House Sparrows: an introduction
Updated: Feb 2, 2021

A small, charismatic passerine with heavy-set finch-like features. They’re musty grey below and on their flanks, dappled with chestnut, auburn and blonde feathers, males having a jet-black ‘scarf’ flowing down their chest. They’re one of two native sparrows to Britain, the other being the scarcer, daintier Tree Sparrow, which has a conspicuous black check spot.
Living in rapacious social groups and nesting together in colony’s, House Sparrows can be identified from a distance away by their noisy, bickering calls, which’re usually two or three toned; whistle-like. But walk up to that echoing, shuddering bush and they suddenly erupt out and away.

Diet:
A driving factor behind House Sparrows becoming so successful and widespread is their talent in spotting a source of food and like clockwork, knowing the least-hazzle way of extracting its energy. For example, instead of hammering aimlessly at a sunflower seed trying to get to its fatty heart, they know it’s better if you scoop it up in your beak, get the positioning right, and press down on it like a nutcracker.
They specialize on Cereal grains, like Wheat and Barley, and have even evolved to digest the high-starch content in the bird food we leave out for them in our gardens. Along with grain and seed, they’ll also happily gobble up leafy greens, and a multitude of invertebrates. Favourites are small beetles, flies, aphids, snails, millipedes and even the alien looking sand-hopper in coastal areas. But they can punch above their weight. They’ve been known to tackle creatures as large as wall lizards!

Distribution:
House Sparrows have conquered the Earth, there’s no doubt about it… They’re now found on six continents, and their global range covers a gargantuan ¼ of Earth’s surface! From humble beginnings munching on grain and living harmoniously with our ancestors in the Middle East (as far back as the stone age!) they’re now so common they are officially “a first class nuisance” in many places (talking about you America).

As for Britain’s range, they live in most habitats, but are rarely more than 100m from people. Their vertical range is an incredible 3 miles (once a hardy Yorkshire pair raised a brood 640m below ground in a coalmine). The only places they’re tentative to colonise are our highest plateaus and mountain’s-and increasingly city centres, which were once their Gardens of Eden. In and around our Capitals like London, this decline is especially stark. Mere decades ago, London was home to 100,000s of the cacophonous, chestnut birds, stuffing the hedges and dappling lawns. Now, sadly they’re a rarity; many parks are silent.
Breeding:
In adequate conditions, House Sparrows are prolific breeders. Both sexes are mature and ready to breed from as young as 6 months! However, it’s not uncommon for young, jumped-up males to fail securing a mate and a territory in their first year, lacking the experience, and impressive chest-patch of older males.

Despite looking a little drab to some human eyes, that scarf of jet-black feathers is a giant badge to the females, saying “I’m manly! Come mate with me, I’ll defend our chicks from Sparrowhawks no problem!”. Interestingly, research shows that size matters to House Sparrows- the larger and darker the bib, the more testosterone a male has, so the poor young ones have more of a goatee than a full-fledged bib.

But, even with the blackest bib in town, some females just aren’t interested. So, you’ve got to perform to her! First, choose your target. Fly in front of her, hopping so you’re in full view. Step two, is to turn sideways, fluffing up your feathers to show off how big and tough you are. All the while, you’ve got to chirp, showing her you’re nice and healthy. If she doesn’t seem interested at first, then pulling back your head; brandishing that handsome bib is worth a go.
Sometimes, one male displaying can draw several others over, which harass the female continuously in a cohort of chirping, bouncing, fluffed-up, suitors.
If he’s successful, they’ll mate. Successful breeding has been recorded in Britain in every month of the year, peaking March-September. Versatile, they’ll happily nest in most places. Hedges, creepers, nestboxes or 1,000m up the Empire State Building like one pair. But the preferred sites are on buildings, ideally the eaves of houses near a green space (e.g. a garden). They have no problem being nest-mates to other birds too, and in England, have been recorded raising chicks with Ospreys and Red Kites!
Why are they declining?

It’s fair to say that House Sparrows aren’t quite the Red Kites or Scottish Wildcats of Britain’s conservation world... Because people have them living (literally) on their doorstep there hasn’t been the outcry for action like with other species. Populations weren’t even researched much until 1977, and since then, they’ve declined by nearly 71% according to BTO.
Research on it is still lacking but declines in invertebrate food and available nesting spaces (our buildings now, lack the crevices they love) are the two main suspects. Increased predation by pet cats, air pollution, and the parasite Plasmodium relictum are also thought to be causes.
What can we do?
Quite a lot! Firstly, more research is needed to dissect the decline, so we can fight it better. Organizations such as the BTO are doing this, and through citizen science projects like ‘Big Garden Birdwatch’, plus volunteering and donating to the research they carry out, we can all do our bit.

Many actions can be done in your own home or garden though. Suffering from similar lung problems as us, House Sparrows are struggling to cope in our chokingly polluted world. So, drive less. Try cycling into work on a Thursday or walking down to that corner shop instead of taking the car. Reduce your waste. Switch to a reusable metal bottle instead of plastic-bamboo toothbrushes instead of plastic. More tips: Helping out House Sparrows (savethehousesparrow.com)

To give them a place to live, you could put up a nestbox or two. Colony nestboxes, with several holes in are especially popular. Try putting it at least 3m up, ideally just under the eaves (although it doesn’t matter if it’s not, it’s just more likely to be occupied). Feeding them is another great way to help. They will eat grain etc., and fat-balls during the winter, but where possible try feeding them mealworms, as without enough invertebrates, the chicks can’t grow properly. For more tips and detail, go to our blog post here: House Sparrows: Extinction in our back-gardens? (savethehousesparrow.com)

Thanks for reading!