GHR's post about house martins set me off wondering about a few local colonies so I set off to investigate with Stevo Lucas and Fran Eggby.
The first stop was Tresinwen Farm where there were usually several nests on the front pine end of the main house. I knocked on the door and asked Richard ( Lewis, the farmer) if he minded me looking around to which he was happy to give his permission. First glance was disappointing with just one nest at the apex of the eaves. However we then noticed six more nests under lower eaves at the side of the house. Altogether four of the nests seemed to be occupied by martins but others were broken or occupied by House Sparrows. We also witnessed a male house sparrow entering one of the HM nests seemingly up to no good.
A smaller colony around Bronmoor had five nests, three of which were definitely occupied by HM's
again one was partially broken and occupied by HS's
Both Mathry village shop and the Church had long had colonies but the shop had but one nest and the church only two of which one was occupied by HM's but unsure of the other, with signs of damage to a third nest.
At Tregwynt, where I had admired at least a dozen pairs of HM's there were fifteen nests, at least four occupied by HS's and so far as we could tell only four populated by House Martins. Again we saw male House Sparrows enter the Martins nest.
In Fran's house in Mathry, she had witnessed a healthy colony of Martins evicted by House Sparrows over the past few years. I had also witnessed House Sparrows trying to evict Swallows in my barn. The swallows put up a bit of a fight resisting the Sparrows but I saw no signs of resistance by the House Martins.
Looking up the RSPB website, https://www.rspb.org.uk/birds-and-wildlife/wildlife-guides/bird-a-z/house-martin/conflict-with-sparrows/ it seems this Sparrow v House Martin is far from unusual. It would seem that at least in our neighbourhood it may well be the final straw for our remaining House Martins...
