Wednesday, 2 February 2011

Forest supports Coal Tit numbers

Coal Tits are one of the most regular visitors to owl hanging feeders, though not necessarily the most obvious. These small members of the tit family come pretty low down the pecking order and are readily displaced from the feeder by their larger and more robust cousins. Because of this they have adopted a different way of feeding. Rather than sit on one of the feeder ports and feed, they dash in, grab a seed and then fly away to eat it elsewhere. This behaviour reduces the chances of a run-in with a more dominant species.

Sometimes, rather than remove a seed and eat it straight away, they will hide the seed, caching it as an insurance against harder times ahead. They are not the only birds to do this, with Jays and Nuthatches perhaps equally familiar examples. The success of this approach obviously depends on the bird being able to find the greater proportion of the seeds that it has hidden, memorising local clues as to the seed’s whereabouts. Coal Tits and Jays are scatter hoarders, placing individuals seeds in different locations, while the Nuthatch will often hoard the seeds in one location. One of my former colleagues, had a Nuthatch which stored vast numbers of peanuts in a spare-room bed, which the bird gained access to through a small window that tended to be left open during the day! Of course not all the seeds are retrieved, and this is why you might find sunflowers growing in unexpected parts of the garden, or young Oak saplings rising from ground well away from any mature trees.

With their rather narrow bills, Coal Tits are birds which favour coniferous woodland, the narrow bill helping them to probe for insect among the pine needles or to take seeds from the cones. With Thetford Forest right on our doorstep, it is easy to see why these delightful little birds are doing so well around here. Blue and Great Tits prefer deciduous woodland and so only occur in low densities in the regimented stands of Breckland conifers, reducing the amount of competition that the Coal Tits face. Coal Tit numbers may well reflect the size of the cone crop in these conifer dominated habitats. Certainly, their use of gardens increases in those years when the conifer seed crop has been poor, suggesting that they are forced to find food elsewhere.

Coal Tits also face competition during the breeding season and are quickly usurped from many nest boxes by larger birds. Because of this, you tend to find them using cavities with the smallest entrance holes, often low down in damaged tree trunks. They must be doing well though, judging by the numbers seen locally.

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