Saturday 25 August 2012

16 years of trapping at Pencaecrwn

Since recording moths & butterflies at our home address in August 1996, 16 years on we have almost reached the 700 species mark. Our results show that the first 300 species were recorded in the first two years, with another 100 added in year three. As expected a gradual tailing off then took place, but what is perhaps a little surprising is that even after 16 years we still continue to add new species, with an average of 9 new species in each of the last five years. Only a few of these are recent colonists, the majority being established residents, presumably wanderers following favourable weather from nearby habitats. If the predicted trend is right we should hopefully reach the 700 milestone this time next year...


  1. Interesting analysis Barry. I wonder if you have the highest garden total in Wales? Still some way to go to reach John Langmaid's 1000+ though!

    It's nice to see that you keep adding new species - gives me hope that my garden may eventually pass the 500 mark (currently on about 450 species after nearly 6 years trapping, but not many added this year).

    George (Llandaff North)

  2. Dave Grundy's review of highest site & garden totals in Atropos 36 gave Neil Horton's in Usk (649 spp) as the highest in 2008, so Barry's certainly seems to be the top one! There must be some other very high totals in Glamorgan though.

    The continued adding of 8-10 spp per year tallies with my experience at Dingestow, which was at 859 in 2008 (but it's a 1000 acre area of farmland and woodland, so not comparable with a garden!). Every year when I was recording properly I added 7 or 8 spp, but they were mostly residents like Eyed Hawk rather than immigrants. I've only had a couple new since 2008 - leaf mines - because I haven't been trapping there.
    John Langmaid's garden was listed at 1002 in 2008; John Radford's in West Sussex was listed as 1223, so appears to be the top one in GB.
    Sam B

  3. It's worth noting that our garden is very unremarkable; we live near the outskirts of Gorseinon and there are a few habitats of interest within a 1km range including colliery spoil, unimproved marshy grassland, woodland and saltmarsh, but our garden is partially illuminated and urban so far from ideal. I do wonder if being at the highest point in Gorseinon (albeit just 50m) increases our chances of attracting migrants and wanderers - does hill-topping occur with resident as well as migrants in this country, I'm not sure? It will be interesting to see how other keen moth'ers lists develop over time...