Text: Triin Leetmaa, Urmas Sellis, Rein Nellis
We’re following the Eagle owl’s nest with a camera for the first time. Although in other parts of Europe the Eagle owls often nest on cliff ledges, in Estonia their nests usually are on the ground next to a stump or a tree trunk, but they can also use the nests of larger birds of prey or other platforms above the ground. There is one such place in Northern Estonia, where hopefully the Eagle owls will nest on an artificial nesting platform this year. The platform, visible in the camera, was built by Randar, who has been following this pair of Eagle owls for many years. Last year, this pair had no chicks, but they had been breeding successfully for several consecutive years before that.
The Eagle Owl is one of the most endangered bird species in Estonia. Population of 30-50 breeding pairs was estimated in 2019. It inhabits mostly the coastal areas of Estonia. In 2021, only four chicks were found in Estonian known nesting sites. Two out of four juveniles died before the winter. The Eagle owl is threatened by human disturbance during breeding season, low numbers of adult birds, abundance of prey and contamination of prey with toxins. The population is also declining in Estonian neighboring countries Finland and Latvia. According to the raptor monitoring schemes the number of breeding pairs in Finland has fallen by 3% a year since the mid-1990s. The Estonian trend is similar, but due to the small number of birds it is difficult to calculate the exact numbers.
The Eagle owls start nesting in February, when the breeding site for the year is chosen and courtship takes place. Very early broods may be laid already in the last days of February, but mostly the female lays 2-3, rarely 4 white eggs, in late March - early April. After 34-36 days incubation, the chicks hatch in late April or early May. The chicks will stay in the nest until mid-June, but they leave the nest before they can fly. Adults feed the young until September. The Eagle owls mainly eat small rodents (especially water voles) and birds ranging from passerine to geese. To a lesser extent also amphibians and reptiles are eaten.
The camera nest is located on the northern coast of Estonia, quite close to the road and farmhouses. Therefore, anthropogenic noises may be heard from time to time. Hopefully, an accidental passer-by will not scare the owls away. Adult birds here do not have rings, so we do not know their origin. The female is a little bigger, she doesn't hoot, but squeaks. We hear the male’s voice more often and also he has visited the nest more frequently so far.
It is possible to pan, tilt and zoom the camera, but we probably will not do it very often. Most of the interesting activities are expected to take place at the nest. It is difficult to find the roosting bird away from the nest as we cannot look above the camera. The camera and microphone are 7-8 meters away from the nest.
The camera is streamed through the Eagle Club Estonia’s YouTube channel (https://www.youtube.com/Kotkaklubi). We recommend following Kotkaklubi channel in case the broadcast needs to be restarted due to technical errors, which may change the direct link of the broadcast. Kotkaklubi channel also features all other nesting cameras of Estonian eagles and black storks, as well as a capercaillie camera.
The Eagle owl nest camera was set up at the beginning of March. We transmit the camera stream via 4G mobile internet, so in case of intensive network use, there may be interruptions in the transmission. The same can happen during maintenance work.
The preparation and recording of the camera signal for streaming takes place with the support of the Estonian Fund for Nature (https://elfond.ee). Events in the nest are documented by the viewers in Looduskalender forum (https://www.looduskalender.ee/forum). The use of the stream from the nest for non-commercial purposes is not prohibited, but please let us know if possible (send a message to urmas(ät)kotkas.ee). The Environmental Investment Centre (https://kik.ee/en) supports the purchase, installation, removal, maintenance and sharing of information of the Eagle owl camera.
Eagle Owl nest camera team and supporters:
Eagle Club – nest related actions, camera installation and information
Beta-Grupp – camera testing and setup, microphone construction, technical support
Looduskalender – forum on the Web
Estonian Fund for Nature - server support
Environmental Investment Center – financial support
Land owner Enno – enabled conditions for Eagle Owl breeding
Inspector Randar – security and survey
Thousands of viewers – The most important, because otherwise the cameras would not make much sense!