8 research outputs found
The limits to population density in birds and mammals
We address two fundamental ecological questions: what are the limits to animal population density and what determines those limits? We develop simple alternative models to predict population limits in relation to body mass. A model assuming that within‐species area use increases with the square of daily travel distance broadly predicts the scaling of empirical extremes of minimum density across birds and mammals. Consistent with model predictions, the estimated density range for a given mass, ‘population scope’, is greater for birds than for mammals. However, unlike mammals and carnivorous birds, expected broad relationships between body mass and density extremes are not supported by data on herbivorous and omnivorous birds. Our results suggest that simple constraints on mobility and energy use/supply are major determinants of the scaling of density limits, but further understanding of interactions between dietary constraints and density limits are needed to predict future wildlife population responses to anthropogenic threats
Effects of service use, family social capital and school social capital on psychosocial development among economically disadvantaged secondary school students in Hong Kong
Typology of students at risk of dropping out of school: Description by personal, family and school factors
Resilience of Greek Youth at an Educational Transition Point: The Role of Locus of Control and Coping Strategies as Resources
coping strategies, locus of control, resilience, well-being, youth,