Heart shaped nest
The nest, which developed its distinctive heart-shape after being removed from the nest box, contained three pale speckled eggs that had failed to hatch last spring.
National Trust rangers suspect that the eggs belonged to a pair of Blue Tits or Great Tits. The birds were either killed by a predator or had been disturbed and abandoned the eggs, the conservation charity said.
The tiny nest, which at around 13.5cm long is about the length of an iPhone 6, was made using horse hair, grass, feathers and moss.
It was uncovered in one of 65 nest boxes that have been installed in the woods at Hardcastle Crags with the help of Calderdale Bird Group. Groups of three volunteers take it in turns to scale ladders in order to check and record the boxes.
By identifying the nests’ builders, rangers and volunteers are able to estimate trends in the breeding bird population – directing how rangers manage the woodland valleys.
Natalie Pownall, National Trust Academy Ranger at Hardcastle Crags, said: “Where eggs have been abandoned, disturbance is the most likely cause. The adult bird can get flustered and if attacked can even damage her eggs in the surprise attack.
“Busy blue tits lay up to an egg a day at the height of the season. It’s an ordeal that requires a huge amount of energy, which is why you’ll see the birds stocking up on fatty foods like peanuts and sunflower seeds in your garden in March.”
With Valentine’s Day looming, birds at Hardcastle Crags are busy pairing up for the upcoming season.
" Our female blue tits are looking for the perfect partner and home to raise her young. Her ideal Romeo will need to bring her insects and other grubs to eat whilst she’s brooding on the nest. Once born, her chicks will need to eat on average 100 caterpillars a day just to stand a chance at survival. "
We’re not sure what happened to the pair that made last year’s nest. But we’re hoping that this spring brings no repeat of last year’s heartbreak.