ONE: Though their typical nest site is a hole in a tree, blue tits have been recorded nesting in all sorts of places: letterboxes and street lamps, inside a crack in a wall or a drainpipe, under a cast iron drain cover and, of course, in garden nest boxes.


Above and header picture: Blue tits photographed in the park by DKG
TWO: A blue tit egg weighs 1 gram, a tenth of its mother’s total body weight; she may produce one a day for more than two weeks. The record is 17 eggs laid by a single female. This is such an enormous investment in the next generation that a pair of blue tits raises just a single brood of chicks each spring,
THREE: Blue tits carefully time the hatching of their eggs to the bud burst of trees, particularly oak trees, and the hatching of the winter moth caterpillars that feed on new oak leaves.


FOUR: Some 98% of British gardens report resident blue tits. It is believed that the recent increase in blue tit numbers may have been helped by the widespread provision of nest boxes and bird tables. Well done!
FIVE: Domestic cats are a major cause of mortality, and responsible for 42% of ringing recoveries. Despite the large numbers of birds killed by cats in gardens, there is no clear evidence that this is causing blue tit populations to decline; in fact we know their population is increasing. Many millions of blue tits die naturally every year, especially in their first year, and there is evidence that cats tend to take weak or sickly birds.


Leave a Reply