Dragonfly

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End 2005 initiative was taken to gather an European atlas of dragonflies. The project is being supported by the dutch European Invertebrate Survey and coordinated by Vincent Kalkmann of Naturalis - National Museum of Natural History in the Netherlands.
The result of this project, spanning 41 countries, is going to be the atlas itself in form of a book. It will contain introductory chapters followed by species accounts for each of the 130+ species encountered in Europe. Each account containing a distribution map and brief information on taxonomy, life history, habitat, flight histograms and conservation status.

<small>An adult male Green Snaketail (<i>Ophiogomphus cecilia</i>) from the summer 2009, perched on a twig

An adult male Green Snaketail (Ophiogomphus cecilia) from the summer 2009, perched on a twig.

Recently a fair amount of my spare time has gone into sorting through the dragonfly collections kept at the Natural History Museum Aarhus. Some of the animals have been ID’ed by the collector and a lot are just tagged with a date and location and pinned. So the job so far has been to double-check identification and identify those that haven’t been given a name yet, note all the info on the collected animal, add co-ordinates and save the lot in a rapidly growing database.
It’s quite fun and a learning experience to sort through all this material. It provides a great opportunity to compare tricky traits between resembling species. (I’ll see if I can use some of those comparisions for a post later on.)
It’s also quite fascinating to see in how good shape some of the animals are, despite being collected back in 1896. (That’s like.. a very very… long time for something that was only meant to last a few months).

<small>A larvae of the Blue Emperor (<i>Anax imperator</i>) awaiting unknowing prey to happen by. This exemplar was photographed in an aquarium early spring 2009 before being put back to its natural habitat. </small>

A larvae of the Blue Emperor (Anax imperator) awaiting unknowing prey to happen by. This exemplar was photographed in an aquarium early spring 2009 before being slipped back to its pond.

We’re soon done with the dry-collection. Next step; the alcohol preserved imagos and a few thousand larvae.
So far the schedule is to have a final database during this spring.

Read more about the project here.

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Keeled Skimmer

Last season (2007) a couple of friends introduced me to the Keeled Skimmer (Orthetrum coerulescens). Since the mid 30’s the Keeled Skimmer (O. coerulescens) was thought to be extinct in Denmark. In 2006 a rather large population was found at Søby, Jutland. By the end of the season 2007 it was known from 4 locations. At the beginning of the species flight-period this year another location was added to the list. One of my goals this year was to find a new, hitherto unknown population.

Male of Keeled Skimmer (O.coerulescens)

Male of Keeled Skimmer (O. coerulescens)

While litterature states the Keeled Skimmer (O. coerulescens) to be found in all sorts of running waters, Read the rest of this entry »

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sympetrum striolatumMale of the Common Darter (Sympetrum striolatum)
Photo details: 50mm - f/4.0 @ 1/160

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The gallery at http://www.nbell.dk/2009/ began as part of a competition between 2 friends and myself. We were having a race to see as many species of butterflies and dragonflies as possible during a single season. A by-product of that first season (2008) was a whole lot of photographs of a lot of different species. This spring we decided to try and put some use to all our photographs. We decided we could try and create a identification key for the danish species of butterflies and dragonflies. While the final goal is a polyclave identification key using our photographic material, theres a few big hurdles to pass first.

C.aenea detail

Note the presence of one crossvein only, in the cubital field of the hindwing. This is characteristic of Cordulia aenea. In Denmark, C. aenea could only be mistaken with species of Somatochlora, which instead have two crossveins.

We want the key to be a tool people can use when they come home with a lot of fritillary sp.’s and darter sp.’s on their Read the rest of this entry »

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