Barn Owls at Sheepdrove

Barn Owls are an integral part of countryside biodiversity. As predators at the top of the food web, they are important indicators of a healthy ecological balance. Here are some notes about how they have fared at Sheepdrove in recent years. 

All monitoring recorded in this article was done under a Schedule One licence. Monitoring a Barn Owl nest site can be done from a distance, but to visit or disturb a Barn Owl nest site requires a licence, as they are a specially protected species.  

Sheepdrove Barn Owls 2009

February snow stayed solidly in place for over a week - two weeks on some parts of the farm - so the normal prey were off the menu. We resorted to putting out food for the owls, set on fence posts. Snow cover made a bad start to the year, but then for the survivors, the warmth of March stimulated grass growth and hopefully breeding in the Field Vole.

Putting leg rings on owlets

As you can see in this video clip, rings with a unique number are used to help monitor the owls. I'm licensed to ring Barn Owl, following training with Colin Shawyer.

June

With the help of Lambourn Valley Barn Owl Group, nest site monitoring began this month. From the results so far, we could see it was a better year than 2008. Out of the first 8 nest boxes, we found:

• a female Barn Owl with 4 owlets
• a Barn Owl pair with no chicks (old eggs left in the box by Tawny Owl and Stock Dove)
• a Stock Dove on 2 eggs
• Jackdaw using 3 boxes
• Honeybees nesting in a tree box!

Despite many appearances and calls by owls (did you know a Barn Owl screeches, it doesn't hoot?) a few farm staff reported 'no owls this year' at their nearest boxes. But these birds aren't always obvious, and since there were more places yet to inspect, we still hoped to find more owls.

July and August

We continued to check boxes and our results got better!

I had predicted that our pair without offspring might start to breed later in the season - and they did. The female is now on her first egg! She has not moulted and weighs over 400g, which shows she's in peak condition for egglaying. Great news, but they have a lot of work to do before we see owlets fledge from there. We hope to have owlets leaving that nestbox by November. (Important note - if we knew she was on eggs we would have left her alone. It was only during monitoring that we found the egg.)

Meanwhile we found 2 more owlets at another site who have already begun to take their first flights from the nest site. They are probably picking up some idea about hunting technique from their parents, and learning by their own mistakes! From experience, I get the impression that at this stage the owlets' killer instincts are not fully honed.

We found a single female too, living in the same barn we'd found her in last year. But where was her partner? In the springtime we discovered a dead male Barn Owl who was ringed. We sent the number to the BTO and records confirmed that he was probably her 2007 and 2008 partner, but died just as the 2009 breeding season began.

Altogether we have a more pleasing set of results now. Back in June we only found 1 breeding pair, but now we know of 3 pairs breeding in 2009. That's not bad at all.

Jason Ball

Sheepdrove Barn Owls 2008

This year was very poor for the owls, here and for the local area generally. We began with what looked like a good rate of site occupation, but wet spells in spring and summer were unhelpful. Only one site was confirmed as having successful breeding. However, barn owl were still being seen and heard all around the farm, and we hope the birds are ready to make a comeback for 2009.

Jason Ball

Sheepdrove Barn Owls 2007

A fantastic year. We saw Barn Owls return to the farmhouse barns (where they had been absent for 3 years) and new pairs took residence in new places. Breeding success was confirmed in 5 other nest boxes, plus we found one pair in a new box who failed to breed this time, but hopefully they'll succeed next year.

Late broods were hatched in some boxes, one in a barn box never used before. Mysteriously, a batch of very young chicks at one box had disappeared by the time we checked later in the season. It's out of reach so the cause must have been natural.

Meanwhile at one of our neighbour's properties - Pounds Farm - I was called out to save owlets who had fallen out of the nest in September. I installed a box for the chicks, so they would not die on the ground below. Barn Owls ignore their fallen young - unlike Tawny Owls. They are doomed to starve if not safely lodged at home. But thanks to the box and the great efforts of our neighbour, these chicks thrived and were flying about in November.

This year I 've been very lucky to get training from Colin Shawyer (founder of BOCN) on how to carry out leg-ringing. This takes quite a bit of experience and practice - not just fitting the ring safely for the bird but also learning how to approach the nest, and how to deal with difficulties. Expertise passed on during previous seasons' work from Colin and Major Nigel Lewis MBE have been invaluable.

Jason Ball

Barn Owls at Sheepdrove 2006

Nest checks in early July 2006 were worrying. There were no eggs, nor chicks in the usual nesting sites. We only had one pair of owls in one box. (Last year there were four.) However, Stock Doves performed very well in many of these nestboxes instead. These birds are not a nuisance like the Jackdaw, which fills up nestboxes with twigs. In fact the Stock Dove is a bird of conservation concern, on the same 'Amber List' as Barn Owl. (As are a great many of our birds of prey.)

At one roost site I found pellets that were unusually small, containing had lots of cockchafer beetle remains. Was that a sign of desperation - because of low vole numbers - or was it simply a sign that these beetles were vastly abundant during early summer and easier to catch than voles?

On 2nd Oct 2006 we checked the nest box with this year's only pair of Barn Owls at Sheepdrove Organic Farm. We hoped that they might have bred late, in response to better vole numbers. Unfortunately they had not. Lots of moulted feathers indicated that they were not about to, either. However, we were heartened to find good signs with regard to food. Pellets were large, and filled with bones from good sized voles.

We hope that over the autumn and winter, plentiful food will bring the owls into good condition ready for egg laying in late spring. Healthy owls should also return to the other nest boxes on the farm. Fingers crossed for 2007!

Jason Ball

Barn Owls at Sheepdrove 2005

At mid-June we found 3 pairs breeding. A pair with eggs (that’s late) and 2 pairs with quite mature owlets. One of the single males mentioned in last year’s notes (see below) did indeed find a mate, but they did not breed successfully this year.

On 4th July, the renowned Colin Shawyer came once again to monitor the birds. At 2 sites we ringed 5 owlets, and another had already fledged.

Colin is qualified to use leg rings to tag the birds, and this helps researchers study questions like: How long do the Barn Owls live? Where do the young set up home? How far do the young disperse when they leave?

At the third site we discovered that the female owl that was on eggs in June was STILL on eggs. That means her early eggs failed. Anyway, she eventually went on to hatch and fledge at least 2 owlets – we think it was 4 owlets but we could not monitor the nest site around fledging time.

Later on, in September, we discovered a new pair in a nest box at the eastern end of the farm. This was a pleasant surprise, and items in the nestbox indicated they had also been breeding. That brought the total number of pairs to 4 for the farm during 2005.

Jason Ball

Barn Owls at Sheepdrove 2004

We recorded breeding by 3 pairs of Barn Owls here in 2004, compared to only 1 or 2 pairs successfully breeding in 2003. Changeable spring conditions seemed to delay some owls. Eggs were laid late… some very late.

Because they need lots of food to raise a family of young owlets, the female is stimulated to lay eggs when her mate brings a plentiful supply of prey items to her. So this delivery of food is an important part of the partnership.

Perhaps an interruption of supply, poor spring weather, or a slow build-up of vole numbers after winter, caused the late egg laying that we found. We wonder if the vole population had still not recovered after the 2003 crash in numbers.

A few males occupied new nest boxes, and so we hoped they would succeed in attracting a mate ready for 2005.

Jason Ball

The 2003 season

Despite the promising signs of a new pair of Barn Owls occupying a new set of barn boxes, and owl pellets in a few new tree-mounted boxes, the 2003 breeding season was certainly not as good as last year.

At first we found only 2 nest sites had breeding, with another 2 pairs seen earlier in the year keeping a low profile, and with no signs of young as yet. Unfortunately when it was time to leg-ring the young, we found one nest site had failed. However there was possibly a new pair starting late in the 2003 season - so perhaps we had 2 pairs succeed in the end!

Two of the nest sites used last year were not occupied by Barn Owls but in consolation at least 1 was taken by Kestrels, who fledged 4 young. Jackdaws were busy in several nest boxes intended for raptors.

A secret video link is installed within one of our Barn Owl nest boxes. Although at the video-linked nest box there were no Barn Owls this year, so not much to watch! This established breeding site only has a single male this year; what happened to last year’s female I do not know. Perhaps she left for another territory, or perhaps she died.

Mortality is very high, and Barn Owls typically live only for a few years. Most fledglings die within their first year. (About 75%.)

Jason Ball

2002 – The farmhouse barns

Here is the story of just one of the Barn Owl pairs.

• Egg-laying began early in the video-linked box at Sheepdrove farmhouse at the Easter weekend (end of March) and things looked very hopeful when the eggs totalled 7.
• April was crucial as the adults stood their ground against Jackdaws who tried to take the nest site and persistently threw twigs into the box on a daily basis for weeks. The Barn Owls managed to cope with the obstruction, and luckily the Jackdaws fulfilled their nesting needs elsewhere.
• May was full of optimism, but we had a heavy share of rain, which may have affected vole numbers and reduced the available time suitable for hunting. Unfortunately just 3 eggs hatched, and only 2 survived past the second week. These owlets both seemed to grow well, though, and soon the mother started to hunt for food along with the male, whose deliveries they had been relying on totally.
• In other nest boxes there were hatchlings too. Last year Sheepdrove’s breeding population of Barn Owls rose from 3 to 4 pairs, and we hoped that we would find results that were just as good this year. Early signs seemed promising, with hissing sounds coming from most of last year’s Barn Owl nest boxes at night – begging calls from owlets inside.
• Viewing the videolink during June revealed owlets with maturing flight feathers. They were learning to use them as they built up their strength, flapping about in the spacious nest box. They became more and more aware of the outside world, starting to perch outdoors to wait for food deliveries. Often they posed quite comically with heads bobbing on their very flexible necks, and jumped on imaginary prey in the nest.
• In July, the time came to inspect boxes and leg-ring the owlets, so expert Colin Shawyer came to the farm. We were pleased to find 4 breeding sites, and one of these pairs appeared to be perhaps trying for a second brood too! The young in the videolink box had fledged slightly before those in other nests, being earlier birds, but one got caught out in harsh rain one night, and Jason had to rescue the bedraggled owlet, not yet able to fly very well.
• By August a 2nd brood had been started by the videolink owls! The female was in a different box now, not on a video-link, so as yet we could not be sure how many young she had.
• In September another pair we suspected of being ready to try a 2nd brood were indeed having another go – great news.
• October brought misfortune for our videolink owls. They lost 2 of the new owlets who each fell from the nest and died either of starvation or cold. A few times when an owlet fell, we managed to return it to the box, the only place where it could receive food deliveries! However sometimes we did not discover the fallen chicks and they perished, because the parents will not visit them on the floor.
• Soon the 4 remaining young in this 2nd brood were taking their first flying trips. Textbooks often say that by autumn the young have left the nest and dispersed. These young did not all disperse by then. Perhaps because they were late offspring, with a distinctly separate nest box, or maybe in part because the territorial behaviour of the parents eased with the season – I do not know.
• At least 2 stayed at the natal site until late December, and I reckon one stayed well into January 2003.

Jason Ball