Species Of The Week Number 34: Blue Tit
One of our most popular garden birds, 98% of British gardens report Blue Tits although they are strangely absent from Orkney and Shetland. Blue Tits are a success story with a 25% increase in population since 1966. There are around 15 million Blue Tits in the UK.
Blue Tits are the biggest user of garden nest boxes. They collect moss, wool and leaves to create a cup-shaped nest. Sometimes they add aromatic flowers to the nest - this has been shown to reduce the amount of micro-pests on the fledglings. The female Blue Tit lays an egg a day for about 10-12 days. Each egg weighs 1 gram. The eggs are incubated for 2 weeks and the young are then fed for 3 weeks until they fledge. The feeding becomes increasingly frenetic as the nestlings grow and demand more and more. The (now dishevelled) parents continue feeding the youngsters outside the nest until they learn to forage for themselves.
Blue Tits rarely travel far, so the ones visiting your feeders in winter are probably the ones nesting locally the previous Spring. Starvation alongside cat predation is the biggest cause of death.
As older readers will recall, in the last century Blue Tits used to be notorious for removing the tops of milk bottles, when doorstep milk deliveries were a big thing. Strong evidence suggests social learning within the Blue Tit population as the practice started in South East and North East England before slowly expanding across the country to its peak in the 1980's. Its demise was not only due to the reduction in milk deliveries but also the introduction of skimmed and semi-skimmed milk. Blue tits are actually lactose intolerant! The fats in the cream which rises to the top of full-fat milk don't contain lactose.
Comentarios
Añade un comentario