle population density. This paper analyses the influence of method of delineation (hairpin calliper, Hardy clipper, or Carter biopsy punch), type of sheep (wrinkled or plain), body region, and sheep individuality on the mean density estimated and on the error of estimation. With either a biopsy punch or a 1 in.2 hairpin calliper in the midside region, sampling errors of the order of 8–11 per cent. were found for density estimates in a series of field observations on Merino and Corriedale ewes, with between-sheep coefficients of variation ranging from 13 to 18 per cent.

Population, density estimates, and conservation of river dolphins (Inia and Sotalia) in the Amazon and Orinoco river basins

2011 ◽  
Vol 28 (1) ◽  
pp. 124-153 ◽  
Author(s):  
Catalina Gomez-Salazar ◽  
Fernando Trujillo ◽  
Marcela Portocarrero-Aya ◽  
Hal Whitehead
Keyword(s):  
Population Density ◽  
River Basins ◽  
Density Estimates ◽  
Orinoco River

The allometry of density within the space used by populations of mammalian Carnivora

2001 ◽  
Vol 79 (9) ◽  
pp. 1634-1640 ◽  
Author(s):  
K Shawn Smallwood
Keyword(s):  
Population Density ◽  
Body Mass ◽  
Mass Density ◽  
Density Estimates ◽  
Carnivore Species ◽  
Female Brain ◽  
Develop Theory ◽  
Allometric Analysis ◽  
Species Specific ◽  
The Relationship

The relationship between body mass and population density has been used to develop theory of how energy is used in ecosystems. The usual allometric density slope, –0.75, was reduced to near zero among species of mammalian Carnivora after Smallwood and Schonewald and Blackburn and Gaston adjusted density estimates by the sizes of the corresponding study areas. In this paper, I restricted the allometric analysis to density estimates made at or near the threshold area, which is the species-specific minimum area likely to support a population. I excluded densities estimated from subpopulations and "megapopulations", thereby removing biases of study design that had previously confused the allometry of population density. Density at threshold area declined with increasing body mass. The population's mass density did not relate to threshold area, within which carnivore species averaged 9 kg/km2. The spatial intensity of oxygen consumption did not relate to body mass, but assuming that species with smaller threshold areas occur at more locations than species with larger threshold areas, one must conclude that smaller bodied species use more energy from the environment than do larger bodied species. Furthermore, threshold area and density at threshold area were most responsive to female brain mass, which provides an ecological allometry that links spatial scale, sensory perception, parental care, life-history attributes, basal metabolic rate, and body mass.

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