Going Wild With Walters -- Archive 1

This is a cumulative archive of the nature column published in the Cambridge Weekly News, from January through December 2002. For more recent accounts see Archive 2 and Archive 3.

The text is by Martin Walters, and the pieces are usually illustrated by the work of local wildlife artists, notably Michael Wood (mainly birds and other animals) and Stella Tranah (mainly plants).

December 2002

Holly, ivy and mistletoe, that yuletide trinity, have long been revered as mysterious plants. Holly leaves were traditionally used as an infusion to treat fevers, rheumatism, and catarrh. The berries tend to be emetic, though they seem to have no harmful effect on wild birds. Ivy was employed against a range of conditions, from rheumatism and sciatica, to coughs, bronchitis and asthma. The leaves were used to make the wreath of Bacchus, and binding the brow with them is alleged to prevent intoxication; so you know what to do after over-indulging this Christmas! Greek priests also gave newly-married couples a wreath of ivy as a sign of fidelity. Mistletoe, sacred to the Druids, was regarded as a symbol of fertility - hence the tradition of kissing beneath it -- and it is also used in 'alternative' medicine, in this case for hypertension, arthritis, and as an anti-cancer agent. The Druids carried clumps of mistletoe to announce the New Year, hence its use around Christmas time. The Norse god of peace, Baldur, was killed by an arrow made from mistletoe, but brought back to life by the other deities, and the plant was then given to the goddess of love. Mistletoe is much commoner in northern France than in England, and it is sometimes known there as 'herbe de la croix', the legend being that Christ's cross was fashioned from its wood, after which the plant was 'punished' by being turned into a parasite. In recent years, mistletoe has increased here, perhaps with the milder climate, and it can now be seen on many trees around Cambridge, notably on poplar. As with many medicinal plants, all three species are poisonous, so self-treatment is definitely not recommended.

The mild weather has brought out the singers, and dawns have recently featured pretty much full song from blackbirds and song thrushes. In Linton churchyard, we were treated to an excellent performance from a mistle thrush, from high up in one of the tallest trees. These 'rehearsals' for the spring choruses are rather uplifting amidst the gloomy fogs and short days of winter. It must have been mild, because in late November there was still the occasional dragonfly patrolling the gardens. Our local great spotted woodpecker has put in an appearance, just like he did last January. I'm fairly sure it is the same bird, as his route was almost identical - starting in our neighbour's apple tree, then moving to a more ancient and gnarled apple a few gardens away. He patiently worked the old wood, prising up the loose bark to get at the grubs beneath, nervously pausing every few pecks to check that all was well.

Illustration of holly, ivy and mistletoe, by local botanical artist Stella M. Tranah

August 2002

Starlings are seagulls are highly adaptable birds, able to benefit from a wide range of foods. Just now both are to be seen, fluttering and gliding in mid-air, feasting on aerial insects, especially on winged ants which tend to disperse in swarms and which fly rather weakly; tasty extras for greedy birds.

It is not only birds which feed on flying insects. Some of their fiercest predators are fellow insects. Watch for dragonflies, those masters of aerial agility. Just now these superb insects are in fine form and extremely active, cruising back and forth over gardens and hedgerows, even far from their watery larval homes. They dart and jink with staggering speed as they chase and capture smaller insects. A dragonfly's bristly legs point forwards and act like a basket to scoop up their prey, which is then transferred to the fierce mouthparts. In our region one of the commonest species is the migrant hawker (Aeshna mixta). In recent decades this species, once a rare immigrant, has colonized much of southern England, and it is particularly fond of gravel pits, of which there are several nearby. Watch for them especially in the afternoon or early evening. Large dragonflies reach speeds of about 36km/hr, quite fast considering their size, and their wings beat about 30 times per second, but it is their manoeuvrability that is so impressive. They can hover, glide, and fly sideways and backwards with apparent ease, and are a real joy to behold. There are about 5,300 species in the world, mostly in the tropics, and we have 38 species in Britain.

Honeybees are also active at the moment, gathering nectar and pollen from a huge range of wild and garden flowers to stock their hives with honey, and harmless hoverflies gather, especially around the flower clusters of umbellifers.

Biennials, such as hollyhocks and mulleins, seem particularly prominent this season, after the very mild, wet winter. These can be up to 10 feet tall, providing a really impressive border display. A self-sown mystery plant with large, coarse leaves with rough hairs has just revealed its identity by producing bright blue flowers. This is borage, a traditional pot-herb, now grown commercially by some local farmers, and spread presumably on the feet of birds. Cotoneasters are also dispersed this way, and the latest British flora lists 45 alien species, though only one is native, on Great Orme's Head near Llandudno.

Illustration of Aeshna mixta by local wildlife artist Michael Wood

June 2002

Swifts are a common sight in Cambridge, and can be seen almost anywhere in the city, partly because there are so many favoured nest-sites (under the slate roofs of terraced houses), and partly because they are almost always airborne. Swifts only stop flying when at the nest, even snatching short naps while in flight.

House martins are smaller and neater and may sometimes be seen on the ground, gathering wet mud from the edges of ponds and puddles. They are colonial nesters, using the mud to constructing neat, oval nests glued tight under the eaves. Their numbers are not limited by a lack of suitable nest sites, and it has always been a mystery to me why they choose some spots over others. Ideal places are buildings with overhangs, preferably close to open, muddy country. Favoured locations are the walls and towers of Addenbrooke's Hospital, and the gateways to some of our distinguished colleges. They seem very traditional and set in their ways when it comes to nesting. Sadly, they are not always welcomed because of the droppings which spatter the ground beneath -- admittedly not a huge problem, and in my view a small price to pay for their pleasant company. I am pleased to see that house martins are still breeding under the arch of the main entrance to King's College, a classy address for any bird! They have been there for many decades, and the enlightened porters seem to respect their squatters' rights.

Swallows are most often seen swooping low over playing fields or meadows, feeding on flying insects. They need open stables, sheds or similar outbuildings in which to build their cup-shaped nests, usually on the top of a beam. They sing as they fly, uttering a long, goldfinch-like twitter as they glide overhead.

Sand martins are the smallest. Watch out for them over reservoirs or rivers, and at gravel pits, where they make use of steep banks for breeding. Sand martins are badly affected by drought in their main wintering grounds - the Sahel region of North Africa, and numbers fluctuate, now showing a welcome slight increase following earlier crashes.

I always watch carefully for a personal favourite migrant, the spotted flycatcher. This is one of the latest to return of all our migrants, not usually clocking in until the middle of May. In my youth we used to see these delightful birds regularly in the Botanic Garden and elsewhere in the parks and gardens of the city, but now records are few and far between. The population has crashed by nearly 80% in the last thirty years. No-one knows the reason, but it may be that crossing the Sahara (which they must do twice each year) has become more hazardous. It is also possible that they have suffered from declines in their insect prey due to pesticide use on farmland and in some gardens.

May 2002

The usual date for the swifts' return coincides with the average date of coming into leaf for two of our native trees, oak and ash. Both vary quite widely - from about April 25th to May 17th for oak, and from about April 22nd to May 12th for ash. This variation is well known to country folks, and has given rise to a familiar saying linked to a rustic weather forecast: "if oak is before ash then we shall only get a splash, but if ash precedes the oak then you may expect a soak". This year the oaks came into leaf well before ash, so according to tradition we should be in for a dry summer! But be warned, for there is a (less well known) version which states just the reverse, so I can always quote that one if proved wrong.

A more dramatic returning migrant to Cambridge is the hobby. Hobbies used to be very rare hereabouts, being more associated with southern heathland, especially the New Forest. But their fortunes have changed over the last 20 years and there may now be as many as 50 pairs in the county. We should rejoice - this is a splendid falcon, wonderfully agile in flight, and one of few raptors able to match the swift in speed. Indeed they can resemble a large swift when seen in silhouette, with their long narrow curving wings and long tail. Hobbies sometimes do catch swifts, but prefer slightly smaller prey, including dragonflies which they catch on the wing and consume in large numbers. They use their talons to grab the insect, then pass it to their beak while in flight. Hobbies are back now, and can often be spotted at Wicken Fen, a favoured hunting ground. Gravel pits and other water bodies are good places to see them, especially at this time of year before they select a nest (usually an old carrion crow's nest) and start to breed, after which they become rather secretive.

For back numbers of this column, visit the Nature in Cambridgeshire website: www.martinwalters.care4free.net.

Illustration of hobby by local wildlife artist Michael Wood

April 2002

To continue the watery theme, when did you last see a water vole? These charming rodents have declined by a staggering 88% across the country in the last seven years. So it is good to hear that they are making a bit of a comeback in the area. This delightful creature, a harmless vegetarian, has been hit hard nationally by a combination of pollution, river 'improvement' and probably also by competition from brown rats and predation by naturalised American mink. When I was a boy I used to watch water voles cruising along Hobson's Brook along the edge of the Botanic Garden. They reminded me of clockwork boats, as they usually swim in a straight line from one safe bankside hole to another. Sadly, they are long gone from this stretch of water, but there are some encouraging signs, and they may eventually return. The recolonisation of our rivers and streams by otters may also help the voles, as the otters, no threat themselves to the voles, tend to keep the mink away. But mink still lurk around the banks of the Cam. Let us hope that otters eventually increase sufficiently to drive them out.

Many people are waiting to hear their first cuckoo, but quite a few stand to be disappointed. Populations of these traditional spring-announcers have crashed over the last several years, but no-one is sure why. One theory is this follows declines in two of their favourite host species, dunnock (hedge sparrow) and meadow pipit. Upland cuckoos tend to use meadow pipits, while lowland and woodland cuckoos often lay their eggs in dunnock nests, or, in marshy areas and reedbeds, in reed warbler nests. Although large birds, cuckoos are not easy to see. They tend to fly rather rapidly and straight, often keeping low or under cover. They can be confused with a kestrel or sparrowhawk as they have barred plumage, and long wings and tail. Small birds will mob a cuckoo as they would a hawk, and this may even benefit the female cuckoo as she seeks suitable host nests, slipping in quickly to leave her egg while the host's nest is unguarded.

Illustration of water vole by local wildlife artist Michael Wood

March 2002

The ‘Backs’ are worth a look this month, especially St John’s College, where the grass is dotted with daffodils, primroses, celandines and anemones – a feast for the eyes and also a good source of nectar for early foraging insects.

The Sunday before Easter is known as Palm Sunday, and for centuries early-flowering trees and shrubs have been used as ‘palms’ to decorate churches at this time. Pussy-willows are one such, and indeed are known in some parts as pussy-palms. All willows and poplars are dioecious, that is the individual tree is either male or female – like most animals. Standing under a male pussy-willow in full flower on a warm day in early spring leaves one in little doubt that the plant is pollinated by insects. Bees, hoverflies and other insects are busy visiting the yellow catkins to collect the sweet, energy-rich nectar. In doing this they get the powdery pollen on their bodies, and a later visit to a female flower may result in the transfer of some of this pollen to the stigmas, thus completing what seems a rather haphazard sexual transfer.

In the hedgerows, the dangling male catkins of hazel are swinging, releasing their dust-like pollen. Here wind does the pollination. The female flower is much less conspicuous and consists of a tuft of bright red ‘hairs’ which trap the wind-borne pollen grains. On any one bush they only appear about a fortnight after the male catkins – a strategy which helps reduce self-pollination.

Many more garden birds are now in good voice, not least the blackbird, in my opinion the best of our songsters, rivalling even the nightingale. The blackbird’s song is loud, distinctively rich-toned and musical, and each singing cock bird has its own version, incorporating special ‘favourite’ phrases. With attention and practice we can learn to tell their songs apart. A blackbird singing on its territory can probably easily detect whether another singing close by is an established neighbour (best ignored) or a potentially dangerous interloper (worth seeing off).

Watch out (and listen) now for returning migrant birds. Wheatears, terns, and sand martins began appearing on southern coasts at the end of February, and it won’t be long now before we hear chiffchaffs in the gardens and woods. Meanwhile, the rooks are well into their noisy nest-building, so spring is certainly not far off.

You can see archived back numbers of this column on the website of Nature in Cambridgeshire – www.martinwalters.care4free.net. This is a publication devoted to the natural history of the county and is published each year, with a range of fascinating articles. Copies of current and back issues are available from: The Herbarium, Department of Plant Sciences, Downing Street, Cambridge CB2 3EA (price £3.50 by post). The website has details of the contents of the issues, as well as links to other sites of local interest, and a section of nature notes and records.

Illustration of celandine by local botanical artist Stella M. Tranah

Now that the days are lengthening, we are all beginning to feel a bit more cheerful, and this includes the birds. Something is stirring, and a change is definitely in the air. Bright in their fresh plumage, the birds are starting to channel their energies into establishing breeding territories, which often means singing very loudly, especially in the mornings. Our blackbird started singing in earnest about 20th January, with the relatively mild weather, and the local song thrushes are now also in good voice. One of my favourite songs is that of their larger relative, the mistle thrush. Loud, yet plaintive and rather monotonous, its song is usually delivered from the topmost branches of a tall tree. The bird itself, with soft grey plumage, is often hard to spot, despite being our largest thrush.

Another favourite songster is the wren. This tiny bird creeps about in the undergrowth, then suddenly stops to produce a fantastically loud medley of shrill notes, in a rapid delivery. Wren populations suffer during hard winters, when the birds occasionally roost together for warmth – sometimes dozens at a time, crammed into a sheltered nook. They are found in most habitats, from upland moorland, to heath, woodland and also in gardens, which partly explains why they are one of Britain’s commonest species.

Although our blackcaps have been less regular of late, I have seen another warbler, a chiffchaff, flitting around the garden. This is either an overwintering bird, or possibly an early migrant blown here by the fierce southerly storms which have been a feature of the recent weather. Silent and inconspicuous now, it will be easily identified later by its song – a somewhat garbled repetition of its own name.

Jackdaws are vocal too, and as they call they indulge in complex aerial manoeuvres – gliding and tumbling above the rooftops in acrobatic displays. The winter flocks of gulls on Parker’s Piece are thinning out, and the black-headed gulls which make up the majority (with a few common gulls) are starting to moult into their breeding plumage. Soon, the dark smudges on their heads will be replaced by a rich dark chocolate crown.

Starlings still gather in the evenings on their way to their large communal roosts, but these too will begin to break up as the birds pair and move away towards their breeding sites. Some of these roosts can be very impressive, such as the one I witnessed recently beneath Brighton Pier, where, at dusk, thousands of starlings swooped low under the railings to gather in chattering hordes for the night.

The other day I spotted a kingfisher sitting patiently on an overhanging willow branch above the stream on Coe Fen, only a few yards from slow-moving rush-hour traffic on Fen Causeway. These superb birds are regular here, and along Hobson’s Brook where they sometimes nest, but you don’t often spot one unless you are out and about early.

Illustration of wren by local wildlife artist Michael Wood

The New Year has brought a flurry of activity into the garden. Our holly tree, which was conveniently bright with ripe berries up to Christmas, is now almost stripped of its fruit by flocks of rather wary, but hungry, redwings, helped out by our local blackbirds. Redwings are winter visitors, mainly from Scandinavia. They are like a duskier version of the song thrush, but distinguished by their bright cream stripes above and below the eye, and by a bright flash of orange-red beneath each wing. Song thrushes are normally solitary, so a flock of small thrushes in winter is usually composed of redwings.

Equally fascinating to watch have been a small group of blackcaps. Their plumage is a soft ashy grey and it is only the male which has a small jet-black cap, the female’s cap being chestnut. The main interest here is that these dainty warblers used to be seen only (or mainly) in summer, being summer migrants like most other warblers, but in recent years we often see them in winter as well. Why should this be? The answer seems to lie partly with changes in the migratory habits of blackcaps from central Europe, some of which have (since the mid-60s) begun to winter to the north and west (where it is relatively mild), rather than stick with the traditional routes to south-west Europe or Africa. They have been pecking at fruit as well – mainly apples still clinging to the trees long after the leaves have fallen. It is a good tip to leave some apples on the twigs for the birds – we have had blackbirds, redwings, starlings and even blue tits feasting on apples, safely out of reach of the local cats. It is quite an art to perch close to an apple, attacking it gingerly from the side – too fierce a peck would send it tumbling to the ground. The blackcaps also forage in the bare twigs of sycamore, taking tiny insects or spiders from the younger shoots, as do troops of dainty long-tailed tits.

Even in this cold, inclement weather some birds are singing. Great tits have been tuning up and will soon begin their monotonous mainly two-tone calls, starlings are beginning to serenade each other with a baffling mix of fluted whistles, but the main songsters now are robins. Both sexes sing to stake out winter territories and can often be heard after dark, especially close to street lights, leading to occasional reports of nightingales! Their song is a varied, rather languid series of pretty, high-pitched notes and descending tremulous trills.

Do remember to put water out for the birds as well as food, especially in freezing weather. They welcome the occasional drink, and will even bathe to spruce up their feathers, despite the cold.

Botanical treasures which have flowered exceptionally well this winter are fuchsias and the sweet-scented viburnum, both of which benefited from the unusually wet and mild autumn, though the fuchsias are now being hit by the frost and need to be brought under cover.

Illustration of blackcap by local wildlife artist Michael Wood