An image of a Willow Tit perched in the canopy of a Hazel.
An image of a Willow Tit perched on an Oak branch. This bird was in the process of opening up freshly emerging leaves and buds.
Lovely to spend time with this pair of Willow Tits today, during our monitoring visit, as they slowly moved around their territory feeding.
From bad to worse…
After being harassed by Marsh Tits, this pair of Willow Tits have now moved c. 180 m south, and have almost finished lining their new nest…
c. 1.5 m away from an active Great Spotted Woodpecker nest…
#Apeckalypse
Beautifully said Richard, from a scientific point of view. These birds are also individuals and pairs differ between each other. All Willow Tit pairs stay close whilst excavating but some stick closer and are more vocal than others, and it's very romantic. Lovely to have a glimpse into their life.
When excavating a nest cavity, Willow Tits share the work, taking it in shifts. These two birds are particularly inseparable - one will often sit on top of the nest or at the entrance whilst the other is inside digging. It’s wonderful to watch.
A new pair of Willow Tits found today on a large ex-colliery site. One of the birds was gathering fibrous strands of nesting material in the canopy. The nest site is an Alder snag with the cavity c. 1 m above ground. Classic stuff, next to a stream, plenty of Willow, Alder and Bramble. Lovely.
Some ominous footage gathered a few days ago from one of the Willow Tit nests we are monitoring. GSW are the most common predator of WT nests in Britain, and having increased by ~400% since the late 60s, it's not a threat that's going away. Let's hope this one has amnesia... #UKBirding #Yikes
It does take a bit of trial and error, particularly with getting the focus right.
The problem is any form of bird feeding in Willow Tit territories is bad news - risk of Sparrowhawk attack, abundant food source triggers excessive caching instinct in Willow Tits (and Marsh Tits), assists Blue Tits (competitors) and Great Spotted Woodpeckers (predators) through winter.
All year round, this pair of Willow Tits at a local public site are caching endless suet pellets, seeds and nuts put out in dozens of locations. Each visit to this exposed stump is seconds away from a Sparrowhawk’s next meal. This is happening in countless Willow Tit territories. It’s tragic.
An image of a dead Ash tree in woodland with a red arrow indicating the location of a Willow Tit trial excavation.
An image of a Willow tree snag in woodland with a red arrow indicating the location of a Willow Tit trial excavation.
An image of a Hazel tree snag in woodland with a red arrow indicating the location of a Willow Tit trial excavation.
Willow Tits are highly adaptable birds when it comes to nest site excavation. Here are 3 examples found during a visit this week to a woodland site on limestone, in Carmarthenshire. In order, these trial excavations (and heights) are in Ash (c. 4 m), Willow (c. 3 m) and Hazel (c. 1.8 m).
This pair of Willow Tits has started excavating a new nest cavity, a second attempt. The first attempt c. 10 m away was finished and ready for egg laying, but the recent warm and dry spell split the very thin cavity walls! Both birds are sharing the digging work, taking it in shifts.
Over three early mornings, a pair of Marsh Tits have attacked the female Willow Tit roosting in this nest box. The MTs are not after the cavity (c. 5 cm excavated), rather appear to be bullying the WTs out of the area, and eventually succeed, after which neither species pays interest in the cavity.
Woodcocks can no longer be shot in Poland. Evidence & pressure from ornithologists/NGOs resulted in full protection for Woodcocks and 4 other species.
Long overdue in Britain too, to conserve UK-breeding Woodcocks... and the migrants coming from/through Poland.
www.cambridge.org/core/journal...
A Willow Tit nest cavity from today, inspected with an endoscopic camera. It won’t be long before the first egg is laid in this nest. Note how different Willow Tit nests are from other tit species, with no moss but other plant materials (then fur etc.). Very distinct, even from Marsh Tit nests.
A stark contrast and critical reminder of what an understorey means in habitat terms regarding Marsh and Willow Tits. Years ago this north Carms woodland was fenced off from sheep. Now, a rich tangle of Hazel, Hawthorn and Bramble is advancing.
And there’s Marsh Tits on this side of the valley…
An image of a female Willow Tit leaving her nest cavity in a Willow snag early in the morning.
An image of a female Willow Tit leaving her nest cavity inside a nest box after roosting for the night.
Fascinating how these two female Willow Tits are going to roost in their nest cavities within a minute or so of each other (around 19.45) and also leaving them in the morning at 6.23. The male birds escort them to bed and are often seen waiting for them in the morning too. Amazing birds.
An image of an old Willow Tit nest cavity in a Hazel snag.
An image of an old Willow Tit nest cavity in a Hazel snag.
An image showing the location of an old Willow Tit nest cavity in the centre of a large Hazel tree on the edge of a farm track in Carmarthenshire.
Willow Tits as ecosystem engineers? This old nest cavity from a few seasons ago is still creating opportunities for other animals. It’s currently stashed nearly to the top with acorns from last autumn. WT nest cavities are often used the next year by Blue, Great and Marsh Tits in Western Europe.
Thanks Rob.
A photo of wet woodland in Carmarthenshire, with a red arrow indicating the location of a partly excavated Willow Tit nest cavity on the dead limb of a Willow tree.
A close up photo of the entrance hole of a partly excavated Willow Tit nest cavity in a mossy dead Willow branch. Tiny chisel marks can be seen inside the nest hole where Willow Tits have pecked away at the soft timber and removed it.
A photo of the end section of a snapped Alder trunk in which Willow Tits have excavated a nest previously, showing how pale and deteriorated the timber has become as it has decayed into a softer state suitable for these birds to dig in.
In Carmarthenshire many of the nest sites chosen by Willow Tits are in Willow and Alder, common species that make up most wet woodlands. Nest excavations often start where dead branches or main trunks break off in strong winds, and the pale exposed timber seems to attract Willow Tits to investigate.
They are filled with a special mixture of wood shavings to the top.
Willow Tit nest cavity entrance hole in Alder snag.
Mature Hazel tree with an Alder snag tightly wedged against the multiple Hazel stems. At the top of the Alder snag there is a hole showing where a Great Spotted Woodpecker has opened a nest cavity of a Willow Tit very recently.
A jagged hole smashed open by a Great Spotted Woodpecker, at the base of a nest cavity of Willow Tits, with some nest material pulled out the hole where the woodpecker searched for food inside.
The inside view of a freshly opened Willow Tit nest cavity, showing the nest materials covered with wood chips where a Great Spotted Woodpecker has broken inside searching for Willow Tit eggs or young.
Earliest ever predation attempt recorded today. Fully excavated and lined Willow Tit nest, found in Alder snag c 2.3 m above ground, 6 m from 2025 nest snag (also predated by Great Spotted Woodpecker - complete nest failure). Very fresh nest material pulled out, likely happened in last 24 hours.
Yes, this is the second season in Wales, before that three years on our nature reserve in Poland working with Willow Tit.
Thank you to @birdsinwales.bsky.social for supporting our Willow Tit Project. With help from WOS we are able to purchase trail cameras and endoscopic equipment to greatly assist in research and data collection. Some highlights from this pair today excavating one of our specialist nest boxes.
The cavity depths do vary, at the end of this season we'll have two years of Welsh data so a larger sample to do analysis on.
Either the endoscope or a thin twig if we haven't got it with us. Easy fix in the field.
Willow Tits are now busily excavating nest cavities across their territories. This pair from today have already aborted a 70 mm deep hole and dug another down to a depth of 120 mm c. 3 m above ground in a Willow snag. Telltale wood chips are scattered underneath on Moss and Bramble leaves.
A Willow Tit nest box being installed on an Alder Tree in a wet woodland.
Sawdust and wood shavings being put inside a nest box.
A nest box roof being screwed in place.
It’s the very last moment for final Willow Tit nest box checks. These boxes are having the infill changed - in such a wet climate this is crucial maintenance to carry out annually. Exciting few weeks ahead now…
Coniferous plantations, and Willow Tits? It’s not the dense conifers, it’s the ‘forgotten bits’ in between that can hold territories. There’s barely a hectare here of mostly Alder and Willow, impenetrable with dense Bramble. No interest in timber extraction. Perfect opportunity for Willow Tits.
A specialist Willow Tit nest box on a tree by a stream in wet woodland, in a Willow Tit territory where Great Spotted Woodpecker often predates natural Willow Tit nest cavities.
Final Willow Tit nest boxes up for 2026 season. Pairs starting to trial excavate nest cavities in most territories. In 2025 50% of nests we monitored were attacked by GSW. Initial data leans towards nests low in Bramble having greater chance of success vs higher exposed nests easier for GSW to find.
Another pair of Willow Tits found where, unsurprisingly, an unmanaged old hedgerow meets a belt of wet woodland. Dense Bramble understorey and deadwood. There’s a deeply concerning rhetoric that WT habitat should be manipulated and managed. This view is driving local extinctions. It’s madness.
