Wednesday, 19 August 2015

Cors Dyfi

On Monday night I headed to Cors Dyfi reserve in the far west of the county, home to the Dyfi Osprey project. I was doing a moth and caterpillar walk at the reserve the following day so I thought it would be nice to have some locally caught moths to show. It was a very still but clear night, which meant cold temperatures. Peter (who I was staying with) joined me for much of the night.

I took 4 MVs and 3 actinics traps, which were run in the car park and along the boardwalk. Despite the cool temperatures, plenty of moths were flying (even in the reedbeds where it was colder still). The actinics were catching a surprising number of the weak-flying geometrids - which were mainly Oblique Carpet, Dark-barred Twin-spot Carpet, Devon Carpet and Cheveron.

There were a few wetland species that occur in very few sites in the county, including Chilo phragmitella, Small Rufous and Crescent. Some of the western species included Marbled White Spot, Large Ear and Golden-rod Pug.

It's currently the peak season of Rosy Marsh Moth. Despite extensive trapping over the years, only one has been caught on the reserve in recent years - given the cold conditions I wasn't really expecting it to turn up. At about, 10pm, however one showed up around the car park trap, and another one was seen soon after on the boardwalk. The moth has not been confirmed breeding on the site so these individuals may be wanderers from the nearby large population at Cors Fochno (around 5 miles away in Ceredigion). I feel it's more likely, however, that the moth breeds on the reserve at a low density, perhaps forming a sink population (that is a population that is part of a metapopulation that cannot sustain itself without some immigration from a source populations, in this case Cors Fochno.)

The second highlight of the night was a single Webb's Wainscot - a new species for Montgomeryshire. It was a good night for wainscots with plenty of Bulrush, Southern and Smoky about the site. Webb's is not a species I'd come across before but it must have been somewhere in my mind, as it was my initial thought and I remember asking Peter if Webb's was on the county list. A look with the book confirmed my suspicion and a check of the websites showed it seemed to be moving up the welsh coast.

A grand total of 92 species were recorded, which is pretty exceptional given the cold conditions; about five of these were new to the reserve.

Had it not been for the need to catch some moths to show people the next day, I probably wouldn't have bothered trapping the reserve on such a cool night, however the new county record, Webb's Wainscot, as well as the third and fourth records of Rosy Marsh Moth meant it was very worthwhile indeed.

Follow the link below for all my pics (all taken on my iPhone so apologies for quality). There's also a full species list:

Cors Dyfi - 17/08/15

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