Counting for conservation

It is at this time of the year that I get a chance to catch up with my field notes and pull together the records of birds, invertebrates and other creatures that need to be submitted to county recorders. Sharing wildlife notes in this way is an important task. Extracting records from notebooks that would otherwise sit on a bookshelf to make them available for researchers and conservationists helps turn a hobby into something with greater worth and purpose. Some of my records have already gone into recording systems that allow the data to flow straight through to the county recorders. My bird records, for example, are recorded through BirdTrack (www.birdtrack.net), a free online system operated by the BTO that I can use in the field through a smartphone app.

The winter months also provide an opportunity to reflect on the season and to place my observations into a wider context. 2014 was, for example, a year in which the breeding season started particularly early for many resident birds, but which was a poor year for many migrants, who returned in smaller numbers than usual. My records of nesting birds underline this, with many early clutches of blackbird, song thrush and (in particular) woodpigeon. In fact, I monitored more woodpigeon nests this year than I have ever done before, with the majority of these encountered much earlier in the season than I would normally find them.

In the case of insects, it is a more complicated story and it is clear that while spring and early summer were good, the late summer and autumn weather conditions rather curtailed the season for many species. It was noticeable, for example, that my late summer garden was rather lacking in both ladybirds and hoverflies this year, a pattern now being reported by other observers.

As well as looking back over the season just gone, I like to use the turning of the year to look forward. I can think about the projects that I want to focus on during the coming year and identify particular sites or species that I want to spend time looking at. It is also a good time to be making resolutions and there is plenty of opportunity for doing more for the natural world.

A bird in the bush

It has been a surprising spring, with many birds and animals active much earlier in the season than has been the case in recent years. Perhaps everything seems so much earlier because of the very slow start to last year, when low temperatures and rain delayed the emergence of butterflies and hedgehogs, and stalled the northward migration of our summer visitors.

One particular feature of this year has been the numbers of woodpigeons breeding early; it seems as if everywhere I look there are birds sat on nests containing eggs or young chicks. A woodpigeon nest is a rather pathetic structure, a few dozen sticks placed together to form a platform. Some are so badly constructed that you can see the eggs through the sticks when viewing the nest from underneath, making you wonder why more nests don’t fail because the eggs have slipped through and fallen to the ground.

Woodpigeons nest in a wide range of places but, this early in the season, most seem to favour the thick cover provided by climbing ivy, particularly where it is growing up a tall tree or shrub. Other individuals place their nests in more exposed locations and there are a number dotted around town which have been placed in trees still devoid of any leafy cover. Such nests often fail because they are easily spotted by predators like crows.

Once you get your eye in you soon discover how many nesting platforms there are in the scrubby cover provided by those scruffy bits of land characteristic of the urban landscape. Occupied nests will almost invariably contain a pair of glossy white eggs; while some nests contain just a single egg, a clutch of more than two eggs is exceptional. The resulting chicks are rather ugly, with narrow heads, grey skin and rather thin, yellow down. Known as squabs, they will be fed initially on crop milk – a substance produced by just a small number of bird species and not dissimilar from mammalian milk – before spending a month in the nest before fledging. Despite the time invested in each nesting attempt, the woodpigeon breeding season will continue on throughout much of the year, giving you a good chance of catching up with some yourself.

After the storm

It is good to be able to slip from the house at dawn and to enter a world that is finally still. The biting and bracing wind has passed and the air holds the carrying notes of song thrush and woodpigeon, both of which hint at the approaching spring. February is a dark month. Part of winter’s realm, she carries not the new year hope of January but instead sits belligerent and brooding. A troublesome month of storms, of rain and rising waters, of a wind that never drops. Will spring ever come?

These final days of the month, however, give hope and the calm that greets this dawn suggests a season soon to change. While I have seen these false hopes before, the hints of spring snuffed out by a weather system bringing chill winds from the north or squally rain from the west, the blooms of snowdrop, aconite and winter heliotrope offer a glimpse of the season to come. And there, among the brash that needs clearing from around the pond, I find a female brimstone. Her yellow-green sulphur proclaims life amid the blacks and dirty browns of rotting wood and leaf. Tenderly, I take her folded wings between thumb and forefinger and place her within the green ivy that coats the ancient wall. She will be safe and sheltered here, ready to stir with the first run of truly warm days.

The small tortoiseshells wintering in our unheated upstairs toilet have already shown their restlessness. On warmer mornings, when the sun’s rays push in through the small window, these wintering house guests can be found fluttering around the upstairs of the house. Come evening, when they are perched on curtain or net, I return them to ‘their’ room.

Droppings in the side passage, both on the flagstones and stuck to the wall, reveal that the brown long-eared bat has also been active. There are few moths coming to the lighted windows at night, so he may be better off remaining in whichever cavity he has chosen for the winter. Perhaps, as it is with me, these stirrings are a response to the changing weather, the lengthening of the days and the turning of the seasons.

A mild end to the year

December has been rather mild overall and there have been times when, working outside, I have been most comfortable in a t-shirt. The mild weather has had an effect on our wildlife too, with a wider range of bird song evident and a distinct shortage of birds coming to visit the garden feeders. Judging by the moth wings scattered on the floor of the passageway at the side of our house, a brown long-eared bat has been equally active over recent weeks.

Coming off the back of a colder spell early in the month, the warm damp air that pushed up from the Azores mid-month seems to have tricked some birds into thinking that spring was on its way. In addition to the characteristic winter song of robin, which adds a melancholy air to the winter months, blackbird, mistle thrush, dunnock and woodpigeon were all to be heard in song from the garden. With the exception of dunnock, these are species that often make their first nesting attempt very early in the year and I would not be surprised to learn of individuals sat on eggs during the first half of January. Even a pair of mute swans on the river were reinforcing their pair bond with display behaviour more usually seen in spring.

That the garden feeders have been so quiet is not just a reflection of the mild conditions, which reduce the energetic stresses faced by small birds, but also the size of the autumn seed and berry crop. The 2013 crop of woodland and hedgerow fruits and seeds has been so abundant that it continues to last well into the winter months. No doubt the lack of a heavy frost has also played its part, since this often see the berries drop to the ground, where they then become accessible to small mammals and other wildlife. While the garden is quiet, the local woods are still busy with birds and mobile flocks of tits and finches can be found feeding among the trees. Siskin and lesser redpoll have been favouring the riverside alders; should the weather turn cold early in the New Year then I would expect the garden feeding station to become a hive of activity.

Look up!

Lift your gaze above the horizontal, directing it towards likely spots as you wander through town, and you will soon discover that there are nesting woodpigeons everywhere. Two of the houses on our street, for example, sport climbing plants that trail the outline of the front door and in each of these, wedged just above the frame, is a nesting pigeon. There are another three nests along the high street, two in trees and one on the top of a metal cage that protects some passageway lighting from the mindless attention of the local hooligans. There is even one in my garden, a bulbous platform of sticks, formed from the combined nests of three previous seasons and many previous nesting attempts. On top of each nest sits the plump and unmoving form of a woodpigeon.

Many of these nests go unnoticed; despite their bulk the sitting birds are usually silent and many of us wander around with our heads down, watching the pavement or avoiding the gaze of passers-by. This is good news for the woodpigeons, incubating their two eggs or brooding young chicks. Not all of the sitting birds will be on eggs or young, however, as the two members of the pair may take turns at sitting on the empty nest in the days leading up to when the first egg is laid.

It might seem odd that woodpigeons only lay two eggs, but it is a feature characteristic of pigeons and doves more widely. Both parents take turns at incubation, the female incubating for roughly 18 hours in every 24, the male the remainder. The birds switch over at or near the nest so the eggs are rarely left uncovered for long.

One curious aspect of woodpigeon reproduction is that the young pigeons are initially fed on crop-milk, something that is known from very few bird species around the globe. Crop-milk is a secretion that is produced within special glandular cells in the crop wall. These cells become filled with a cheese-like substance and, when full, are sloughed into the crop from where they are fed to the young by regurgitation. The sloughing does not happen continuously and there appears to be a trigger that causes the cells to be released en masse just prior to the time at which the young are due for a feed. Feeding visits to the young decrease with age, the diet also switching from crop-milk to other material, so that older chicks may only receive feeding visits twice a day. This may reduce the risk of an adult being followed back to the nest by a predator and less activity at the nest also makes them more easily overlooked by us.

Woodpigeons start nesting

Over the last few days I have noticed a growing and untidy pile of sticks on the roof of the chicken run. These are arranged in such a way as to suggest they have not come to rest here naturally. In fact, they are evidence that the Woodpigeons have initiated another nesting attempt in the Holly tree under which the chicken run is placed. Looking up into the tree’s branches, the scruffy excuse for a nest can be plainly seen, complete with a broad, square ended tail poking out behind.

I always feel a little disappointed by the Woodpigeon’s clear deficiencies in the building department. Not only does the nest seem woefully inadequate, full of gaps through which both sky and egg may be seen, but there is a sense of laziness that comes from the pile of wasted sticks below the nest. I cannot comprehend why the pigeon fails to make use of these. If a stick does not hold its position during building, but falls to the ground below, why does the pigeon not pick it up and try again? Surely, it must be less demanding to pick up the stick instead of going elsewhere to find a replacement.

While other birds build their nests and rear a family with industrious commitment, the pigeon’s approach seems lackadaisical, half-hearted and, to be brutally honest, amateurish. They lay just two eggs and it is not unusual to find one or both smashed on the ground beneath the nest, especially on days when there is a bit of a breeze. The females do, however, sit fairly tightly once they have begun incubation, patiently passing the 16­ or so days before the eggs come to hatch.

Young pigeons (which are known as squabs) are decidedly ugly, especially when newly hatched, but they grow rapidly and soon acquire a covering of body feathers. The squabs are reared on a diet of ‘milk’ (more properly known as ‘crop milk’), which the parent regurgitates from special cells in its crop. A hungry chick will force its head into its parent’s open bill to receive a mixture of water, fats and proteins not dissimilar to mammalian milk. For the first few days this is all that the young chicks receive but as they get older other foods are introduced into their diet. The production of crop milk by birds appears restricted to all pigeons and doves, and at least some penguins and flamingos.

Woodpigeons will have been nesting since very early in the year but late summer is very much the peak in their nesting activity, as pairs attempt first or second broods in the thick deciduous cover that is now much in evidence.

Woodpigeons keep on nesting

The Woodpigeons are nesting again, this time back in the Holly tree above the chicken run. It seems to be a never ending process; nesting attempt follows nesting attempt, with most doomed to failure, a seemingly dismal cycle of poor parenting. That the Woodpigeons should fail so often could reflect the density of cats, many of which stalk this urban area, but I don’t think that this is the whole story. With just two eggs per nesting attempt and a pitiful excuse for a nest, these birds just don’t seem to have it in them to make a proper go of it. While other species build well constructed and intricate nests deep within cover, the pigeons seem to just sling a few small twigs together somewhere obvious and hope that this will suffice. More often than not, I find the eggs smashed on the ground beneath the nest, the result of a windy day, a lack of robustness in the nest’s construction or a clumsy parent.

The surprising thing is that these birds are doing so well, with a population that has gone through the roof over recent years, thanks largely to changing agricultural practices. You cannot move for Woodpigeons; even here in town they dominate the bird community, hoovering up food from bird tables or delivering a monotonous dawn chorus with their ‘take two cows, taffy’ call. It would be fine if they were attractive, elegant even, but they come across as clumsy, overweight and, let’s be honest, rather dim. To see a Woodpigeon attempt to perch on a hanging feedeer reveals a triumph of determination over brains. However, there is one thing that Woodpigeons do which does suggest some initiative. When it rains they line up on the fence and each bird raises first one wing then the other high above their head, allowing the raindrops to wash the underside of the wing.

The increase in Woodpigeon numbers may be having a knock-on effect on another monotonous songster, the Collared Dove, whose numbers locally seem to have taken something of a dip over the period that the Woodpigeons have been on the increase. The doves are a rare visitor to our garden feeding station these days, seemingly ousted by a succession of pigeons that waddle around on the ground beneath the feeders or clamber in a most comical manner over the Hebe in search of fallen seed. I guess that I have a grudging respect for them; that they have been able to increase their numbers despite their seeming inadequacies suggests they must be doing something right. I think it must be a combination of persistence and adaptability that has served them so well.

Pigeons feast on ivy berries

The end wall of my garden is hidden beneath a mass of ivy. Arising from a single trunk, whose girth far exceeds that of my thigh, the ivy has spread nearly thirty feet, bushing up and out along the wall. Over recent weeks the ivy has become the favoured dining location for the local woodpigeons, which have come to feast on the unripe berries. The antics of these birds are a delight to watch and I have been surprised by their agility. Individuals clamber about among the foliage, sometimes bracing themselves with half-open wings and stretching head down to reach more distant fruits. They rarely seem to over-balance but do, on occasion, appear less than dignified in their posture.


A hungry woodpigeon will fill its crop with a very large meal, eating up to 450 berries in a sitting, and will follow this with a long period of rest and digestion. Individuals that have had their fill loaf about in the tall trees beyond the end of the garden, sitting high and alert to occasional forays by the local sparrowhawk. It is during late winter that woodpigeons typically turn to ivy. The berries are nutritious and have an especially high fat content. Interestingly, when ripe, they are known to be moderately poisonous to mammals and at least some birds, if eaten in any quantity. It is not clear if the woodpigeon is immune to the toxins or whether it is able to deal with them by being particularly careful in how it treats the fruit once eaten. Perhaps the berries contain fewer toxins when unripe. The berries are an important stopgap, a food that is available at a time when other favoured foods have become scarce. Certainly, the pigeons seem to move onto ivy berries earlier in years when the autumn beechmast crop has been poor. 


Ivy is not the only winter food that woodpigeons have learnt to utilise. They have also taken to oil seed rape in a big way and the introduction of this crop has made a big difference to our woodpigeon population. Historically, under farming regimes with over-winter stubbles followed by the spring sowing of cereals, the lack of suitable food between January and March was known to be the controlling factor behind woodpigeon population change. Many woodpigeons would starve during this period and the population would be kept in check. With the introduction of this new crop, the brake halting population growth has been removed allowing our woodpigeon population to expand in the manner that it has over the last ten years. This may be one of the reasons why so many woodpigeons seem to descend on my garden at this time of the year.