Odonata drift: a reassessment

Abstract

More than 400 scientific journal articles and gray literature reports that addressed macroinvertebrate drift were reviewed and 63 articles were found that reported on the natural drift of Odonata at some taxonomic level. Forty-three species and 44 genera within 15 families (nine Zygoptera; six Anisoptera) were documented in the drift. Drift of another 13 species and eight genera was inferred from indirect evidence. The mean drift density reported was 0.03 m -3 (range < 0.001-0.153 m -3 ), which is relatively low, but not unexpected because benthic densities of Odonata are often lower than those of the macroinvertebrate taxa that occur more frequently in the drift. Percent composition of odonates in the total drift was invariably < 10% and usually < 1%, but the percent was slightly higher if expressed as biomass or volume because odonate larvae are relatively large. Most odonates that drifted were not full grown. High flows were often associated with drift of Odonata, but not exclusively so; drift was highest at night and during summer months. Accidental (catastrophic) drift and active, behavioral drift to colonize new habitats and reduce crowding are thought to be the primary causes of Odonata drift, but its ecological significance would benefit from more research. The presumption that Odonata have a low predisposition to drift is probably not uniformly accurate. Use of drift nets specifically to collect odonates is unlikely to be as efficient as other collection methods in most circumstances, but it should not be entirely dismissed because drift nets are easy to set, relatively clean to operate, do not destroy habitats, and provide integrated samples of various habitats where it might be difficult or unsafe to use other methods.

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

“…On the other hand, upstream or downstream movements are common in odonates [62], for instance, to explore the area, to compensate for downstream larval drift [63], and to choose sites where competition between adults, larvae, or during emergence is lower [64]. Although we do not know the magnitude of these distances, individuals of T. oscillans could travel up to 2 km upstream and be able to return, as has been reported for Calopteryx haemorrhoidalis (Vander Linden), a damselfly of similar size (45-48 mm) [65], whose adults have also been observed to move from one stream drying up to another that was permanent.…”

Richness and structure of an Odonata larval assemblage of a cloud forest stream in western Mexico

“…The predominance of H. capitalis is probably due to the abundance of branched roots of riparian trees and debris trapped between rocks in streams, combined with the numerous rapids along the course of the water, which represent a favorable habitat for larvae. As an endophytically ovipositing species that uses the roots (live plant substrate), the larvae obviously disperse towards other substrates by passive or active drift ( Dubois 2020) as this species was frequent in almost all types of sampled substrates. In general, Calopterygidae always contributes one to four species to the mountain assemblages.…”

Upstream and downstream movements in adults of stream-dwelling Odonata

“…The great majority of reports (on several species) on along-stream movements of Odonata species showed a significant prevalence for nett upstream Fraser (1936: 393) displacement (Table 1). Such movements would compensate for downstream drift of larvae (Müller 1982), which undoubtedly sometimes occurs in Odonata in swift streams (Dubois 2020). Among the four flight types functionally defined by Corbet 1999: 384), type-4 (migration, one-way) fits best with drift-compensating upstream movements.…”

“…The great majority of reports (on several species) on along-stream movements of Odonata species showed a significant prevalence for nett upstream displacement (Table 1). Such movements would compensate for downstream drift of larvae ( Müller 1982), which undoubtedly sometimes occurs in Odonata in swift streams ( Dubois 2020).…”

“…Such drift may not be unusual in Odonata. Dubois (2020) found it documented in no less than 43 species and in another 13 species where he inferred it from indirect evidence. The possible mechanism behind the preference for upstream movements by adults is, however, less clear.…”