Nesting Pairs and Chicks Raised (2006-2021)

Here are the breeding results we have recorded in bar chart format.

Over the last 16 years the number of breeding pairs, although very variable, has slowly risen and in 2021 reached a new peak of 41.

In 2021 the number of surviving chicks was also much higher than average.  Even allowing for the fact there were more breeding pairs the success rate was above average. This would indicate that there was a plentiful food supply and favourable weather conditions. In 2020 and 2021 the breeding population may also have benefitted from reduced human interference due to the various COVID-1 9 restrictions. Another important factor, we feel, is our continual programme of maintenance of existing sites. Most of our work involves both repair of boxes and the barn roofs that protect those situated within farm buildings.

Average Number of Chicks per Pair (2006 - 2021)

This chart shows the average number of chicks raised by each pair.

The brood size over the years is 3.5. In both 2020 and 2021 the average chicks raised per pair was a remarkable 4.0 which is a very high figure compared to previous years. Indeed, this is one of the highest figures seen in the UK.

Survival rates are always higher in those years when there is a plentiful supply of mice and voles. When prey populations are low then this will affect the survival rates of chicks. The reasons for variation in mice and vole populations is not well understood.

Another factor is the weather. Owls need dry and quiet conditions in order to hunt. Wet and windy conditions usually means that hunting success falls to nearly zero. Extended periods of wet and windy weather will increase chick mortality rates.