They do what they can, but tits have it extremely difficult due to the cold spring. Peter de Vries of the Netherlands Institute for Ecology (NIOO) even comes across nesting boxes in which all young birds are dead. The problem is that there is hardly any protein-rich food available.
The NIOO has been following the tit population in the Netherlands for years. For example, the birds on the Westerheide near Arnhem are accurately counted. De Vries is saddened by the result. And that is mainly because there are hardly any leaves on the oak trees due to the cold. No caterpillars without leaves and no food for the young without caterpillars.
“The oak is a breeding ground for nearly a hundred butterflies, including the oak processionary caterpillar. Because the oak is later than normal, the caterpillars are also later than usual. As a result, the young tits starve in the nests,” says the researcher at Gelderland broadcaster.
Brood does not coincide with caterpillar peak
Tits can use certain tricks. “Because of the cold, they try to delay their brood a bit. For example, the great tits have laid their eggs as late as possible, the clutches are smaller than usual and the parents have longer and more breeding breaks, which means that the parents regularly get rid of the eggs. to delay hatching, “said De Vries.
But it has been so cool for so long this spring that the tits simply fail to level their brood with the caterpillar peak.
Albert de Jong of bird work group SOVON is not in favor of hanging tit balls (or fat balls) to alleviate the need. “Offering more food in this way does not help, because the tits need a lot of protein-rich food during this period. And that’s only in insects.”
So we have to wait for higher temperatures. Then things can quickly turn out, says researcher De Vries. He expects that tits will just start the second leg of this season.
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