Autumn bird migration news: A north/south divide
Each week Paul and Nick from the BTO are updating us on all the comings and goings of autumn's bird migration. We'd love to hear what you've been seeing too, whether in your garden or out and about.
The blackcap, marooned on Fair Isle © Mark Taylor/BTO
There has been a north/south divide this week, and the further north you go the greater the divide. The very strong south westerly winds have remained gale force for most of the week in the very north of Scotland and the northern isles, grounding large numbers of geese and swans and effectively bringing any migration there to a complete halt. At present there are around 30 blackcaps on Fair Isle, Shetland, that will be unable to leave until the wind drops considerably.
Further south the winds have been much lighter and at time movement has been impressive. The first large arrival of starlings occurred at the beginning of the week, along with impressive numbers of finches, linnet being the most numerous of these, accompanied by smaller numbers of goldfinches and chaffinches.
Ring ouzels stop over in the UK on their way to Africa © Tommy Holden/BTO
Winter thrushes continue to arrive whenever conditions allow. While the redwings and fieldfares may not go much further than the UK, the ring ouzels that have arrived with them this week will be making their way to North Africa to spend the winter months in and around the Atlas Mountains. Late October and early November can be a great time to catch up with this enigmatic thrush, some even turn up in gardens at this time.
The first of the Bewick's swans have begun to arrive © Jill Pakenham/BTO
The strong winds have held up a few of our departing summer visitors but for the 30 swallows that are still in the Christchurch Harbour area in Dorset the higher than average temperatures for the time of the year will mean that there will still be plenty of aerial insects around to feed-up on ahead of the long journey south.
The first of the Bewick's swans from the Arctic Russian tundra have begun to arrive on the east coast. If the winds are as light as they are forecast to be this weekend, we could see the arrival of more of these wild swans, along with further arrivals of starlings, goldcrests and woodcock, the latter two nearly always seem to arrive at the same time.
Question of the week: Do all birds migrate in flocks?
The simple answer to this is no.
A lonesome migrant: the corncrake © Edmund Fellowes
Many of our birds will undertake migration alone. Warblers, flycatchers, chats and birds like quail, corncrake and cuckoos undertake their huge migrations to Sub-Saharan Africa entirely alone. However, for others, flocking is the norm, thrushes, starlings, finches and pipits all migrate in loose flocks and utter contact calls to keep these flocks together.
For most wildfowl, not only is flocking the norm, migrating with the rest of your family is too, making this time of the year a good time to get an indication how good a breeding season birds like whooper and Bewick's Swans have had.
It's unclear why different birds use differing migration strategies. Warblers in the UK are mainly nocturnal migrants, whilst the North American warblers migrate during daylight hours. However, for our summer visitors that cross the Sahara, a night crossing might be much more beneficial than one undertaken during the searing heat of the day. We do know that one of our satellite tagged cuckoos did actually cross the desert during the day, so we still have quite a lot to learn about birds on migration. To see where our five cuckoos (including Martin and Chris) are now visit our special tracking website.