Migration

Here at  Sandwell Valley the big autumn migration is well underway with birds coming and going daily.

The concept of migration, especially regarding birds, conjures up images of travelling great distances, crossing continents, seas and desserts to reach warm wintering areas with an abundance of food. Of course for some birds this is true and here you can find a map showing the satellite tracked journeys recently undertaken by five cuckoos as part of a BTO project.

However, migration is not limited purely to the transcontinental travellers; it also applies to those who only move short distances. Possibly the best example of these movements are the dispersal of juvenile birds from their parents territory. Over the last week we have seen this movement illustrated by grebes here in the Valley. Today, for example, there were three fully fledged juvenile great crested grebes on the lake despite us knowing full well that only one chick had survived from our residents breeding attempts. This individual was still around the adult birds (despite now being able to feed its self) but there were an additional pair of juveniles who were staying close to each other and feeding together – clearly a pair from another nest elsewhere who have been moved on by their parents.

Getting back to the distance migration, we are seeing (or not seeing as the case may be) the evidence of this going on. Sightings of the warblers are becoming less frequent as they have either departed for warmer climates or are keeping a low profile while feeding up to start their journey. There was a male blackcap and chiffchaff doing exactly that in the bushes along the driveway this morning. Groups of house and sand martins can regularly be seen feeding over the lake as they pass through and there were a late pair of swifts seen today (swifts are one of the first migrants to leave).

For a lot of birds Sandwell Valley is used as a service station along their migration routes – while flying high over Birmingham, it stands out like a beacon as a good place to refuel before continuing a journey. This is especially true of waders, and we often have visits of just a day or two while they feed and rest. Recently we have seen black-tailed godwit, greenshank, green and common sandpiper – the common sandpiper being the only one to have stayed more than a day.

The final word on migration (well, the final word in this blog – I don’t think there is ever a final word on migration) is to mention the arrival of our winter residents. Although it is too early to be seeing any returning goldeneye or goosander (other than our injured resident), we have seen the arrival of teal, shoveler and pochard. It is difficult to say whether these birds are just passing or will be with all winter, but it’s great to see them back (even in their rather drab eclipse plumage). The other winter resident which has been seen on a couple of occasions now is the beautifully camouflaged snipe. Although all snipe shaped visitors which have been seen so far seem to have been just passing, it won’t be long before they take up residence for the winter months.

So there you go, some along to Sandwell Valley and try your hand at spotting some migration in action!