Faded Pincertail Onychogomphus costae in Madrid

John Muddeman
23/09/2013 11:17:02

A few pictures of this remarkable species which was refound in Madrid last year, 105 years after the only specimen record was taken at an unknown site.

Posted in: Dragonflies and Damselflies, Endangered Wildlife and Habitats | Madrid | Mainland Spain, Central Spain

Faded Pincertail male
Onychogomphus costae© John MuddemanFaded Pincertail Onychogomphus costae is a rather scarce dragonfly and endemic to arid parts of the W Mediterranean. It is also a notoriously enigmatic species in Europe, and not easy to see within its limited range in Spain and Portugal, and the remarkable and thrilling discovery of a population in Madrid in summer 2012 is a typical example of how elusive it is!

The first and only record for Madrid was a specimen in a collection, and without location details, noted by the famous entomologist Navás in one of his works around the turn of the 20th century. Then 105 years later, photos of both males and females, taken by chance, showed that it was still present! The first photo published on the Biodiversidad Virtual website - a citizen science project to collate geo-referenced wildlife records - has naturally received a flush of comments, and includes links to the paper describing this rediscovery.

Faded Pincertail female
Onychogomphus costae© John MuddemanMid August I finally found a few hours to go and have a look. Picking out possible sites to easily access the river was simple on Google Earth and I arrived around midday. Astonishingly, within just 15 minutes I came across the first individual, the single female shown here, perched in the dead flower stems of a crucifer, some 15-20m from the river, and perhaps, as it appeared to be teneral, it allowed a series of pictures. One thing that was immediately apparent was that it was a fraction smaller than I'd imagined and at a glance looks not unlike a teneral darter Sympetrum species. Closer views of course showed it was quite unlike anything else, and the pink underside to the eyes were particularly striking to me!

Luck was definitely on my side, and over the next hour or so I found a couple of males as well as at least two different mating pairs. As it got even hotter though, Faded-Pincertail pair
Onychogomphus costae© John Muddemanthe various individuals present got increasing more flighty, and would often rise rapidly up from their perching sites and disappear off at high speed, often to either not reappear, or once spooked, be difficult to approach again.

Following official publication of the record, accesible via the Researchgate link in the comments noted above, I have been able to look at the distribution of the species a little more, and not surprisingly, my location is not the same as the rediscovery site. Furthermore, more individuals found by friend, wildlifer and amateur photographer Abel López just a few days later increase this range even further. One of these can be seen here.

Obviously, several questions remain, such as proving breeding, and the true size of the popultion and its full distribution, since these two new sites in 2013 extend its known range along some 12km of river! With plenty more habitat available both up and downstream, plans are in place to visit both at different times and also to further sites in order to try and obtain a better estimate of the population and its range. With all records made during just a 5-day spread in mid-August, perhaps the species has simply been overlooked as it genuinely exhibits a very short flight period during a very hot time of the year when few naturalists would visit the area. Another Faded Pincertail pair
Onychogomphus costae© John Muddeman

Please note that bigger versions of these pictures can be seen on the Biodiversidad Virtual website:

Faded Pincertail male
Faded Pincertail female
Faded Pincertail pair
another Faded Pincertail pair

Related Information:
DRAGONFLY TRIPS IN & AROUND MADRID

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