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  • 1
    Electronic Resource
    Electronic Resource
    Contradictory findings in studies of sex ratio variation in roe deer (Capreolus capreolus) (1999)
    Springer
    Behavioral ecology and sociobiology 45 (1999), S. 339-348 
    Details
    ISSN: 1432-0762
    Keywords: Key words Local resource competition ; Maternal care ; Roe deer ; Sex ratio ; Trivers and Willard model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Patterns of sex ratio variation and maternal investment reported in the literature are often inconsistent. This could be due to intra- and inter-specific variation in social systems, but may also be a result of the a posteriori nature of much of this type of analysis or the testing of models which are inappropriate. Two recent papers reported directly opposed results concerning variation in offspring sex ratios in relation to maternal condition in roe deer, interpreting the results as support for the Trivers and Willard model and for the local resource competition hypothesis, respectively. In this paper, we present data on offspring sex ratios and early juvenile body weight from two long-term studies of this species to test predictions arising from these two models concerning sex biases in litter composition and maternal care. First, we observed no consistent pattern of sex differences in an index of weaning weight or body weight at 1 month old in either population, indicating a lack of sex bias in maternal care. However, in one population, higher maternal body weight was associated with higher juvenile body weight of daughters, but not of sons. Secondly, we found a negative, but not statistically significant, relationship between maternal body weight and litter sex ratio such that heavier females tended to produce more daughters and lighter females to produce more sons. These results indicate that roe females which have additional investment potential available do not invest it in sons, as predicted by the Trivers and Willard model. Our results may provide some support that roe deer are subject to local resource competition acting at the level of the individual mother; however, the fact that particular trends in sex ratio data can be explained in functional terms provides no indication that they are actually adaptive.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002650050569
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  • 2
    Electronic Resource
    Electronic Resource
    Conservation of biodiversity in Scandinavian boreal forests: large carnivores as flagships, umbrellas, indicators, or keystones? (2000)
    Springer
    Biodiversity and conservation 9 (2000), S. 857-868 
    Details
    ISSN: 1572-9710
    Keywords: biodiversity ; boreal forest ; carnivore ; conservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Large carnivores are often used as focal species (indicators, umbrellas, flagships or keystones) in conservation strategies either aimed at conserving carnivores, the rest of the biodiversity that occupies their habitats, or both. We evaluate their suitability for these roles in the context of boreal forest biodiversity conservation in the muti-use landscapes of Scandinavia. The enormous conflicts, especially with livestock, that carnivores cause in these areas makes them very controversial flagships to the extent that it may affect rural people's attitudes to conservation in general. Because of the broad habitat tolerance of large carnivores and their prey, and the difficulties in surveying carnivore numbers, they are very insensitive and impractical indicators of forest biodiversity. This ability of large carnivores to thrive in industrial forests means that the many species that are sensitive to modern forestry will not fall under the umbrella of areas managed for large carnivores. If large carnivores have a keystone function with respect to affecting the density of their ungulate prey it is likely to lead to even further conflicts with hunters who gain economic benefit from harvesting wild ungulates. In other words, none of the classic `ecological' arguments are likely to help justify large carnivore conservation, and large carnivore conservation is unlikely to help conserve the rest of the boreal forest's biodiversity. Based on these arguments we recommend that (1) justification for large carnivore conservation focus on the real philosophical and value orientated reasons rather than ecological justifications, (2) that this conservation should be brought about in practice by dedicated management programs that specifically address the conflicts caused by large carnivores, and (3) that boreal forest biodiversity is best conserved by specific actions designed to establish reserves or change forestry practices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008969104618
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