Today we completed our survey of the nest boxes in Adel Woods. We started the survey on Sunday the 9th, when we surveyed about two thirds of the boxes. (You can find out what we discovered that day by clicking here.)
This morning we met at 10 am at the Slabbering Baby entrance to Adel Woods at 9.55 am. Steve Joul drove his landrover down to the Slabbering Baby and we set off up the Meanwood Valley Trail, past the pond, to nest box 35, which was the next nest box to be cleaned when we finished on the 9th. It was a pleasant morning and there were five of us, including Steve.
Having cleaned nest box 35 we made our way down the Meanwood Valley Trail to the Seven Arches, cleaning another fourteen nest boxes, finishing with box 39, to the right of the path. We then put up nearby two more nest boxes donated by Rob and Tina, having numbered them 50 and 51.
What we discovered
Like many of the nest boxes we surveyed on the 9th, most nest boxes contained two nests – one from Spring 2020, and another on top of it from Spring 2021. This was because we were unable to clean and survey the boxes in January 2021 due to Covid 19.
People are often surprised that great tits and blue tits don’t simply re-use an existing nest, but they don’t even though it clearly takes a huge amount of time and hundreds of trips to make a tit nest from moss and grass. No doubt there is an evolutionary advantage to raising chicks in a new nest as the old nests are often full of fleas and mites which would harm the young brood.
Nest box 35, the first we surveyed, also contained 7 unhatched eggs, so the likelihood is that in Spring 2021 the nest was wholly unsuccessful.
We found two nest boxes which had been used by nuthatches. You can always tell a nest box has been used by nuthatches before opening them because nuthatches fill all of the gaps in the nest box, particularly around the lid, with mud. The nest inside is totally different from a tit nest in that it is made of bark chips and looks like a bowl of bran flakes!
We were amazed to find in one nest box a hibernating noctule bat. Needless to say we immediately closed the nest box and put it back up without cleaning it. Perhaps we shouldn’t have been surprised because we found a hibernating noctule bat in the same nest box in January 2020, so it was probably the same individual. What was interesting was that the nest box had also been used by nuthatches to bring up a family in Spring 2020 or 2021 – so it was a bit like a timeshare!
Noctule bats are the UK’s largest bat and you can find out more about them on the Woodland Trust’s website here.
We have one particularly large nest box which is about 45cm deep which is supposed to be for treecreepers or starlings. We have never had treecreepers or starlings in it, though we have found tit nests in it in the past – which makes you wonder about young fledglings having to fly up to the exit hole to leave the nest! In 2020 we found a tit nest and a mummified squirrel in the box. This year we found about 30 cm of dried leaves in the box, so it had clearly been used for nesting by a squirrel.
Several nest boxes contained bird droppings on top of the nesting material, indicating that they had been used for roosting since the last breeding season. Several contained moth larvae which chew the wood of the nest box and create a very tough spongy material in which they pupate. It also tends to glue the lid of the nest box shut!
So that is it for another year. When walking through Adel Woods this Spring, keep an eye out for our nest boxes and take a few minutes to watch from a distance and see who is using them. Pretty well all of the nest boxes you see will be used.