Starlings in survival fight

PEOPLE DON’T like starlings. They are noisy, aggressive and greedy. Their nests, often in the roofs of houses, are a total mess and they gobble up everything on the bird table, leaving nothing for the smaller birds.

I open a mist net in my garden most mornings and starlings are among the birds most frequently caught. Each autumn, starling families range over a wide area and invading my garden. The babies aren’t streetwise and occasionally, an entire family is caught.

Starlings are interesting birds to ring. They are resourceful, opportunistic and some of them travel huge distances. Their social behaviour too is interesting. In late summer, for example, young starlings gather into juvenile-only flocks, easily recognised because the birds are brown rather than black and lack the white spots which give starlings their name. Just why they form these locks is unclear. Perhaps youngsters have special food requirements, which differ from those of adults.

Later in the year, the juvenile flocks merge with adult ones, forming huge concentrations near roosting sites at dusk. A great starling flock wheeling in the evening sky is one of the great wildlife spectacles of these islands. But there is a more pressing reasons to ring starlings; their numbers have declined over the last 20 years and we don’t really know why.

A starling catch is a mixed blessing. These birds are very strong and tough. When caught in a net they won’t just sit around waiting to be released. Instead, they struggle to free themselves, becoming ever more entangled as they do so. The strong legs, with their sharp grasping claws, can tear a net. The one in my garden has to be replaced every year.

About 2.25% of starling rings are subsequently reported, a higher percentage than for most small birds but you still have to ring a lot of starlings to get meaningful results. I have managed to ring a few hundred over the years. Up to now, all of the ring reports have been of birds found locally. Our local starlings seem to be residents, which never venture more than a few kilometres from Malahide where I live.

I was rather surprised this week, therefore, to receive, not one but two reports of starling rings from the British Trust for Ornithology, which runs the ringing scheme. The first report was of a juvenile, ringed soon after fledging, which had been found, dead, about 2 km away from where I live. The find did not, obviously, make a major contribution to our knowledge of starling migration.

However, the bird was over seven years old when it died and this is interesting. Very few small birds reach such an age. In one study, 40% of starlings had died within nine weeks of fledging, when food was plentiful. When food was scarce, up to 60% had perished.

Few songbirds, of any species, live to see their first birthday. However, if they manage to make it through their first year, their survival prospects improve. Any bird, which manages to reach the age of one, has a set of genes which give it some advantage over others. Then nurture, as well as nature, begins to favour it; the year’s experience of life will have taught the bird many valuable lessons. It will have gained a detailed knowledge of its area. It knows where to find food, where to roost and where it might nest. It will have encountered the local cats and become aware of the danger from cars. Knowledge is power, so, as they say, ‘the older a bird gets, the older it gets’!

However, although its survival prospects improve with the years, the threat of sudden death is ever present and even old birds live in a precarious world. The starling which reached the age of seven in Malahide is, therefore, a bit special. It is difficult to estimate the proportion of starlings living that long but it is certain to be less than one in a hundred. Of course, some individuals live much longer than this. Over 1.3 million starlings have been ringed in Britain and Ireland, 39,000 of them being subsequently reported. The oldest recorded was a one ringed in Suffolk in 1983 and found in Novgorod, Russia, almost 18 years later.

The second report this week was of a Malahide starling found dead in Derby in the north of England. It was an adult when ringed so we don’t know its precise age. However, it too was a mature bird, at least six years old when it died. But the find is interesting in another respect. This is the only one of my Malahide starlings to be found abroad or indeed to be found far from where it was ringed.

There seem to be two components to our starling population. Resident birds breed locally and neither they, nor their offspring, go anywhere. Then there are starlings which flood into Ireland each winter from places as far away as Eastern Europe and Russia.

In theory, the Derby bird could be one of these migrants, coming regularly to our shores and ringed by me on a previous visit. However, it was found dead on August 2 and it’s unlikely that a visitor from far afield would be in Britain so early in the season. It was, in all probability, a local Malahide bird, which had emigrated to Britain. Our starlings may not be such sedentary stay-at-home birds after all.

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