Long-distance migration in dragonflies and damselflies
The insect order Odonata currently includes approximately 6,390 described species worldwide. Most people know dragonflies and damselflies as insects seen around ponds, streams, rice fields, and wetlands, but the lives of some species extend far beyond these familiar habitats. Certain dragonflies and damselflies leave the places where they emerged and move with seasonal shifts in wind, rainfall, temperature, and the distribution of suitable breeding sites. Some even cross oceans, forming large-scale aerial migrations that are far more extensive than their delicate bodies might suggest.
Migratory species are estimated to account for up to 2.9% of all odonates when both confirmed and possible migrants are included. Confirmed migratory species occur in four dragonfly families and two damselfly families. Among dragonflies, migrants are found in Aeshnidae, Corduliidae, Gomphidae, and Libellulidae, with the strongest concentration in Libellulidae, which includes 62 confirmed migratory species. Among damselflies, confirmed migrants occur in Coenagrionidae, with eight species, and Lestidae, with seven species. Within Coenagrionidae, the genus Ischnura includes five confirmed migratory species, making it the damselfly genus currently known to contain the highest number of migrants.
Migration in Odonata can be divided into two major forms: multi-generational migration and single-generational migration. Multi-generational migration is the more common form among insects. In this system, one individual usually does not complete the full outward and return journey. Instead, the migratory circuit is completed by the next generation, or by several subsequent generations. This pattern reflects the short lifespan and rapid generation turnover of many insects.
The green darner, Anax junius, is one of the best-studied examples of multi-generational migration. This species occurs from Central America to southern Canada and breeds mainly in shallow lakes and ponds. In spring, adults arrive from southern regions on warm winds and enter northern breeding areas, especially near the northern edge of the species’ range at approximately 39–47°N. After this generation breeds in the north, its offspring emerge during summer. Some remain and breed locally, while others accumulate fat reserves in late summer or autumn and migrate southwards to warmer regions, where they may continue breeding either en route or after arrival. As a result, this species includes both migratory and resident individuals. Migrants develop rapidly within a single season and enter migration after emergence, whereas residents develop more slowly, enter diapause, and emerge the following year.
Some tropical and subtropical dragonflies are closely tied to seasonal rainfall. These species use wind systems to move away from dry regions and toward areas where the next rains are expected. The globe skimmer, Pantala flavescens, is thought to cross the Indian Ocean, moving between India and East Africa over remarkable distances.
In Odonata, the main known form of single-generational migration is altitudinal migration. This type of migration usually covers much shorter distances than latitudinal migration. Its purpose is temporary refuge from high temperatures, drought, or other adverse conditions in lowland breeding habitats. Individuals leave after emergence, before they are fully mature, and move to higher, cooler, and wetter mountain habitats. When lowland conditions again become suitable for reproduction, they return. The Japanese red dragonfly Sympetrum frequens is a well-known example. In spring, newly emerged adults migrate in large numbers to cool highlands. After the autumn rains arrive and temperatures fall, they return to lowland rice fields to breed. The distance covered can reach approximately 60 km.
Migration requires energy, and many migratory dragonflies store fat as fuel for long-distance flight. Fat storage has been reported in at least seven migratory dragonfly species. In the green darner, fat reserves can account for 20–30% of total body mass. When migration occurs mainly over land, individuals can stop along the way to feed and rest. Ocean crossings are far more demanding. The globe skimmer is estimated to travel approximately 6,000 km within a single generation, a journey that likely requires suitable fat reserves, the ability to select favourable winds, and efficient gliding flight. This is also why migratory dragonflies often have relatively large, long, smooth wings and a larger anal lobe, wing features that may help reduce the energetic cost of long-distance flight.
For long-distance movements, odonates may use seasonal winds, trade winds, cold fronts, or warm air masses as favourable opportunities for migration. Flying with tailwinds can reduce the energetic cost of movement, while the ability to compensate for crosswind drift helps individuals maintain a preferred direction of travel. At times, dragonflies fly close to the ground within the flight boundary layer, roughly 1–10 m above ground, where wind speeds are weaker and individuals can better control their flight direction. At other times, they fly much higher and use winds for long-distance transport. The globe skimmer, for example, has been recorded by vertical-looking radar at approximately 200–1,000 m above sea level. Odonates may also use landscape features, the sun, or polarized light for navigation, but the precise mechanisms underlying long-distance orientation remain unresolved.
The main reason odonates migrate is that their breeding habitats are seasonally unsuitable. In temperate regions, winter temperatures fall too low for normal adult activity. Some species survive these periods by entering diapause as eggs, larvae, or adults, while others leave cold regions and return only when conditions again become favourable for breeding. In tropical and subtropical regions, the major constraints are often drought and high temperature, and many dragonflies move with rainfall and wind systems. Anax ephippiger, which moves across Africa, Asia, and Europe, provides a clear example of this rain-following strategy. Its larvae can develop rapidly in temporary, sometimes brackish water bodies, usually emerging after about three months. Young adults then move with rain-bearing weather systems. During migration, they may feed, mature, mate, and lay eggs, and then continue migrating afterwards.
Migration may also be influenced by population density and collective behaviour. Large dragonfly swarms have been reported from every continent where odonates occur, and some contain millions or even billions of individuals. A large swarm can itself provide a visual cue that attracts both conspecific and non-conspecific individuals, a process described as entrainment. In some species, migration may also become more frequent after mass emergence or overcrowding. In Siberia, large-scale movements of the four-spotted chaser, Libellula quadrimaculata, have often occurred in years with high population density. When local density exceeded three individuals per square metre, individuals were more likely to form conspicuous aggregations, followed by the departure of large numbers from the original habitat. However, this relationship between density and increased migration cannot be applied to all dragonflies. Studies of the green darner have not found a clear link between population density and migration.
Most migratory odonate species are listed as Least Concern on the IUCN Red List, possibly because they tend to be highly mobile, widely distributed, able to exploit temporary resources, and capable of crossing major barriers. Some migratory species have recently expanded their ranges in Europe or North America, suggesting that they may be more flexible than many resident species under a warming climate. At the same time, climate change can alter wind patterns, rainfall cycles, drought frequency, and water quality, all of which may disrupt the conditions on which their migrations depend. Conserving migratory odonates therefore requires more than protecting a single pond or wetland. It requires an understanding of the breeding sites, stopover habitats, and high-altitude refuges they use across different seasons. Their movements form an ecological process closely linked to climate, aquatic habitats, and life history.
Author: Shui-Ye You
Reference:
Hedlund JSU et al. (2026). Flight of the dragons: a global review of migration in Odonata. Biological Reviews.
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