Willow Tit: hanging by a very frayed thread

 

I’m not sure when it became a thing that people walking would leave patches of seed at the edges of paths.  I’ve seen photographers and birders do it, especially when trying for a photograph, but there seems to be a recent trend of random dog-walkers just leaving small patches of seed.  The good intention is clear – a small act of provision for local wildlife – but in the context of the staggering amount of land being taken locally for development of houses (2500 on this greenfield site within five years) and businesses it’s very much a sticking plaster over a big issue.

Good intentions aside, this is potentially a damaging activity.  Today it benefitted me in my search for Willow Tits by bringing them to visible sources of food so that I could count them – while I could hear them all around me in the hawthorn hedgerow of my local patch, they can be very difficult to see and count without using playback – something I have done as part of the official wet scrub Willow Tit survey with Lancashire Wildlife Trust, but that I don’t do unless part of the survey.  However, it is well-documented that feeders and feeding contribute to a number of problems that undermine the help they bring to Willow Tit.  I’m no expert, but reading the excellent The Marsh Tit and the Willow Tit by Dr Richard K Broughton and paying attention to the widely available scholarship on BlueSky has left me in no doubt that what feeding gives with one hand it takes away with the other. 

Firstly, the supplementary seed is more likely to boost numbers of species that are bolder than the timid Willow Tit.  Every patch of seed I saw today had at least four Great Tits actively feeding, and the Willows were waiting until their larger cousins had finished eating.  Great and Blue Tits will evict Willow Tits from their nest holes, and given that Willows bore their holes new every year, each time they lose the investment in a nest hole, that costs a brood of chicks.   Swelling numbers of Blues and Greats with this unnatural source of food means there is more pressure than ever on nest sites.  The seed patches put down at Cutacre are within the nest territories of Willow Tits.  While chicks are not fed seed, adults will continue to take easy food during the breeding season.  Each feed flight where they return to their nest hole during the season (starting in March) leads to a risk of being followed by other birds and evicted from the nest. 

Secondly, the risk of spreading disease rises sharply when seed and feeders are used.  Concentrating birds at unnaturally big sources of food means communicable diseases are much more likely to be picked up by individuals.  If this impacts for example the local Blue Tit or Goldfinch population, they will likely recover as Greenfinches have done over the last decade.  If this impacts Willow Tit, there is no residual population to spill out and replenish numbers.  The fragmentation of habitat prevents Willow Tits from moving to suitable locations, given that Willows rarely travel more than half a mile from their natal site during their whole life.  While there are reasonable populations of Willow Tits within 10 miles of Cutacre, it would take 8-20 generations of Willow Tits moving through (non-existent) good corridors of habitat to find nest sites at Cutacre should disease kill them off.  Twenty years of development and habitat loss will not improve their chances of recolonising.

Thirdly, providing food has meant that Willow Tit predators that will also eat suet or fat balls such as Great Spotted Woodpecker have become superabundant in the last few years.  Not only will GSW take Willow Tit chicks as food, they will destroy the nest hole by enlarging the soft, rotten wood to get at the contents.  This has a double impact: the woodpecker kills an existing brood and prevents the Willows from having a supplementary brood in the same location.  The effort to excavate a new nest hole is so high that any pair of Willow Tits that have a brood predated by GSW are unlikely to breed again this year.  There have been a small number of GSW at the Willow Tit woodland at Cutacre over the last six years, but this has risen from (probably) one pair in 2020 to (probably) three pairs in 2025.  Certainly, four birds at once in a very small area of woodland is not unusual now, where it was unheard of four years ago.

This is to say nothing of the serious numbers of dogs walked at the site, all of which shed chemical anti-flea solutions into water systems and this of course will kill micro-wildlife, affecting the food-chain of birds that survive on insects and invertebrate life as nestlings.  The pressure on Willow Tits to survive in this atmosphere is intense.

 

Yet persist they do, and while they persist they’re the single biggest draw in returning to my patch every week.  Such charismatic birds, with real character and a huge appeal.  Though they have such a wide distribution around the world, and while I live in one of the "strongholds" of the species, their continued existence in England seems to be hanging by a very frayed thread.