Barn Owl Ringing update - many pairs did not breed

A long and intense day of ringing at the Duhallow Barn Owl sites was tough going, not least because of the appalling weather, but also because most sites had no chicks. of 12 nest sites visited, only 2 had chicks, 5 chicks in total. A summary of the sites visited is shown below. The stark realisation is that it looks like they are having their worst breeding season to date. 

• Tree nest near Newmarket – no signs at the nest, though birds have been seen nearby recently.

• Old cottage, NW Duhallow – Recent signs of owls, no chicks.

• Large derelict farmhouse, NW Duhallow – no signs, nest abandoned.

• Two story derelict farmhouse, NW Duhallow – 2 adults present, young possibly present, needs further investigation.

• Cottage near Newmarket, 2 adults present, 4 abandoned eggs found, no chicks.

• Tree nest near Newmarket – Three young.

• Old cottage near Rathmore – Recent signs of owls, no chicks.

• Quarry, Duhallow – at least 1 adult present, no chicks.

• Disused Cottage near Ballydesmond – recent signs of owls present at nest, no chicks.

• Derleict cottage near Ballydesmond – female present, no chicks.

• Nest box near Ballydesmond – Adult pair present, no chicks.

• Nest box near Ballydesmond – 2 chicks.

More on these sites soon.

2 of a brood of 3 chicks ringed today at a tree nest site in Duhallow today. The eldest chick on the left shows a considerable age difference to its youngest sibling, perhaps as much as 10-12 days. The lateness of this brood is also noteworthy – these youngsters won't be leaving the nest until late September, perhaps even October. (Photographed under licence: M.O'Clery).

ABI group attend Barn Owl ringing

The Acquired Brain Injury (ABI) group from Castleisland attended the ringing of two Barn Owl chicks at a site in Co. Kerry recently. The ABI group built a series of nest boxes for our Barn Owl and Kestrel projects (you can see that post on this page HERE).

 Members of ABI Ireland, with the landowners and their families, at the Barn Owl ringing, July 2013 (M.O'Clery).

Brin McDonald (Duhallow Birdwtching Club) and Maura Walsh (CEO at IRD Duhallow) with one of the younger enthusiasts, at the Barn Owl ringing, July 2013 (M.O'Clery).

Chimney nest box chicks ringed

The Barn Owl chicks which featured in recent posts were ringed this week. They were about 50 days old, not quite fully grown. They would be due to fledge around the second week of August and as such, are the earliest Barn Owl chicks in our study area so far this season

Barn Owl chicks ringed at the chimney nest box site in Co. Kerry, July 2013 (Filmed under licence: M.O'Clery and J.Lusby).

The previous recent posts which featured this site can be seen on this page HERE, and HERE

Recent Barn Owl ringing results

The following resulted form two days of ringing of Barn Owl chicks this week at known nest sites in Kerry.

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Nest box site, Dingle Peninsula – No birds present.

Nest box site, Dingle Peninsula – 1 chick ringed.

Old farmhouse, Dingle Peninsula – 1 adult female ringed. No chicks.

Derelict cottage near Castlemaine – 1 of 3 chicks ringed.

Derelict church near Castlemaine – No birds present.

Quarry, east Kerry – 1 adult present. No chicks

Chimney nest box, east Kerry – 2 chicks ringed.

Castle, Kerry – 2 chicks ringed.

Old cottage near Castleisland – 1 adult present. No chicks

Old farm buildings near Castleisland – 2 adults present, no chicks.

So, ten sites which so far have produced eight chicks. Well below average. Worryingly, two traditional sites seemingly had no birds present.

Quarry site in Kerry where Barn Owls are present in a small tunnel in the rock face. An adult was seen here, but it is possible that young were undetected further along the rock shaft, so a watch at dusk is still needed here to determine if there is any young here (Photo: M.O'Clery).

Two chicks fledged from this site last year, but this year only one of the adults were present and no chicks. The nest was in the chimney, though the adult was roosting in the tiny roofspace on the left of the building, accessed through a single missing slate (Photo: M.O'Clery).

Barn Owl chick, or fluffy toy?

Barn Owl chick, Co. Kerry, 24th July 2013 (M.O'Clery).

If cuteness was an Olympic sport, this Barn Owl chick would win gold...

Barn Owl chick, Co. Kerry, 24th July 2013 (Filmed under licence: M.O'Clery).

This chick is about 20 days old, just old enough to regulate its own body temperature. The nest was in an old cottage in east Kerry, and is one of the few broods of three we have seen so far this summer.

The Barn Owl Survey in action

This video shows an examination of a known Barn Owl site in Co. Kerry. There have been signs of the birds presence in this old farmhouse each year since the site was discovered in 2008, but the owls have not yet bred here. Two nest boxes have been placed inside the house, the site is very isolated and rarely visited, and there is ideal hunting habitat nearby, so it is absolutely perfect for Barn Owls.

Every known site in Duhallow and Kerry is checked by us at least once each season. It can take a number of years for a site to be occupied, in some case four years or more, and at others, seemingly suitable sites have never been occupied, but in one notable case, Barn Owls occupied and nested in an Owl nest box within just a few weeks of its installation.

Let's have a look and see what's going on here...

How long does a Barn Owl live?

Two year old female Barn Owl, Co. Kerry, 24th July 2013 (M.O'Clery).

Barn Owls are generally short lived birds, and since ringing of Barn Owls began in Ireland in 2008 only a handful of birds ever caught and ringed have been three or more years old. This is a two year old, a female, which was trapped at the same site as last year, an old mansion in Kerry in July 2012 (you can see an account of that on this page HERE)

Barn Owls which are kept in captivity regularly live to be 15 or even 20 years old, but they obviously don't face the same hazards as a bird in the wild. In Ireland, our studies show that at least half of all birds which fledge from the nest will not make it to their first birthday, and it is rare indeed to find a five year old bird. There are a number of sites which we know have been occupied by Barn Owls for 20 or more years, but this does not mean it is the same individual owls in residence, rather there has been a whole series of replacements over the years.

Barn Owl attacked by Sparrowhawk

While conducting an evening watch on a Barn Owl nest box site on Friday a most unusual event was witnessed by Michael O'Clery...

The scene of the action – the nest box on the chimney, the telegraph pole and the grey roof of the barn behind (Photo: M.O'Clery).

"From my position, hidden by the field edge, I could watch one of our nest boxes, on top of a chimney in Co. Kerry. As dusk fell, an adult Barn Owl flew out of its roost in an adjacent barn and landed on a telegraph pole near the nest box. One of the young Barn Owls saw the adult land and came to the entrance of the nest box and started 'snoring' loudly for food. The adult looked toward the box and then started to stare at the rough grass below its high perch.

"Judging by the intensity of the attention, I thought I might see the adult Barn Owl make a kill on some small mammal below, however another movement behind the owl caught my attention. A female Sparrowhawk flew low and fast over the roof of the barn and flew straight at the Barn Owl.

"The owl was oblivious to the approaching danger from behind, but at the very last second turned, saw the Sparrowhawk, and virtually leapt into the air to meet the Sparrowhawk, talons to talons, before flying downward, low and fast into the nearest copse of trees. The Sparrowhawk which had to stall mid-flight, then twisted to make a 180 degree turn to pursue the owl with astonishing acceleration. The initial loss of speed of the Sparrowhawk however seemed to just allow the owl time to make good its escape and the Sparrowhawk pursued the owl to the edge of the treeline before gliding up an over. It seems the owl had a very narrow escape."

Female Sparrowhawk (Photo: Ben Phalin).

Female Sparrowhawk with a freshly killed Magpie (Photo: David J. Coley).

Barn Owls have few predators, and on the continent, Goshawks are the only raptors which have been regularly documented as killing Barn Owls in the wild. However in two studies on mortality of Barn Owls in England, of nearly 300 documented deaths of Barn Owls, three were attributed to Buzzards, and one to a Sparrowhawk.

A female Sparrowhawk will regularly take relatively large prey such as Woodpigeon and Magpie. The weight of an adult Woodpigeon is about 400 grammes, whereas Barn Owls typically weigh in at about 280 to 310 grammes, so it would seem that Barn Owls might well occasionally feature on the Sparrowhawk menu.

Two Barn Owl chicks in one of our nest boxes

Birds of prey in general are suffering one of their worst breeding years yet. We saw in an earlier post how Long-eared Owls suffered an almost complete collapse of breeding attempts with only five chicks produced from 61 sites nationwide. Reports are that Peregrine falcons too have suffered breeding failure with for example only one nest of a sample 19 producing young in Kerry/Cork (and the chicks were robbed from that one). Kestrels failed to breed at most sites, though the ones which did breed fared well.

Barn Owls nest later in the year so we are only now beginning to see how their season is developing and unfortunately, it is not good. Quite a few sites checked so far have been abandoned, and adults are not breeding at others. Nests with chicks are proving the exception this year.

At least here we have a bit of good news – two healthy looking chicks in one of our nest boxes yesterday while checking our Duhallow sites. They are about three weeks old, and none of the flight feathers are yet visible. They should be at the nest for another month and a half, so will be fledging in late August or early September. Working backwards, if they are 21 days old, they must have hatched around the last day of June, which means the eggs were laid around the last days of May, about 4 weeks later than the average date of around 7th May.

Two Barn Owl chicks at a nest box in Duhallow, 19th July 2013 (Filmed under licence: M.O'Clery).

Barn Owl chicks in chimney nest box

Nest box on top of the chimney of an abandoned cottage, Kerry, 17th July 2013, and (inset) a close-up of the box (M.O'Clery).

At last, some good news on Barn Owls. There are at least two chicks in one of our nest boxes in central Kerry. Have a look and listen to the video clip and you can hear the distinctive 'snoring' call of two or more chicks from inside the box.

From the volume of the calls and the brief glimpses of one of the birds taking a peep out of the box, they look to be about 40 to 45 days old, or about two-thirds of the way to fledging.

This site had three young last year and featured on the 'Living the Wildlife' documentary by Colin Stafford Johnston which aired on RTE last April. Thankfully, it has proven the exception so far this season, with most Barn Owl sites visited in our survey so far either  abandoned, or the adults have not bred.

We will be ringing the chicks at this site shortly, so check back for more soon.

In the first part of the clip, the snoring starts quietly as dusk falls (accompanied by singing Whitethroats in the background, formerly a rare summer visitor to Kerry, but making a strong comeback this summer).

In the second part of the clip, later in the evening, keep an eye on the entrance to the box as the snoring intensifies when one of the young spots an adult on a nearby telegraph pole and comes close to the entrance in its eagerness to get some food (filmed under licence: M.O'Clery).