Nest boxes valuable in good nesting season for Barn Owls

With numerous Barn Owl nest boxes now in place at carefully selected sites throughout Duhallow, their value has been shown this summer with several boxes newly occupied by the owls.

The barn below had one of the first nest boxes to be installed in Duhallow, back in 2014. However, despite checking it each year, there was no sign of any Barn Owls moving in. Until this summer. When checked in August, there were three young Barn Owl chicks inside. 

Three young barn owls in a newly occupied nest box, near Ballydesmond, August 2018.

Across Ireland, there are nest boxes which have been in place for many years before owls have moved in. In one case, in Kerry, it was eight years before the nest box was occupied, in Tipperary one was in place for almost 15 years before the owls finally decided to take up residence.

The fastest any box has been occupied was at another site in South Kerry when the box was installed in early April and the birds moved in and laid eggs just 3-4 weeks later. That is rare of course and it is more typically 2 to 4 years before boxes are used. Even in seemingly perfect sites some boxes have never been used though, as we have found out, it pays to remain optimistic!

Newly installed outdoor-type Barn Owl nest box, north Duhallow.

Most nest boxes are of an indoor type, placed in a disused barn or derelict building. Some are outdoor-type boxes, such as this one (above) in the north of Duhallow. Most of these are placed in trees, where suitable buildings are not present.

Barn Owl chick, east Duhallow, August 2018.

And the rewards of course are great. Barn Owls are one of the most beautiful of birds.

Barn Owl chick, near Ballydesmond, August 2018.

Overall, where the number of chicks was accurately known at individual nests, there was an average of 3.14 chicks per nest in Duhallow, well above the national yearly average of 2.2, so it has been a good year for the species here.

In total, 22 chicks were found, and 12 of these were ringed, so if we encounter those birds again we will have a good history of each.

Two young Barn Owls, near Dernagree, August 2018.

The above Barn Owl chicks were the latest in terms of timing. While most other nests were finishing up and the chicks fledging, this newly occupied nest box in an old barn has four chicks which have at least another month to go. Hopefully the autumn weather will be kind to them as they won't be flying for another five weeks or so, well into September.

Single Barn Owl chick in roof space, near Dromina, August 2018.

Although many of our nest sites are now in safe nest boxes, there are still those in more traditional sites, old buildings and ruins. The one above has its nest in the gap between a corrugated iron roof and the old thatched roof of a derelict cottage, a perfectly secure nest site, though pretty warm in the sun!

Fledged Barn Owl near Mallow, August 2018.

The bird above was one of three chicks which fledged from another newly occupied nest box. All three were old enough to fly well, though they were still hanging about the nest box, hoping to be fed by the parents when they return after dark. Eventually they will have to fend for themselves and head out into the world to find a nest site and a mate of their own.

Destroyed Barn Owl nest box, near Kanturk, August 2018.

Although the nesting season is winding down, there is still work to be done. A few nest boxes such as the one above, have been destroyed by winter storms and will have to be replaced, and there are numerous potential new sites where nest boxes can be installed. The 2018 breeding season, more than ever, has shown that Barn Owls will readily take to well-placed and maintained nest boxes, and these sites, with the cooperation of the landowners, provide some of the safest and most productive nest sites for this beautiful bird.

Four Barn Owl chicks near fledging

Here's what a healthy brood of four Barn Owl chicks looks like!

Two male and two female Barn Owl chicks are on the verge of fledging from this nest box in east Kerry. All the fluffy down is now gone, and they are now almost indistinguishable from adult birds.

This footage was taken on the early morning of 15th July and, by 18th, there was only one chick left at the box, so the video shows almost the last time these four will be together. Over the next week or two they will be fed by the adults in and around the site but, increasingly, away from the box itself. Soon they will learn to fend for themselves, and go their separate ways.

(You can click the arrow icon on bottom right to see the full resolution video).

 

Four Barn Owl chicks at a nest box in Co. Kerry (Filmed under licence from NPWS: M.O'Clery & J. Lusby).

Film from a Kerry Barn Owl nest box

Here is some recent footage from a Barn Owl nest site in Co. Kerry. There are four chicks within, the oldest about 25 days, the youngest about 15 days old. The male and female are busy feeding them each night. Some things to look out for... 

The male delivers prey in the early part of the video, but note the paleness of the outer wing. He is easily distinguishable from the female who appears toward the end of the video - she has more barring on the secondaries (outer wing) and primaries (the longest wing feathers) as well as a more heavily barred tail. Not all pairs are so readily sexed, as there are some females which are only faintly barred and some slightly barred males, but this pair are particularly easy to distinguish.

Notice that both the female and male are already ringed with a small metal band on their legs. An adult male and an adult female were ringed at this site in 2012, and a different female was ringed in 2013.

The last clip shows the female outside the box, but the chorus of hisses and bill snaps is from the chicks, who either heard or saw something which alarmed them, perhaps even the female arriving at the nest.

Hunting seems to be good. One Bank Vole is offered to a chick, but it turns out it already has one. In another part of the clip, you can see the chick eat one item, while another lies uneaten at its feet. This surplus is often consumed by the chicks during the following day.

(You can hit the arrow icon in the corner of the video for a full screen view)

Barn Owl nest camera, Co. Kerry (Video: M.O'Clery, filmed under licence from NPWS).

And here's the same box, about a week later...


Barn Owl nest camera, Co. Kerry (Video: M.O'Clery, filmed under licence from NPWS).

Barn Owl ringing shows value of nest boxes

As the ringing of Barn Owls gets underway in Duhallow this season, the true value of nest boxes is becoming ever more apparent, both in Duhallow and beyond. In the post below, you can see the storm-damaged cottage near Newmarket, which was a nest site for Barn Owls for many years. From a ringed adult female at this site, we have discovered that she (and possibly her male partner) have relocated to a modern barn 2 km away in which one of our nest boxes was placed three years ago. The barn would have otherwise been unsuitable for nesting Barn Owls, but now, to the delight of all those involved with the nest box scheme, the Barn Owl pair have four well grown chicks in the nest box. 

Four Barn Owl chicks from the nest box near Newmarket. The owls moved in some time after February 2014. Pictured holding the owls, Brin McDonnell of the Duhallow Birdwatching Club, and Elsa Corkery, UCC (M.O'Clery).

At another site near Kanturk, when a tree nest was destroyed by storms in 2013, a nest box was put in place in the shattered tree trunk. One bird was present last summer, but this year a pair was again present, and one chick has been successfully reared in the nest box. In both these cases, we would have lost the Barn Owl nest sites if it weren't for the nest boxes. Incentive indeed to keep up the hard work in locating new suitable sites for boxes, making, installing and monitoring them.

The Barn Owl nest box wedged into the shattered trunk of the tree near Kanturk. Thankfully, Barn Owls have moved back in and nested successfully in the box this year, with one chick, below. (M.O'Clery).

John Lusby (BirdWatch Ireland), Dario-Fernandez-Bellon (UCC) and Ilsa Corkery (UCC) retrieving the Barn Owl chick for weighing, measuring and ringing (M.O'Clery).

The Barn Owl chick (M.O'Clery).

The same is now happening in Co. Kerry where several sites would now be lost were it not for careful placement of nest boxes.

Storm damage impacting Barn Owls

One of the largest trees in Duhallow, one which has hosted a Barn Owl nest for the past two summers, is no more (for an account of this site, see HERE).

The tree, a massive Montery Cypress, in all its' glory, in summer 2012. The Barn Owl nest entrance is circled (all photos: M.O'Clery).

While checking on nesting progress at Kestrel and Barn Owl sites today, the giant Monterey Cyprus was found to be collapsed on the forest floor, and looked to have taken several other nearby trees with it. No doubt a victim of the February storm which hit the south-west of Ireland, the area nearby which had hosted a Long-eared Owl nest in 2012 was also flattened by the hurricane force winds.

The giant tree and nest site are shattered wreckage on the forest floor.

Another site destroyed by the winter storms, a cottage near Newmarket, roof ripped off, and now abandoned by Barn Owls.

Not all bad news however. One traditional and one new nest sites had chicks in them, including this 10 day old Barn Owl chick. This was the youngest of two chicks at this nest box site.

Duhallow Raptor Report 2012-13 now available to download

The Duhallow Raptor Conservation Project Report, 2012-13 is now available for free to download. It shows the results from the major two year project on Raptors in Duhallow, including detailed information on all the fieldwork, nest box and publicity aspects to the work.

Summary: In 2012 the Duhallow Raptor Conservation Project (2012 – 2013) was established to undertake innovative and strategic monitoring of Barn Owls, Long-eared Owls and Kestrels in Duhallow to further our understanding of their conservation requirements and to increase awareness and appreciation of their populations.

Some of the highlights of the Report include:

 Strategic work was undertaken in three 10 x 10km survey squares to determine densities of owl species. A density of 2.6 breeding pairs of Barn Owl per 100km2 was recorded -  higher than similar findings elsewhere in the country.

A buildings survey for Barn Owls in the three 10 x 10km survey squares found a site availability of 14.6 suitable buildings per 100km2 and located seven nest sites and 13 roost sites. 

 An innovative playback and acoustic survey was also employed for Long-eared Owl for the first time in Ireland. A total of six breeding sites and seven active territories were confirmed across the three survey squares, representing a minimum density of 4.3 Long-eared Owl territories per 100km2.  

The general and strategic survey confirmed a total of 70 raptor nest sites and territories in the study area in 2012, which included 29 nest sites, nine occupied territories and 32 roost sites. 

Of 35 Barn Owl sites in Duhallow, 20 were confirmed nesting sites and 15 were regular roosts. 

In 2012, a total of eight Long-eared Owl nest sites were located and an additional nine occupied territories, and a single Kestrel breeding attempt and 17 roosts.  

A total of 68 raptor nest sites and territories were confirmed in the study area in 2013, which included 33 nest sites, 11 occupied territories and 24 roost sites. 

Of 40 Barn Owl sites, 24 were confirmed nest sites and 15 were regular roosts. 

A total of 18 active Long-eared Owl sites was recorded in 2013. Eight were nest sites and nine were occupied territories from 2012 which were resurveyed in 2013, of which only one was active. One new nest site was also located. 

One known Kestrel nest site and two occupied territories were also located in 2013 and nine roost sites recorded.

Monitoring of the 20 confirmed Barn Owl nest sites during the breeding season 2012 revealed that 13 (65%) were successful, while the remaining seven (35%) failing to fledge young. 

A breeding success of 66.6% was recorded at six known breeding attempts for Long-eared Owl with an average brood size of 2.2 young per brood.

Seventeen Barn Owl sites remained active in 2013 (an occupancy rate of 85%) though nesting took place at only three of these (a success rate of 17.6% of occupied nest sites). 

From eight active Long-eared Owl nest sites in 2013, six remained active in 2013 (an occupancy rate of 75%), though all failed to breed. 

Nest boxes

One of the first formal nest box schemes for Barn Owls and Kestrels in Ireland was undertaken for this Project. A total of 44 artificial nest sites have now been installed in Duhallow including 29 Barn Owl boxes and 15 Kestrel boxes, representing one of the highest densities in the country. 

An awareness campaign was also managed throughout the project, and the work was publicised through posters (162), and a wide range of events and presentations (16), articles in newspapers and magazines (16), and features on websites (8). 

This blog was also set up in March 2012 to make the project accessible to the general public. A total of 155 posts with information, photos and footage were featured, which attracted 37,506 page views from over 20 countries.  

A documentary on the project was also filmed for “Living the Wildlife” which aired on RTE in April 2013 and was repeated in December 2013.

To download the full report, go to this page HERE. (Opens a new window, on www.box.com, where you can view and download the file. File size is 7.9Mb).

Road casualties mount

Barn Owl road casualty, Co. Kerry, November 2013 (M.O'Clery).

Several Barn Owl road casualties have been reported over the past months, each a blow to a population which has been diminished by a record poor breeding season in 2013. The new bypass in Tralee has claimed one, and another, reported to us yesterday, was also killed by a car.

This one had a ring on its' leg, and a check of the records revealed that it had been ringed as an adult female, by John Lusby, on 27th June 2013 at a nest site near Kenmare. Last summer, she had just one chick in the nest, one of the few we were able to find in south Kerry last summer. She was found dead by the roadside just 9km WSW from the nest site, on the outskirts of Kenmare, 149 days after it was ringed. A sad end to a beautiful bird.

New nest boxes

Mid-winter, and a good time to install some more Barn Owl boxes. Below, the Rolls Royce of nest boxes, due to be trialled in Ireland this summer.

The box was made by the Acquired Brain Injury group in Castleisland, Co. Kerry, for placement at an outdoor site, attached to a tall wooden pole. This design has been successful in parts of Britain, especially in areas that have good hunting habitat for the owls, but no suitable indoor nest sites nearby. 

Most Barn Owl nest boxes in Ireland are of the indoor type, as outdoor boxes are much more vulnerable to storms, they need outdoor materials (such as marine ply) and are thus more expensive to make. 

Raptor talk in Newmarket

Merlin (Photo: John Fox).

John Lusby, Raptor Officer with BirdWatch Ireland, will be giving a talk on Ireland's smallest falcon, the Merlin. It is to be held on Wednesday 18th December 2013 at the James O'Keeffe Building, Newmarket, Duhallow, at 19:00. Admission is free.

For information on the James O'Keeffe Building, and how to get there, visit this website HERE (opens a new window).

John has been conducting a ground-breaking survey on this elusive species, one of the rarest breeding raptors in Ireland.

Winter roost

Barn Owl roosting in a garage, south Kerry, November 2013.

Barn Owls must forage much further for food in winter, and radio-tracking studies have shown that they can travel up to 7 km from their nest site in winter. This bird was recently frequenting the inside of a garage over a two week period, roosting on a pile of turf. It's unusual to have one visit such an open site, as they will normally try to hide away during the day.

(with thanks to Pat McDaid)