I is for Icterine Warbler

Icterine warbler (Hippolais icterina).

The icterine warbler only just about classifies as a British Bird, but there is a severe shortage of natives beginning with ‘I’. It is a passage visitor (stops off on migration) and scarce migrant breeder in Britain.  It is usually found on the mainland in Western, Central and Northern Europe, all the way up to subarctic Russia. It is therefore surprising that Icterine warblers do not breed on our temperate isles more regularly. Perhaps crossing the waters of  the channel and the North Sea are just a little too much of a stretch on their exhausting  migration.  Although like many of our migrants the icterine warbler winters in sub-saharan Africa, it is excluded from the Mediterranean by its close and similar relative, the Melodious warbler (Hippolais polyglotta), which is also an occasional visitor to Britain.

Icterine warblers look as if they have been completely washed with yellow, including their greyish-green back.  The clue is in the name, as The name icterine means “yellowish’. This distinguishes them from our more common phylloscopid or leaf warblers, the Chiffchaff (Phylloscopus collybita), Willow  warbler (P. trochilus)and Wood warbler (P.sibilatrix), which are more greeny brown and only partly yellowed.
But icterine warblers don’t just have pretty looks, they also have a great voice. Their long, loud,  babbling, eclectic and almost electric song seems to carry on forever. To add to the song’s complexity, it sometimes also incorporates mimicry of other bird calls.

Otherwise, ‘Ickies’* have rather typical warbler habits. They are shy and spend their time skulking in vegetation, usually only  given away by their voice. They forage amongst the leaves for insects and summer berries.

Icterine warblers settle in habitats with dense hideaways such as woodlands, scrub and the edges of forestry plantations, preferably in river valleys.  They have only been confirmed breeding five times in Britain, all of which were in the Scottish Highlands. The first record was in 1992 and the latest in 2009, when two pairs bred. The young successfully fledged from at least two of these attempts, including four young raised in Orkney in 2002¹.

They use Britain more regularly as a hotel than as a nursery. An average of 137 drop in per year making them one of our most common rarities ². Such visits often occur as crowds of birds rather than the occasional lost soul, and bigger crowds are thought to be related to breeding years . In the summer of 2009, 50 individuals were reported whereas a record 175 appeared in the first breeding year.

The detection of British breeding icterine warblers is thought to be a testament to the efforts of modern bird recording schemes. Britain is one of the great birdwatching nations, and the recent attempts to survey every square kilometre of the islands , in ‘tetrads’ mean even our wilderness areas miles from the nearest bird hide do not go unchecked. Thus the activity of such elusive birds gets noticed, and protective measures can be put in place.

It is interesting to think of this attractive visitor becoming more common in Britain. Perhaps it might follow the example of the Collared dove (Streptopelia decaocto), once a rarity from the mainland that had birdwatchers flocking, and now a staple garden bird. Only time will tell.

*I didn’t make it up. This is a common term used by birdwatchers.

References

1- Alan Tilmouth. (2009) BTO Atlas work produces Icky results. Available from: http://www.birdguides.com/webzine/article.asp?a=1764

2- Robert A Robinson. (2013)Profiles of birds occurring in Britain and Ireland-Icterine warbler Hippolais icterina   [Vieillot, 1817]. Available from:  http://blx1.bto.org/birdfacts/results/bob12590.htm

H is for House Sparrow

House Sparrow (Passer domesticus)

If I could pick a bird that means the most to me, it would be the house sparrow. Part of daily life at home was  to wake up to the discordant chirrups of the clan in the hedgerow, watch  them streaming to and from the feeder in the chicken  coup (never mind the bird table!) ,see them take dust baths on the garden path and hear them tumble shouting through the bushes in a dominance squabble .  Sparrows were the mainstay of our garden before the fancy finches arrived when sunflower hearts were provided, and thankfully it continues to support a strong population.

The house sparrow is a typical “little brown job” for birdwatchers, particularly the more uniform female. But look closer and you will see intricacy in their plumage with a surprisingly rich palette of browns and greys.  The male sports a grey cap trimmed with reddish brown, and a black beak and eye surround which give him a haughty expression. His most distinctive feature is a scruffy black bib. The size of this correlates with his fighting ability, so signals his dominance to other males and prospective mates. The female is a more modest dusty brown with a dark eye stripe and pale brow and her beak is yellowish. Juveniles are similar to females, but dumpier and with yellow “lips” around the bill that disappear with age.

Though they have a strong beak designed for seed-eating, sparrows are omnivorous (feeding off plant and animal matter) and take a variety of foods. They will nip the buds and flowers of plants, but also pick off insects such as ants, aphids and caterpillars. Sometimes they dart out of bushes, or comically hop along rooftops after flying insects. Importantly, young sparrows require protein-rich insect food in their early life.

The sparrow’s prolific breeding habits are part of their success. They may have 3 broods a year, and may show their uglier side in order to achieve this. Affairs, infanticide (by both males and females) and even eviction of other bird species, such as house martins, swallows and tits from their nests are all common practice.  Whilst such behaviour clashes with human values, it is simply a part of the sparrow’s ecology. They have also been helped in their world conquest by humans, who introduced them to America and New Zealand making them the World’s most widespread bird.

Few other British birds have such an intimate association with humans. It is difficult to imagine this species existing without us, occurring as it does around farms, industrial buildings and of course houses and residential areas whilst being largely absent from the wider countryside*. Their name ‘domesticus’ refers to their association with houses. They are such a part of British life that this line-up wouldn’t be complete without them.  It is therefore surprising the sparrow is not doing so well in modern times.

The sparrow’s history is thus intertwined with our own. As a flocking bird with a taste for grain, it was arable farmer’s enemy number one . A price was put on their heads and they were heavily persecuted. They were even eaten, especially their eggs which provided a free, to people who placed nest boxes on their home fronts to harvest them.

Then, in the 1800’s when farmhands moved to the cities in search of work, the sparrow was there too.  Feeding off spilt grain in horse fodder, the insects in their manure and human scraps and sharing the tenements as roosts and nests, they provided little reminders of home to many, whose attitudes changed towards these common birds.

The movement towards feeding wild birds in the Victorian era was eagerly received by the sparrow. They became a fixture of urban parks, where they grew tame and delighted visitors by feeding straight from their hands, a pastime within living memory.

House sparrows continued as a constant among the British public, but then, in the 1990’s a drastic  decline of this super-common bird raised surprise and alarm. In 2002, the RSPB declared it a red status species due to this rapid drop in numbers.

This was part of a decline in several phases since the 1920’s, caused by different factors in urban and rural areas. Rural sparrows became a victim of increased agricultural efficiency during and after the Second World War which affected all farmland wildlife. The reduction in arable weeds, intensified grazing and shift from ecologically diverse hay meadows to plain, grassy silage reduced the natural seed and insect foods in summer, whilst improvements in harvesting and storage meant less spilt grain as a winter food source. Hedgerows were removed, taking with them the sparrow’s roosts and shelter. Cities provided some refuge from these impacts, but the changes in transport and in urban planning, increased tidiness of gardens, and even blocking up of building eaves to discourage them all had their impacts.

But there is still hope for the house sparrow. They aren’t declining in all British cities, and numbers are actually increasing in Wales and Scotland. So perhaps the homage to J.J. Audobon’s illustration of the now extinct Carolina parakeet ( Conuropsis carolinensis) isn’t so appropriate. 

You can help conserve house sparrows in your garden by providing plenty of bushes or a hedgerow (preferably a native species) as cover habitat, putting up sparrow nest boxes (preferably several individual boxes close together, as they dislike the disturbance caused by commonly marketed multi-chamber boxes)  and of course feeding and watering the birds. They are not fussy. Mixed seed, sunflower hearts, peanuts and suet will all be appreciated.  

With the help of ordinary townspeople, the sparrow may still cling on. I hope it does.  Britain would be a much poorer place without this common and characterful bird.

House sparrows are not the only sparrow in the British Isles. Their rarer, more strictly rural cousin, the Tree sparrow (Passer montanus), has an entirely chestnut cap, a black cheek patch and near-white (as opposed to grey) underparts. Confusingly, the dunnock (Prunella modularis) is commonly called the ‘hedge sparrow’, and though the plumage is remarkably similar to the female house sparrow, they are unrelated. Their name is a relic from a time when ‘sparrow’ applied to any small, brown bird. In relation to this, in the sparrow’s scientific name passer we see the origin of ‘passerines’, the entire group of perching birds.

To find out more about the great house sparrow decline, visit http://www.ndoc.org.uk/articles/Decline%20of%20the%20House%20Sparrow.pdf

*Specifically, more than 60% of the population live in built up areas, with more than half of these occurring in suburban areas, according to the BTO’s Breeding Bird Survey.