The Dragonflies
(Insecta: Odonata)
of the Columbia Basin, British Columbia:
Field Surveys, Collections Development and Public Education
Dragonfly Habitat In the Columbia Basin
1. Large
lakes (wave-washed shores with little vegetation)
Some southern lakes, such as Christina, Columbia, Wasa, and the
southern parts of Kootenay to name a few, have wave-washed shores
with little vegetation. The dragonflies associated with this habitat
are: Argia emma, Enallagma carunculatum (in Scirpus
beds), E. ebrium, Aeshna umbrosa, Gomphus graslinellus, Ophiogomphus
severus and Macromia magnifica. In large, deep lakes
north of the southern valleys, the waters are colder and less productive,
and dragonflies are restricted to shallow waters in sheltered bays,
where the fauna resembles that found in small lakes and ponds.
2. Small
lakes and ponds (floating, but little emergent vegetation)
A wide variety of small lakes and ponds are present in the Columbia
Basin, and an equally diverse array of Odonata: Enallagma ebrium,
Aeshna canadensis, A. eremita, A. multicolor, A. palmata, A. tuberculifera,
A. umbrosa, Cordulia shurtleffi, Epitheca spinigera, Somatochlora
albicincta, S. cingulata, Leucorrhinia glacialis, L. hudsonica,
L. proxima, Libellula julia, L. lydia and Sympetrum vicinum.
3. Alkaline lakes
These salty lakes occur primarily in grasslands and open forests
in the dry, warm southern valleys and plateaux. These species are
able to live in this unusual habitat despite the often high salinity,
and their life histories enable them to take advantage of the ephemeral
nature of the shallower lakes and ponds: E. boreale, Lestes congener,
L. unguiculatus, Sympetrum corruptum, and S. costiferum.
These species are not restricted to this habitat.
4. Cattail/bulrush
marshes (including margins of lakes and ponds)
Marshes dominated by tall stands of cattails (Typha) and
bulrushes (Scirpus) are most common in nutrient-rich, warm
waters at low to medium elevations. They are especially common in
the Columbia River Valley between Columbia Lake and Golden. Species
associated with this habitat are: Lestes congener, L. disjunctus,
L. dryas, L. forcipatus, L. unguiculatus, Enallagma carunculatum,
E. cyathigerum, Ischnura cervula, I. perparva, Aeshna californica,
A. canadensis, A. constricta, A. interrupta, A. multicolor, A. palmata,
Anax junius, Leucorrhinia intacta, Libellula forensis, L. lydia,
L. pulchella, L. quadrimaculata, Sympetrum costiferum, S. danae,
S. internum, S. obtrusum, S. occidentale and S. pallipes.
5. Sedge
marshes (additional image)
Sedges (Carex) form dense stands around many lakes and ponds,
especially at medium and high elevations. Species associated with
this habitat are: Lestes congener, L. disjunctus, L. dryas, L.
forcipatus, Coenagrion resolutum, Enallagma boreale, E. cyathigerum,
Nehalennia irene, Aeshna interrupta, A. juncea, A. palmata, Epitheca
spinigera, Somatochlora semicircularis, Libellula quadrimaculata,
Leucorrhinia borealis, L. hudsonica, Sympetrum internum and
S. obtrusum.
6. Ephemeral ponds
(temporary ponds)
In addition to some saline ponds that may disappear during hot weather,
fresher ephemeral waters support the following species: Lestes
dryas, L. unguiculatus, Sympetrum corruptum, S. madidum and
S. pallipes. Some of these species overwinter as eggs in
the dry pond basin.
7. Small
peatland ponds with aquatic moss
Peatlands are poorly drained wetlands where decaying moss and other
vegetation accumulates as peat. Ponds in these sites generally at
moderate to high elevations may be bordered with floating moss or
firm peat. This habitat supports the following species: Coenagrion
interrogatum and A. subarctica, among others.
8. Shallow
sedge/moss fens
Peatlands affected by flowing water, evenly vegetated with sedges
and dotted with shallow pools, host a particular assemblage of species:
Enallagma boreale, Coenagrion resolutum, Nehalennia irene, Aeshna
sitchensis, Somatochlora franklini, S. semicircularis and
S. whitehousei.
9. Streams
(additional photo)
Odonata are not normally found in the cold streams of mountainous
areas. The following species living in flowing waters are generally
restricted to the warmer slow-flowing, southern lowland streams
or montane streams that drain lake basins, beaver ponds or peatlands.
Calopteryx aequabilis, Argia emma, Ophiogomphus occidentis, Stylurus
olivaceus and Macromia magnifica are restricted to the
southern valleys. Aeshna umbrosa and Ophiogomphus severus
are more widespread and also live in lakes. Somatochlora
forcipata is restricted to the Rocky Mountains, S. minor
and S. walshii are more widespread in small montane streams.
10. Springs
and shallow seeps
Some of the more uncommon species of Odonata are associated with
small springs and shallow seeps. Amphiagrion abbreviatum
is widespread in such habitats. Argia vivida is, for the
most part, restricted to warm springs in the mountains. Cordulegaster
dorsalis is found in many warm streams draining lakes on the
west side of the Coast Mountains, but in the Columbia Basin has
been found only in spring-fed streams.
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