Every year we visit all our barn owl boxes at least twice in a year. The first to clean out and maintain each box and the second to return in the breeding season to check whether any owls have produced eggs or young in them. The first visit is undertaken in the winter months in less than pleasant weather and the activity lasts for many months due to the amount of work that is required.

 

The barn owl boxes are mounted in suitable locations across the owl conservation area.

 

The second is in the early summer and is always far more pleasurable. It is on this visit we see a result for all the hard work previously undertaken. It involves transporting and carrying a ladder around the scores of boxes we are required to visit in our barn owl conservation area and carefully checking inside for any young produced.

 

Each box is visited to check if breeding has occurred.

 

With the birds being classified as a Schedule One Protected Species, the person checking has to be a qualified, registered permit holder by law. The discovery of young is very rewarding as we peer into each box’s dark interior. If young birds are present we establish their stage of development and record it. With the original batch of eggs usually hatching progressively over a three week period there is often a staged difference in their achieved growth.

 

Eggs found with the first one already hatched.

 

It then has to be calculated when the average brood size will be ready to record sex, age and have legs large enough to accept an identification ring. This is then noted and a return visit is scheduled to undertake the task.

Having established a presence, intermediate return visits are undertaken to ensure their ongoing welfare until they fledge successfully. This captures any reduction in the number of chicks in the brood occurring as they develop, or any poor health or other condition that might threaten their survival. Often in times of food shortage, the largest chick can consume the smallest one to ensure the survival of the fittest. On occasions, previously healthy developing birds can be found dead, either singly or collectively, or missing completely due to predation.

 

This picture shows two healthy chicks found on an initial inspection. On the next visit they were found to have been predated and had vanished without trace. 

 

Deaths can also sometimes be attributed to disease or poisoning. The poisoning can occur if the prey the parent birds catch for them have been subjected to herbicide spraying in fields where the mice or voles reside, or vermin poisons to reduce a pest presence. Wherever possible a cause of death is sought.

 

Two dead partly grown barn owl chicks found in a box situated in a meadow that had recently been sprayed with herbicide by the landowner to remove ragwort.

 

The stage of growth the young have reached varies from box to box. The checks are undertaken in a short space of time but the young found can vary from eggs to very large youngsters almost ready to fledge. This means that the timings of the return visits to record and ring them are spread over many weeks to catch them at the optimum stage of growth when they are large enough for recording but not too large to be difficult to handle. The curved talons on the bigger youngsters are often identical to those of their parents, and once embedded in the flesh of your hand are difficult to remove. Thus, the preferred size is opted for where possible. Whatever stage they have reached, they are always handled very sensitively with minimum distress being caused. They are gently returned to the safety of their boxes afterwards.

 

Each young barn owl is handled very sensitively and gently returned to its box when recording is completed.

 

This year’s results for the number of broods found in our barn owl conservation area were remarkably high and so took many weeks to monitor and record. This success is due mainly to the care and attention we give to our boxes and the welfare of the birds, and the plentiful availability of the prey they rely on. The prey numbers can vary from year to year depending on seasonal weather, and owl breeding numbers tend to fluctuate to match it. The more prey available, the larger the broods generally are. With each of our boxes positioned in areas with suitable surrounding habitat to readily provide prey, the good results we experienced this year reflect that all conditions were favourable.

 

One of the boxes found where voles caught by the parent birds at night were left to sustain the youngsters during the day.

 

Owls tend to mate for life and select a home range to live in. There is a one to four kilometre radius barn owl requirement around each box for different times of the year depending on food availability. There can be two or three boxes in this range which they frequent regularly. Once a barn owl has established a home range, it will usually remain there for the rest of its life with its mate, as they are very faithful to each other and their area.

Box selection for breeding depends on them selecting the most suitable for their needs in any given year, but they generally use one or two. It is important that barn owls stay in one area so that they can memorise their favoured roost sites, the best hunting places, and the clear flight paths that connect them. These flight paths are important so that they don’t fly into anything in the darkness which is their favoured time for hunting. It can also be critical for their survival in the winter or other times of food shortage, and especially when they have young to feed.

 

Boxes utilised regularly by barn owls within their home range.

 

This makes the surrounding countryside of paramount importance to provide adequate foraging to owl populations and why development incursions into this home range not only displaces roosting sites, but destroys the habitat that is so vital for their survival. We are constantly having to represent such countryside interests in all greenfield development proposals for these reasons. Representing the interests of the owls is vital to maintaining their populations, as their future is badly threatened by the  steadily increasing loss of natural environment.

 

Another swathe of vital greenfield habitat utilised by foraging barn owls in our conservation area is lost to development.

 

Our barn owl conservation area has been expanded many times to off-set some of this damage and now encompasses most of southern Mid Sussex and adjacent settlements. This expanded area causes us a tremendous effort to maintain the boxes over the vast distances we are required to travel, but at least we are successfully sustaining their population. The owls within our conservation area are flourishing and this is reflected in this year’s results. Some of these results are illustrated below.

 

One of the first boxes visited this summer found these three occupants. Note the difference in their stages of development.

 

The next box had four very young barn owl chicks in.

 

On the same day this box was found with just a single but very healthy occupant.

 

Another box visited that day had one unhatched egg and four youngsters of varying sizes.

 

This box had two chicks occupying one side….

 

….and two on the other side, making a grand total of four very healthy youngsters.

 

One to four owls were found in most of our breeding boxes this year.

 

It has been one of our most successful years for young owl occupation of our boxes to date….

 

….with the majority of box locations visited revealing yet another family of barn owl chicks.

 

The age of each chick was recorded on the first visit….

 

….and an estimate was made of timing of the return visit to record them.

 

Due to the considerable variation in the ages of the youngsters found….

 

.…the sequence of return visits to record them at the required size….

 

….meant that the huge owl conservation area was required to be criss-crossed many times over several weeks.

 

This ensured that they were all dealt with at a stage they had grown sufficiently to be able to accurately record sex, development and age…. 

 

….whilst still being of a size that could easily be handled.

 

Even on the first visit some chicks were small, cute and downy….

 

….while others were already large enough to be dealt with immediately.  

 

For these larger birds a very quick return was made.

 

Not all owls were pleased to see us on the second visit and were determined not to co-operate….

 

….but the authorised team gently took charge and each was meticulously recorded with an identification ring placed on its leg.

 

The team was formed of a sufficient number of people to carry all the equipment required over the large distances across fields.

 

In some boxes we found a number were almost full size and ready to fledge.

 

The larger the birds found, the more difficult they were to handle, but they were all recorded in the same way…. 

 

….but with a greater respect being given to their sharp talons.

 

The smaller chicks were more easily dealt with….

 

….and seemed to appreciate the smart leg bracelet we fitted.

 

When recording had finished, they were carefully placed back into their respective boxes.

 

It was ensured that all the birds were completely settled before we departed. 

 

This one had its plumage almost completely in place, but still retained an amount of down beneath.

 

These siblings demonstrated their staggered development due to progressive egg hatching, with the oldest on the left and the youngest on the right.

 

On their return to the boxes, they usually scurried to the furthest corner….

 

….a little unsure if they were to be disturbed further….

 

….or whether they could once again relax.

 

They are without doubt one of the most beautiful of all the birds in our local countryside….

 

….and worthy of the considerable effort we expend to sustain their population.

 

We engage fully with all landowners within our conservation area and provide any help or advice they seek so that we can jointly safeguard the interests of our local barn owl population. We are very grateful to them for their continuing support for our conservation effort and to our group volunteers who willingly form the teams to allow us to undertake the large amount of work required to meet their needs. Without this effort and support, the future of the barn owl would be severely threatened.