by Mike Dilger
July
Marginally shading August for the mantle of ‘warmest month’, the colour purple often holds sway across town and country in July as flowers like Buddleia, Heather and Knapweed all bloom profusely to coincide with the super-abundance of insects emerging in the long, warm days of Britain in mid-summer. While a whole plethora of butterflies and dragonflies take to the wing to make the most of their short lives, many birds, however, will be keeping a far lower profile. With courtship and territorial songs suddenly replaced by subdued contact calls and the sound of incessant begging from young still in the nest, for the avian fraternity July is primarily a time for feeding, fledging and moulting.
Early July
Finally, after just over a month of incessant incubation in the perpetual daylight of the Arctic tundra, those breeding Bewick’s Swans that managed to keep a whole host of marauding predators away from their clutch should be finally welcoming their newly hatched chicks into the world. It seems the hatching process can be a protracted one, with the chicks emerging over a period lasting anywhere between one and three days. From research carried out on the breeding grounds it seems that around 90% of the eggs will hatch, while the other 10% were either infertile or the embryo died during development. Throughout this key period both parents will be close at hand to ensure any unwelcome visitors are kept at bay and once dried off, the downy young will be fully sighted and able to feed themselves within hours of emerging into the maritime tundra.
Also able to rear just a single brood during the brief northern Scandinavian summer, most Waxwings should by now be busily feeding their young at the beginning of what is statistically the warmest month of the year in the taiga forests. Needing to brood the grey-brown chicks much less from around day six means the female will suddenly become freed up to help share the chore of finding enough food during what will be the youngsters’ phase of quickest growth and most rapid development. After being fed initially on protein-rich insects such as mosquitoes and midges, the parents will then subsequently feed their noisy young on a combination of invertebrates and locally foraged fruit. Certainly in the Swedish taiga forests the young Waxwings will probably be fed a combination of Crowberry, Bilberry, Cowberry and Bearberry. Having flowered in May and June, most of these plants should be forming their clusters of fresh berries by the time the Waxwing chicks are at their most ravenous. Further east in the Russian Federation, the later arrival of spring might just mean the nestlings have to settle with any berries still remaining from the previous year’s stock, in addition to a healthy supply of flies, beetles, flying ants, caddisflies and other insects.
Compared to Waxwings, the Puffin parents will have to make far longer foraging trips during the breeding season if they are to locate sufficient food for their single chick back on dry land. How far the Puffins travel to catch fish for their subterranean Puffling was, until recently, little more than educated guesswork. Research work carried out on the large Skomer colony, in west Wales, found 85% of Puffins recorded within 15km of the island were carrying fish out at sea, meaning these must have been birds returning back with food for their chicks. However, on the remote islands of St Kilda off west Scotland, the researchers had to travel 40km from the islands before the majority of Puffins were seen to be carrying fish, suggesting that the birds may have to forage at greater distance. More recently seabird researchers Mike Harris and Sarah Wanless have successfully managed to attach GPS (Global Positioning System) loggers to a number of Puffins on the Isle of May, situated at the mouth of the Firth of Forth in east Scotland, and found that the average distance the Puffins were travelling to feed was 38km, with a maximum recorded of 64km – a long way indeed for a fish supper!
Fish are of course never evenly distributed across the seas and oceans, but distinctly clumped, and so finding the discrete shoals of fish in the vast open spaces of the North Sea, Irish Sea and north-east Atlantic Ocean could potentially be very difficult. It seems, however, that Puffins, through trial and error, must be able to quickly familiarise themselves with the best feeding areas. Despite being intensely sociable birds on dry land, Puffins seem to shun company at sea by keeping spaced out across any possible fishing areas. It’s believed that each Puffin dive will rarely last longer than a minute, with the bird then taking a brief rest on the surface before slipping below again. Using time-depth recorders attached to Puffins, Sarah Wanless and her colleagues recorded one Puffin making an astonishing 194 dives in 84 minutes, which suggests that the Puffins don’t dive anywhere near as deep as Guillemots and Razorbills, for example. Below the water Puffins suddenly become transformed into lean, mean swimming machines as the pressure compresses their feathers flat to the body and the wings are suddenly transformed into powerful flippers able to propel the bird through the water at a surprising speed. With the feet acting as both rudder and stabilisers, their manoeuvrability is another tool in the armoury helping them to snatch any unwary prey.
Further results from four time-depth recorders attached to Puffins feeding chicks revealed that, on average, each bird made 1,148 dives per day and spent 7.8 hours under water. From this revelatory data it has been extrapolated that Puffins may catch a fish on only two out of every five dives, and so energy-demanding is this occupation that 90% of all the fish they catch will be purely for their own consumption, with no more than 10% destined for the chick waiting back in its burrow! Of course, unlike the Blue Tits feeding their chicks, which will return to feed their young with a single caterpillar each time, Puffins are famously able to carry many fish at a time. This ability to catch more fish while still holding on to the ones already caught is achieved with backward-pointing spines, called denticles, on the roof of the mouth. Adopting the ‘belt and braces technique’, any food caught is prevented from being dropped by a rough covering at the back of the tongue, and finally the load they’re able to carry is also maximised with the help of a flexible hinge between the lower and upper mandibles.
With Sandeels being the main prey for British Puffins, the number they’re able to carry will vary between colonies, different pairs and from year to year. Billfuls of between four and twelve seem the norm at many colonies, but an unbelievable 61 Sandeels and a Rockling observed being carried by one bird returning to feed its chick on St Kilda is frankly astonishing. Historically, there was a suggestion that the Puffins arranged the fish to be positioned alternately in the bill, so that the head of one fish would be placed adjacent to the tail of the next and so on, but in reality the fish are carried in a haphazard fashion and presumably held in the same orientation as when the fish was originally caught. However they’re arranged, once the adult is content it has caught a sufficient number, it will then head back to the puffinry, where it must face one last challenge before the chick receives the reward its patience deserves.
Having now hatched around twelve weeks ago, the juvenile Tawny Owls, like the Pufflings, will still be reliant on their parents for providing 100% of their dietary needs. Despite being fully mobile, fledged young from the same nest will still frequently choose to roost close together at a few favoured spots as they wait for their parents to bring in food. It seems the parental care that the adult Tawnies provide is confined to the provision of food and defence against predators, with little evidence that they actually train their young how to hunt or catch prey. This is a different ethos to Peregrine Falcon parents, which take the tutoring of their offspring very seriously when it comes to passing on best hunting practices. Once their young have begun to master the art of aerial food-passes, the parents will then move on to delivering live birds. These usually tend to be feral pigeons that the parents have already caught alive, only to be released, possibly in a dazed and confused state, as catching practice for the young. Initially there are plenty of near-misses as the quarry either escapes or has to be subsequently recaptured and killed by the parents, but the youngsters will soon become proficient at catching and dispatching the prey item with the minimum of fuss.
As the young Blue Tit
s begin to disperse further afield from where they were reared, they will not be figuring prominently on any Peregrine Falcon’s radar, but much higher on the list of any local Sparrowhawk, which would jump at the chance of an easy meal of a ‘naive fledgling’ or two. In addition to running the very real risks of predation, the number of caterpillars in the trees may have already passed its peak too, leading to starvation and any diseases brought on by being in poor condition, which can be major stumbling blocks during this seeming ‘time of plenty’. However, there is substantial help for the many Blue Tits which fledge from suburban locations, thanks to easy feeding opportunities offered up in many gardens. Certainly in the south of Britain, most gardeners who regularly leave out peanuts and sunflower hearts can be sure of seeing a steady stream of juvenile Blue Tits in the early part of the month. Distinctive with their greenish caps and yellowish cheeks, many juveniles can now be seen dashing from the cover of the surrounding bushes to the feeders as they attempt to grab an easy beakful of food.
Any adult Blue Tits freed from the constraints of looking after their young should by now be able to concentrate on finding sufficient food to fuel their annual moult, which could carry on at least up to early September. Of course, adult Nightingales will not have the luxury of being able to carry out their wing moult in such a gradual fashion as their flight feathers will be needed to power them to Africa, and so a rapid moult will make them far less mobile at this time. Needing to keep flight to a minimum, it’s thought that the adults will choose sites away from the breeding grounds, which offer both rich feeding opportunities and plenty of places to hide away from any predators during this perilous period.
Having also deserted their breeding grounds, the adult Lapwings and any fledged juveniles will by now have been absorbed into large, mobile moulting flocks. As good feeding opportunities for these flocks in summer may be both widely spaced apart in the countryside and ephemeral by nature, the Lapwings will need to ensure they’re able to stay aerial. This of course means – like with the Blue Tits – that the wing moult is a long, drawn-out process, not finishing until early September. Also needing to be prepared for the rigours of winter ahead, the juveniles will begin a partial moult by shedding some of their fledging feathers. Clearly distinct with their short crest, buff face, scalloped back and wing feathers and incomplete breast-band, the juveniles will also show a shorter wing than fully adult birds with a clearly narrow primary area in flight. It will not be until December, and some seven months after hatching, that they will finally be looking pretty similar to the parents that successfully raised them earlier in the year.
Early July should also see the second brood of fledged Robins receiving their final life lessons before branching out on their own. Providing their parents haven’t opted for a third brood, the chicks from this second clutch will have had the benefit of both parents’ attention in helping briefly to cushion them from the harsh realities of life while they learn the skills necessary for surviving on their own. After just three weeks following their parents’ lead, the young are considered as ready as ever, and with little or no ceremony simply disperse into the countryside to prepare for the difficult times ahead. The departure of the young will trigger a number of changes in the adults. Firstly the pair will kick-start their annual moult, a slow process which may well take up to eight weeks as feathers worn down by the rigours of the breeding season, exposure to ultraviolet light and the attentions of parasites are replaced. During the moult, the strict territoriality which had been in place since the previous autumn will also break down. Not needing to hold a territory will render the Robin’s song redundant with the knock-on effect that July and August are the only months of the year when town and country are devoid of their beautiful songs. In contrast to the rest of the year, when Robins will be both loud and visible, this vulnerable period will find them keeping mostly hidden away in the undergrowth as they concentrate on finding sufficient food to power the growth of their replacement feathers. Becoming antisocial once again, any remaining pair bonds quickly dissolve as each bird returns to splendid isolation.
While the adult Robins retire from public view it’s quite a different scenario for any Swallows intent on laying their second clutch. For those pairs successfully raising a first brood, it’s highly likely that they’ll have an ‘if it ain’t broke, don’t fix it’ attitude towards their relationship and will stay together for the rest of the breeding season. But matrimonial strife, brought on by the first clutch failing, can often result in the pair opting instead for a quick divorce to try their luck elsewhere. Clutch size is thought to be lower for second broods as the amount of daylight available for feeding slowly declines, but the number of eggs can also be influenced by the condition and experience of the female. When the clutch is completed, it will once again be the female’s responsibility to incubate the eggs through to hatching while the male bides his time in preparation for the new arrivals.
Any fish observed being carried back to the nest-bank and down the tunnel will be a sure-fire sign that the second clutch of Kingfisher chicks will have finally hatched out in their dark and gloomy, but well protected, chamber. The first small fish initially brought in will then be carefully placed head first down the gape of the naked and blind chicks as they digest the first of many similar meals over the course of the following 24 or 25 days.
Having already departed our shores on their long migration back to the Congolian rainforests, by early July the male British-breeding Cuckoos will have dispersed in a wide arc across Europe. Despite the BTO’s satellite-tracked Cuckoos being reported at this stage from a whole host of countries right across Europe, there are already early signs indicating a split between those Cuckoos that are opting for the more westerly flyway through Spain, and other individuals that are planning to take the far more central European migratory route through Germany and Italy. Irrespective of the direction chosen, presumably experience will also play a key part in the birds’ survival as any seasoned campaigners link up with those rich feeding sites familiar from previous migrations. The Cuckoos’ mission at this time of year is quite simple – to stock up as well and as quickly as possible before heading south across the Mediterranean Sea, crossing most, if not all, of the Sahara Desert in one fell swoop.
Thousands of kilometres away in Britain, and after around 17 days spent dining in its host’s nest, and a similar period begging from its hoodwinked foster parents, the Cuckoo youngster should by now be on the threshold of independence. Leaving its hosts to rescue what remains of their breeding season, the young Cuckoo will then begin seeking out hairy caterpillars, which also happened to be the food of choice of its parents earlier in the summer. With the young Cuckoos only just learning to feed themselves, it’s remarkable to think that their errant parents will have already departed for the continent, leaving the chicks they never met to begin their long migration alone down to their wintering grounds in the heart of Africa.
Mid-July
After little more than two weeks on a diet of berries and mashed up insects, the young Waxwings will be already be raring to sample the delights of the taiga in summertime. They will fledge looking remarkably inconspicuous and with only a hint of the crest, black bandit’s mask and pinkish coloration so distinctive of their parents. Fluttering out one by one, the young are initially barely able to fly, and so will need to stay close to their parents for a further two weeks until the power of flight has been mastered, they have learnt the best locations for feeding and become proficient in the most effective techniques for catching insects. Sitting almost astride the Arctic Circle, the city of Rovaniemi is the commercial capital of Finland’s northernmost province, Lapland, and will certainly have a healthy population of Waxwings breeding in its surrounding forests. At this time of year, the average daily temperature in Rovaniemi will reach an annual high of around 15°C with daylight virtually around the clock. These conditions should enable Waxwing families to have plenty of time and opportunity to feed well before the slow and
inexorable descent towards winter eventually forces them off their breeding grounds and to a more benign climate further south.
Even further north than Rovaniemi, on the Russian tundra those Bewick’s Swans with recently hatched chicks will be keen for their brood to leave the nest for the relative sanctuary of nearby water as soon as possible. The instant the family unit can become mobile the cygnets’ survival prospects will be hugely enhanced, as being on water will instantly offer more protection from most land-based predators, while the broken terrain away from the nest should also offer more opportunities to remain safely hidden were danger to beckon. Unlike Mute Swans, the recently hatched cygnets will not ride on their parents’ backs and are still brooded regularly at night and during inclement weather. The parental duties will also be split at this stage, with the job of brooding the young largely falling to the female, while her mate’s responsibility is to keep a constant lookout for predators such as Arctic Foxes. If a fox does approach too closely, the male should be able to use his size, bulk and aggression to drive away most unwanted attention, but irrespective of the male’s attentiveness, a number of young will inevitably be predated early on. Upon leaving the nest the cygnets are totally capable of feeding themselves; however, when very young they will still have to rely on at least some help from their parents with the collection of any food simply out of reach. Many bird species will dissolve the family ties not long after their young fledge, but this isn’t the case with Bewick’s Swans, as the bond will only continue to grow stronger between the young and their parents as the season progresses. In fact, so pronounced is this familial affiliation that those youngsters successfully managing to fledge from the tundra will, in all likelihood, stay together with their parents through the subsequent winter right up to spring the following year.
