Climate change could deprive pygmy owls feed stocks from which these birds depend in winter. As found by Finnish ornithologists, the more rain falls during autumn, the higher the risk that the supply of food rots. This, in turn, reduces the chances of owl survival. Because global warming leads to increased precipitation in high latitudes, at some time in the future storage of feed will cease to justify themselves. However, it is unknown whether pygmy owls to abandon this behavior or continue to waste energy on him. The results of a study published in the journal Global Change Biology.
Winter — a serious test for animals living in a temperate climate. To survive difficult times, some of them since the autumn of create food stocks are used in the following months. For example, pygmy owls (Glaucidium passerinum), the smallest owl from the forests of Northern Eurasia, produce many small birds and mammals and store them in secluded places like tree holes. Due to the low temperatures, these reserves are stored all winter and the owls serve as a reserve source of food.
Unfortunately, due to global warming the winter air temperature often rises above zero. During the thaw “refrigerators” owls don’t work, so that stocks can quickly deteriorate. A team of ornithologists led by Julia Matera (Giulia Masoero) from the University of Turku decided to find out how little owls cope with this problem.
The research focused on the population that lives near the town of Kauhava in Western Finland and uses for nesting and storage of artificial bird houses. From 2003 to 2018 scientists three times a year checked the quantity and condition of inventory: in late October — early November, late November — early December and late March — early April. Only during work were analyzed 702 “fridge”, which belonged to 354 individuals. To know individual birds helped ring and tag.
Information on stocks compared with the data on air temperature, precipitation and snow depth during three periods: from the first to the thirtieth of October, that is to start collecting food; from 15 November to 15 December, when a major part of the reserves; and from December 15 to March 15, when owls eat stored food. In addition, the analysis added the results of the population census is the main food of owls — red (Myodes glareolus) and grey voles (Microtus).