Swift and house martin blog- May 18th

Swift Diary

Last year’s breeding swifts arrive generally between very late April and late May. The pattern is different each year. For example 2022 saw a quick build up with most here by 16th May and last year’s was very staggered with birds still arriving in late May. This year our colony is very slow to build up. This can influence the structure of the colony. If they all arrive close together pairs tend to reunite but staggered arrivals (as this year) sees birds seeking new mates and fights when original partners do return. It is not really possible to assess swift breeding numbers until the end of May/early June, so don’t assume if you are not seeing many swifts now, that there isn’t still time for them to return.

We continue to host one breeding pair of swifts in box 2- we had three pairs breed last year, down from four pairs in 2022. So two out of six are back. We haven’t seen any new arrivals since 9th May. There is still plenty of time for last year’s breeders to arrive, but I know from chatting to friends that many colonies are nearly fully assembled, so why isn’t ours? It’s not just our house colony, but our village as a whole. After last year’s decline of breeders and lack of new prospecting tenants, it is very easy to see how a smaller colony can vanish. But thankfully we’re not there yet. Currently Gilling East has less than a quarter of its 2022 breeding swift population back. 2023 saw a decline on 2022 of about 40%, so I wonder how this year will play out?

The rise of swifts in Gilling East in 2022 and fall in 2023 has been very much echoed by the British Trust for Ornithology’s Breeding Bird Survey results for 2023 which shows a big drop from 2022-23 in the Yorkshire/ Hull region. I wish we knew why. You can read the report here

https://www.bto.org/our-science/publications/breeding-bird-survey-report

Source BTO Breeding Birds Survey Report 2023

Some colonies locally appear to be thriving but this is not the whole story- to assess populations you have to look at the wider area rather than single colonies. Swifts are colonial and it could be that with a decline their range has contracted so smaller outlying colonies suffer as birds move to be with larger colonies. That’s just a theory but I have seen the same happen with declining populations of house martins and swallows, so why not swifts? It is concerning that colonies where there are ample nest sites for expansion decline, as it shows that swifts are vulnerable to other factors, probably weather in our case.

Even though the weather is fine and warm the sky is quiet. A brief flurry of activity yesterday was a bit of a false dawn as no new birds came to roost and there was no activity in the evening or this morning. So once again I find myself asking questions as to why this is so?

I did have one or two flypasts of three birds (including our breeding pair) yesterday which was a joy to see though short lived and now I yearn for more. Our single pair quietly comes and goes but at the moment we don’t have a colony of swifts, we have one pair. I should emphasise that there is still a week or so for numbers to catch up last year’s, but I find the differences in build up of colonies interesting to look at. I hope to blog again soon with more news about our latest arrivals!

I’d be interested to hear from anyone else whose swift numbers are well down at this point. Also if you had a noticeable decline on 2022 numbers last year. Do drop a comment with location in the comments box below.

House Martin Diary

House martins look to be in better shape than swifts here at the moment, though as with swifts others report the exact opposite. I think we have five pairs settled, to be confirmed. The middle of May onwards usually sees an arrival of younger house martins born last year. These birds can be seen building nests in late May and June and often only raise one brood before they leave. These first time breeders are often first to use artificial nests at new sites so their is everything to play for on the next month or so if you have provided some.

I’ve been sketching pied flycatchers and redstarts this week. These birds inhabit a few woods on the North York Moors. I visited one such wood on Thursday. The bluebells were at their best and the air was full of their scent. What a privilege to live near this habitat.

Our pond has come alive with the sight of large red and azure damselflies laying eggs, actually more than we’ve ever seen. In the evening beautiful Mayflies dance in the air above the garden. The weather is warm and spring is reaching its peak, all that’s missing is the sound of Gilling East’s swifts.

All text and images copyright Jonathan Pomroy 2024

House martins and swifts on May 9th

Portrait of a swift- watercolour