Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil.
J Evol Biol. 2010 Jan;23(1):175-84. doi: 10.1111/j.1420-9101.2009.01894.x.
There is a gap in terms of the supposed survival differences recorded in the field according to individual condition. This is partly due to our inability to assess survival in the wild. Here we applied modern statistical techniques to field-gathered data in two damselfly species whose males practice alternative reproductive tactics (ARTs) and whose indicators of condition in both sexes are known. In Paraphlebia zoe, there are two ART: a larger black-winged (BW) male which defends mating territories and a smaller hyaline-winged (HW) male that usually acts as a satellite. In this species, condition in both morphs is correlated with body size. In Calopteryx haemorrhoidalis, males follow tactics according to their condition with males in better condition practicing a territorial ART. In addition, in this species, condition correlates positively with wing pigmentation in both sexes. Our prediction for both species was that males practicing the territorial tactic will survive less longer than males using a nonterritorial tactic, and larger or more pigmented animals will survive for longer. In P. zoe, BW males survived less than females but did not differ from HW males, and not necessarily larger individuals survived for longer. In fact, size affected survival but only when group identity was analysed, showing a positive relationship in females and a slightly negative relationship in both male morphs. For C. haemorrhoidalis, survival was larger for more pigmented males and females, but size was not a good survival predictor. Our results partially confirm assumptions based on the maintenance of ARTs. Our results also indicate that female pigmentation, correlates with a fitness component - survival - as proposed by recent sexual selection ideas applied to females.
根据个体状况,野外记录的生存差异存在差距。这部分是由于我们无法评估野生动物的生存状况。在这里,我们应用现代统计技术对两种蜻蛉的野外收集数据进行了分析,这两种蜻蛉的雄性都采用了替代生殖策略(ART),而且两性的健康状况指标都是已知的。在 Paraphlebia zoe 中,存在两种 ART:体型较大的黑翅(BW)雄性,它保卫交配领地,体型较小的半透明翅(HW)雄性通常充当卫星雄性。在这个物种中,两种形态的健康状况都与体型大小相关。在 Calopteryx haemorrhoidalis 中,雄性根据自身状况采用策略,健康状况较好的雄性采用领地性 ART。此外,在这个物种中,两性的健康状况与翅膀色素沉着呈正相关。我们对这两个物种的预测是,采用领地策略的雄性的生存时间比采用非领地策略的雄性短,体型较大或色素沉着较多的动物的生存时间会更长。在 P. zoe 中,BW 雄性的生存时间比雌性短,但与 HW 雄性没有区别,而且不一定是体型较大的个体生存时间更长。事实上,体型影响生存,但只有在分析群体身份时才会产生影响,在雌性中表现出正相关关系,在两种雄性形态中则表现出略微的负相关关系。对于 C. haemorrhoidalis,色素沉着较多的雄性和雌性的生存时间更长,但体型并不是一个很好的生存预测指标。我们的研究结果部分证实了基于维护生殖策略的假设。我们的研究结果还表明,如最近应用于雌性的性选择思想所提出的,雌性的色素沉着与一个适合度成分——生存有关。