Final phase of Long-eared Owl survey

The fourth and final phase of the 2012 Duhallow Long-eared Owl Survey will begin on 1st August.

The first phase in April was the tape-playback of the calls of adult Long-eared Owls, and all responses from adult birds were recorded in three 10 km squares in Duhallow (each 10 km square equals 100 square kilometres). This phase resulted in 6-7, 3 and 3-4 territories being located in each of the squares. However, not all Long-eared Owls will respond to the tape, so three follow-up visits were planned, in May-June, in July, and again in August.

Long-eared Owl chick (Photo: Eric Dempsey).

Since then, with two full re-surveys of the three squares, some additional territories were located by listening for young Long-eared Owls calling at night (you can hear what they sound like on this page HERE). The final phase which is about to start will be a final re-survey of the three squares in the hope of locating any late-nesting Long-eared Owls. Although most Long-eared Owls will have already finished breeding this year, and the young fledged and dispersed, there are still reports coming in from around the country of Long-eared Owl chicks calling, as recently as Friday last, so it is possible that one or two more may be found in the Duhallow squares.

Either way, it looks as though Long-eared Owls outnumber Barn Owls by about two to one in the three 10 km squares.

More Duhallow Barn Owls ringed

Two more Barn Owl chicks have been ringed at a site in Duhallow which we saw in a slightly earlier post below ('Can NAMA help Barn Owls?').

There were three chicks in total, but it seemed that two had already fledged and moved out several days ago, though as it transpired, the two were roosting at the back of the house. When John Lusby visited the nest site on Tuesday, he was able to capture, weigh, measure and ring two of them, before returning them to the nest site.

Barn Owl chicks, Duhallow, 24th July 2012 (F.O'Sullivan. Chicks ringed under licence from NPWS).

Three is a very good brood size this year, with only a few other sites producing three chicks. Most have seen just 2, while several more nests have failed completely. The one positive aspect of the poor breeding summer for the owls is that at least none of our Duhallow sites have been completely abandoned. At all the failed sites, one or both the adults are still present. Should next spring and summer be even a little better than this one, there is every chance they will breed again.

Barn Owl nest camera goes live

Ireland's first Barn Owl web cam went live this afternoon.

Screengrab from the Mooney Barn Owl Nest Camera. The adult male delivers a Bank Vole to the two chicks.

The camera can be accessed through the Derek Mooney page on the RTE website HERE. Click on the Barn Owl image on that page to see live footage of the owls, which are in a Co. Kerry nest box.

John Lusby on Mooney radio show today

John Lusby, with Barn Owl, June 2012 (Photo: M.O'Clery).

Tune in to Derek Mooney's radio show today (Wednesday 24th July), from 3pm on RTE1, for an interview with John Lusby about Barn Owls. John is the Raptor Officer for BirdWatch Ireland, and is the leading expert on this species in Ireland.

Young Barn Owls disperse

The young owls, in the post below, seem to already have dispersed, just days after the discovery of the nest in an unfinished, new-build house. The chicks were almost adult-like on 19th July and by 23rd seemed to have already vacated the nest site, though one was now using the adult's roost site. Below, perhaps the last view of a chick at this nest this year. 

Barn Owl chick, Duhallow, 22nd July 2012 (Photos: F.O'Sullivan).

Where might this fledgling end up? Most will disperse to within 10 to 50 kilometres of their birthplace, but some might go further, and in theory, this young bird could turn up anywhere in Ireland. Barn Owls can breed at one year of age, but most will die before reaching that stage. Any number of possible threats await them, from collision with cars and overhead wires, to poisoning and starvation. It's a tough life out there, and only the hardiest (or luckiest) few will survive to breed next spring. Let's hope this one finds a good territory of his or her own and makes it through those difficult first months.

Could NAMA help Barn Owls?

Why on earth have we posted a photo of the gable end of an unfinished house? 

Is this one of the many unfinished 'NAMA estates' or apartments that litter the Irish countryside after the property bubble burst so spectacularly? Well, this particular house in Duhallow has a slightly different history and remained incomplete following the untimely death of its owner about 2 years ago, but in the meantime, some unexpected tenants have moved in... 

Click on the photos for a closer look.

Adult Barn Owl, Duhallow, 18th July 2012 (Photo: F.O'Sullivan).

The Barn Owl in the photo is one of the adults of a pair which nested in the building this summer. The photo shows one at the roost site entrance yesterday morning at 6.00am. The nest entrance was on the opposite side of the same gable, in a similar hole, and contained at least 2 well-developed young, probably around 50-55 days old. They should be ready to take their first flight any day now, and we hope to ring the nestlings soon, before they depart.

While surveying for Barn Owls, there is of course a need to search disused and derelict buildings and ruins, but this is the first time a nest has been discovered in Ireland in a new, unfinished, building. Could there be other Barn Owl nests in some of the many houses and estates that lie idle throughout Ireland? We will obviously have to look harder at these types of building in the future.

Screeching fledglings

The three chicks ringed at a tree site in Duhallow two weeks ago (see the post HERE) are doing well, despite the atrocious weather. A check on them a few nights ago at dusk saw all three flying competently around the nest site, and two eventually moved away into the trees, still snoring for food from their parents. One, perhaps the youngest, stayed close to the nest, calling frequently. Have a listen to the video. It's nearly dark, so the video can't pick up the birds in the foliage, but the snoring calls are distinct, and have developed into an occasional full-blooded screech. 

Three Barn Owl chicks near their nest, now at the flying stage, and no doubt soon ready to leave the area to find their own territories (Filmed under licence: M.O'Clery).

All three fledglings could leave the nest area at any time now. The dispersal of young Barn Owls generally occurs two to four weeks after they are able to fly, occasionally longer, but it could be in any direction. Who knows where they might end up once they leave? Many ringed birds have been re-found just 10-20 km from their birthplace, but others have crossed the country.

No breeding at Duhallow Barn Owl site

Barn Owls moult their feathers gradually throughout their lives. However, there is some variation in the timing. For example, while the female is incubating eggs and tending young chicks, she is permanently at the nest for almost 2 months, during which time she is fed by the male. During this 'down time' she moults some of her feathers, when there is less pressure on her to hunt efficiently. At the same time, males suspend their moult while provisioning the female and young, and rather than have energy spent on replacing feathers, it is used to provide food for the female and young over the entire breeding period. Once the breeding season is over, both male and female resume the gradual moult of their feathers.

The video below was filmed last night at one of our Duhallow nest sites in a derelict cottage. We see very fresh pellets (indicating the adults are still present) and a series of newly moulted feathers, including a large flight feather (a primary). There were many fewer feathers on our last visit here about two weeks ago and during last nights' visit the cottage was utterly silent – no young chicks calling for food and no activity noted around the nest – the conclusion being that it is most likely that the adults have failed to breed, and as a result, have resumed their moult. Perhaps another effect of the extremely wet summer.

Video of fresh pellets and newly moulted feathers below a Duhallow nest site. Signs that breeding has not taken place (Filmed under licence from NPWS. M.O'Clery).

Bad weather taking its toll

The wettest June on record at all but two weather stations in Ireland has taken a huge toll on the success of Kestrel, Long-eared Owl and Barn Owl nests, and July seems to faring no better. Although most Kestrel chicks will now have fledged, the average brood sizes throughout Ireland have been well down on last year, and they have been notably scarce in the Duhallow survey squares this summer. Long-eared Owls have also suffered and only a few of the nests located during the early phases of the survey still have young. Many potential territories which were located in the first survey phase in April seem to have gone utterly silent, implying that the adults either failed to breed, or didn't even attempt to nest this year. We know of one nest which was predated, but at another, although predation can't be entirely ruled out, the two young disappeared from the nest area after two days of heavy continuous rain in early June, a deluge during which the nearby Blackwater River overflowed and flooded adjacent farmland.

Barn Owl nests have also had poor productivity all over Ireland this summer, and the known nests in the Duhallow region have had mixed fortunes. Successful sites had 2, 3 and 3 young, and there is at least 1 chick at another inaccessible site. At another site in a rock crevice, the adults have disappeared and not bred, while at one of the tree nests, there is no indication of breeding, though the adults are still present. One traditional site in a chimney was deserted, though there were a few fresh signs of an owl or owls still present. Several other sites are still to be checked, but hopefully some will prove to have successful broods.

This tree in Duhallow has a Barn Owl nest (visible close to the top of the central trunk), and a pair were present here in late May. However, when checked in June, it was empty, though the adults were still present in the area. It is possible they may be nesting elsewhere nearby, though, as with many nests in Cork and Kerry this summer, the adults may not breed at all (M.O'Clery).

Three tree chicks

As promised, details of another of the Duhallow Barn Owl tree nests (featured in a previous post HERE). The site was visited on Thursday last in the company of NPWS Ranger Barry O'Donoghue and Brin MacDonald to ring the chicks, and not a moment too soon. All three were almost ready to fledge, being about 65, 62 and 60 days old. Only one had some last traces of downy feathers, the other two were fully grown and ready to face the outside world. Had we visited this nest only a few days later, we might well have found an empty nest.

One of the chicks (M.O'Clery).

Video of the ringing of the chicks (Video: John Lusby & Michael O'Clery).

The nest was in a huge pine tree in the middle of a woodland, and as this was the first visit to the site, it was a bit of a surprise to find that the nest cavity was rather shallow. There was really just room for the three chicks to shelter from the elements and not much more. However, all three were in good health, showing that the parents had chosen their nest site well.

Pot-bellied Barn Owl

While measuring and weighing three chicks at a nest box site in Co. Kerry last week, our attention is drawn to the fact that this brood have been particularly well fed...

Pot-bellied Barn Owl chick (Video: I.Kavanagh).

First Duhallow Barn Owl nest box

Great excitement on Friday last when one of the Duhallow Barn Owl nest boxes was checked, and two chicks were found within (see video). This box was placed in a barn in Duhallow last November by Brin McDonald and John Lusby, as part of a pilot programme, funded by IRD Duhallow. It is the first confirmed successful nest in a nest box for this project. Let's hope there will be many more.

John Lusby looks inside the box - two chicks! (Video: John Lusby). (All visits to Barn Owl nests are carried out under licence from NPWS).

Brin holds the two chicks. They are about 40 days (left bird) and 45 days old (Photo: M.O'Clery).

Part of this year's Duhallow Raptor Conservation Project will involve placing five more Barn Owl nest boxes at suitable sites in the coming autumn. Many such sites have already been identified, so hopefully this will just be the beginning of many more successful Barn Owl nest boxes.

Some Barn Owl sites lost

Although the Duhallow Raptor Conservation Project has located several new Barn Owl nest sites during survey work this summer, two tree nests seem to have failed. One had the female sitting tight inside the nest cavity about five weeks ago attended by the male and showing every signs of breeding but, upon inspection last week, proved to be empty.

The second, also a tree nest, was also empty and seems to have been used by Jackdaws this summer. However in both cases, adult birds are still being seen in the vicinity. It is possible they have nested elsewhere nearby, so while it will take further investigation to see if this is the case, at least we can say that for the moment, the sites themselves have not been abandoned.

With the assistance of Ranger, Tim O'Donoghue, John Lusby climbs to the cavity in the Beech tree. Unfortunately the call came down that it was empty (Video: M.O'Clery).

Second day of filming

Duhallow Barn Owls once again featured in a documentary by Colin Stafford Johnson and his crew on Friday last, during his second day of filming in the region. Colin was particularly keen to film the chicks being ringed at a site which has featured here in previous posts – a hollow tree in a garden (see the earlier post about this site HERE). They were about 45 and 50 days old, and will be ready to start flying in less than a fortnight.

John holds the young Barn Owl, while being interviewed by Colin.

One of the Barn Owl chicks with an admiring audience.

Time and effort

Many Barn Owl sites are fairly accessible, once you know where they are. Others are more difficult, occasionally involving multiple ladders and ropes to climb to the nest. Some nests have been monitored for many years, including this one in Co. Kerry, but the time and effort involved to reach them can be considerable. Have a look at this extraordinary place...

Screengrab of the derelict house (John Lusby).

It's hard to believe places like this exist, but when you are in the business of Barn Owl surveying, it becomes apparent just how many derelict buildings there are dotted around the Duhallow countryside.

Long-abandoned by people, now occupied by bats and Barn Owls (Photo: M.O'Clery).

Journey through the building as John Lusby investigates the Barn Owl nest (under licence from NPWS and kind permission from the owner). (Video: John Lusby).

To reach the Barn Owl nest at this site involves climbing up through the derelict house, past gaping holes in the floors, past crumbling masonry and long-forgotten items of furniture, past a room where bats hang from the ceiling, out an upper window, and onto a roof. From there, a ladder is lifted into place to climb the last bit of slate roof to reach the nest – a hole in the chimney, about 20 metres (50 ft) high. 

Duhallow owls to feature in RTE documentary

 Documentary maker, Colin Stafford Johnson joined the Duhallow Raptor Conservation Project team for two days filming on Wednesday and Thursday last. Colin and his team, Dom on camera and Craig on sound, were able to film John Lusby as he ringed Barn Owl chicks at various locations around Cork and Kerry. It is hoped the programme will air in the autumn.

John Lusby retrieves one of two chick from the chimney of a derelict cottage in Co. Kerry...

... filmed by the crew from the 'Living the Wildlife' series.

Colin holds one of the chicks (Photos: M.O'Clery).

A Dingle visitor to Duhallow

A 're-trap' is when a bird is already ringed, then once again trapped and released, sometimes at the same site, sometimes elsewhere. In the past six years, with an ever-growing number of Barn Owls being ringed throughout Ireland, the number of re-traps has also risen. They can give an extraordinary insight into a Barn Owls life, its movements and lifespan, and demonstrate the valuable information that can be learned from ringing birds.

When John Lusby inspected this site in Duhallow on Friday last, he found a Barn Owl in the chimney of the disused house. 

(You can click on any of the photos for a closer view)

John Lusby inspecting the chimney at a site in Duhallow (under licence). Barn Owls had bred here in 2010, but were absent in 2011 (M.O'Clery).

To his surprise, it was an adult bird and already ringed. From his database, he discovered the bird was a female and had been ringed as an adult near Ballyferriter on the Dingle Peninsula last summer, 80 km to the west. Then, she had been trapped and ringed by John, along with the male and her four young, at their nest in a nest box. She was at the time one year old, so now would be two.

A two year-old female Barn Owl, originally ringed near Ballyferriter (M.O'Clery).

The ring on her right leg bearing her unique identifying serial number (M.O'Clery).

The nest box at Ballyferriter was predated in the past three weeks, the chicks most likely taken by a Pine Marten, so this raises the question, did she leave her nest in Ballyferriter after the young were taken? Or has she been in Duhallow for a while, and the Ballyferriter site taken over by another female? When examined by John, she had a brood patch on her stomach (an area of bare skin for transferring body warmth onto her eggs) and was, at 480 grammes, very heavy for an adult bird. It is possible she was full of eggs and about to lay at the Duhallow site.

She was returned safely to the chimney, leaving us puzzling how little we know about the movements and habits of Barn Owls in Duhallow, but grateful for this small but detailed insight into this wandering female's life. We will check back at this site to see what happens.