Sex ratio, survival, and recapture rate in a Cuban population of the damselfly Hypolestes trinitatis (Odonata: Megapodagrionidae)

Abstract

Male-biased sex ratios in adult odonate populations have been the subject of vigorous discussion between the students of this order of insects. The debate has centered on whether the observed male bias in many populations is real, perhaps due to unequal survival rates, or whether it is an artifact caused by differences in recapture probabilities. A mark-recapture study to assess the relative contribution of survivorship and recapture rates on male-biased sex ratio was performed in a Cuban population of the damselfly Hypolestes trinitatis. Maximum likelihood theory and Akaike information criterion were used for parameter estimation and model selection, respectively. Females in the sample were outnumbered two to one by males. Estimated recapture and survival rates were 0.188 (females) and 0.638 (males), and 0.933 (females) and 0.944 (males), respectively. Recapture rates only partially explained the bias since the population sex ratio estimated after correcting for differences in this parameter was male biased (1.5). The observed higher survival probabilities in males could have generated the male-biased population sex ratio. Therefore, we concluded that the observed male-biased population sex ratio in H. trinitatis is real.

Demography and Behaviour of Teinopodagrion oscillans (Odonata: Megapodagrionidae) in a Protected Area of the Colombian Andean Region

“…In general, observed lifespan is higher in males, and this has been explained by their behaviour because males usually remain closer to the water than females, and, as a consequence, male recapture rates are higher (e.g., [42]). For instance, in Hypolestes trinitatis (Gundlach), an endemic damselfly from Cuba, which has many ecological similarities with T. oscillans, recapture rates were much higher in males [43]. The estimated survival rate of T. oscillans, 0.946, is one of the highest ever estimated for adult odonates, identical to the male survival rate estimated for H. trinitatis [43] and similar to other species with highly territorial behaviour [12].…”

“…For instance, in Hypolestes trinitatis (Gundlach), an endemic damselfly from Cuba, which has many ecological similarities with T. oscillans, recapture rates were much higher in males [43]. The estimated survival rate of T. oscillans, 0.946, is one of the highest ever estimated for adult odonates, identical to the male survival rate estimated for H. trinitatis [43] and similar to other species with highly territorial behaviour [12]. Some Calopterygids, Polythorids, Lestids and Thaumatoneurids have daily survival rates above 0.96 (e.g., [44,45]), which translate into expected longevities of around 24 days, using the formula of Cook et al [45].…”

Different stress from parasites and mate choice in two female morphs of the blue-tailed damselfly

“…Adult Odonates populations often have male-biased sex ratios at the breeding habitat (Corbet and Hoess 1998;Foster and Soluk 2006;Cordoba-Aguilar 2008). This bias could be attributed to a high female mortality, to females using alternative habitats (Stoks 2001;Johansson et al 2005;Torres-Cambas and Fonseca-Rodríguez 2011), or to higher female mortality in the larval stage (Johansson et al 2005). In some cases, it has been questioned as to whether male-biased sex ratios in Odonate populations are real or artificial, but current data suggest that the biased sex ratios are real (Stoks 2001).…”