Wednesday, 14 March 2018

Is it time to develop a ‘High Altitude Dipterists Group’?

I have felt for a long while that Dipterology in the UK was missing a trick because so few people do any field work at higher altitudes. David Horsfield and Iain McGowan have done a tremendous amount over the years, but they are the minority. Stuart ball and I have done a little bit – looking primarily for Gonathrus planiceps on Cairngorm, Glenshee and in the higher parts of the Pennines. In so-doing we have managed to find a few records of interest but in the course of many visits have only once found a single Gonarthrus! We believe that it is only found above 2,000 feet, so the numbers of potential locations are quite small outside Scotland. But, who goes high in England and Wales and makes a real effort to look for Diptera? 

Figure 1. Flush above Glenshee ski centre
The reality is that upland entomology is hard work and the range of species is quite small compared to a nice lowland woodland! Nevertheless, it is an important fauna and is one that is quite likely to be seriously affected by climate change. After all, our mountains are quite low and changes to the temperature profile could be dramatic. Some while ago, Stuart modelled the possible range of Cheilosia sahlbergi and predicted that it could be lost by the end of this Century! Those predictions come with a big ‘health warning’ but they highlight the possible plight of upland invertebrates.

Today, I was reminded further of how limited current recording is at higher altitudes. Martin Drake sent me maps of two montane Dolichpodids: Dolichopus maculipennis and Hydrophorus rufibarbis (Figures 2 & 3). They tell an obvious story of how poorly worked the uplands are! Although there are lots of old records there are frighteningly few modern ones. This deficit is almost certainly a lack of recorder effort.

Figure 2. Distribution of Dolichopus maculipennis as currently on the Dolichopodidae scheme dataset. The black dots represent most recent records.

Figure 3. Distribution of Hydrophorus rufibarbis as currently on the Dolichopodidae scheme dataset. The black dots represent most recent records.
Stuart and I have often discussed the idea of forming a ‘high altitude group’ to address this deficit. We are not as young and fit as we once were, but there ought to be lots of young entomologists just waiting for a challenge. I think in my 20s I could easily have been pushed into the mountains – especially if it had involved a bit of ropework and climbing. Most high altitude Dipterology simply requires a bit of strenuous exercise – so here is the challenge to the younger generation: how about looking high up for your Dipterological experience? The advantage is that the species range is quite small and there are lots of possibilities of short papers and articles on your findings – the literature is highly deficient.

In the meantime, I really ought to rise to the challenge of looking for upland Dolichopodidae and of course Platycheirus melanopsis and Cheilosia sahlbergi. The former was once known from the Lake District and I’ll bet it is still there! And what is there on the higher reaches of Snowdon, Tryfan and the higher peaks of North Wales?

Who said that all the low-hanging fruit had been picked? There is plenty to do looking at flush systems on different rock types and some nice ecology to be done. All it needs is a few energetic youngsters!

1 comment:

  1. Thanks for highlighting this Roger. I'm a high level walker and runner myself, usually in the lake district and always take a specimen tube or two along with me on a walk or a run (small net on walks only!). In the main I'm generally looking for beetles at altitude, mainly because I'm more familiar with montane beetle species but I would be delighted to collaborate on a high altitude diptera group.