March First Egg Dates

Full Breeding Mode

Little Owls are in full breeding mode so this is an excellent time of year to seek them out. The adult birds are very vocal at this time of year, particularly at dusk, and they are more likely to be seen in daylight hours as they try to keep up with the rising food demands of their fast-growing chicks. You can familiarise yourself with different adult and juvenile calls if you click here.

As expected, April nest box checks showed that some Little Owls have bred earlier than average in 2014. A box was checked on the 25 April and it contained four nestlings, which were three to five days old. You would usually expect to find a partial or full clutch around mid to late April. This pair’s first egg date was in March, which is very early for Little Owls!

Early first egg dates have been observed in many avian species in 2014, including Barn Owl and Tawny Owl. The mild winter and spring weather meant that prey numbers were higher earlier on in the year, which allowed some females to reach breeding condition earlier than usual. Some females are still incubating their eggs and I will provide a more detailed summary of Little Owl first egg dates and productivity data later on this year. If you monitor Little Owl nest sites, don’t forget to submit your data to the BTO’s Nest Record Scheme, details of which can be found here.

As Little Owls are in the midst of their breeding season, I thought I would take this opportunity to describe this species’ courtship behaviour, timing of breeding and incubation duration.

The Little Owl is a primarily monogamous species and pairs usually occupy the same territory throughout the year. Territory size can vary in relation to seasonal changes in prey abundances. The breeding season begins between January and March, which is when the male bird becomes more territorial and pair bonding starts.

Egg laying usually begins from mid-April onwards, with most first egg dates falling between the 11 April and 8 May 20141. Eggs are usually laid on alternate days and as an example, it would take a female Little Owl seven days to lay four eggs. With an average clutch size of three or four eggs and incubation duration of 30 days, first hatch dates are usually from mid-May onwards.

little_owl_chick_catherine_cotton
Photo | © Catherine Cotton

This is a close-up photo of a pre-fledging chick age c. 18 days old. You can still see its fluffy white down with brown colourings emerging, and this chick branched seven days later. Little Owl nestlings and fledglings are very vocal and on a warm and clear summer evening, their begging calls can travel quite a distance across several fields.

We are just weeks away from the first emergence of grey, fluffy chicks from their natal sites. So remember to look and listen out for them and add your sightings to this website!

  1. Robinson, R.A. 2005 | BirdFacts: profiles of birds occurring in Britain & Ireland BTO Research Report 407. BTO, Thetford | bto.org/birdfacts, accessed on 08/05/2014

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