Robin tops numbers in the garden

BIRDS visiting gardens are the only wild creatures which most people encounter nowadays.

BirdWatch Ireland organises an annual survey of these conservation ambassadors and the results for last winter, one of the coldest of recent years, have just been published.

Oran O’Sullivan, writing in Wings magazine, discusses the trials and tribulations our songbirds experienced when temperatures were, on average, two degrees below normal.

About 1,000 people, from all over the country, contribute to the survey each year. Between December 1 and February 28 they record the species visiting their gardens and the numbers seen at any one time. Only birds which land on the site qualify for inclusion — ones flying overhead are excluded.

An exception is made for birds of prey, such as sparrowhawks and kestrels. Contributors must indicate how big their gardens are and whether they are ‘urban’ ‘sub-urban’ or ‘rural’. If there are berry-producing trees and shrubs, or food is put out for birds, details on these are included.

At the end of the season, BirdWatch subjects the data to a number-crunching exercise to see how each species has fared. While the results can’t tell us how many garden birds we have, comparisons can be made between years.

The results for last winter suggest birds which frequent gardens throughout the year coped well with the adverse conditions. A location with bird-tables and nut-feeders is surely the best place for a bird to be when the going gets tough. As in previous winters, the robin was the most frequently occurring garden bird, being recorded in 99.5% of sites. Blackbirds came in second and blue tits third. The great tit lost out to the chaffinch for fourth place.

Size mattered. Tea in a cup cools down sooner than water in a kettle because small things lose heat faster that big bulky ones. Cold weather, therefore, hits little creatures particularly hard. The wren, weighing a mere 10 grams, dropped four places in the league table to become the 12th most common winter resident. Our smallest bird, the goldcrest, has most to fear from the cold; it’s only half the weight of a wren. Down by six places since the previous year, it’ now ranks 30th on the winter list. The long-tailed tit also suffered. Weighing a mere 8 grams, it lost eight positions in the table, the biggest decline of any species. Seen in 42% of gardens, it’s in 26th place. Our smallest finch, the siskin, fell five points compared to the largest, the greenfinch, which lost three.

Birds have an advantage over other creatures when the going gets tough; they can fly to more hospitable climes. Cold weather abroad sent us lots of migrants last year. The winter will be remembered for an extraordinary influx of redwings during its coldest period. Open spaces, especially along the eastern seaboard, had flocks of these glamorous thrushes. The species ranking increased by a stunning 15 places in the league table. Berry-bearing shrubs, such as cotoneaster, are a lifeline for hungry redwings. They also benefit song thrushes, up six ranks in the table.

The other winter thrush, the fieldfare, is less common in gardens; it’s a bird of orchards, parks and farmland. Last winter, however, it turned up in 49% of gardens, improving its ranking by at least 16. Starlings visit Ireland in greater numbers when winters are severe. They ranked 8th compared to 12th a year earlier. “Not surprisingly, given the direction of bird movements from the continent, all the east coast counties figured strongly in the bird diversity listing”, says O’Sullivan. Eighteen of the top 25 gardens there recorded 33 or more species.

Longer-term comparisons reveal some worrying trends. Greenfinch numbers continue to decline, down by over 50% since the winter of 1997/8. On the other hand goldfinch numbers have doubled since 2005/6.

* www.birdwatchireland.ie