Search results for "Wolf spider"
showing 4 items of 14 documents
A trade-off between sexual signalling and immune function in a natural population of the drumming wolf spider Hygrolycosa rubrofasciata.
2005
The field of ecological immunology is ultimately seeking to address the question ‘Why is there variation in immune function?’ Here, we provide experimental evidence that costs of ubiquitous sexual signals are a significant source of variation in immune function. In the mating season, males of the wolf spider Hygrolycosa rubrofasciata drum against dry leaves while wandering around the habitat searching for receptive females. According to a previous study, the male metabolic rate during the drumming increases 22-fold compared to the resting metabolic rate. In the present study, we examined whether investment in costly courtship drumming decreases male immune function in a wild population of H…
Honesty of agonistic signalling and effects of size and motivation asymmetry in contests
1999
Game theoretical models predict that the main function of fighting behaviour is to assess the relative fighting ability of opponents. The sequential assessment game has often been used to investigate contests, while honest signalling theory has received much less attention. With the wolf spider Hygrolycosa rubrofasciata we investigated whether male agonistic signalling can reveal honest information about fighting ability, and how size and motivation asymmetries affect male fighting behaviour. We also determined whether male–male competition affects the courtship behaviour of the males. We found that agonistic drumming activity is an honest indicator of male fighting ability, and that relati…
Overwintering survival in relation to body mass in a field population of the wolf spider ( Hygrolycosa rubrofasciata )
1999
Body size is often considered to be an important trait affecting individual fitness. In arthropods, females commonly benefit from larger size directly through increased fecundity (Roff, 1992), and males through increased mating success (Andersson, 1994). It has also been suggested that larger individuals may in general have a better survival than smaller individuals (Calder, 1983; Peters, 1983). From this suggestion it may be predicted that during stressful environmental conditions larger individuals should do better than smaller individuals.
Female choice for male drumming in the wolf spiderHygrolycosa rubrofasciata
1997
Mate preferences in invertebrates have usually been studied with simultaneous choice exper- iments alone, which allows eVective detection of any preferences but does not tell much about the strength of inter-sexual selection. Under natural conditions females frequently have to rely on sequential choice, and choosy females may incur opportunity and direct costs such as loss of time when they reject a male. Female preference in the wolf spider Hygrolycosa rubrofasciata for two components of male courtship signalling, rate and volume, was investigated. Both of these characteristics were tested with a sequential choice set-up and the eVect of volume also with a simultaneous choice method. Femal…