An East Yorkshire nature reserve has recorded its highest number of barn owl chicks in a single season.

Tophill Low Nature Reserve witnessed the extremely unusual sight of two separate sets of chicks being produced by the same parents in the same season, which means the Yorkshire Water-owned site has celebrated nine of the birds being born in the same box in the past few months.

The combination of a harsh winter in 2013 which resulted in a disastrous breeding season, and the ideal conditions over the past 12 months is thought to have resulted in the barn owl boom.

Richard Hampshire said: “We’ve never seen the same pair of owls produce two sets of chicks in the same season so we’re absolutely delighted to get this unexpected second set.

“The mild winter last year and warm temperatures over spring and summer have meant there’s lots of mice and voles around, which the owls love to eat, so the mating pairs will be having a good time of things.

“We think that’s why this year has been such a good one for barn owls and it really is the sort of season our region, and the bird-lovers within it, has been crying out for.”

Joanna Richards, of the Yorkshire Wildlife Trust said: “The success of barn owls at Tophill Low Nature Reserve is really something to celebrate and fits with the pattern that has been seen across Yorkshire this summer. Numbers had reached a concerning low in 2013, but the better weather has been kind to them, and numbers of voles, a key food item, have been high. Vole populations are cyclical in nature and this year was a boom year, which has aided the population growth.

“Places for barn owls to nest and roost had also created problems in recent years, with barn conversions and the removal of old trees reducing the number of nesting places traditionally used. Yorkshire Wildlife Trust has been able to put up a large number of barn owl boxes across Yorkshire, including along the River Hull valley, thanks to the support of members of public. This will hopefully provide sites for this year’s young to utilise next year, including those born at Tophill Low this summer.”