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PATTERNS OF NATURAL SELECTION ON SIZE AT METAMORPHOSIS IN WATER FROGS
Simple relationships between larval growth and postmetamorphic fitness components, and support for this frequently made assumption about size at metamorphosis are found are found.
MATRIX MODEL INVESTIGATION OF INVASIVE SPECIES CONTROL: BULLFROGS ON VANCOUVER ISLAND
This study shows how demographic information can be used to maximize the efficacy of control efforts, and the results are likely directly applicable to other invasive species with complex life cycles.
Collapse of South Africa's penguins in the early 21st century
The number of African penguins Spheniscus demersus breeding in South Africa collapsed from about 56 000 pairs in 2001 to some 21 000 pairs in 2009, a loss of 35 000 pairs (>60%) in eight years. This…
Beyond bioclimatic envelopes: dynamic species' range and abundance modelling in the context of climatic change
B. Huntley (email@example.com), D. G. Hole and S. G. Willis, Ecosystem Science Centre, School of Biological and Biomedical Sciences, Durham Univ., South Road, Durham DH1 3LE, UK. P. Barnard,…
PREDATOR-INDUCED LIFE-HISTORY PLASTICITY UNDER TIME CONSTRAINTS IN POOL FROGS
- R. Altwegg
- Environmental Science, Biology
- 1 September 2002
The results suggest that time constraints critically affect the role of predators in the life history of pool frogs and might change the relative importance of lethal and nonlethal predator effects on their population dynamics.
Phenological Changes in the Southern Hemisphere
The largest meta-analysis to date of phenological drivers and trends among southern hemisphere species, assessing 1208 long-term datasets from 89 studies on 347 species shows an advance in the timing of spring events, although substantial differences were apparent among taxonomic groups and regions.
moult: An R Package to Analyze Moult in Birds
- B. Erni, B. Bonnevie, H. Oschadleus, R. Altwegg, L. Underhill
- Biology, Environmental Science
- 7 February 2013
The moult package for R implements the Underhill-Zucchini models, allowing the user to specify moult models in a regression type formula, and the functions allow the moult parameters to depend on explanatory variables.
Generation time and temporal scaling of bird population dynamics
Both the strength of total density dependence in the life history and the magnitude of environmental stochasticity, including transient fluctuations in age structure, increase with generation time, indicating that the relationships between demographic and life-history traits in birds translate into distinct population dynamical patterns that are apparent only on a scale of generations.
How Life History Influences Population Dynamics in Fluctuating Environments
Based on long-term studies of growing populations of birds and mammals, population dynamics is analyzed by using fluctuations in the total reproductive value of the population to account for random fluctuations in age distribution.
Demographic effects of extreme winter weather in the barn owl
Overall, survival decreased non-linearly with increasing winter harshness in adults, and linearly in juveniles, and brood size was not related to the harshness of the preceding winter, revealing complex interactions between climate and demography.