08 • 09 • 2015
Fall migration of birds
One by one or in small groups, rows, and V formations – migration is under way in the skies of Latvia. Every year, with cold weather approaching, and with lesser food reserves available, Latvia is abandoned by birds that nest here, as well as birds that only pass through during their migration.
Although migratory birds are the largest bird group in Latvia, in terms of number of species, the majority of them are passersby and do not nest here. Moving from nesting regions in taiga and tundra over the so-called Baltic Sea Bird Migration Route, thousands of different birds transverse Latvia.
Migration time
Species that are the first ones to come back from their winter hideaways, are among the last to leave in the fall. Fall migration cannot be precisely predicted, as departure does not depend solely on weather conditions.
Bird migration can be observed already in early summer. In June, cross-bills appear, headed south. At the beginning of July, the first wading birds – clidrids, plovers, phalaropes – pass over Latvia. The local species – lapwings, sandpipers, curlews – also relocate. July is also a time when Latvian nesting birds migrate to warmer countries.
Migratory birds, whose diets consist only of insects, begin their flight to warmer countries in July and August. Among them are songbirds – various warblers, reed warblers, chiffchaffs, wagtails, redstarts, flycatchers, nightingales, etc. Also - swallows, martins, and swifts, who subsist only on small flying insects, begin their departure without delay.
Swifts have not been observed in Latvia since the middle of August – they are on their way to a warmer climate in Africa around Equator and beyond. However, swallows and martins still appear here and there.
Not always birds disappear for the winter due to lack of food. Although the amount of food is still sufficient, already at the end of August, white storks gather in flocks to exit, facing a long and lengthy road. At best, they reach central and southern Africa at the end of October, but usually in November or even December. The early mass departure does not mean that no white stork will appear in Latvia in September. Black storks, too, can still be seen in some spots.
With time, the early migrators and passersby are gradually accompanied by other bird species. The migration in Latvia usually takes place in September and October. The most active, and thus most noticeable and audible bird migration and departure happens in the second week of September, when birds, if the weather allows, can be seen and heard day and night. If one gets lucky, it is possible to experience a rut song – a melody sung by a male in the fall of the first year of its life.
Geese and cranes
In September, birds assemble in groups large or small to relax and gather strength for further flight. The most noticeable ones are common starlings, fieldfares, woodpigeons, crows, which just stand or rustle somewhere in fields or roadsides. Feeding in waters this month are ducks, grebes, cormorants, swans (though young swans learn only in September how to take off). Drained fish ponds are densely populated by herons, among which are great white herons.
The local cranes that are gradually sided with immigrant birds, are gathering in ever larger flocks. During the day they feed, but in the evening – collectively travel to their sleeping areas. In the morning, they head back to their feeding places. This is why cranes in September are most often seen in the morning and evening, when the direction of their flight is not necessarily related to their winter destinations.
In the second half of the month, increasingly more wild geese are passing through. But the most remarkable (noisy) time of migratory birds is still ahead. Let us wait for October!
In October, one after another V-shaped flocks of cranes and geese fly south, south-west, and west, but compared with September, their numbers decrease. However, the variety if migratory birds is still huge. One can comparatively often see and hear various blackbird species, as well as common starlings, crows, woodpigeons, chaffinches, green finches, goldfinches, siskins, bullfinches or robins, buntings, long-tailed tits, redbreasts, etc.
Traveling day and night
Nature has made sure that a number of migratory birds be distinct “day trippers” – for example, tits, chaffinches, crows, diurnal predators, while others – distinct nocturnal migrators, for example, night hawks, redbreasts, flycatchers, blackbirds, warblers, and various owls. Of course, there are many species whose members fly south both during the day and night. Among the ones crossing Latvia - storks, starlings, geese, ducks.
Migratory birds of the fall
Each species migrate to specific places, covering known routes every year. Departure in the fall usually takes place in a more leisurely and timely manner than returning in the spring. The small birds are usually accompanied by predators – during the day they are under the eyes of sparrow-hawks and falcons, but overnight – owls.
