Owls in Estonia

Twelve different species of owls have been registered in Estonia. The following species are regular breeders: Tawny Owl, Tengmalm’s Owl, Short-eared Owl, Long-eared Owl, Ural Owl, Pygmy Owl and Eagle Owl. Winter visitors Hawk Owl and Great Grey Owl have also nested on occasion. The Snowy Owl is an irregular winter visitor, and the Barn Owl and Little Owl are vagrants.

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Tawny Owl (Strix aluco) has been chosen as the Bird of the Year for 2009 by the Estonian Ornithological Society. It inhabits Estonian cultural landscapes including parks, cemeteries, and forest patches between fields. The species is widespread in the western part of the country and on the islands. Tawny owls have occupied 10% of the nest boxes which have been placed for them. There are two plumage colour morphs of the Tawny Owl – grey and light brown. Studies carried out in Estonia between 1977 and 1990 of 251 adult birds have shown a slight majority of grey birds – 54,6% – in comparison with light brown – 45,4%. In the Bird of the Year project the Ornithological Society will pay significant attention to the distribution of tawny owls with different colorations in Estonia.

The number of breeding pairs of the Tawny Owl has been estimated at 1000-2000 between the years 2003-2007. The average population density is 3.5 pairs per 100 km2. Approximately 3000-6000 birds winter in Estonia. Between the years 1922 and 2007, 1394 birds were banded. The first ringing of the Tawny Owl was done in 1937. There have been 48 recoveries of the Tawny Owl, whereas 2 birds have flown out of Estonia to northern Latvia. One banded bird from Finland and one from Latvia have entered Estonia. According to banding data, 18% of banded Tawny Owl nestlings perish within their first year of life. The oldest banded tawny owl wore its ring for 6 years, 10 months and 6 days.

Klaara and Klaus, 2009:
The first egg was observed on March 01 2009, and by March 11 2009 there were a total of 5 eggs. On March 22 2009, an egg was stolen by a pine marten. The first egg hatched on April 04 2009 and by April 06 2009 all the eggs had hatched. The first owlet left the nest on May 05 2009 and by May 09 2009 the nest was empty.

The location of the nest was in a tree next to a road, and traffic noise was often evident. Numerous birds visited the nest entrance and the following were observed/captured on screen shots: Woodpecker, Nuthatch, Tit, Starling, Blackbird. A spider also built a web at one point, partially obscuring the camera. One time, a passing cat was caught by a forum watcher.

Once the owlets had hatched, Klaara and Klaus turned into prodigious hunters, and the nest was often littered with dead rodents. One screen shot showed 3 mouse/rat tails. Both parents dropped off prey, and sometimes both visited the young at the same time. One night, 19 food drops were observed. Food seemed to consist of mice, rats, voles, birds and frogs. It was noted both owls looked after the chicks, Klaaus often coming to the nest when Klaara was out, and occasionally both owls were in the nest together.

2010
The first egg was observed on April 06 2010, and by April 14 2010 there were a total of 4 eggs. The first egg hatched on May 07 2010 and by May 12 2010 all the eggs had hatched. Only one owlet survived to fledge, leaving the nest on June 10 2010.

The location of the nest was the same as in 2009, in a tree next to a road, and traffic noise was often evident.
The winter of 2009/2010 was particularly harsh in Estonia; temperatures were very cold and there was a lot of snow, which remained on the ground for longer than normal. Spring was delayed by at least one month, which in turn delayed the mating season by one month. The hard winter led to a reduced food supply and small mammals and birds were hard to come by for the owls once they had to hunt for their offspring. There seemed to be a lot of insects/parasites/flies in the nest this year. The death of three of the owlets was attributed to parasites and starvation.
Biggie spent 10 days in the nest by himself before fledging. During this time, he was observed burying the body of his dead brother, dancing around, stretching, sleeping (a lot!) and climbing up and down to the entrance continuously towards the end of the watching period. He spent a lot of time calling to his parents. Perhaps in an effort to get him to fledge, the parents would often ‘tease’ him by showing him food and then leaving with it. Biggie proved to have quite the personality and although the times between feedings grew longer and longer, he managed to get his parents to feed him up until the day he left.
This year the camera was available in colour, which sometimes worked and sometimes did not. However, all screen captures were of excellent quality, and high-quality photographs and videos were posted by the forum users. One of the benefits of the colour camera was that forum users were able to see the owlets had ‘pink spots’ on their bodies as their feathers grew in, which could not be observed last year.

Unlike last year when many species of birds were observed visiting the nest, the only reported bird this year to visit was a starling.
After the first egg was laid, Klaara would often leave the nest to hunt. It was not until all four eggs were laid that she began to incubate them. There was a definite lack of food this season, and at no point were more than 5 prey observed in the nest; there was certainly not the ‘food larder’ that we saw in 2009. Prey consisted of moles, mice, birds and frogs. Both owls hunted and fed their offspring.