Seasonal effects of density on territory occupation by males of the satyrine butterfly Paryphthimoides phronius (Butler 1867)

Abstract

Territorial defense in butterflies may be related to both population density and climatic conditions. If these factors change throughout the year, males are expected to adaptively adjust their behavior in order to maximize reproductive success. In this study, we analyzed the annual dynamics of territory occupation by males of the satyrine butterfly Paryphthimoides phronius at a mildly seasonal subtropical site in southeastern Brazil. We investigated the relationship between the number of defended sites, number of males disputing mating areas, proportion of males adopting alternative mate-locating tactics, and the proportion of time invested in territorial disputes with annual variations in temperature and male density. We found little support for the influence of temperature on the dynamics of territory occupation. On the other hand, the number of defended sites increased with male density, whereas the number of males inside each territory, the proportion of satellite males, and the proportion of time spent in territorial disputes were unrelated to variations in population abundance. Territory defense seems to be adopted whenever possible. We conclude that, instead of increasing the number of individuals disputing the same territory during months of high population abundance, males apparently opt to colonize and defend new and, maybe, suboptimal areas.

Dense, small and male-biased cages exacerbate male–male competition and reduce female choosiness in Bicyclus anynana

“…in butterflies, Alcock, 1994;Alcock & O'Neill, 1986;in ungulates, Isvaran, 2005). There are no such data to our knowledge for B. anynana, but the density threshold at which such breakdown occurs is likely to be very high in this species as in other butterflies in which territory defence seems to be adopted whenever possible and independently of density (Bergman et al, 2007;Bergman & Wiklund, 2009a, 2009bKemp, 2001;Peixoto & Benson, 2009). Absence of field data quantifying the different types of male behaviours prevents us from comparing our laboratory results with the dynamics of mate competition in the wild.…”

Territory Availability at Different Spatial Scales does not Affect Fighting Investment in Males of the Lycaenid Butterfly Strymon mulucha

“…On the other hand, males of the butterflies Paryphthimoides phronius, Hypolimnas bolina, and Anartia jatrophae do not abandon territoriality when density increases (Lederhouse et al 1992;Kemp 2001;Peixoto & Benson 2009). For instance, when the density of males of the butterfly Strymon melinus per territory increases, individuals tend to abandon the territorial behavior (Alcock & O'Neill 1986).…”

Do Feeding Resources Induce the Adoption of Resource Defence Polygyny in a Lekking Butterfly?

“…Perhaps, even if the resourced‐based sites receive both sexually and non‐sexually receptive females, the total amount of female arrival may compensate for the expected preferential arrival of sexually receptive females at sites without resources. Alternatively, as territorial males rarely copulate (Peixoto & Benson 2009a,b), the chances of finding a sexually receptive female during the lifetime may be very low, and evaluation of territory quality may be unimportant. Consequently, males may defend a mating site irrespective of the presence of resources (e.g.…”

“…Males of the bushbrown butterfly Paryphthimoides phronius (Buttler, 1867) (Nymphalidae: Satyrinae) typically occur in forest edges where they defend territories in sunny clearings without feeding resources that may be used by females throughout the year (Peixoto & Benson 2009a,b) – a mating system that can be regarded as a dispersed lek (Alcock 1981). Heavier males preferentially defend such sunny clearings, while lighter males apparently wander in the vicinity of territories and occupy them in the absence of owners (Peixoto & Benson 2008).…”