LC
Brown Fish-owl Ketupa zeylonensis



Justification

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). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to 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.

Population justification
The global population size has not been quantified, but the species is reported to be generally uncommon (del Hoyo et al. 1999). In Europe the population is estimated at 50-80 pairs, which equates to 100-160 mature individuals (BirdLife International 2015).

Trend justification
The population is suspected to be in decline owing to ongoing habitat destruction.

Ecology

This species is found in deciduous, semi-deciduous and open evergreen woodland as well as well-vegetated ravines, steep banks and canal sides, old plantations and groves with mature trees. It is almost always found near water. In the Middle East it occupies undisturbed wadis and valleys with trees and bushes in hilly areas. In China is uses streamside forest. It breeds between November and May in the Indian subcontinent and in Turkey juveniles are seen from June to July (Mikkola and Willis 1983, Holt et al. 2016). The species is thought to pair for life. Nests are built in hollows or depressions in trees, rock ledges or steep stream banks, normally near water. Old raptor nests are sometimes used as well. Clutch size is typically two. Its diet is mainly fish, frogs and freshwater crabs. It will also eat crayfish, snakes and lizards and occasionally rodents and birds. It hunts from perches overlooking water from where it swoops down and seizes prey from the water. It will also wade after food. This species is resident (Holt et al. 2016).

Threats

In Europe little is known of this species. It is apparent that locals have known of these birds for some time but not of their rarity and as a result, fish farm workers have shot them due to their food preference. Disturbance from humans, such as those wishing to see this rare species is a threat (van den Berg et al. 2010). Extirpation in Israel is thought to be as a result of mass poisoning of rodents in the 1950s by agricultural chemicals, as well as draining of Lake Hula and adjacent swamp, and pollution of rivers (Holt et al. 2016).

Conservation actions

Conservation Actions Underway
Bern Convention Appendix II. CITES Appendix II. Suggested it be named in Turkish as Yenger Bayku?u (Crab-owl) as opposed Balik Bayku?u (Fish-owl).

Conservation Actions Proposed
The areas where it resides should be protected from environmental changes such as logging and infrastructure development (van den Berg et al. 2010). Research into European population should continue. Local people could be educated on the rarity of this species and involved in its protection. To minimise disturbance to the small European population, controlled eco-tours should be developed and protected areas created where the species is found (van den Berg et al. 2010).

Acknowledgements

Text account compilers
Ashpole, J, Butchart, S., Ekstrom, J.


Recommended citation
BirdLife International (2020) Species factsheet: Ketupa zeylonensis. Downloaded from http://www.birdlife.org on 24/09/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/09/2020.