By Derek Gruar, RSPB Conservation Science, Hope Farm
All inspections and ringing of nesting barn owls on the farm are covered by a Natural England S1 Disturbance Licence.
For only the second time in the eleven years since RSPB became the owners of Hope Farm, we are pleased to be the custodians of a family of barn owls nesting in one of the three special owl nest boxes that we have sited around the farm.
Adult owls were first observed in the box in late June during a routine check of nest boxes. The first eggs were recorded two weeks later and a full clutch of seven eggs was laid.
Incubation for barn owls takes 4-5 weeks, so during this period we didn’t disturb the birds and the first nestlings were seen about a month after we had confirmed the clutch size.
The eggs are laid and hatch a couple of days apart, giving a range of ages within a brood. This acts as a safeguard for the owls to fledge at least one chick, as it is not uncommon for the oldest chicks to prey upon the youngest in lean times. Happily in this case when the nest was checked again, six of the seven eggs hatched and all chicks were doing well three weeks after the first chick hatched.
In mid-September when the six chicks were aged between 40 to 50 days old, the birds were fitted with individually numbered rings, thus enabling us to determine the fate of these birds in the future and possibly giving us an idea of how far they disperse into the local landscape.
For all six chicks to reach this age suggests that there is a good supply of small rodents on which these birds prey upon. Here at Hope Farm, we have created a series of different field margins that are attractive to small mammals and in turn these margins used by birds such as barn owls and kestrels.
We expect that the first birds will fledge in late September or early October and we will keep you posted on the outcome.
If you'd like to build an owl box to encourage barn owls onto your your farm, find out how to build it and where to site it here.