Migration

Which direction do birds fly in autumn? Do starlings migrate? Why are blackcaps now seen here in winter? Find out about migration marvels, fantastic flights and amazing journeys.

Migration

Your questions

Can swallows stay in the air for up to two years? chevron-down

Sent in by Pete Riley. 20 February 2019

 

We’ve had two very similar questions sent in to us this week about swallows - those fantastic birds which typify our summers, and are certainly in evidence at the moment.

 

Our second question came from Tricia Napoli-Mole from Coventry who asked “My husband swears swallows never land. Is this true?”

 

Swallows fly here each spring from Africa, an epic journey for such small creatures, and they often cover 200 miles a day. 

 

They have been recorded flying at up to 35mph and their superb navigation skills mean that they return to their same nests each year.  They feed on flying insects and can be seen swooping over farmland or water where these are plentiful. 

 

They do land though, but not often, and one of their favourite perching spots is telegraph wires where you will recognise them from their dangling tail streamers. The masters of the skies then, or are they?

 

Swifts or swallows?

The subject of these two questions really ought to be that other summer visitor from Africa: the swift. Now this bird almost never lands and young swifts, which will not breed until their second year, probably never touch down between flying from the nest and returning to breed. 

 

It seems exhausting to us, who are mainly rooted to the ground, but swifts have the perfect shape for this existence. They have long wings and slender bodies and are not encumbered by long legs or tail. In fact, they are not adapted to being on the ground at all and when one does land it is purely by accident and they usually need help. 

 

Breeding birds will sleep in the nest, and what a relief that must be. Otherwise they sleep on the wing - the only bird known to do this. 

 

Swifts are magical, mysterious birds, and a true delight to have as a brief summer companion. Sadly, their numbers are in steep decline and there are far fewer screaming through our summer skies.

 

Please help us to protect them by taking part in our swift survey.

This morning I've seen thousands of woodpigeons passing over my flat. Can you throw any light on this? chevron-down

Sent in by Clifford Trethewey. 28 November 2011

 

Clifford asked: 'This morning I have never seen so many woodpigeons in flight in my life of 70 years. From 9.30 am they have been passing our flat on the edge of East Grinstead in thousands flying SE in beautiful weather. Can you throw any light on this? We have open fields around us, but it is also modestly urban.'

 

We have received a few similar reports of large flocks of woodpigeons being seen heading south. In fact, several flocks have recently been sighted flying over The Lodge here in Sandy.

 

We tend to think of woodpigeons as fairly sedentary birds but they are strong, powerful fliers. During the autumn, be it the first frosts, or shorter daylight hours, something urges them to fly south, so the ones flying over your flat on the edge of East Grinstead, were on migration.

 

However, there is still a great deal of mystery as to their final destination; there is little evidence to suggest that they actually leave the UK, not in large numbers anyway.

 

They are regularly seen over the sea but it is possible that they are just moving along the coast rather than crossing the Channel for instance. One thing we do know is that these winter movements have been much in evidence this year so perhaps this may lead eventually, to a few more clues as to their winter haunts.

Do swallows fly continually during their migration north or south, or do they rest now and then? chevron-down

Sent in by Lois-Anne Brown, South Africa

 

Adult and juvenile swallows start to move south by mid-August as the autumn migration begins. Autumn migration is rather drawn out with birds moving short distances every few days to settle at lower latitude roosts. The average body mass of the birds using such roosts gradually increases into the autumn. As the weather becomes less stable, this essentially forces the push southwards.

 

For example, Irish breeding swallows cross into Wales and then southern England during August. The vast majority of British breeding birds then leave our southern shores during September with gradual southerly movements.

 

The spring migration is a far more straight through run of affairs - the birds have more of a necessity to get where they are going. There is a high level of competition amongst males to secure a mate and nesting site.  In spring, experienced birds may be able to return from South Africa in about five weeks at a speed of about 300km per day.


 
Although swallows are thought to exclusively migrate long distances each winter to equatorial regions, a substantial minority winter between their breeding territories and wintering strongholds.

 

Swallows breed across Eurasia, from Morocco to Ireland and Norway in the west and on similar latitudes across to Japan and southern China. They also breed extensively across North America.

 

In winter, they are found widely in Africa south of the Sahara, from Pakistan, to New Guinea and northern and central South America.

 

Within Europe, a few straggler birds winter in southern and Western Europe and are recorded annually in Southern Spain. In recent years, a few swallows have with increasing frequency been recorded over wintering as far north as Britain and Ireland– a probable indicator of the effects of climate change. Small numbers winter regularly in North Africa and there are also small resident (or partly resident) populations in eastern Mediterranean countries.

 

From bird ‘ringing’ we know that juvenile dispersals begin in July. Newly fledged birds stay around the breeding site, being fed by their parents for several days. Earlier broods can stay put around the nest site for as long as six weeks. Juveniles then enter communal roosts (getting used to the area they will return to next year) while adult birds finish the late broods (as many as three per year).

My wife says robins migrate - I say NO! Who is right? chevron-down

Sent in by Denzil R. Perry, Dorset. 

 

In a way, you are both right!

 

European robins (Erithacus rubecula) live throughout Europe (except in the far north), Russia and western Siberia. British and Irish robins are largely sedentary, and most do not move more than 5km. Those that do are usually adult males moving between their breeding and winter territories.

 

However, some UK robins, mostly females, will cross the Channel to spend their winters in warmer climes, in some cases as far south as southern Spain and Portugal. Continental birds also pass through on the east coast of the UK on passage further south.

 

At the same time, our resident birds are joined by immigrants from Scandinavia, continental Europe and Russia, which come to the UK to avoid the severe winters there. These visiting birds are generally paler in colour and are less 'tame' than UK birds. This is likely to be because in their home countries they are woodland birds and have less contact with humans.

 

Much research has been carried out into the lives of robins and it has revealed that they are one of the few UK species that sing all year round. Both males and females sing to declare and defend their own individual territories outside the breeding season, and their songs are more or less identical.

 

Around Christmas-time, robins begin to explore other robins' territories in the hope of finding a mate. The majority will have paired up by mid-January and the females will stop their territorial singing. However, the males will continue to sing to declare the 'ownership' of what has now become a joint future breeding territory; one which they will fight to the death to defend - in some populations, up to 10% of adult mortality is accounted for by territorial disputes. 

 

On occasions, robins will sing long into the night, especially in urban areas where there are streetlights. They are often the earliest birds to start the dawn chorus and one of the last to stop in the evening.

Do starlings migrate and if so, when? chevron-down

Sent in by Susan Taylor, York.

 

Most of us think of starlings as being resident birds and, it is true, that most are always with us.

 

Others are migratory though. These account for the huge increase in the starling population which occurs when birds, from northern Europe, arrive to spend the winter in the UK because the weather is relatively mild here and they will be able to find food and shelter before returning to their breeding territories.

 

They begin to arrive during September but the majority of starlings will arrive in October, before the winter weather sets in. Most of the birds coming to the UK are from Scandinavia but one individual, caught during an autumn bird-ringing session in Bedfordshire, already had a ring, put on the previous spring in Lithuania.

 

During winter, starlings roost together and these are not just a few birds huddling in thick cover. One site was a roosting place for over one million birds!

 

One of the great birding spectacles of the winter is the starlings' pre-roost assembly, known as murmurations. Prior to settling down for the night, small flocks of these gregarious birds swoop around, joining together until there is one enormous, swirling mass: an amazing sight.

 

Having entertained us throughout the winter, starlings will return to their breeding territories during February and March.

Do birds migrate from east to west in Europe? chevron-down

Sent in by Majd riad Abu Sada, Palestine.

 

The principal direction of migration for British breeding songbirds is north-south. In the northern hemisphere, a northerly movement occurs during spring as birds return to breeding grounds in more temperate climes. During autumn, the movement is southerly, to regions where the climate is more suitable and food is more abundant.

 

Young birds require a diet that is rich in protein in order to develop feathers and muscles. This protein is not available in seeds and most fruit, so by migrating to areas where there is an abundance of protein-rich insects, there are clearly benefits for many species. It is perhaps not surprising that many European summer migrants are insectivorous.

 

Although the general direction of migration is north-south, there is a south-westerly or south-easterly bias between individual species. For example, the British population of lesser whitethroat undertakes a south-easterly migration to eastern Africa and the Arabian Gulf regions during the autumn, whereas the similar and closely related common whitethroat migrates on more of a south-westerly bearing, wintering in the western Sahara and east to Sudan (Urban et al 1997).

 

In the northern hemisphere, the main exchange of species between continents occurs with European breeding birds wintering in Africa and to a lesser extent, Asia. Some seabirds, notably the Manx shearwater, may make it to the eastern seaboard of South America. An exceptional example of inter-continental migration is the bar-tailed godwit. A bird was satellite-tracked from its wintering grounds in New Zealand to breeding territory in Alaska – a flight of some 11,500 kilometres.

 

Within Europe, the blackcap will migrate during the autumn months on a north-westerly setting from breeding grounds in south-eastern Europe to spend the winter in Britain and the low countries.

Do any species of birds hibernate? chevron-down

Sent in by Emily Messer, Yorkshire. 16 November 2007

 

There is one bird which is known to hibernate throughout the winter - the common poorwill. This small relative of the nightjar is found in western states of the USA such as California and New Mexico where it inhabits open areas of low vegetation and rocky outcrops.

 

As a nocturnal hunter of insects, the poorwill would struggle to find enough food to survive  during the cold winters. When faced with harsh weather and little food, this unique bird hides away in rocky crevices and hibernates through the winter, emerging in spring when the temperature has risen and more insects are active.

 

Here in the UK, bats, dormice and hedgehogs are most commonly associated with hibernation. Birds, instead of hibernating, use migration to avoid adverse conditions. Our summer visitors such as the swallow head south to warmer climes whilst many birds that breed further north, such as the redwing, head to the UK to spend the winter as it is comparatively mild. Colonial roosting is another way to conserve energy and body heat. The wren has been documented to share a nest box overnight with up to 60 other wrens!

 

Although birds in the UK do not hibernate, one species uses a similar strategy to cope with periods of cold weather and low food availability. Young swifts go into a state of 'torpor' which is where the body temperature and metabolism is greatly reduced in order to save energy. The energy saved by reducing activity in this way allows these birds to survive for short periods of time until conditions improve.

 

Torpor is a commonly used survival strategy in a number of bird families across the world such as the hummingbirds, nightjars and swifts. Much of the research on torpor in birds has been conducted in North America where many of the species can be found in a torpid state during cold spells. Torpor is usually only a short term solution to allow birds to survive cold nights.

Do swallows hibernate? chevron-down

Sent in by Lizzy Agora. 22 February 2008

 

Swallows do not hibernate although they do 'disappear' during our winter.

 

At one time, it was thought that they spent the winter hibernating in mud banks, even under the River Thames. This was understandable as it must have seemed that they vanished just as the weather began to turn colder for the winter. It was known that many wild creatures hibernated so assumed that swallows did the same. We know now though, that they are not sleeping, they are just elsewhere. 

 

They migrate, flying south to spend the winter in a warmer climate with an ample supply of the insect food they need. The swallows, which we see during our summer in the UK, fly all the way to South Africa. An incredible journey for such small birds that can fly at up to 22mph covering 200 miles in just one day. 

 

They usually return to our shores during April and May, although early birds may be spotted during March, so it will soon be time for us to look skywards to spot the first swallow of spring and very welcome they are too. 

Why do some geese fly north and some fly south? chevron-down

Sent in by Colin Davies, Aberdeen.

 

Large numbers of pink-footed geese arrive in the UK from their breeding grounds in Greenland and Iceland. Thousands spend the winter on the eastern coast of Scotland. These birds start to arrive from early to mid September, with numbers increasing up to mid October.

 

They roost on estuaries and lochs where they are relatively safe from predators, with favoured sites being Loch of Strathbeg, where as many as 66,000 have been recorded, Findhorn Bay, with an estimated winter population of 25,000 and rising and the Ythan Estuary and Slain Lochs near Aberdeen, which holds around 20,000.

 

During the autumn and early winter mornings, pink-footed geese move from these roost sites to stubble fields, where they will feed upon spilt grain. Late afternoon sees the return flight to the roost sites, the birds' ''yak'' calls carrying for several miles on still days. I would imagine that what you are seeing is a combination of birds visibly migrating south, and birds that have already arrived moving between roost and feeding sites.

I saw a blackcap in my garden but I thought they were only here in the summer. Was this unusual? chevron-down

Sent in by John Waites, Farnham.

 

The fluting, melancholy song of the blackcap is one of the finest to be heard in the British countryside during the spring and early summer months. 

 

These master songsters arrive here in spring from southern Europe and North Africa and this is where they will return in the autumn, so where have the blackcaps that spend their winters with us arrived from, and what are they doing here?

 

We’ve learned from ringing (when birds are trapped by trained volunteers, fitted with lightweight metal leg rings, then released unharmed) that these birds will have bred in central Europe.

 

Interestingly, it is only since the mid-1960s that these 'continental' blackcaps have been known to winter in the UK, and the reasons are not yet fully understood. One possible suggestion is that the increased popularity of garden feeding and the planting of berry-laden shrubs has made the UK a more attractive winter destination. Another that the westward migration of this central European population is an 'insurance' strategy to ensure the long-term survival of the species.


 
Whatever the reason, these delightful little warblers are a welcome addition to our winter wildlife.

How far North do nightingales come? We heard what sounded like its birdsong in Northumberland. chevron-down

Sent in by Lynne Russell from Warkworth, Northumberland. 29 May 2013

 

Nightingales are African migrants, they reach the UK in April from Europe so tend to arrive in the South Eastern part of the UK with their main breeding territory focusing on Kent, Sussex, Cambridgeshire, Hampshire, Wiltshire, Suffolk, Norfolk and Essex. They do also breed in Lincolnshire and this is generally as far North in England as you would find them. 

 

However, as with all migrant birds they can turn up anywhere and over the past few years we have had reports of them being seen in Cleveland, Durham and even Argyll so one turning up in Northumberland is not that unlikely! 

 

Don’t forget that other quite tuneful birds are also found to be singing at night during the Spring, these include Blackbirds, Robins and Song Thrushes so it is often that these get confused for Nightingales.

Do blackbirds migrate? chevron-down

Sent in by Mrs Elsie Titley, Newcastle-under-Lyme. 

 

Most of the blackbirds that we see from day to day here in the UK will be resident birds that do not stray far from their home range. However, it is right to say that blackbirds are migratory.

 

The blackbirds that live in northern Europe such as the Scandinavian countries, will fly south-west to spend the winter. The colder climate further north will make food hard to come by, so these birds may appear in the UK during autumn for our less severe winter.

 

There have been records of resident birds making journeys across the UK on an annual basis. One such bird, nicknamed Homer, has travelled from a garden in Thetford, Norfolk where he has spent the summer, to Devon where he has wintered for at least three years.

 

Blackbirds will quite often change their habits and distribution over the year. We often see them in gardens raising families and feeding during the spring and summer where they can raise up to three broods. After the breeding season, birds will moult into new feathers and lie low for a few weeks as they are vulnerable at this time. After the moult, the bird's primary objective is to feed up for the winter. This results in many birds leaving their garden breeding grounds and travelling to areas where they may take advantage of the abundant natural food supplies.

 

This autumn has been prolific in terms of the berry and nut crops and will provide birds and other wildlife with all the nutrients they require to get them through the winter.

 

Hedgerows and wooded areas with berry and fruit bearing trees are the best places to see blackbirds at this time of year. The UK resident birds will start to come back to gardens later on in winter and the migratory birds will return to their breeding territories in early spring.