Social media is awash again with concern about swift numbers. I can only report on my own area and similar observations from friends in various locations. What I can say is that during windy, wet or cool weather I am very familiar with swifts ‘vanishing’. Our own colony has four breeding pairs this year up from two last year.
Breeding swifts seem to be doing well. They are incubating without fuss, changing over incubation shifts within the normal time range. This means that they are finding enough food to sustain themselves and they are not having to leave their eggs uncovered. The question I would love to answer is where do they feed? They fly off low, quickly leaving the colony airspace. Then they have something like an hour to feed before they take over incubation duty again. I imagine that they have well ‘trodden’ circuits which maximise feeding potential. In the strong winds recently I have seen swifts and house martins feeding on the sheltered side of woodland, a well recognised feeding technique. Sometimes they nearly skim the tree canopy in search of insects which are kept close to the foliage.
Some older non breeders/first time breeders are here but they are reluctant to prospect in the windy, cool conditions. Many are probably feeding over water and roosting above it while the weather remains cool so won’t even be visiting colonies. Some of these birds would ‘bang’ breeders nest sites in warm weather, but I have only seen this behaviour very briefly(2/6/22) on a morning before windy weather really set in. Swifts, though amazing fliers, don’t cope particularly well in confined airspace when crosswinds and unpredictable air currents caused by gusts surround buildings; even experienced breeders can take several attempts to enter a nest site in these conditions.
First time breeders do not necessarily have to occupy nest sites the year before. These birds sometimes prospect(probably males) then attract a mate in. They have usually already found a mate and paired in the air at this point, so their prospecting tends to be efficient and often quick to result in possession of a nest site.
I have felt the lack of aerial displays keenly because for two weekends I’ve had visitors for open studios and I love to show them swifts performing low level over the garden- there has not been one flypast in two weekends. Fortunately we have had cameras on nest sites so they can see incubating birds but no birds have lingered in the airspace above the colony. In perfect swift weather a swift can leave its nest and ascend high to feed, it probably doesn’t have to go far simply catching insects high above the nest before descending for its incubation shift or to feed young.
I am very confident that when the wind drops and the forecast warmer air drifts up from the south swift aerial displays and prospecting will resume quickly. Every swift season is different but the amount of activity we see is very much controlled by weather conditions. Strong winds are one of the biggest factors influencing how many swifts we see- strong winds keep insects low. The last few days have not been particularly cold and with light winds we would have seen far more swifts over colonies. The arrival of the youngest non breeding swifts looking to join colonies occurred on 23rd June in 2020/21; it is only after then that we see the peak annual numbers and the most impressive displays people tend to remember.
It still amazes me that breeding swifts can be so discrete and I can easily understand how people think there are none around or that populations are depleted, but as I write our swifts are all incubating, yet not one swift has lingered in the air above our colony or two nearby colonies this morning. For now the sky remains swiftless save birds occasionally arriving and departing to look after the eggs
Swallows and house martins
I would never be complacent about swifts, but as far as I can see they are doing well in this area. In our village we have seen a substantial increase in the last two years and Helmsley and Ampleforth seem very well populated. But swallows and house martins are a different story. Swallows have abandoned many former nest sites, which remain unchanged- they are simply not returning. The days of driving around countryside and seeing swallows around nearly every farmstead are gone for now. Similarly house martins have abandoned former nest sites which remain unchanged in many villages and towns. I wish I knew why? It could be a perfect storm of events or one single factor- we can only speculate.
We are very fortunate to have five pairs of house martins (up from none in 2019) but this doesn’t represent the wider picture. I have a feeling that isolated birds are gathering in ‘hub’ sites because they are colonial species. These sites can give a false impression that there is nothing wrong, but further afield a large proportion of former nesting sites are deserted due to the population crash. Recently when swifts have been absent the house martins have provided us with their summer soundtrack. In all but the worst conditions they tend to stay close to the colony and give us continued pleasure when the swifts are elsewhere.
It can be hard to find hope at times. It really does feel as if we are watching an extinction of favourite summer migrant species, at least on a local level. If we could identify the exact cause it might be possible to help their recovery, but if for example this is a result of our changing climate global and individual responses are needed. What you can do is provide some artificial nest cups for house martins and swallows and set aside areas for insects to thrive, not just flowers but cover where they can breed and rest. A pond encourages an array of insect life. Talk to others about these birds, enthuse about them, help people who already have them to know how important every nest is and tell them how privileged they are to be supporting an endangered species.
All text and images copyright ©️Jonathan Pomroy 2022