Wonderful world of Woodcock
They fly like bats, squeak like pigs, and behave like nothing else alive. But we may be about to lose them forever
We need to understand this woodland wader much better if we are to give it the chance of long-term survival, says Ben Macdonald
DUSK SETTLES OVER a forest clearing. A Nightjar churrs. Tawny Owls clamour from the heart of a plantation. Then strange croaks and ‘tiziks’ carry across the sharp outline of the fading pines. There follows an odd, bat-like apparition. The bird flies with a comical lack of urgency. It appears to go round in circles – repeatedly travelling the same prescribed highway in the evening sky. Observers often watch with a sense of bemusement. This is, we might think, a very strange bird. A woodland wader that flies around like a bat, squeaking like a pig. We puzzle, we shrug, and we move on with our daily lives. But in recent decades, breeding Woodcock in Britain have dramatically declined in numbers and range. Now is the time to understand their world.
Few actions are mysterious to those who perform them. Take the man who skips certain stones on a pavement. He does so for a reason. He may look bizarre to passers-by, but intent and purpose dictates his actions. Rarely, if ever, is human or animal action performed without reason. The same is true, of course, for birds. And the same is true for the Woodcock. This bird may leave us in the dark, but they have a clear strategy for survival that leaves little to chance. Their secret life has as much purpose and order as our own. Woodcock obey the same fundamental ecological rules as any other species. The difficulty is, these rules are hard for humans to decipher. In this article, I will try to lay bare the Woodcock’s life – to show how it makes sense. Few naturalists have cracked the Woodcock. John Walpole-bond, Desmond Nethersolethompson, Grahame de Fourges, Tester and Watson, Morgan and Shorten, Andrew Hoodless – these are some of the patient elite who have given us much of what we know today. For an extraordinary journey into the Woodcock’s world, Waders and their Breeding Haunts, by Nethersolethompson, offers unparalleled insight. In this article, I have simply reproduced, in brief, the findings of others, for your enjoyment. Roding is carried out by males. As sexes are almost identical, this was an uncertain point for decades. It was eventually proven by Marcstrom (1974). A rather unusual naturalist, Marcstrom shot 400 vocal roding birds as they passed overhead in Sweden over the course of several days. All but two were males. Hulten (1970) found that 6.5% of birds flying at dusk were female, but that none of these female birds used vocalisation. True ‘roding’ – vocalized flight for the purpose of advertisement – is therefore a primary means of display by male birds. In late winter, early, silent roding can take place. I have observed roding in several counties but only noted vocalisation from March. Des Fourges, in Sussex, found that vocalized roding could commence in early February (Nethersole-thompson, 2010). Roding then continues throughout the course of the breeding season, generally until the end of July. Males rode on a tightly defined circuit. Tester and Watson (1973) observed roding for 33 days. They found that each male tended to rode the same circuit, over the same ground. Circuits were often aligned with ‘topographical features in the
landscape’, such as rides. This theory was given extra weight by the fact that, when one male was killed, another, remarkably, replaced his exact circuit two days later. What to humans resemble random flights are, in fact, carefully marked highways in the sky. These aerial circuits are the real estate of the Woodcock. Each male has an aerial home range. Hirons (1980) found that circuits sometimes overlap, with some tolerance between males when this happens. Two birds, seen flying and chasing together for protracted periods, can be explained by one of two outcomes. Des Fourges believed that most aerial interactions are between males, with one chasing another off his circuit. On many occasions, three to four birds were involved in these probable displays of aerial competition. Often, the nature of the interaction gives away the gender of the bird. I have observed several ‘bumping’ encounters, as birds meet in the air. Most often, these then resume roding, after having re-defined their respective home ranges. These aerial contacts are, in my own view, routine territorial disputes between males.
A unique courtship
Sometimes, however, aerial interactions involve the pursuit of a female. Nethersole-thompson describes males “twisting after the other bird in typical wader sexual pursuit pattern… giving high-pitched squeaking pip-pip-pips”. He cites Brewster (1978), who observed a vocal bird pursuing another. It was joined later by a third, with the two pursuing birds being vocal. In the Forest of Bowland in 2013, I watched a dawn ‘spiralling’ flight between two birds. One was vocal, the other silent. Rather than both birds resuming roding, the pair descended into a nearby strip of birch woodland. My personal interpretation of this was a display flight,
preceding copulation. If the first purpose of roding is for males to advertise themselves and define territories, the second is to promote chances of mating. Most field observations concur that mating is initiated via roding. There are two main theories as to how this happens. Nethersole-thompson (2010) points out that many early naturalists (Pay 1937, Hagen 1950 and Muller-using 1960) believed females called down males as they roded overhead. However, there is little direct evidence for this. Most insights point to another explanation. This is that the male attracts the female’s attention as he rodes overhead. The female then makes some form of aerial contact. At this point, display, chasing and, if successful, copulation, commence. Numerous observers bear witness to this. Nethersole recounts how a female, incubating a clutch of eggs, was passed several times by a male, overhead. Eventually she flew to join him. M. Chance found that females joined males in flight, after they had been circled several times. Nests were later found below the contact point. Des Fourges experienced this same contact behaviour four times in as many years. Two colleagues of mine in Lancashire, who found eight Woodcock nests over seven years, did so by carefully watching for a silent female to ‘rise’ below a roding bird. On most occasions, the vocal male brought his silent mate down into the woodland. Roding ceased after this point, and mating was presumed to take place. Pairs were later found below the ‘contact’ point. In each case, nests were found within 100m, up to two weeks later. Walpole-bond observed females darting up below roding males, with nests found on the following day. Coupled with Nethersole-thompson’s observations, this suggests that females can continue to interact with males even when incubating a complete clutch of eggs. A variation on this interaction is one where the male descends to the female. Puchalski (1938) observed a male descend to a female incubating an incomplete nest – mating followed. It should be remembered, though, that such interactions are far harder to observe. Unless an observer has a ‘fix’ on a female, it’s impossible to say why a male has dropped into a wood. In my mind, a mating descent by the male probably happens just as often as an ascent by the female, but is witnessed less often by observers. The only proven mating sequence in Woodcock is where contact is initiated via roding. My own view is that initial pairing begins in the air. Once a nest is established, and initial mating has taken place, the logical sequence is that the male descends to mate nightly with his now sedentary mate, until her four-egg clutch is complete. All of this explains why roding is highly regimented and deeply logical. Males rode to define territory, advertise presence, and, possibly, assess competition. Their activities advertise them to ground-based females and initiate contact. Like other waders, aerial chases lead to ground-based copulation. But why do Woodcock continue roding throughout the summer once they have, apparently, paired up? The first thing to consider is whether males are polygamous. Do males abandon females once they have laid, and head off to find new partners? Do they continue roding so they are available to mate again, following the failure of nests? A few things are clear. Almost all those who have regularly found Woodcock nests have done so by entering woodland where a pair’s descent took place. Males and females have then been seen together. Nests
Females left the nest 4-7 times a day, averaging 27-29 minutes off the nest to feed. Birds never foraged more than 30m from their nests, generally flying from near the nest
have followed close-by. Waders and their Breeding Haunts gives a body of evidence for this, which I will, for reasons of space, omit. Not only is this the best-known method for finding Woodcock nests, but these insights reveal what happens between display and nesting. Males, it seems, stay close to females until the clutch is completed. This is the only behaviour that makes evolutionary sense, because mating must occur four times – once for each egg. Hirons (1980) proved this better than most, finding that radio-tagged males stopped roding for intervals of one to 11 days while with females. Most probably, males associate with females before, during, but not after, laying. Females incubate alone. Des Fourges (1977) studied nesting females intensively, for periods of 24 hours at a time. Females left the nest four to seven times a day, averaging 27-29 minutes off the nest to feed. Birds never foraged more than 30m from their nests, generally flying from near the nest, but walking back. Feeding took place after sunrise, and shortly before sunset, never during the night. These are what some rather disparagingly refer to as ‘anecdotal’ observations. I call them firsthand insights. These observations are not only invaluable, but often reveal the only possible behaviours that make sense in an evolutionary context. It is totally logical that female Woodcocks wake up and leave their nests to feed at first light, replenishing calories lost during the night. Almost every other species does the same. It is logical that they incubate periodically through the day, feed before dusk and then hunker down to shelter eggs when nocturnal ground predators are most active. As males play no further role in raising young, it is widely accepted, though not fully proven, that they mate again. This would explain, among other things, continuous roding. Hirons (1980) found that a radio-tagged female, whose clutch had been predated, re-laid 12 days later. Several other naturalists have found females capable of laying again. Whether Woodcock are truly double-brooded is unknown. My instinct is that, like similar waders, they are programmed to mate again and lay replacements – quickly and routinely – to mitigate high levels of predation. Females will re-lay, like any wader, but are not proven to raise two broods. Males, in all probability, mate again, but it is unknown whether they do so with the same female. Say, however, you have a wood with a single male and female – a regular occurrence at isolated, smaller woods. Unless the male takes some counter-evolutionary vow of chastity, it seems probable he will further the future of his species by mating with the same female later in the season. Soon, telemetry studies will hopefully prove this beyond doubt. Woodcock have evolved a clever breeding strategy, based around mitigating predation and maximizing chances of success. Males give themselves maximal exposure to females through continued circuits of their territory. Females have every chance to interact with one or more males. Males remain with females until clutches are completed, playing no further role in raising young. At this point, females incubate alone and, if predated, the cycle starts over. Males further the chances of the species by continuing display throughout the summer. Subsequent mating leads to replacement clutches, mitigating effects of predation. Secrets of a secretive life This, in brevity, is how breeding Woodcocks seem to operate. But what is their habitat? What do they require to survive? And why are they declining so fast across the UK today? Woodcocks, for starters, don’t use wood. They don’t nest or perch in trees. They don’t feed in trees. They don’t feed on the products of trees – nuts, mast or fruits. Woodcocks are entirely insectivorous, nest on the ground, and fly in the sky. Why, then, do they need wood at all? Let’s start with the premise that Woodcock and Snipe share fundamental similarities. Both are
ground-nesting, camouflage-using waders. Both require soft, damp feeding grounds rich in specific insects. Both require drier sites to nest, where their broods can find cover. Both are, as with any ground-nesting birds, adversely affected by undue disturbance and predation. Woodcock and Snipe both display in the air, pursue females in flight, and mate and nest on the ground. For Woodcock, the sole purpose of woodland, then, is to create optimal foraging and nesting conditions for its evolutionary needs. A long-term study of Woodcock habitat and diet by Hoodless (2007), confirmed that earthworms are the most important dietary element in terms of dry weight and frequency. In terms of frequency of consumption, adult diet is dominated, in order, by worms, spiders, millipedes, true beetle larvae and rove beetles. With chick diet, easily-digested earthworms become even more important, constituting 50-80% of dry weight biomass eaten. Other key items in chick diet, especially in southern England, are ground beetles, rove beetles and millipedes. From the deciduous plantations of Whitwell Wood, in Derbyshire, to the upland birches of Millden, in Angus, Hoodless found that these feeding requirements are consistent. Overall, studies show different data on insect families consumed. All agree, however, that earthworms are crucial for both adults and chicks. Woodcock select breeding sites where availability of these resources is high, but where adjacent sites exist with ample protection from predators. Hirons (1987) found that when feeding and rearing broods, Woodcock favour young stands of trees, with high earthworm density and dense ground vegetation for cover. When nesting, birds prefer areas with more open ground. Hoodless (1994) found that in birch plantations, half of nests were in bracken and heather outside of woodland. In Borders, many birds nest on open moorland, using woods for feeding. One Thetford Forest keeper told me that Woodcock, with their 360 degrees of vision, like to command a wide view of their surroundings when nesting.
A frontier existence
Woodcock occupy a woodland frontier – between damp, rich, exposed feeding soils, with cover – and drier, open nesting sites, with leaf litter and other camouflage-enhancing qualities. A range of landscapes can create these conditions. The New Forest, the Caledonian Forest, the Forest of Dean. All three of these landscapes harbour good populations of Woodcock, but are very different in age, composition, altitude and character. Today, however, many of our wooded landscapes are losing Woodcock at an alarming rate. The trend between the First and New Atlases shows significant range losses across Britain. Recent evidence from the BTO’S 2013 Woodcock survey suggests that Woodcock occupied just a third of non-random woods surveyed, and had declined by 8% at overall study sites since just 2003. Occupancy apparently increased by 18% in northern England but declined by 21% in southern Scotland. Occupancy was lowest in south-west England and Wales, and highest in northern England, eastern England and northern Scotland. Strongholds now include wooded landscapes such as Strathspey, Kielder Forest, Thetford Forest, the Forest of Dean and the New Forest, extending eastwards into Sussex. So what does this tell us about Woodcock today? Firstly, Woodcock need lots of wood. Fuller
(1982) found that the species prefers large wooded landscapes. The Woodcock’s breeding strategy evolves around a multiplicity of mating opportunities. Males and females must have numerous chances to interact, mate and re-lay in response to high levels of ground predation. In the long-term, therefore, only populations in large, connected woods have a strong chance of survival. Retaining extent is vital for Woodcock persistence. Secondly, Woodcock show a very strong preference for woods with an open field layer. They need ground-level cover – but not understorey, which stifles aerial movement and restricts open space for feeding and nesting. Trees may create good feeding conditions, but too many trees shut off sunlight that promotes humus-rich soils – the layer where earthworms thrive. Kirby (2005) found that British woods, devoid of regular clearing, coppicing and ride-creation, are slowly becoming overgrown. Many young conifer plantations, once ideal for Woodcock, are now no longer suitable. Deciduous woods have likewise darkened as coppice has matured unchecked. Space – rides, glades, clearings – must be recreated in our forests. Woodcocks need these open areas to nest, and to exploit large tracts of sunlit, basic soils for earthworm food. It is the well-lit, worm-rich spaces between trees – not trees themselves – that Woodcocks need. Certain woodland types have proven successful for Woodcock across Britain, and across many decades. Damp, young birch-woods are prime. These often contain rich, damp soils, dense bracken, open glades and well-lit forest floors. Younger Hazel coppice can replicate these characteristics; so can young conifer plantations, with grass and space between trees. In ancient, mature woodlands, Woodcock favour open Beech and Sycamore, where plants like Dog’s Mercury take the place of birch-wood bracken by providing feeding cover. In all cases, moisture promotes earthworm density and accessibility. Many of our woodlands, desiccated by over-planting and over-draining, are drying out. We need to ensure woods remain both damp and open, with ground cover for predator concealment, but plenty of sunlight to foster worms. We need to act fast to retain Woodcock as a British breeding bird. Then, this bat-like wanderer may continue to delight for centuries to come.
RARE SIGHT It is rare enough to see a Woodcock om the ground, but two together is exceptional NIGHT FLIGHT Two birds flying together could mean male on male aggression or a prelude to mating of a male and female
CRYPTIC Woodcocks blend beautifully with the leafy woodland floor WOODLAND NEST Woodcock eggs are laid in a minimal nest on the ground Even the fluffy babies have cryptic patterning for camouflage in woodland MINI-WOODCOCKS
SUNNY GLADES Woodcocks need sunny glades for maximum earthworm production In flight, Woodcocks are bulky, long billed waders
WORM-EATER The bulk of all Woodcocks’ diets consists of earthworms