Sexual Competition in Scatophaga Stercoraria: Size- and Density-Related Changes in Male Ability To Capture Females

  title={Sexual Competition in Scatophaga Stercoraria: Size- and Density-Related Changes in Male Ability To Capture Females},
  author={G. Borgia},
The behavior of males near the oviposition site of Scatophaga stercoraria is highly variable, being dependent on male size and on male density conditions. At low density males are often territorial with dominance relationships, the largest male often initiating high intensity attacks. At high densities attacks are much less intense, with more symmetrical interactions among males. Large males are most active under all density conditions. Absence of small males from high density pats, even though… Expand
Mate selection in the fly Scatophaga stercoraria: female choice in a male-controlled system
Females paired with large males gain more rapid copulation and oviposition, with lower risk to the female and her progeny; and greater ability to escape danger during copulation, which may account for female preference for large males. Expand
Size-dependent alternative male mating tactics in the yellow dung fly, Scathophaga stercoraria
It is demonstrated that when an alternative resource is present where females aggregate (i.e. apple pomace), smaller males will redirect their searching for females from dung to the new substrate, providing further support for the existence of an alternative male reproductive tactic in this species. Expand
Effects of sex-ratio manipulation on territoriality and spawning success of male pupfish, Cyprinodon pecosensis
Temporal or spatial changes in the operational sex ratio of a population may have profound effects on the dynamics of the breeding system by affecting the proportion of males adopting primary and secondary breeding tactics, variance in reproductive success, and intensity of sexual selection. Expand
Effects of age and body size on the male territorial system of the dragonfly, Nannophya pygmaea rambur (Odonata: Libellulidae)
Multiple regression analysis showed that most of the variation in male mating success could be explained by two variables related to weather conditions (number of synny days during the reproductive span of each male, and number ofsynny days while each male occupied a high-quality territory) and not by male size. Expand
The Behavioral Ecology of Libellula luctuosa (Burmeister) (Anisoptera: Libellulidae): I. Temporal Changes in the Population Density and the Effects on Male Territorial Behavior
A single population of a common pond dragonfly, Libellula luctuosa, was studied at a site where the density of males increased dramatically during the breeding season, resulting in a change in the operational sex ratio with variations in male density. Expand
Effects of seasonal variation in operational sex ratio and population density on the mating success of different sized and aged males in the yellow dung fly, Scathophaga stercoraria
Both the intensity of selection on male size and the opportunity for selection decreased with season and the number of males per pat decreased and OSR became more female–biased towards the end of the flight season. Expand
Density‐dependent influence of male characters on mate‐locating efficiency and pairing success in the waterlouse Asellus aquaticus: an experimental study
Multivariate analyses indicated that density affected morphological correlates of the mating success of males, with body size being the main determinant of pairing success in males at a high density, whereas only antennae size significantly affected access to females at a low density. Expand
Distribution of male yellow dungflies around ovipasition sites: the effect of body size
It is suggested that good prospects in taking females over from other males must make the strategy to search for females on older droppings profitable, and that large searching males are not predominantly found at fresh droppings when the probability of catching unpaired females is highest. Expand
Competition for Territorial Sites and Alternative Mating Tactics in the Dragonfly, Nannophya Pygmaea Rambur (Odonata: Libellulidae)
Not all males are territorial however, some try to 'sneak' copulations with females attracted to established territories, and highly contended territorial sites attract more females than others, and daily mating frequency is highest in males occupying these territories. Expand
In species with resource-defence polygyny, males fight for access to the resources used by females, and during the aggressive interactions some males are excluded from the best mating areas, and the advantage of large body size is expected on theoretical grounds. Expand