Once there were many house martins that nested under the eaves of the Sea Mills Station building and also on houses along the street. For various reasons there was a drastic decline in numbers until we only had two pairs breed here successfully in 2023.
We observed the birds trying to build and then abandon incomplete nests, which was disappointing. Thus only two pairs remained and they re-used the nests left from the previously year, that needed very little repair. The other nests had all fallen off the building or crumbled past repair.
Mark Glanville (Bristol Swifts) and George Ashwell decided to do something to help and together they traced the owners of the building and got permission to put up prefabricated nests. A total of sixteen nests were then put up around the building on 13th March. Then there was a long wait to see if the house martins returned and whether they would actually use the nests.
The first house martin was seen over the building on 19th May. By the end of May the birds were testing out the nests and by mid-June, two pairs had settled into two of the nests, though other house martins seemed to be visiting a few of the other empty nests.
It was fascinating to watch the birds bringing white feathers and pieces of dried grass to line the nests and we were confident that we had at least two pairs ready to settle. We didn’t manage to attract any more pairs but over the next few weeks these adult birds were busy flying to and fro.
Tiny parts of egg shells were seen on the ground under the nests on 23rd June. The first week of July saw the first chicks peering out with their gaping yellow mouths demanding food. There were at least three chicks in each nest, possibly more. By the end of July the chicks had obviously fledged and were now moving into the adjacent empty nests for a bit of space but still demanding to be fed by the adults.
We then observed juvenile house martins peeping out of nests that had previously been empty and trying out nests on the other sides of the building. One adult pair then settled into a nest on the platform side and started a second brood.
On 17th August we saw the egg shells below that nest so we knew the chicks had hatched. The same day a large flock of up to 30 house martins swooped down to the building and flew to nearly all the nests, visiting most of them and peeping out. Hopefully they are choosing a nest for the next year.
The second brood of chicks successfully fledged and were seen leaving the nest to feed by mid September. We are now in the third week of September and the house martins are away feeding by day but a small group return each evening to squeeze back into the nests overnight.
Thanks go to the B.O.C. (Bristol Ornithological Club) for funding the eleven nests that were bought. Mark made the other five nests himself. The birds have used both types showing no preference.
For next year we hope that the birds will return in greater numbers. Having pre-formed nests means the birds are saved at least ten days of nest building, that have often failed for various reasons. The hope is that the colony can be built up to its previous numbers, though there are many other factors that have resulted in the decline in numbers of this delightful bird.
