Ecological factors limiting the distributions and abundances of Odonata

Abstract

Many ecological processes contribute to regulating the distributions and abundances of odonate species. In local populations, mortality imposed by predators (including cannibalism and predation by other odonates) on larvae appears to be the dominant factor limiting abundances of many odonate species, although lower growth rates due to food limitation and stress responses to the presence of predators also contribute to limiting population sizes in most species that have been studied. Little is known about such processes in the adult stage of the life cycle, but parasites have been shown to limit adult survival and fecundity. Predation also causes many species to segregate among different water bodies with different top predators in eastern North America: different assemblages of odonate species are found at ponds and lakes that support centrarchid shes than at shless ponds and lakes. However, this pattern of species segregation between sh and shless water bodies is not apparent in other parts of the world. Stream-dwelling odonates also show analogous types of segregation to different types of stream (e.g. small creeks compared with large streams and rivers), but the ecological processes that enforce this segregation is not known. Many unanswered questions about the ecological regulation of odonates makes them a continually fascinating group for study.

Associations of Dragonflies (Odonata) to Habitat Variables within the Maltese Islands: A Spatio-Temporal Approach

“…While adult choice of habitat probably plays a proximate role in setting the environmental limits, species distributions, these are probably ultimately set by processes acting on the aquatic larval phase (McPeek 2008). A survey of Odonata larvae was carried out from January-March, of the same year; this is the period when adult Odonata are not usually observed on the wing.…”

“…The adults are conspicuous, easy to record, taxonomically well studied, and susceptible to habitat changes induced by human activities, all characteristics desirable of bioindicator groups (Brown 1991). Surprisingly, however, very little is known about the autoecological factors limiting species distributions to particular habitats (McPeek 2008), which may include sites and resources for larval development, emergence, adult foraging, mate seeking, oviposition, and nocturnal roosting.…”

<em>Boyeria irene</em> (Fonscolombe, 1838) y <em>Cordulegaster boltonii</em> (Donovan, 1807) (Odonata): dos estrategias en cuanto a sustratos de emergencia de larvas en un mismo hábitat

“…En cuanto a la depredación, puede llegar a regular la abundancia de las poblaciones de larvas (McPeek & Perckarsky, 1998), de modo que para minimizar el riesgo de depredación las larvas de odonatos adquieren determinados comportamientos como, por ejemplo, disminuir la tasa de movimientos, ocultarse en refugios, etc. (Wiseman et al, 1993;McPeek, 2008).…”

Analysis of urban impacts on aquatic habitats in the central Amazon basin: Adult odonates as bioindicators of environmental quality

“…Many species are habitat specialists, being sensitive to changes in the environment, and may become extinct more than generalist species (Dolný et al, 2012;Suhonen et al, 2010). In the case of damselflies (Zygoptera), species diversity appears to be influenced primarily by environmental heterogeneity (McPeek, 2008), with more complex habitats favoring the establishment of larger numbers of species, given that these insects require riparian vegetation with perches due to their reduced dispersal capacity, as well as areas for foraging and reproducing, and to provide refuge from predators (Corbet, 1999;Johansson, 2000). By contrast, the removal of riparian vegetation may be favorable to the dragonflies (Anisoptera), which are generally larger in size and more tolerant of disturbance, given that they require open areas, such as forest clearings, in which to absorb sunlight (De Marco and Resende, 2002;May, 1976May, , 1979May, , 1991.…”