With the advent of spring comes a new cast of birds to delight and entertain us. Before April is out most of our summer migrants will have arrived and be busy claiming territory, selecting mates and otherwise engaged in propagating their species. Among the more familiar and obvious species that chose to spend the long bountiful summer days with us are the hirundines – swallow, sand martin, house martin – and the common swift. The latter is often confused with the other species but is in a totally separate family group. That need not bother us because we are simply concerned with trying to correctly identify the birds we see, so let’s do just that. Welcome to the WingSearch2020 Identification Guide to Hirundines and Swift
Often the first of this group to arrive in the latter half of March, the sand martin is a small, mainly brownish bird which tends to be associated with water to a greater or lesser degree. Certainly, it can often be seen hawking insects over lakes and slow-moving rivers in the early part of its stay, and its habit of nesting in sand banks lends itself to association with wetland habitats. Sadly, sand martins are no longer as common as they once were. As a boy I remember seeing their breeding colonies in every available gravel pit, cliff face and river bank, even utilising defunct water pipes beside the river in the very centre of Norwich. Colonies during the 1960s commonly contained several hundreds of pairs with two numbering 1,500 pairs. Nowadays they are far less numerous and widespread tending to favour sea cliffs for nesting, at least here in Norfolk, although a few small colonies exist in gravel workings elsewhere in the county. The best places to see them in East Anglia between April and August are either on the sand cliffs along the north-east and north coasts of Norfolk or the artificially created sand bank at RSPB Minsmere in Suffolk. During 2019 much controversy was created by a decision by North Norfolk District Council to net over breeding cliffs in order to carry out a stabilisation programme to protect the Bacton gas terminal. The outcry caused via social media caused the council to U turn, whilst highlighting the precarious plight of these small birds that choose to grace the UK every summer. They are after all long-distance migrants with any number of other natural obstacles to overcome. Sand martins will begin to migrate back to Africa, south of the Sahara, during July, with most having departed by the end of September.
House martins arrive a little later than sand martins with most taking up summer residence during the second half of April to early May. They are much darker in colour, having shiny metallic blue upperparts with bright white underparts and a noticeable white rump. Like the sand martin their numbers have declined markedly in the UK over the past few decades. Where once breeding colonies numbering into high double and even three figures were commonplace, one would now struggle to find anything other than a few pairs on suitable buildings. As a poignant example, during 1930 a competition was held to find the largest colony in Norfolk, the winner being a farmhouse at Cringleford which boosted 106 nests. In stark contrast the 2018 Norfolk Bird & Mammal Report could only quote the largest colony of 15 pairs at Wissington. Very few, if any now nest in Norwich where I remember during the late 60s watching adults feed young in nests above the front doors of bungalows close to my home. Such was the competition for breeding sites at that time that some opportunists started building nests on a notice board advertising development of a new housing estate – getting in first as it were. Sadly, those sights are well and truly locked in the past. An aptly named species, the house martin is very much associated with manmade structures where it will breed on any building that affords an overhanging protective shelf upon which the mud nest can be anchored. Happily, although greatly reduced in numbers, the species is still widespread and a few pleasantly chirruping birds can generally be found hawking insects over most rural villages.
The fabled true indicator of the arrival of spring, the swallow is known to everyone. It is an iconic bird representing the gateway to warmer, longer days when sunshine and soft breezes caress our faces. Twittering birds will turn up unerringly at their traditional nest sites in the second half of April. Settling down to breed by the early days of May – I wrote about their affinity with the Norfolk Wildlife Trust reserve at Ranworth Broad here. In North America it is called the barn swallow, an apt name which encapsulates its love of breeding around farms where insect food is bountiful and sheltered nesting sites proliferate. More intense use of pesticides here together with drought conditions in wintering grounds have led to a slow but steady decline in numbers – depressing isn’t it? However, swallows are still quite common and can be encountered all over rural parts of mainland UK. Swallows have a pleasant twittering song, much more complicated than the simple calls of the previous two species. They are glossy blue on the upperparts and a buff white underneath. Crucially as an identification aid, they have long tail streamers which no other bird under consideration here possess.
The swift, although superficially similar in appearance to the preceding three species, belongs in a separate family group. It is a completely different beast. Swifts spend nearly all their lives on the wing; they do not ‘sing’, they do not perch, they do not really build a nest. But they do breed in man-made buildings and therefore being close to us humans are often confused with the hirundines. Swifts are the latest of this group to appear, seldom do they turn up before the last few days of April and even then it will generally be at wetland sites rich in insect life enabling them to feed up after the long migration. They will appear over their traditional breeding grounds in cities, towns and villages sometime during the first week of May, chasing each other through the air with their screeching courtship chases. You can find out more about swifts here. I always think that when I see my first swift, I can safely say summer has arrived; it always gives me a feeling of great comfort and satisfaction. Conversely their early departure in August leaves me feeling bereft and sad – a reminder that our all too brief summer is coming to a close. It also emphasises that fact that these birds are not British but are really African species that choose to spend 3 months of the year with us, taking advantage of long daylight hours and abundant food supplies to breed. Swift populations are sadly declining and we need to help them where we can. Putting up swift nest boxes is a good way to help them since modern houses offer them little in the way of access to roof cavities. You can find out more here.
Sand martins have light chocolate brown plumage with a distinct brown band across the chest. The wings are broad at the base and roughly triangular in shape. The upperparts are uniform in colour and the underwing is all dark. The tail has a shallow fork. Only likely to be seen over water when freshly arrived or at breeding grounds in sandy cliffs/quarries
House martins have dark glossy blue plumage with no markings on the underbelly or chest. The underwing is dark and the tail slightly deeper forked than the sand martin. Much more likely to be encountered in towns and villages.
Swallows are best told from the previous two species by their long tail streamers. The red facial markings can be difficult to see in the field (the image earlier shows the face to look all dark). The upperparts are a glossy blue and the underparts are a creamy off white. The wings are distinctly two toned .
Swifts are the largest of this group and are fast moving birds that will never be seen on land or perched. The overall appearance is of a uniform dark bird, although good views may show the white throat pouch. The significant identification point is the long, thin sickle shaped wings. The tail is moderately forked but nowhere near that of a swallow.
The swallow is an agile bird and will tirelessly hawk low over meadows or water looking for insect prey. Even when well spread the long outer tail streamers are noticeable as is the row of white spots on the tail feathers. Note wings are relatively broad.
A swift in untypical pose, but illustrating the difference in tail feathering and wing length which even when fully spread are still narrower than the swallow. Swifts hunt aerial plankton generally at height. They seldom hunt low over ground, but will do so when there is a hatch of insects or when weather conditions forces their food to fly low.
House martins build nests of dried mud pellets under overhanging eaves. Here their colonial nesting behaviour is clear as is the bright white rump.
Young house martins show a distinct dark cap with clear divide between the bright white throat and underside.
Young sand martins in a typical nest burrow in a sandy cliff face, Note the much more smudgy facial appearance with no clear divide between crown, face and breast.
Swallows build a shallow nest lined with feathers balanced on a beam or shelf within a covered structure, for example a barn, shed or bunker or under a bridge. My friend and I found such a nest that had been in use for over 10 years that had attained a height of 45cm.
Adult swallow (probably male) – note the deep red throat patch and forehead and very long, thin tail streamers (the female has slightly shorter streamers than the male).
Juvenile swallow – note the washed out, light orange throat and forehead and very short tail streamers (not even as long as length of closed wing)
Adult sand martin with throat pouch full of insect food for its young. Note uniform light brown plumage and well defined facial patch.
Juvenile sand martin – note scaled effect of feathering and smudgy brown colouration of cheeks.
Juvenile swift – note scaled patterning of feathers but still a classic swift shape of long scythe like wings.
Hope that helps you tell the difference between these sometimes tricky species. Let me know what you think – all feedback welcome as is any ideas you may have for future articles.