News on Cazuma pincertail in Andalusia

G3-guides was lucky and honoured to organize two dragonflies tours rambling Southern Spain in late spring 2023, with, firstly, a group of friends all members of the Libellenvereniging Vlaanderen, Flanders group of Odonatology (Belgium) and later with a delegation of the Nederlandse Vereniging voor Libellenstudie (NVL), Dutch Dragonfly Society (The Netherlands). The trip was the perfect occasion to visit some of the best localities for Odonata in Málaga and produce a long list of records which are much needed for long term surveys of dragonfly populations. In this blog post, we will focus on the major finding of those expeditions: the discovery of a population of Onychomphus cazuma, a species new to Andalusia (1).

The finding was fully reported in Discovery of a population of Onychogomphus cazuma in Andalusia, Spain a paper published in the recent issue of Notulae Odonatologicae (see abstract) by Prunier and De Knijf. We love this scientific journal produced by Osmylus Scientific Publishers and an expert team of odonatologists in a totally independant fashion. A well established international scientific journal polished by its editors as a work of craft is quite unique among the business of the academic publishing industry.

Our paper is quite detailed, so we will not repeat here. The starting point of the research was a mysterious picture taken in 2010 and published on Observation.org that could not be correctly identified. After Onychogomphus cazuma was described new to science by a Spanish team, the record made surface but the identification was still inconclusive although something interesing was going on.

A preliminary visit to the area permited to identify potential habitats for the species… And to our great astonishment, we actually found the dragonfly in the “only place I can think it could breed“.

As soon as we reach the site, we observed exuviae and larvae in emergence. We were lucky that our visit coincides with a period of strong emergence for gomphids in Andalusia, right after heavy rains in mid-May. We do not only focus on dragonflies adults, but  also study exuviae, which is usually the best option to detect rare and elusive species. Thanks to the unique larval mask feature among Spanish Onychogomphus, it was quickly clear we were successfull in finding our target. At first, we were unsure if this could even be a new species… But when the specimens were properly observed with high magnification, the only option left was for Onychogomphus cazuma. What a remarkable finding.

Surgencia del Tajo del Buitre: a seepage by the road side that always catch the eyes whenever you pass nearby for its lush vegetation… and really a small and restricted habitat. In consequence, the only Andalusian known population of Onychogomphus cazuma must be extremelly tiny (my personal guess around 50 individuals or less). Should we publish such a finding with so many details? This questions haunts me for many weeks. Will we make the conservation of the species better or worst by spreading the news?

The site is exposed to trampling by buses. With the recent aperture of the famous and much advertised Caminito del Rey, the conditions have changed tremendosuly locally and the traffic on the road crossing the Desfiladero de los Gaitanes is currently very high. We have only discovered the population when it faces a tremendous treath.

Finding of course new localities for the species in the Baetic mountain range. This can only be achieved focusing on the specific habitat of the species in Andalusia. Permanent seepages (that probably do not frost in mounatain ranges such as Cazorla and Sierra Nevada) are rare in our Mediterranean region and are strongly impacted by global warming. Will we be able to detect new sites?