Species account

Black-tailed Skimmer (Orthetrum cancellatum)    (Linnaeus, 1758)
   Skimmers (Libellulidae) [Dragonflies]    BTSK    24821
Stor Blåpil (dk)   Centinela Colinegra (es)   Större Sjötrollslända (se)  
Synonyms (common):
Libélula Azul (es) Libélula Centinela (es)
Synonyms (scientific):
Libellula frumenti Müller, 1764
Libellula lineolata Charpentier, 1825
Hydronympha helvetica Buchecker, 1876
Orthetrum kraepelini Ris, 1897
Orthetrum guptai Baijal, 1955
Orthetrum cancellatum orientale Belyshev & Doshidorzhi, 1958
Measurements:
To 44-50mm Ab 29-35mm Hw 35-41mm
Generations:
Flight period:
JFMAMJJASOND 
Scan
EU
Identification:
A robust dragonfly with the abdomen laterally flattened, typical for the genus. But not as broad as on the Libellula species. And also lacks the black spots on the hind wing of these species. The leading edge of the forewing is pale.

When young the yellow base color shines through from a distance, and it is easy to identify the species by color and flight. But later it appears remarkably diverse when seen in flight, often leaving the impression, that some other (darker) species is in play.

The mature male is unique in Denmark with the combination of the blue abdomen with a black 'tail' toward the tip, about one fourth of the length of the abdomen. On the Keeled Skimmer (only in Jutland in Denmark) the black tail is much shorter, and the animal in general more narrow.
Female eye color very variable, bluish, greenish, brownish.
Similar species:
Life stages:
The mating wheel is established in flight and the following mating takes place in vegetation along the shore or in bushes or trees. It takes about 15 minutes. The solo flying female then drops the eggs over the shallow water dipping her tail into the surface where there are few water plants. The eggs hatch after 5-6 weeks and the larvae live at the bottom, either in-between rotten plant material or buried in the mud, and develop during 2-3 years. The transformation takes place close to the shore or up to 10 meters away and several meters above the ground in bushes or trees.
Distribution:
Most of Europe; absent northern Fennoscandinavia including most of Norway. Also present NW Africa and patchily from Turkey, Black Sea region, west Russia through the Middle East and C Asia to Mongolia and Amurland. In Denmark widespread in all regions.
Habitat:
In Denmark open terrain with lakes or water-bodies with scarce vegetation. Accepts brackish water. Also in mature broad-leaf forests. Very adaptable, but disappears from water bodies with too much vegetation.
Behavior:
-Often prefers to sit on the sun-exposed ground, stones or low branches. Or deep in-between tall grasses when cooler and more windy.
- The larvae can endure longer periods in dried-out environments while buried in the mud.
Endemic:
Status
Common and widespread through entire Denmark, including all larger islands. Stable or increasing.
Comment:
Black-tailed Skimmer 404    (2 photos)
2020-07-09    Kalvebod Fælled (Tårnby), Denmark

Imago Male
Rather common in the area around Pinseskoven.



Black-tailed Skimmer 410    (2 photos)
2020-07-11    Kalvebod Fælled (Tårnby), Denmark

Imago Male
Pinseskoven. Immature.
Black-tailed Skimmer 1151    (2 photos)
2022-07-16    Kalvebod Fælled (Tårnby), Denmark

Imago Male




Black-tailed Skimmer 1150    (2 photos)
2022-07-16    Kalvebod Fælled (Tårnby), Denmark

Imago Male




Black-tailed Skimmer 1427    (1 photos)
2023-05-26    Hedeland (nature trail), Denmark

Imago Male
South side of water holes along Herredsfogedvej.

Young. My first this year.



Black-tailed Skimmer 1620    (1 photos)
2023-06-08    Allgunnens Naturreservat (Kalmar), Sweden

Imago Male




Black-tailed Skimmer 1548    (2 photos)
2023-06-15    Kalvebod Fælled (Tårnby), Denmark

Imago Male
Enghøj. Teneral.
Many present today over the lake, and then this teneral animal just getting started.



Black-tailed Skimmer 1676    (1 photos)
2023-06-24    Herlufsholm Kostskole, Denmark

Imago Male
Susåen ved Herlufsholm.
A single male landed in what was unquestionable Blue Chaser territory. Separated by the dark-green eyes and lack of the black patches at the base of the hingwings.



Black-tailed Skimmer 2029    (1 photos)
2023-07-27    Skær Sø (Egtved), Denmark

Imago Male
An unusual individual with black markings up the abdomen, thus resembling a Blue Chaser [Spidsplettet Libel].



Black-tailed Skimmer 2189    (1 photos)
2023-08-13    Hvidovre Strandenge, Denmark

Imago Male
Leading toward to end of the season, and a single animal of this species was all I saw today. But in good conditions, not at all tired of living in this world, I imagine.



Black-tailed Skimmer 3301    (4 photos)
2025-07-19    Han Vejle (skjulet), Denmark

Imago Male
Two different animals. Photo 1-2 (female?), 3-4 (male).
While hunting for Baltic Hawker the animal in photos 1-2 landed on the railing. The only species that seems to do this at this site is cancellatum, naturally preferring open sun-exposed perches. But when looking at it at first it didn't look skimmer-like, and I started to hope that it finally could be a Baltic. Female then because it looked greenish. Click click and I saw what looked like two pale thorax ovals and no shoulder stripes. Not really good for a Baltic but until proven otherwise, I was still hoping. But looking again, and closer, it didn't really match. A Migrant Hawker (A. mixta) on the other hand also has the pale yellowish ovals and only shows faint shoulder-stripes. In the sun and from the dirty backscreen I concluded that it had to be a such female. Hasty perhaps, but good enough for me, and not extraordinary in anyway since they have started to fly by now.

But then when going through the photos now, it is obviously not a mixta, nor any other hawker, but indeed a cancellatum. Everything on the animal fits a younger individual - except for the two well-defined ovals! I've never seen a cancellatum showing this kind of thorax pattern, and I understand well, why I got confused. Most often the thorax-side is uniformly colored, perhaps with black lines to separate different sections.

Most often you see the species from the side or from above, and it has a tendency to hold the wings down, hiding the thorax, why you have to have a side-front angle to the animal to see the thorax well. But that said, I'm still certain that this pattern is not normal, and checking my own photos and ones online, I have only been able to find few similarly-looking individuals, but practically none that looked as marked as this one. And the male in photos 3-4 as well.

Aberrant
Black-tailed Skimmer 500    (1 photos)
2021-06-08    Kalvebod Fælled (Tårnby), Denmark

Imago Female
Young. Aging because of the bright yellow colors of the abdomen. The mature females becomes darker. One the most common dragonflies on Amager now.



Black-tailed Skimmer 553    (1 photos)
2021-07-21    Store Hareskov (Gladsaxe), Denmark

Imago Female




Black-tailed Skimmer 668    (1 photos)
2022-05-22    Kalvebod Fælled (Tårnby), Denmark

Imago Female
Pinseskoven.

Female by the separate appendages. Young individual, by principle, being one of the first I see this year.



Black-tailed Skimmer 1152    (1 photos)
2022-06-29    Kalvebod Fælled (Tårnby), Denmark

Imago Female




Black-tailed Skimmer 1088    (3 photos)
2022-08-13    Kalvebod Fælled (Tårnby), Denmark

Imago Female
Pinseskoven.
Mature female looking all dark from a distance. I only saw this animal today.



Black-tailed Skimmer 1785    (1 photos)
2023-07-14    Kongelundsområdet (Dragør), Denmark

Imago Female
Skovfogedmarken.
Mature female consuming a fly.



Black-tailed Skimmer 1818    (1 photos)
2023-07-18    Kongelundsområdet (Dragør), Denmark

Imago Female
Skovfogedmarken.
Dark and old. Two were hanging out in the clearing today with few other dragonflies.



Black-tailed Skimmer 2291    (1 photos)
2023-08-30    Kalvebod Fælled (Tårnby), Denmark

Imago Female
A late female looking for ...