...and yet another unusual Barn Owl nest

Barn Owls can nest in a variety of sites, once the basic criteria are met – undisturbed, dry, large enough to take a family of owls, and usually high enough to be out of the reach of ground predators. We've already seen some of the more unusual nest sites in Duhallow, such as the tree nests HERE, and HERE. 

Around Ireland, the list of nest sites also includes old churches, derelict buildings of all types, quarries, chimneys, castles and more recently of course, nest boxes. But how about this one? Not quite in Duhallow, but not far from it either. The only Barn Owls we know of in Ireland that have chosen to nest in a water cistern… Filmed yesterday.

Barn Owl nest, in a water cistern, Co. Kerry, June 2012 (Filmed under licence from NPWS. M.O'Clery).

Feeding time

Below a short video of an adult Barn Owl arriving at dusk at a tree nest site in Duhallow.

The adult arrives (bottom left) before flying to the nest entrance with the prey for the chicks (M.O'Clery. Filmed under licence from NPWS).

Before the adult arrives, the chicks make a regular snoring call, demanding to be fed, but as the adult arrives with the prey, there is a sudden clamour to get the offering. Older chicks will call loudly like this throughout the night.

Third phase of Long-eared Owl Survey under way

Three 10km squares in Duhallow are undergoing a thorough survey for Long-eared Owls. The first phase in early spring involved tape playback of the Long-eared Owl's calls to elicit responses from adults holding territory. The second, third and fourth phases are to listen for young Long-eared Owl chicks in the same areas during June, late June/July and August respectively. 

With the third phase now underway, the number of possible territories stands at 3, 3 and 7 in each of the 10km squares. However, early indications are also that several of the known nests have failed, either due to predation by Hooded Crows or Pine Martens, or possibly due to the recent heavy rainfall. On the other hand, some nesting areas which weren't apparent from the playback phase have been found by locating the loud chicks. When the third and fourth phases are completed it will be possible to work out a thorough account of the population density of this elusive species.

Inside a Barn Owl nest

Ringing birds at the nest gives valuable information about the young, such as their weight (and thus their state of health) as well as brood size (number of chicks) and their stage of growth. From this you can also work out the dates they hatched, and the dates the eggs were laid, all immensely important in trying to apply conservation measures for this secretive species.

Female Barn Owl in front of two chicks, at their nest, which is about a metre (3 feet) along a horizontal shaft of an old chimney system in a derelict house in Co. Kerry. The floor of the nest is covered in dried pellets of fur and bone which over time have actually formed a dry and insulated floor  (Photo, taken under licence from NPWS: John Lusby).

Occasionally one or both Barn Owl adults will be caught at a nest, and in this case at a site in Kerry, the female was still attending the two chicks. She was carefully removed, along with the two chicks, for ringing. We had also caught and ringed a female at this site in 2011, but were a little surprised to find that this female was unringed, and therefore not the same which successfully reared two young last year. 

Female Barn Owl wing showing uniformly aged flight feathers, indicating that she is one year old. You can click on the image for a closer view  (Photo: M.O'Clery)

Feathers on Barn Owls are moulted (replaced) in a known sequence, and the main flight feathers only start to moult after their first year. In the photo, you can see that all the main flight feathers are of equal length and wear, so we can conclude that this female is one year old. In an older bird, there would be an obvious difference between one or more new feathers which would grow to replace older feathers.

Long-eared Owl duet

Some audio, taken two days ago, of two well-grown Long-eared Owl chicks calling from a wooded area near Newmarket. These are the chicks recorded in an earlier post HERE. Compare how much stronger their voices are after 18 days. The two are calling alternately from perches high in trees about 30 metres apart and the sound was carrying for almost 700 metres on this calm, still night.

Two Long-eared Owl chicks calling (M.O'Clery).

The young owls are flying competently at this stage, and were well away from their nest.

Another extraordinary Barn Owl nest

While surveying dense woodland in Duhallow for Long-eared Owls on Saturday night last, the sound of 'snoring' Barn Owl chicks was certainly not expected. Barn Owls are typically birds of open country, foraging over field edges and rough grassland, yet there was no denying that somewhere within that dense, dark forest there was the continuous 'snoring' of Barn Owl chicks. It took a bit of time to pinpoint the sound, but it was eventually tracked to a cavity in the trunk of huge Cypress, with a Barn Owl nest containing certainly two, perhaps three young, probably about 25-30 days old, being fed by the parents. Here's a photo of the tree, taken the following afternoon.

Barn Owl nest entrance (circled) in dense woodland in Duhallow (M.O'Clery).

From below, there were no visible signs of the nest – no pellets, feathers or droppings – and the entrance is hidden by ivy. One of the most difficult nests to find, and really only detectable by the calling chicks. The nest entrance is about 20 feet from the ground, so it may be possible to ring the chicks in the coming weeks.

This is the third Barn Owl tree nest to be found in this 10 km Survey square. It brings to five the number of known nests in the square, the highest of any 10 km square in Ireland. It is also the only 10 km square in Ireland with more than one tree nest, and the only nest so far discovered in Ireland that is within dense woodland. 

More on this nest soon…

Video of Long-eared Owl ringing

A video of the ringing of a Long-eared Owl chick near Newmarket, 4th June 2012 (M.O'Clery).

Bill-snapping

This Long-eared Owl chick, ringed near Newmarket on Monday last, is making a loud clicking or snapping noise with its bill. This noise, with quiet hisses, is made in response to any threat, and can be made even when the bird is holding food in its bill, so it is not made by the bill snapping shut, rather with the vocal chords (M.O'Clery).

Video of a young Long-eared Owl 'bill-snapping' (Video: M.O'Clery).

Long-eared Owl chick

The Long-eared Owl nest which has been mentioned in previous posts (eg, this one HERE), was visited on Monday last to try to ring the chicks. John Lusby was able to scale the tree and catch one of the two chicks. The eldest, at about three weeks old, was already able to scramble nimbly about the branches and avoid being captured. This phase of the development of young Long-eared Owls is known as 'branching'. 

Long-eared Owl chick, at a site near Newmarket, 4th June 2012 (M.O'Clery). Click on the image to see a closer view.


Long-eared chicks can scramble about and even fly short distances by 25 days old while Barn Owl chicks would be 65 days old before attempting their first flight. This is probably a mechanism to avoid predation of the chicks in the more exposed nest sites of Long-eared Owls.

Kestrels ringed

A brood of five Kestrel chicks was ringed yesterday at a site in Duhallow. John Lusby, Raptor Officer with BirdWatch Ireland, was able to retrieve the chicks from their nest in a long shaft set into a cliff face.

John temporarily removes the chicks from the nest (M.O'Clery).

The five chicks (M.O'Clery).

Kestrel eggs are laid a day or two apart, and they hatch at a similar rate, so the ages of these chicks vary from about 11 days to around 18 days old. Each of these chicks had very full looking pot-bellies (you can see this on the centre bird), and were all at healthy weights for their ages, so seem to be faring well. Brood sizes are typically four to five eggs, occasionally six.

Very brave, or very foolish...

Barn Owls and Jackdaws have a very uneasy relationship. Jackdaws are often found nesting at the same sites as Barn Owls – derelict buildings and ruins, especially old chimney systems – and they can compete directly for the same nest sites. On the one hand, Barn Owls nesting in chimneys will often only find the site suitable after Jackdaws have repeatedly dropped sticks down the shaft in the hope of blocking it and forming a protected nesting platform. Barn Owls will often take over these stick nests deep inside chimneys, and a third or more of all Barn Owl nests in Ireland are as a result of them commandeering old Jackdaw nests. On the other hand, several suitable Barn Owl nest sites, and sometimes Barn Owl nest boxes, have been filled with sticks by Jackdaws to the point where they are no longer of use to the owls

Where there is an established Barn Owl nest, as in this instance at a site in Co. Kerry, despite there being dozens of Jackdaws in the vicinity, all seem to know to avoid the old farm shed with the owls in it. Barn Owls can and will kill an intruding Jackdaw. This short clip, taken yesterday evening,  shows an unusually brave, or an unusually foolish Jackdaw land on a beam in the shed, only to have the resident Barn Owl take a swipe. No doubt this intelligent and fast-learning crow will know not to chance his luck there again.

Lucky Jackdaw (Video: M.O'Clery).