Search results for "Sexual selection"

AN ANALYSIS OF CONTINENT-WIDE PATTERNS OF SEXUAL SELECTION IN A PASSERINE BIRD

2006

Patterns of selection are widely believed to differ geographically, causing adaptation to local environmental conditions. However, few studies have investigated patterns of phenotypic selection across large spatial scales. We quantified the intensity of selection on morphology in a monogamous passerine bird, the barn swallow Hirundo rustica, using 6495 adults from 22 populations distributed across Europe and North Africa. According to the classical Darwin-Fisher mechanism of sexual selection in monogamous species, two important components of fitness due to sexual selection are the advantages that the most attractive males acquire by starting to breed early and their high annual fecundity. W…

Habitat Differences and Variability in the Lek Mating System of Black Grouse

1996

Spatially fixed territoriality has been regarded to be a general feature in lek mating systems. In the absence of territories, however, the nature of leks may change remarkably. We compared leks of black grouse in areas, where territoriality was governed by habitat characteristics. On ice-covered lakes, where the lekking ground was homogeneous and offered no landmarks by which the displaying males would be able to recognize territory boundaries, the male aggregations were mobile. 'Classical' leks on bogs, however, were stable. It also appeared that on mobile leks, as compared to stable leks, the opportunities for females to choose their mates were reduced. The distribution of mating success…

Fluctuating asymmetry and copulation success in lekking black grouse

1997

Abstract In lekking black grouse, Tetrao tetrix males at the centre of the leks obtain more copulations than males at the edges. We found that males with territories at the edge of the lek obtained fewer matings and also have the most asymmetric tarsi. However, when considering the tail ornament (the lyre) no correlation between asymmetry and mating success was found. Although females are unlikely to select males on the basis of tarsus symmetry, asymmetry in this trait may reflect male condition. We suggest that males in poor condition, as reflected by higher levels of fluctuating asymmetry in the tarsi, do not achieve central positions on the lek arena. This would account for the lower suc…

Personality and body condition have additive effects on motivation to feed in Zebra Finches Taeniopygia guttata

2012

Several hypotheses have been proposed to account for the adaptive evolution of person-ality, defined as inter-individual differences in behaviour that are consistent over timeand across situations. For instance, the ‘pace-of-life syndrome’ hypothesis suggests thatpersonality evolved as a behavioural correlate of life-history trajectories that vary withinpopulations. Thus, proactivity, corresponding to higher exploratory tendencies or higherboldness levels, has been linked to higher productivity or mortality rates. However, theextent to which proactivity is associated with a higher motivation to forage remainspoorly understood. Moreover, although personality and its effects on foraging behavi…

Density‐dependent influence of male characters on mate‐locating efficiency and pairing success in the waterlouse Asellus aquaticus: an experimental s…

2005

Population density is likely to determine the form of competition in which males are engaged for access to females. At low density, scramble competition should be of paramount importance because of the low probability of encounter between males and females. Consequently, sexual selection should favour characters that allow rapid detection of females. Conversely, at high population density, sexual selection should favour attributes that raise the fighting ability of males because of the more frequent contacts between males. These general predictions were tested in this study for the precopulatory mate-guarding isopod, Asellus aquaticus. In this species, male-biased sexual dimorphisms are rep…

BLOOD PARASITES AND MALE FITNESS IN THE PIED FLYCATCHER

1993

In vertebrates the effect of parasites on host ecology has almost been ignored. Recently the view that well-adapted parasites do not harm their hosts has been challenged and there is growing evidence that parasites do have a present-day effect on a great variety of host fitness components. The pied flycatcher is a small migratory passcrine bird. Any decrease in condition caused by disease should affect its ability to cope with physical demands of migration. Here we examine whether blood parasites have any effect on male arrival time. Males infected with Trypanosoma arrived on average 2 days later than males with no Trypanosoma infection. Infected males also had shorted tails and tended to h…

Context-dependent effects of tail-ornament damage on mating success in black grouse

1994

Winter male plumage coloration correlates with breeding status in a cooperative breeding species

2007

The function of colored ornaments is usually related to the signaling of individual quality in intra- and intersexual interactions. In cooperative breeding species, where only a fraction of the male population access the breeding status and the other fraction has the option to help breeding pairs, colored traits might provide the females with a reliable information on the quality of potential mate. Males of the cooperative breeding azure-winged magpies (Cyanopica cyanus) display conspicuous blue plumage coloration. Here we explored the role played by structural blue coloration of males and the probability of becoming a breeder or a helper. Birds were trapped during 4 consecutive years, and …

A mate to die for? A model of conditional monogyny in cannibalistic spiders.

2012

Monogynous males in various species actively limit themselves to mating with a single female in their lifetime. Whereas previous models have considered monogyny as an obligate mating strategy, here we explore the potential of monogyny to evolve as a context-specific (conditional) behavior. Using a state-dependent dynamic game model based on the biology of the cannibalistic spider Argiope bruennichi, we confirm that conditional monogyny can evolve under broad conditions, including an even sex ratio. We predict that males should make a terminal investment when mating with large, virgin females, especially if population density is low and the encounter occurs late in the season. We encourage e…

2014

Captive breeding for conservation purposes presents a serious practical challenge because several conflicting genetic processes (i.e., inbreeding depression, random genetic drift and genetic adaptation to captivity) need to be managed in concert to maximize captive population persistence and reintroduction success probability. Because current genetic management is often only partly successful in achieving these goals, it has been suggested that management insights may be found in sexual selection theory (in particular, female mate choice). We review the theoretical and empirical literature and consider how female mate choice might influence captive breeding in the context of current genetic…