What's going on News Nature news - success at the sand martin wall? We’ve finished the annual clear out of the sand martin wall in the Wetlands area of Millennium Country Park, as the birds have all migrated to sunnier climes now. The wall contains 88 pipes in 2 different sizes, which are packed with sand and partially capped with a sand-heavy cement mix at the start of spring every year. This set up mimics the cliff faces where the birds breed and nest. Once nesting season is over and the birds have fledged our team return to clear the pipes, which is when we know for certain how many holes have been used for nesting. This year 36 of the 88 pipes showed signs of nesting - this is more than we've had in recent years, but sadly doesn't beat our record of around 80 from a few years ago! This footage from March last year shows the pipes and wall in use: There were more holes with abandoned eggs, and one which looks like it had been attended by a opportunistic blue tit. The abandoned eggs may have been late second broods or the adults may have been disturbed – we restrict public access to the nest bank area because of wildlife and safety concerns, we do know that there has been some trespassing over the summer and this could have resulted in some disturbance. The sand martins stay with us for the whole summer, before migrating back to the Sahara, Africa in September where they spend the winter.