Great news: there are little barn owl hatchlings squeaking and hissing from the nest box!

The male barn owl brings in voles to feed the young as well as his mate.

Two weeks ago I wondered out loud whether our male had found a new mate. It’s unusually late to start a nest for barn owls in this region. Even second clutches (meaning that the owls start another nest in the same breeding season after the young from the first nest have fledged) are normally laid in June or early July, so we didn’t have much hope. But last month, while Tony McLean in Yorkshire waved ‘his’ barn owl fledglings goodbye, it turns out our female was busy laying eggs.

Of course, we didn’t even know there was a female at that time. This is exactly what’s so fascinating about barn owls. They conduct their lives so quietly and unobtrusively that you barely notice they’re there at all. It’s especially remarkable considering their size – they’re not small birds. Even when you’re trying to keep track it’s hard to lift the veil of mystery that surrounds their lives. Most of the year the only hint of their existence is the smell of their poo!

Five barn owl hatchlings huddle for warmth.

I did a quick inspection of the nest yesterday by peering through a little hatch in the nest box. Laying on a five centimeter thick blanket of mouse remains was a little pile of hatchlings, five in total. I estimate they are between one and around twelve days old. And maybe there are even six little ones by now, as there was also an egg that should have been about to hatch. As you can see their eyes are still closed and they can barely lift their heads. At this stage the down covering hasn’t developed yet and they’re unable to regulate their own body temperature, so they’re all huddled together and the female still broods them until the youngest one is about twelve to sixteen days old. All this time she can’t go out to hunt, and so the male is left with the burden of providing food both for the chicks and for her (see the top photo).

In temperate regions barn owls feed mostly on voles. The one in the photo below was dropped on the floor during the night. I’m not completely sure why, but my guess is it happens by accident now and then. While the owls have keen night vision, they hunt mostly by hearing and a motionless vole in a pitch-dark barn may still be lost between the pellets and droppings. The floor is littered with dead voles in various states of decomposition, but this one looked like it could wake up any minute. It was still soft so I left it on a beam where the male often sits and by morning it was gone. It’s the least I could do with all the disturbance I’m causing …

Voles are the main food source for barn owls in temperate areas.

The male will bring in up to sixteen voles and other prey items in a single night, and so it’s no surprise that the chicks grow rapidly, putting on about 13 grams a day – about what they weigh when they hatch. They reach their maximum weight after about five weeks, but it will be another month before they fledge. During this time their bones and feathers are still developing, and they’ll start to look more and more like these little fellows I photographed several years ago:

Young barn owls almost ready to leave the nest.

Unfortunately I will not be around for all of that as I have to return to Groningen soon, but I’ll definitely try to come back in a couple of weeks to check up on them.

As always, prints are available. You know where to find me.