- Strix funereus Linnaeus, 1758
Boreal Owl, Tengmalm's Owl
IUCN: LC; Be (II); EUBD (I); CITES (II); RDBUkr: Рідкісні
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (extent of occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be fluctuating, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The global population is estimated to number > c.1,700,000 individuals which equates to 1,130,000 mature individuals (Rich et al. 2004). The European population is estimated at 90,900-309,000 pairs, which equates to 182,000-619,000 mature individuals (BirdLife International 2015). Europe forms approximately 26% of the global range, so a very preliminary estimate of the global population size is 700,000-2,380,000 mature individuals, although further validation of this estimate is needed. The population is placed in the band 700,000-2,400,000 mature individuals.
Trend Justification: The population is suspected to be fluctuating owing to fluctuations in prey populations. In Europe the population size is estimated to be fluctuating (BirdLife International 2015).