Friends of Adel Woods

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.

It is 12 years since the Friends of Adel Woods made and put up our first nest boxes in Adel Woods under the tutelage of Steve Joul, senior ranger with Leeds City Council. Since then we have surveyed them every year – except for last year when we were in a Covid 19 lockdown. This year, your correspondent was intrigued to find out how our feathered friends have fared without their annual spring clean in January 2021.

Most of the nestboxes are the tit boxes which you can see high up in trees throughout the woods. However, we also put a number of robin boxes out of sight within thick holly bushes – not a pleasure to survey! Robin boxes differ from tit boxes in that robins like to nest in a box with a large open front. This means that they have to be placed somewhere hard to find, to keep them safe from predators like magpies, woodpeckers and squirrels.

It was rather “parky” as we met in Old Leo’s carpark at 10 am, but fortunately the weather warmed up surprisingly quickly and we had a very enjoyable and successful day. In the morning there were eight of us including Steve.

We followed our usual route, heading along Crag Lane towards King Lane and taking the first turn left into Alwoodley Plantation where we surveyed our first boxes. We then made our way through the plantation, turning left at the practice rugby ground to come back to Crag Lane. We then continued along Crag Lane to the picnic area surveying nest boxes along the way.

By then it was lunchtime and we broke off for lunch after returning along Crag Lane and cleaning and surveying “Tina’s nest box”, a woodcrete nest box near the entrance to Old Leo’s car park.

After an enjoyable lunch break, five of us resumed our survey, making our way down the Meanwood Valley Trail from the picnic area towards Adel Pond. We finished as dusk fell at about 4.20 pm.

So what did we discover?

In all, we surveyed twenty two nestboxes today. Most of the tit boxes had been used. Of the three robin nest boxes we surveyed, only one had been used for nesting – by a pair of great or blue tits!

Blue tits and great tits nest once a year and do not re-use old nests and so, as expected, we found that most of the nestboxes contained two nests, one (from Spring 2021) on top of an earlier one from 2020.

We were surprised to find that most of the lower nests from 2020 had been “processed”, presumably by insects, almost to a kind of dust. The photograph below shows the difference between the condition of the earlier nest (on the right) and last year’s nest (on the left).

As is usual a number of the nestboxes contained one or two unhatched eggs – as in the photograph above. The nest on the left also contained a number of droppings, indicating that the nest box has been used for roosting by adult birds since the breeding season.

One of the things which we find each year is that tits like to use coloured man-made fibre in building their nests. In the photograph above, we can see blue, green and white fibre, but we also found plenty of bright orange fibre in other nests. We speculate that these fibres must have been collected from lost tennis balls, or possibly discarded clothing – though we have never found that number of tennis balls, or much clothing with those colours!

Usually we find one or two nuthatch nests, but none of the nestboxes surveyed today had been used by nuthatches in 2020 or 2021. Nuthatch nests are very different from tit nests as they are made from bark chips – looking rather like a bowl of bran flakes – rather than moss and grass. And it is usually possible to tell from the outside that a box has been used by nuthatches because they seal up any gaps between the lid and the box or in the sides of the box with mud.

There were two sad finds, reminding us that life in the wild can be harsh. One nest box contained twelve unhatched eggs. Another contained the skeletons of eight well developed chicks. Presumably, in each case the adult tits had fallen prey to a sparrowhawk or suffered some other sad fate.

We are completing our survey on Sunday the 23rd January. See our website for details! In the meantime, here are some photos of today’s activities.