by Mike Dilger
By contrast to Bewick’s Swans needing around 30 days to incubate their clutch, Waxwings will see their young hatching in just half the time. Certainly in northern Scandinavia laying normally begins in mid-June, but can occur before in those years when spring – and crucially the snow melt – occurs earlier than normal. Due to the short Arctic summer, Waxwings, like Bewick’s Swans, are only ever single-brooded, and although anywhere between four and seven have been observed, the most commonly recorded clutch size is five eggs. Smooth and glossy in appearance, the eggs are pale or greyish-blue, and tend to be sparsely marked with black and grey spots that occasionally show blurred brownish edges. Like many of the smaller passerines (or perching birds) incubation is by the female alone and is only thought to begin once the clutch has been completed. Due to the fairly cold ambient temperature in June, the female will rarely leave the eggs and so will need to rely on the male to keep her nourished during her vigil with a cocktail of regurgitated fruits and insects. For the males, any brief antagonism which occurred during the nest-building and egg-laying phases should have been quickly put to one side as their natural sociability once again returns, allowing them to re-form flocks. Waxwings are generally not thought to breed in their first year, but this still doesn’t stop any yearling birds returning to the breeding grounds as they join the roving flocks of breeding males. Being amongst their more learned peers will enable them to learn the ropes with the ultimate aim of finding a partner and rearing a family of their own the following year.
By mid to late June, those pairs of Kingfishers which were able to lay their first clutch as early as April may well by now be already incubating their second clutch. For the parent not sitting on eggs, its time will be divided between fishing, preening and resting. Fishing for an experienced bird during this time of plenty should be a doddle compared to the leaner times between autumn and early spring. In Britain during the breeding season Kingfishers will consume a wide variety of fish including Bullhead, Minnow, Three-spined Stickleback, Loach, Grayling, Carp, Perch and Pike – in fact any fish that have reached the ideal length of around 7 to 8cm. In the brackish waters of the Thames in London, Kingfishers have even been spotted catching small flatfish, but by far the commonest species taken are Minnow, Stickleback and Bullhead. Needing to eat roughly their own body weight every day, Kingfisher expert David Boag estimated that each adult requires around 18 fish to be sufficiently well fed. However, as soon as the second brood hatches the number needed will rise substantially!
Late June
It’s astonishing to think that for those bird species rearing only one brood, the end of June will already signify that the breeding season is already drawing to a close for another year. Most traditional breeding locations of Lapwings, for example, should by now be deserted as the adults and young suddenly enter the sociable period of the calendar by coalescing into post-breeding flocks. Away from their breeding grounds Lapwing can be frequently mobile, making their movements difficult to track, but it’s highly likely that any shifts in location will be dictated by the two most important factors in their lives – food availability and the weather. In addition to British-breeding Lapwings dispersing into flocks to feed and moult, the east coast of Britain may well already be seeing the first of a number of influxes of Lapwings which summered on the continent. These first immigrant Lapwings will probably be individuals that either failed to fledge young, or were simply unable to gain a territory and a mate. As the summer slowly unfolds, the numbers arriving from the Netherlands, Denmark and France will undoubtedly increase to such an extent that by the time winter has fully taken hold, the population of Lapwings in Britain will have more than doubled from around 130,000 breeding pairs to around 620,000 birds.
Commonly rearing two broods on the continent, the relatively cool summers in Britain mean Nightingales here are only ever believed to practise a ‘one clutch’ strategy. Having fledged earlier in the month, the families should by now be breaking up as it becomes every bird for itself while they stock up on food in preparation for their long southward journey. In addition to bidding their young farewell, the adults will not only be dissolving their pair bond but also be actively moulting with a degree of urgency as the primary feathers must be replaced before migration. Aiming to leave for their African wintering quarters in August, it’s thought that the entire wing moult of adult Nightingales may take no longer than 30 to 35 days. This contrasts sharply with resident British Robins, for example, which due to their more sedentary lifestyle can afford the luxury of replacing their flight feathers at double the amount time taken by the Nightingales. So skulking are Nightingales at this time that there are very few records of adult birds observed in the hand after the breeding season, but certainly one individual examined on 9 July had all of its first five primaries in active moult, with none of the replacement feathers being more than a third of their full length. Moulting at such a pace must have meant that this particular bird will have been little more than flightless at this time.
Having begun to moult even before their young fledged, the far more protracted feather replacement of adult Blue Tits will see their plumage not looking fresh again until at least September. The timing of Blue Tit breeding attempts of course varies enormously according to location, so while northern Blue Tits are still likely to be feeding young in the nest in late June, those young which fledged from southern Britain earlier in the month will already be severing the parental ties. Having successfully graduated from their two-week course in finding food and avoiding being eaten, the youngsters will now have to put what they learnt into practice!
Certainly in the southern half of Britain many first broods of Swallows should now be at the point of fledging. As few nests fail completely, Barn Swallows usually have a healthy breeding record, with 90% of eggs laid going on to hatch and a further 80 to 90% of those hatching successfully managing to fledge. This means that a nest of four or five fully-feathered young, busily stretching, flapping and preening, can quickly become a hot and crowded place as departure day approaches. As the young prepare to leave, both the number and size of feeds by their parents are thought to slightly drop in order to encourage the birds out of the nest and onto a nearby roof, tree branch or overhead wire. Exactly when the young fledge depends on both the ability of their parents and the abundance of food, but tends to vary anywhere between 18 and 23 days, with an average time settling at around three weeks. Once one fledgling makes its bid for freedom, it tends to embolden the rest to leave too, with all the young usually departing on the same day. Certainly the first week of liberation will see the young staying close to the immediate vicinity of the nest site, while keeping away from any other Swallow families also busily fledging. Here the youngsters’ strategy is to initially remain quietly perching until one of their parents approaches with food, whereupon they will instantly turn into full begging mode by fluttering their wings and calling vociferously to attract attention. Any Swallow youngsters partly obscured at this stage will need to ensure their calls are loud enough for the adults to find them.
After just a few days the youngsters will have gained sufficient confidence in the air to see them flying up to meet the parents, to receive their food quotas. As they learn to catch insects for themselves, many flight trainees will also hone their flying skills by using objects like grass stems or feathers, which are frequently dropped, before then being re-caught on the wing. Even a week after fledging, the young may return to the building where they nested, the vegetation close by or even the nest itself to roost each night, by which time they should also have mastered the ability of finding and catching enough food to keep them sufficiently well fed. Only when reaching this point of independence will the youngsters then begin mixing with any of the other Swallows from neighbouring nests as the family structure slowly begins to break down. Relieved to be in a position to abdicate any responsibility towards their first brood will mean the adults can then turn their attention towards the laying of a second clutch. In a study of
Danish Swallows, 70% of pairs that went on to lay a second clutch used exactly the same nest, and new nests were only more likely to be constructed in those cases where an infestation of mites had built up to such a level that it would have heavily impacted on the well-being of the chicks.
As the Swallows are preparing to lay their second brood, the short incubation period and quick fledging times of British Robins should mean that by late June many established pairs will already have fledged their second brood. It’s thought that the majority of Robin pairs will only attempt a third clutch in an exceptional year, with most settling instead for just the two broods. Stopping at two will mean the female has no need to sidle away either to make a new nest or spring clean one of her previous efforts, but will enable her instead to be on hand to ensure as many youngsters as possible are carefully steered through to the point of independence in early July.
The end of June should also see any Kingfisher pairs that attempted to raise a second brood midway through their second incubation stint of the year. With the fledged youngsters from the first brood long since having been chased out of their parents’ territory, a quiet normality will have temporarily returned to the riverbank as the female once again carries out her sitting vigil. Brief respite from the dark monotony of the nest chamber will only come when she is called out by her mate for a stretch and an opportunity to catch a fish or two, before then disappearing back up the tunnel before her eggs begin to chill.
Unlike Kingfishers, where the adults drive away their newly fledged offspring no more than four or five days after leaving the sanctuary of their bank-side nest, Tawny Owl parents are willing to cut their delinquent offspring considerably more slack when it comes to ushering them towards self-sufficiency. Despite having climbed out of the nest cavity as early as May, the youngsters will in all probability still not yet have caught a single item for themselves, as they relentlessly beseech their parents to keep up the constant supply of food. In all likelihood it will be at least another month before these slow-coaches finally realise the only way to get ahead is by taking matters into their own talons. Despite flecks of down still being present around the facial disc and across the wing coverts, giving them a ‘frosty’ look, the young will now begin to resemble their parents much more closely with each passing week.
Like the Tawny Owls, Peregrine Falcons are another species willing to give their young plenty of time to learn the complex array of techniques needed for hunting before the apron strings are finally cut later in the year. The Peregrine adolescents also seem much keener students than the lazy juvenile Tawnies and by now should have already developed all-important confidence in the air as they begin chasing each other, harrying passing gulls and practising the stoop that will ultimately reap dividends when hunting for themselves. All these exercises might look like play to the uninitiated, but in fact are a vital step in both improving coordination and strengthening their flight muscles. At this stage some of the aerial flight lessons can be amazing to watch, particularly when the adults fly in with food. Streaking across the sky, the adult can often have all the screaming youngsters on its tail, with the successful juvenile either taking the prize by flipping underneath its parent to grasp the prey straight from the talons or catching the food in mid-air after being dropped by its diligent parent. As the young grow stronger and more able on the wing, the parents may well then decide to move away from the nest site during the day to escape their incessant begging, only returning either with food or to roost.
With begging practised to a fine art, the Cuckoo chick by late June will be driving its foster parents on to keep it fed, close to the nest from which it fledged, as it works steadily towards independence. The Cuckoo’s biological father, however, whose sole contribution to parenthood was impregnating the youngster’s biological mother, will by now have either left Britain, or at least be on the verge of departure. Obviously the window in which the females are able to target hosts’ nests is quite a small one, and so by late June, as the females target the last of any late clutches, the redundant males will have little qualm in leaving the females and chicks to their own devices.
Certainly Chris the Cuckoo, satellite tracked by the BTO from when he was initially tagged as a one-year-old bird in 2011 until his untimely death in the summer of 2015, was recorded as leaving for the continent anywhere between 17 June and 7 July. This suggests that most male Cuckoos rarely spend more than seven weeks – or a mere 14% of their year – in Britain, before then crossing the English Channel for all points south. From the data collected from Chris and the other tracked Cuckoos, it seems that upon leaving Britain they are in no hurry to move south too rapidly and often appear quite happy to feed up in north-west Europe for at least a week before turning towards the Mediterranean. June 2012, for example, was a very eventful time in Chris’s life, as he bucked the trend of other years by taking in a European tour which started in Belgium, before then visiting Germany, Luxembourg and the Netherlands in quick succession, only to end the month back in north Belgium, near the docks at Antwerp! Despite no females having yet been tracked, as their marginally lighter weight still prevents the current version of satellite transmitters from being attached, there is currently no reason to suggest that the females will do anything radically different to the males when they too leave a short while later.
Safely ensconced underground, once the Puffin chick reaches around a week old, it should be able to maintain its body temperature well enough so that it can be left unsupervised while both parents are out fishing. The adults never bring food in at night, and there is also a very pronounced rhythm to when fish are delivered, with a high frequency of feeds in the morning, a tailing off during the middle of the day and a resurgence again in the evening. These pronounced peaks and troughs may well be due to the behaviour of the fish that are being exploited by the Puffins, with Sandeels more actively feeding in the water column in the morning and fish like Sprats rising closer to the surface at dusk. Once the morning’s fishing gets under way, the traffic of birds flying to and fro can be very clearly seen at large puffinries, with the adults frequently returning like geese in a ‘V’ formation to deliver sustenance to their waiting chicks. Once the food has been dropped off, the parent will often not fly back out to sea immediately, but use this brief period of respite to glean from other Puffins valuable information, not just about the directions leading to the best fishing areas, but also the type and quantity of food being brought in.
The frequency of feeds during the course of the day will depend on how far the parents are foraging out to sea and the availability of food, but generally most chicks will receive anywhere between three and eleven feeds in a day, with four to six mealtimes being most common. When younger, the Puffling would have been carefully fed beak to beak by its parents, but as it develops, the parents may confine visits to simply dumping the catch on the floor of the burrow and leaving the youngster to waddle down in order to feed itself. The chicks are able to put away a surprisingly large amount of food, and seem to have no problem in polishing off every last morsel brought in by their parents. When not eating or sleeping, the growing Puffling will also become much more mobile underground and spend an increasing amount of time preening, scratching and playing with any nesting material close by. The period when the young hatch also seems to coincide with a small window of time when a few of the two- and three-year-olds from previous breeding seasons pay the colony a visit. Too young to breed and presumably dropping in just to conduct a reconnaissance, these adolescents with their dusky faces and thin bills will often stand out like sore thumbs amongst the throng of adults in all their breeding finery.
As the teenage Puffins familiarise themselves with a thriving puffinry, finally towards the end of the month the female Waxwings breeding up in the taiga forests of northern Scandinavia and Russia should see the first chicks chipping out of their eggs after around a fortnight’s incubation. The young, like many perching birds, hatch naked and blind, and so will initially be totally
dependent on their parents for their every need. Due to the remote locations where Waxwings breed, relatively few data have been collected on their breeding habits, but a study in southern Norway revealed that the young were still brooded by the female for long periods even at five days old. While the female broods the chicks, the male’s responsibility will be to forage for food. Mostly insect food is considered to be brought in during the first few days and the regurgitated bolus of insects will either be passed to his mate to feed the chicks, or fed directly to each expectant red gape in turn.
Even further north on the Russian Arctic tundra, those Bewick’s Swans which both laid claim to a territory and built a nest should by now be well into their 30-day incubation period. Despite the vast majority of swans making the journey all the way back to the breeding grounds, for one reason or another a large proportion may have already made the decision not to breed. Without the stresses and strains of incubating and rearing cygnets, these non-breeding birds will have plenty of time to feed in the perpetual daylight experienced during the summer solstice north of the Arctic Circle. When not feeding or sleeping, the young swans will also probably be making use of any spare time to practise the art of courtship in the hope of having more luck the following year.