Justification of Red List Category
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 decreasing, although the rate of decline does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to 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 size has not been quantified. This species has been described as rare overall, but is common in Misiones, Argentina (Holt et al. 2020).
The species is suspected to be in decline, mainly caused by habitat loss. A recent deforestation analysis found that tree cover loss within the species' range amounted to c. 10% over the past three generations ([16.8 years; Bird et al. 2020], Global Forest Watch 2021, using Hansen et al.  data and methods disclosed therein). Based on annual rates of tree cover loss over the past five years, this rate is projected to increase up to 12% over the next three generations (Global Forest Watch 2021, using Hansen et al.  data and methods disclosed therein). The species remains rare in some parts of its range (Holt et al. 2020) and it may also be subject to trade that could accelerate declines beyond the rate of habitat loss alone. Overall, the species is suspected to be declining at a rate of 10-19% over three generations.
Strix hylophila is a patchily-distributed, but locally common species occurring in the southern Atlantic Forest of Brazil (from Minais Gerais to Rio Grande do Sul), east and south Paraguay and extreme north-east Argentina (Holt et al. 2020).
The species is found in both lowland and montane forest from sea level to 1,810 m (Quintero & Jetz 2018, P. Dahal (unpublished 2021). It appears to naturally occur at low densities, and is considered highly sensitive to disturbance (Parker et al. 1996, Holt et al. 2020), although some observers report birds present in small (>6 ha), disturbed blocks of habitat (A. Bispo per F. Olmos in litt. 2003). The species may therefore also be found across secondary growth forests, degraded forests, and plantations, including forest edges (Holt et al. 2020).
The species' primary diet includes small mammals, birds, and insects, as well as reptiles and amphibians (Holt et al. 2020). Breeding seasons, although uncertain, are likely to be between December and mid-March (Holt et al. 2020).
The extent of habitat loss mainly through logging and burning throughout its range is likely to affect the species. In Paraguay, the species' range is largely restricted to the Paraná watershed, where virtually no forest cover now remains outside of a few poorly protected reserves. The species could be internationally traded; 28 records are found in the Species360 ZIMS Database, and it is known to be present in institutions outside of Brazil (B. Phalan in litt. 2022).
Conservation Actions Underway
CITES Appendix II. It has been recorded form a number of protected areas including Rio Doce State Park (Minais Gerais), Aparados da Serra National Park (Rio Grande do Sul), Itatiaia National Park, Serra da Cantareira State Park (São Paulo) and Iguazú National Park (Misiones) (del Hoyo et al. 1999, C. O. Gussoni per F. Olmos in litt. 2003, Holt et al. 2020). It is listed as nationally Vulnerable in Argentina (Aves Argentinas and Ministerio de Ambiente y Desarrollo Sustentable de la Nación 2015).
Text account compilers
Benstead, P., Olmos, F., Phalan, B., Sharpe, C.J. & Symes, A.
BirdLife International (2022) Species factsheet: Strix hylophila. Downloaded from http://www.birdlife.org on 27/11/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/11/2022.