Nightingales in November (22 page)

Once a bird that nested in caves before humans began to construct their own accommodation, many Swallows have nowadays opted for rural buildings as nest sites, with farmyard barns and cattle stalls amongst their favourite locations. The substrate to attach the mud nest to needs to be suitably rough, so cracks, corners or any type of fixing will all help secure the nest if no horizontal support, such as a beam, is available. Nest sites will also need a clear flight path for safe and rapid access and exit, and nests also tend to be sited at locations to protect the chicks from bad weather and against any variety of predators.

In terms of their breeding patterns, Swallows can be considered similar to Lapwings, in that they usually breed either solitarily or in loose, social groups. For those birds that have taken the gregarious option the territories and nests are never immediately adjacent to one another, as is the case with Sand Martins nesting cheek-by-jowl in a sandbank, but instead have a large degree of separation. For example, different Swallows will frequently hold territories in separate outhouses of the same farm, or at the very least at the opposite ends of a large barn, where an informal arrangement seems to be made which ensures that the nests are out of a direct line-of-sight with each other.

As the male Swallows begin to nail down territories in anticipation of the arrival of the females, the male Cuckoos will still be short of their final destinations in Britain. It seems the case that both the route taken back from Africa and the prevailing climate at this time of year will have a huge impact on the Cuckoos' progress as they work towards their breeding grounds. Take Chris, for example, which is still the only Cuckoo to be followed by satellite over three separate springs on his way back to Britain. In 2012, come the middle of April he was thought to be held up by poor weather in north-west Italy, while in 2013 he was in northern France close to the border with Belgium by this time, with spring 2014 seeing him in central Spain, having possibly been delayed crossing the Sahara.

With the returning Cuckoos spread in a wide European arc as they close in on Britain, mid-April at many puffinries will be the time for established couples to conduct a quick spring clean of their previously used burrows, with egg laying just a couple of weeks away. Most burrows will at some point have been constructed by the Puffins themselves, although on Skomer Island off west Wales, pairs without a burrow have been known to misappropriate Rabbit or Manx Shearwater burrows for their own use. Typically a touch longer than the human arm, the ideal burrow is usually situated on a 20–40° slope with the opening facing out to sea. This entrance will then form a narrow, blind alley dug through the soil or peat that ends in a slightly elevated and wider nest chamber. In favoured nesting sites these burrows can be at such high densities that there may only be a few centimetres of ‘wall' separating some of the burrows. In a flourishing puffinry, any newly formed pairs or evicted couples may well have to start
digging a new home from scratch. Excavation and restoration is carried out by both birds, with the male thought to carry out the largest share of the workload as he uses a combination of bill and feet to dig down into the peat or soil.

Compared to Guillemot and Razorbill colonies, which are deafeningly noisy, puffinries are generally much quieter places. Once members of a pair are together in their underground burrow the occasional groan can be heard, but recordings made with sensitive microphones show that in fact a whole range of vocal activity below our audible range frequently takes place just under our feet. In addition to preparing the burrow, this is also an important time for Puffin pairs both to demonstrate their bond to one another and declare site ownership. The most frequent demonstration of ‘married status' to neighbouring Puffins is when a pair engage in ‘billing'. This bill-clacking behaviour usually happens when a puffin lands by its mate either at a club or the burrow. This billing can quickly become an infectious activity as surrounding pairs copy the behaviour and spread the love like a Mexican wave! Individuals will also ‘spot stomp' around their burrow, a ritualised behaviour that involves raising and lowering alternate feet with their webs spread, while remaining on one spot – which in the world of the Puffin simply says ‘This is mine, all mine!'

As Puffins re-familiarise themselves with their burrows, it seems that the Bewick's Swans will also be reacquainting themselves with well-known and previously visited stopover sites across Estonia and Latvia during much of April. With the Russian Arctic still almost certainly frozen over in this month, it seems that the spring migration for Bewick's Swans back up north is a leisurely affair taking anywhere between eight and ten weeks. This contrasts with their autumn migration to Britain which has been calculated as only taking between
four and six weeks, as the rapidly plummeting temperatures and shorter days combine to play a large part in forcing their movement towards the Gulf Stream-warmed countries of Britain and the Netherlands. During this period of the year, Eileen Rees from the Bewick's Swan research team at the WWT thinks that around three-quarters of the population of swans from the European or north-west flyway may well be widely dispersed across Estonia's wetlands. In addition to important coastal sites such as Matsalu Bay and Pärnu, where the swans will be principally feeding on pondweed, they may also be taking advantage of any ice-free floodplains and agricultural areas further inland, while waiting for the ice to retreat further north.

As Waxwings also continue their migration north with winter slowly beginning to relent, April may well see a gradual change in their diet. Having force-fed themselves on little other than berries for over six months, the first warm days of spring will see an emergence of swarms of insects – a vital source of some much-needed protein for the birds. Keen to take full advantage of any good feeding opportunities that arise along the way, the Waxwings' technique of catching insects, as they sally to and fro from open perches, will see them plucking any midges and mosquitoes straight from the air.

Back at the Tawny Owl nest, the young chicks appear to spend large parts of the day sleeping, and on the few occasions when the female needs to leave the nest to defecate or cast pellets, they will often huddle together to reduce heat loss. However, within a week of hatching, the scanty down they were born with will quickly become a far more plentiful covering. Feeding also becomes easier for the chicks once
their eyes start to open after around 12 days, enabling them to take far more initiative in begging for prey items brought into the nest. Unlike the chicks of Robins and Blue Tits, for example, the small owlets don't produce their faeces in neat sacs, so their excrement is often simply eaten by the female. If the male is providing plenty of food at this stage, any uneaten remains in the nest can quickly build up, attracting flies, and so the brooding female will also have to make sure that the young chicks are regularly preened to keep them as clean and healthy as possible during this period of incarceration.

Requiring around two weeks less incubation time than the 28 to 30 days needed by the Tawny Owl, female Robins – certainly in southern Britain – will see their first chicks emerging with late April approaching. As soon as the chicks hatch, the female's first action is to remove the now redundant eggshell from the nest – part of which may be eaten if she is calcium deficient. The chicks are looked after by both parents, but the female's brief, certainly for the first few days, will be to brood them. Hatching naked, they're unable to maintain their own body temperature and will quickly die from being chilled if exposed to any April showers at this sensitive stage. During these early days, if the male brings back food while his mate is brooding he will pass it directly to her to feed the chicks. Fed on a high-protein diet of spiders, beetles and worms, the young grow incredibly quickly and will rarely spend more than two weeks in the nest before starting to fledge.