Ringing tales: Barn Owls - BirdWatch Ireland
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Barn Owl in Ash tree nest
Photo: Mike Brown
Ringing tales: Barn Owls
In the fifth in our series on bird ringing, Brian Burke talks to BirdWatch Ireland’s Raptor Conservation Officer
John Lusby about how ringing has been an important part of his Barn Owl research
■ What is the focus of your project? to the nest within five to ten minutes. The range of places that Barn
The focus of the project is to assess Barn Owl occupancy and Owls nest can definitely present some challenges, such as castles and
breeding performance at selected nest sites throughout the country. other large ruined, stone structures and hollow cavities in trees.
To do this, we visit nests and ring young Barn Owls (under licence), We have also fitted GPS transmitters to adult Barn Owls to learn
which allows us to gather information on the health of the population, more about their foraging behaviour and specifically how they use or
their breeding trends and the movements and survival of individual avoid road networks. This has required a lot more planning, patience
birds over many years. and long nights compared to the ringing and nest visits, but it has
provided a wealth of important data to inform their conservation.
■ Why did you pick this project or species?
When Alex Copland and I first started to focus on Barn Owls, there ■ What interesting things have you
had been very little work done on this species in Ireland. This was learned so far?
despite the fact that Barn Owls had declined dramatically over Where do I start! One of the first things that we learned was that Irish
previous decades and today remain a red-listed bird of conservation Barn Owls are very different to their counterparts in Great Britain.
concern in Ireland. We felt this needed to be rectified, as there was a Irish Barn Owls have significantly larger home ranges, their foraging and
poor understanding of their ecology and conservation requirements
in an Irish context. Ruins like this one of an ancient priory in County Tipperary are excellent sites
for nesting Barn Owls. Photo: John Lusby
Secondly, Barn Owls are apex predators, which sit at the top of the
food chain, so, by monitoring them, we don’t just learn about the owls
themselves: they also give us insights into the health of the wider
countryside ecosystem, environmental processes and human-induced
pressures that affect other wildlife.
Finally, but importantly, I have always had a special interest in Barn
Owls, and I think this is important, especially when setting out to
establish a long-term monitoring project.
■ Can you tell us about how you monitor
and ring them?
Barn Owls have quite a long breeding season – the young are in the
nest for close to two months before they fledge – so as long as nest
visits are well timed, ringing young Barn Owls is generally straight-
forward. We record the number of young and take a range of
measurements of each chick, which allows us to estimate their age,
their sex and their general condition, before fitting them with a metal
BTO leg ring. The ringing is quick and easy, and the chicks are returned
22 W I N G S S UMME R 2021
Distribution of Barn Owl occupied sites located in the Republic of Ireland in the period Barn Owl chick during ringing at nest site in Kerry. Photo: Michael O’Clery
2010-2020. Barn Owls have been faring particularly well in the south-west in recent
years.The Greater White-toothed Shrew, a recent arrival to this area, was first recorded
in 2007 in Tipperary and has been spreading rapidly ever since. Map: John Lusby ■ Have you recorded any significant
movements or long-lived birds?
breeding ecology is very different, their diet is different (we lack several Michael O’Clery and I ringed a brood of three chicks in County Kerry
of the small mammal species present in Great Britain; however, the in 2015, of which two were subsequently found dead on roads. One of
Greater White-toothed Shrew is present in Ireland but not Great these was killed on the M8 motorway in County Tipperary; the other
Britain), and the availability of nest sites in Ireland is different to Great was found dead on a dual carriageway in County Derry, a distance of
Britain too, which all creates different, Ireland-specific over 350 kilometres from its nest in Kerry – the longest
challenges for our conservation efforts. movement that we have recorded.
Recently, we have learned that Irish Barn In February of 2016, an adult male Barn Owl was
Owls are in fact genetically distinct to British found dead on the Tralee bypass.This bird had been
Barn Owls, through a study led by the ringed, so we were able to identify it as the male
University of Lausanne, on which we that had bred in a nearby nestbox for the previous
collaborated. Ringing records were used three years. Given the timing, especially the fact
to assess movements of individuals and that the breeding season had already begun, we
gene flow between Ireland and Great thought this nestbox would not be used that
Britain, which shows the value of this data season. However, some weeks later, Michael found
and its many applications. that another male was present with the female at
Although nest visits are primarily carried Greater White-toothed Shrew the nestbox! This ‘new’ male had been ringed as a chick
out to ring young Barn Owls, we also collect a Photo: John Murphy in 2008 (one of the first Barn Owls that I ringed) at a
range of other information at the same time, which castle 20km away.This male was therefore nine years old in
has provided many fascinating insights.The Greater 2016, and it bred successfully with the resident female the following
White-toothed Shrew was first discovered in Ireland year, producing three young – making it, at ten years old, the oldest ➤
in 2007 – with colleague David Tosh – in Barn Owl
pellets collected as part of nest visits in Tipperary, Movements of a satellite-tagged female Barn Owl (inset) near Cashel, Co Tipperary, in 2017, revealing
and we continue to monitor the shrew’s range how her travels frequently took her across the busy, and deadly, M8 motorway. Images: John Lusby
expansion in this way.
Cashel, Co Tipperary (female)
The GPS tracking has provided amazing insights
into how Barn Owls move through and use the
countryside, and their interactions with major
roads. We learned that roadside verges are an
important foraging resource for Barn Owls,
although they’re high-risk. We have used this
information to develop mitigation standards for
major roads, which were recently implemented by
Transport Infrastructure Ireland and will hopefully
help to reduce Barn Owl vehicle collisions in
future.
We have also learned that providing Barn Owl
nestboxes in suitable locations works... and it
works well! In 2020, there were fifty-nine
nestboxes being used by breeding Barn Owls, a
new record, and this number continues to increase
each year.
W IN GS S UMMER 2021 23
birds that we have ringed, it is because they have been found dead,
so when we see one of ‘our’ ringed birds doing well and we can
trace back its movements and life history, this is something special.
Also, definitely one of the main positives of this project is the
collaboration and working with so many dedicated people. The
Barn Owl monitoring is only possible thanks to the extensive network
of volunteers and National Parks and Wildlife Service (NPWS)
rangers who report sightings and nest sites, assist with monitoring and
ringing, build and monitor nestboxes and report Barn Owl mortalities.
In recent years, I am also delighted to say that we have expanded
the team of ringers that focus on Barn Owls. Until recently, I was the
only one ringing Barn Owls in the country; now we have a small but
dedicated and well-coordinated team, which includes licensed ringers
Sam Bayley, Alan McCarthy, Michael O’Clery, Áine Lynch, Barry
Nolan and Mark Stanley.
On a personal note, one ‘high’ that I will never forget is when
monitoring a nest site in Tipperary, sitting on a wall inside a castle at
sunset, decked out in camouflage gear. A female Barn Owl emerged
from the nest at the very top of a high chimney and flew down and
landed on my knee and proceeded to preen herself... until the sound
of my heart thumping made her realise what she was perched on!
Barn Owl nest with chicks in cavity in old building. Photo: John Lusby She let out a blood-curdling scream inches from my face and flew off.
A memorable if not deafening encounter, and there are so many
ringed Barn Owl on record in Ireland. We have more like it.
not been able to find out whether this male
is still present and breeding at this site, ■ What should people look out
although we hope to in 2021. for and where should they
report any sightings?
■ What are some of the Please report information on Barn Owls – potential
highs and lows that nest sites, nestboxes, dead Barn Owls found – on
you have experienced the BirdWatch Ireland website or by email to
on this project? jlusby@birdwatchireland.ie.
Thankfully, there are a lot more highs Barn Owl nest visits and ringing is carried out under
than lows... or maybe I have just blocked Barn Owl box in roof of barn special licence from the NPWS and the BTO (British
out most of the lows! I remember in the Photo: Michael O’Clery Trust for Ornithology). Barn Owls are very sensitive to
early days struggling to find occupied nest sites disturbance and suspected nest sites should never be
and spending many long and lonely nights in dark approached or interfered with in any way.
castles without seeing or hearing Barn Owls. How things have BirdWatch Ireland wishes to acknowledge the support of Dublin
changed! Last year we confirmed 192 occupied sites, and we ringed Zoo, which has provided funding for the Barn Owl monitoring on an
271 Barn Owl young from 93 broods, which is a record. annual basis. In 2020, Galway County Council and Creative Ireland,
In 2020, Barn Owls had a productivity of 2.97 young per Tipperary County Council and Cork County Council provided
breeding attempt, which is the highest recorded to date in Ireland. funding for the Barn Owl monitoring in the respective counties. IRD
One aspect of the work that always gives me a high is when we Duhallow and the Duhallow Birdwatching Group fund the Barn Owl
encounter a bird as a breeding adult that we ringed as a chick, conservation project in Duhallow through LEADER programme. Huge
sometimes many years later. Most of the time, when we encounter thanks go to the landowners who allow us access to their lands ■
Old ruins are ideal nesting sites for Barn Owls. Photo: Michael O’Clery Adult Barn Owl flies out of its nest site in old ruin. Photo: Mike Brown
24 W I N G S SU MME R 2021
You can also read
