Hello! As you might know already, we have a sand martin bank. You can see this from the Family Hide on the right hand side, or from the left hand side of the Wader Scrape. They are beautiful little birds, in fact they are the smallest Europeans hirundines...( the collective term for swallows and martins.) They are incredible flyers who fly mainly over water, snapping up invertebrates on the wing. A couple of times in the last 50 years there has been a drought in Africa, where sand martins go for the winter. This then caused a European population crash. Read more about the sand martins on the RSPB page here.
Our assistant warden Kate gave me this info....
Sand martins, it seems are quite fussy and don’t like it wet or drafty. So we have taken measures to counteract this by draft proofing the holes with Persian carpet and foam on the inside! Each hole has a flap on the side so we can monitor the nest and the wooden flap also helps form a seal around the hole so no drafts get in! Each hole also has sand from a local quarry which has been sieved by our volunteers so it gets rid of all the big stones and rocks and its quite fine. The birds then build a nest on the sand against the back of the chamber (the back of the chamber is lined with the carpet!) and some birds have more elaborate nests than others. Some nests are a work of art with feathers curved around the hole and carefully places grasses, moss and feathers. Others are a bum-scraped hole with a few bits of grass and small duck feathers!!
The banking is made out of breeze blocks with terracotta pipes as the nest chambers. There is an anti-predator shelve below the lowest holes to stop them jumping up into the holes. The moat around the banking also acts as a good anti – predation method. The roof is wooden with a plastic lining and pea gravel on the top.
Here are a few photos.
Laying the foundations.
Half finished...
Putting in the chambers...
Inside, down the middle...
And a sand martin chick, aged nine days + :)
More info from Kate!
Sand martin breeding figures.
2011 – The Family Hide side had 2 holes occupied with 3 broods in total. One pair had 2 broods the other only 1. The wader scrape side was more popular, with 8 holes occupied and 12 broods in total. 4 pairs second brooded and 4 only had single broods.
By holes occupied, we presume they are a pair and if they 2nd brood that it’s the same pair having another brood in the hole. Although we haven’t proved it in our banking, pairs can triple brood, We suspect a triple brood if a hole is newly occupied next to a hole which had a second brood in. The nest holes can get very dirty and full of parasites and bugs so pairs will switch holes if the parasite burden gets too much.
We monitor the sand martin banking from inside and outside and compare what we see. So far we have found out that by looking at the amount of activity on the outside of the banking (birds flying in and out of the holes), you often get a higher figure for occupied holes than looking on the inside of the banking. So last year, we recorded birds going in and out of 62 holes on the wader scrape side and 44 on the family hide side, but this only corresponded to 5 holes from the whole sand martin bank used!
2012 – The Family Hide Side of the banking had 1 hole occupied and there was one brood fledging 3 chicks. The wader scrape side was more successful with 4 holes occupied and 6 broods in total. 2 pairs had 2 broods in them and the other 2 only had 1 brood in them. Each brood had 4-5 chicks fledge successfully. The total number of chicks for last year was 30 – we rung 27/30 of them. We didn’t ring the 3 chicks from the family hide side as they had already fledged when we got to them!
So, if you are in either of those two hides, keep your bins pinned to the bank, you are quite likely to see sand martins flying in and out, or peeping out or just 'hanging' in front of one of the chambers...
Enjoy, gorgeous to watch!