News for May 2001
Bird On! News
27th April 2001
Bird song at its peak
MAY is the peak month of the year in Britain for birdsong, when it seems that every bird that can sing does so, at least at dawn. Birds sing for two reasons: to establish a territory and to attract a mate. Thus with most of our familiar summer migrants, the males generally arrive back on the breeding grounds before the females. The first returning birds select the choicest habitat, and then sing to attract the returning females and to warn off rival males. They carry on singing with enthusiasm when their mate is laying eggs, and incubating them, but song starts to fall off once the young have hatched.
Nightingales, for example, sing from the moment they arrive in mid or late April through to the end of May. Unmated males may continue to sing a little longer, but most birds that have paired and have young sing only occasionally and intermittently in early June. Not all our songsters share the abrupt cut-off of the nightingale: blackcaps and garden warblers, for example, continue to sing well into June, and sometimes July. Birds that have several broods, such as blackbirds, also continue to sing for longer periods, though by the first week of July few blackbirds are still performing.
The best way to learn bird song is to spend time in the field with an expert - someone who really knows the calls. The second method is to track down and try and see every singing bird whose song you don't recognise. This, of course, assumes that you will be able to identify the bird when you do see it. Frustratingly, many birds like to sing unseen from dense cover. Both garden warblers and blackcaps, which have confusingly similar songs, usually sing from hidden perches. It is usually best to wait and watch. Once you have pinpointed the singer, it will only be a matter of time before it moves. If, however, it senses your presence, it will either stop singing or simply slip away, probably unseen. Some species are notoriously elusive. Nightingales, for example, can be exceedingly difficult to see in Britain, though in southern France or Spain, where they are generally much more common they are more likely to sing from an exposed perch. I have even seen nightingales singing from telephone wires, something they never consider doing in England.
Listen to a CDThe third way to learn song is from a tape or CD. The latter is much the best, as you can simply tap in the track number, and instantly find the song or call you want. There are a number of excellent CDs available, of which one of the best is the recently re-issued British Bird Sounds on CD. The recordings are taken from the extensive collection of the British Library National Sound Archive. There are two CDs, featuring 175 of the most commonly heard British birds. With less than a minute available for each species, compilers Ron Kettle and Richard Ranft had to choose the most typical or characteristic calls, and this they have done admirably. A 20-page booklet accompanies the CDs, not only telling you when, where and who made each recording, but other species that can be heard in the background. Each track is preceded by a spoken announcement of the bird's name, allowing you to learn the songs without having to refer to the notes. As a comprehensive introduction to bird sound, it's hard to fault.
Late cuckoosMuch of April was dominated by northerly winds, and as a result the majority of summer migrants were rather late returning to their British breeding grounds, with few early records. I didn't hear my first cuckoo until April 25th, an exceptionally late date for my corner of Kent where my earliest record is April 12th. My local house martins have yet to appear by April 27th, though in exceptional years they have put in their first appearance by the middle of the month. However, when they do at last arrive, they will find a smart Schwegler double nest box waiting for them. I also put up two Schwegler tit boxes in early April. Blue tits inspected both boxes within an hour of them being erected, and one has been adopted, with the occupants busy carrying nesting material to the box in late April. Tits are relatively late nesters, as their brood has to hatch at the peak period for finding caterpillars. These are the staple diets of the chicks, though the adults will appreciate a ready supply of either peanuts or black sunflowers.
Goldfinches in the gardenThough in the past I have often recorded goldfinches flying over the garden, they rarely stopped. Then, in early February, a single goldfinch made regular visits to the black sunflower feeder. Once perched on the feeder this particular bird feasted for lengthy periods, aggressively repelling other visitors, such as greenfinches and chaffinches. On one occasion two othergoldfinches joined it, but they proved to be equally unwelcome. I always keep binoculars handy, so was able to enjoy my unexpected visitor in close up. There are few more handsome small birds than the goldfinch, with its striking red face and black and white head, not to mention the beautiful gold bars in the wings. It's an unmistakable species, for there is no other bird you can confuse it with.
I didn't see any goldfinches in late February or early March, but by the end of March a single bird was coming regularly to the feeder once again. It carried on doing so in early April, soon joined by one or two others, with a peak count of five birds on Easter Sunday. Now the visits are no longer occasional or intermittent and there is usually a goldfinch or two present in or around the garden for most of the time.
It is curious that it has taken goldfinches so long to discover the delights of black sunflower seeds. In recent months many other garden-bird feeders have reported goldfinches being attracted to black sunflowers. What's more, once they have found a feeder, word seems to get around and numbers soon start to increase, until a semi-resident flock (or charm) is established. That seems to be what is happening here. Quite what will happen when my birds start breeding remains to be seen, but I will be continuing to feed the black sunflowers throughout the summer in the hope of keeping them coming.
Goldfinches are on the northern edge of their range here in Britain, and to see them in abundance you have to go to the Mediterranean. Many British goldfinches go there, to, for only a minority of our breeding birds winter here. The majority move to Belgium, western France and Spain. Some travel considerable distances, with the maximum recorded distance for a British ringed bird being 1,200 miles.
A century ago goldfinches were much rarer in Britain than they are today. Their attractive colours made them popular cage birds, and it was trapping for the cage-bird market that caused their scarcity. Today they are doing well, with numbers stable, or even increasing slightly. This is in marked contrast to many of our other finches. The last 25 years have seen bullfinch numbers down by 56%, linnets by 55% and lesser redpolls by an alarming 94%.
Foot and mouth on the declineThough the foot and mouth epidemic appears to be declining, its impact will be felt for many years to come. It seems certain that many farmers who have had their animals slaughtered will be reluctant to return to livestock farming. In many cases this is bad news for nature conservation, as lots of species of birds depend on grazing for the maintenance of the habitat they require. However, headage payments made under the Common Agricultural Policy (CAP) encouraged very high densities of sheep in many upland areas, and here the grazing pressure was detrimental to the heather moorland. A reduction in grazing pressure may well benefit the moors, and the birds that breed on them.
It is not just birds that like grazed pastures. Several of our butterflies do, too. Of all Britain's butterflies, it is the marsh fritillary that depends most heavily on grazing. Its name is misleading, for it isn't a marshland species, but it does like damp, unimproved pastures. Marsh fritillary numbers first started to decline in the late 18th century, when it was still a widespread species throughout much of the British Isles. Today it is extinct in eastern England, and its remaining English strongholds include the military ranges of Salisbury Plain, and the Culm grasslands of Devon and Cornwall.
Several of the biggest colonies in Devon are around Holdsworthy, which has been badly affected by foot and mouth. The short-term loss of grazing should not have too great an impact, as colonies have been known to survive for as long as a decade after grazing has stopped. However, if farmers decide not to go back to grazing their pastures with cattle, then Devon's marsh fritillaries will be in serious trouble.
Despite the Government's encouragement to county councils to re-open the countryside, most have been reluctant to head its advice and reopen their footpaths. This continues to frustrate many birdwatchers, especially as no association has been proven between the spread of foot and mouth and walking in the countryside. Fear of foot and mouth is such that by closing paths, councils feel they are doing something positive, even if it is a total waste of time. It seems likely that unless paths open again soon, many people (and not just birdwatchers) will start to ignore the restrictions on access.
There has also been considerable debate as to whether animals can either carry or spread the disease. Despite a plethora of rumours, MAFF has not confirmed the presence of the disease in any wild deer. Both roe and muntjac deer are known to be vulnerable to foot and mouth, while red and fallow seldom show any symptoms. In contrast, wild boar are highly susceptible. Fortunately Britain's feral boar population is concentrated in East Kent and Sussex, well away from any confirmed foot and mouth outbreaks.
According to the experts, foot and mouth is not a serious disease for wild animals, and most animals recover naturally. It also seems unlikely that any of our native mammals could become a reservoir for the disease here. In cases of foot and mouth around the world, it has invariably been found that domestic stock infects wildlife, and not the other way round. Furthermore, once the disease dies out in domestic stock, it soon disappears from wildlife, too. Hopefully, the disease is way past its worst, but will sufficient measures be introduced to make sure that it never strikes here again?