Tree Sparrow (Passer montanus) Photo By Laitche – Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=2841616

Dear Readers, you would be forgiven for thinking that the only true sparrow species in the UK was the House Sparrow (Passer domesticus), that small chirpy denizen of urban spaces, and another Red Listed species. However, in lightly-wooded country and on farmland edges,  preferably where there are a few old hedges, you might see the Tree Sparrow (Passer montanus), with its chestnut head and black cheek-spot (both sexes and juvenile birds look alike). The bird is slightly smaller than the House Sparrow, and is described by the RSPB as being ‘more active’, though I’ve seen some pretty active House Sparrows!

Sadly, this inoffensive little bird has seen a breeding population decline of over 93 percent between 1970 and 2008. There have been some recent signs of improvement, but the BTO (British Trust for Ornithology) notes that for every Tree Sparrow seen today, there were twenty in 1970. There is a phenomenon whereby we overestimate population recovery because we don’t have accurate data on how many of a species there once was, and the BTO statistics help us to realise this. The range of the bird has also shrunk, with East Yorkshire now being a stronghold, while many parts of southern and western Britain no longer have Tree Sparrows. The birds sometimes do a short migration during the winter from Yorkshire to Suffolk, returning ‘oop north’ in time to breed.

While the cause of the population decline is unclear, two factors do seem to be important. One is the availability of food in the winter – Tree Sparrows often rely on the remnants of harvest in stubble fields, and this may not be available where arable land is intensively farmed.  There is some evidence that provision of winter seed helps the species, as it does with other farmland birds. A second cause could be that, in the breeding season, both House and Tree Sparrows turn to insect food to feed their fledglings and nestlings – I’ve witnessed House Sparrows hawking for flies and mosquitoes and stuffing them into the gullets of their eager youngsters. Tree Sparrows appear to rely on things such as wetland-edge habitats and drainage ditches for these invertebrates, but these, too, are often no longer available due to intensification of agriculture. In Northern Ireland, farms which actively aimed to promote the return of Tree Sparrows, providing winter food, invertebrate habitat and nest boxes (like House Sparrows, Tree Sparrows like to nest communally) has seen an increase in numbers. Let’s hope that more farms across these islands follow suit.

Tree Sparrow (Photo Richard Crossley, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons)

Here’s a picture of the House Sparrow, just to highlight the differences.

House Sparrow (Passer domesticus) Photo Richard Crossley, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons

And here are the calls of the two species. First up, here’s the Tree Sparrow (recorded in Sweden by Ulf Elman).

And here’s the House Sparrow, recorded in France by Martin Billard.

Tricky, eh? To my ear, the Tree Sparrow’s call sounds slightly more high-pitched, which is what you might expect from a smaller bird.

Interestingly, although the Tree Sparrow is a bird of mainly rural spaces in the UK, in Asia it is most commonly seen in towns and villages. In China, it was Tree Sparrows who were targeted when Chairman Mao decided that the birds were eating too much seed, and so school children, amongst others, were tasked with keeping the birds from settling so that they died of exhaustion. As we’ve seen, however, sparrows also eat lots of insect prey in the summer months, and so as the bird numbers went down, pest numbers went up. We meddle with nature at our peril, as we see so often.

A Fledgling Tree Sparrow (Photo By Aomorikuma – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4331913)

And finally, a poem. Not necessarily about a Tree Sparrow (though in a way this is a ‘tree’ sparrow, as you’ll see,  and not really appropriate for August, but I couldn’t resist. See what you think.

Christmas Sparrow
by Billy Collins

The first thing I heard this morning
was a rapid flapping sound, soft, insistent—

wings against glass as it turned out
downstairs when I saw the small bird
rioting in the frame of a high window,
trying to hurl itself through
the enigma of glass into the spacious light.

Then a noise in the throat of the cat
who was hunkered on the rug
told me how the bird had gotten inside,
carried in the cold night
through the flap of a basement door,
and later released from the soft grip of teeth.

On a chair, I trapped its pulsations
in a shirt and got it to the door,
so weightless it seemed
to have vanished into the nest of cloth.

But outside, when I uncupped my hands,
it burst into its element,
dipping over the dormant garden
in a spasm of wingbeats
then disappeared over a row of tall hemlocks.

For the rest of the day,
I could feel its wild thrumming
against my palms as I wondered about
the hours it must have spent
pent in the shadows of that room,
hidden in the spiky branches
of our decorated tree, breathing there
among the metallic angels, ceramic apples, stars of yarn,
its eyes open, like mine as I lie in bed tonight
picturing this rare, lucky sparrow
tucked into a holly bush now,
a light snow tumbling through the windless dark.

Tree Sparrow feeding its fledgling, by Huang-Quan (903-965 ) By Huang Quan (903-965) – http://www.my51a.com/product/list_23_53.html , item 131479. (This is a higher-resolution version than the one that was uploaded at zh:写生珍禽图.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=111528413