Animal Diversity Web

Ge­o­graphic Range

The Eurasian scops owl (Otus scops) has a very broad ge­o­graphic range. The non-breed­ing ge­o­graphic range is in Africa and in­cludes the west African coast from Sene­gal south­ward to Liberia, to the east African coast from Sudan south­ward to Kenya. The range con­tin­ues north­ward to the south­ern bor­ders of Mau­ri­ta­nia, Mali, Niger, Chad, and Sudan, and south­ward to the bor­ders of Cameroon and Kenya.

The breed­ing range en­com­passes three con­ti­nents: Eu­rope, Africa, and Asia. In Africa, it is found in parts of Mo­rocco, Al­giers, and Tunisia. In Eu­rope, it ranges as far west as Por­tu­gal to as far east as Greece. The area ex­tends north­ward to France and cen­tral Slove­nia in south­ern Eu­rope, and Es­to­nia in east­ern Eu­rope. The range ex­tends south­ward to Naples, Italy. In Asia, it ranges north­ward to St. Pe­ters­burg, Rus­sia and south­ward to Pak­istan. It is found as west as Turkey to as far east as Mon­go­lia. The breed­ing range is nearly ab­sent from Kaza­khstan.

Res­i­dent pop­u­la­tions are found in south­ern Eu­rope as far west as Spain and as far east as Cyprus. This area in­cludes the south­ern­most parts of Spain, Italy, Greece, and is­lands in the Mediter­ranean Sea. ("Otus scops", 2015; Denac, 2009)

• Biogeographic Regions
• palearctic
  • native
• ethiopian
  • native

Habi­tat

Eurasian scops owls are found in semi-open, arid land­scapes. Some pop­u­la­tions are a trans-Sa­ha­ran mi­grant found in sub-Sa­ha­ran sa­van­nah dur­ing the win­ter months. Breed­ing grounds typ­i­cally are open habi­tats, rich in in­sects, that in­clude large old trees with cav­i­ties. These owls also can breed in small wood­lots. They can be found in rocky, moun­tain­ous re­gions (such as the Alps), cul­ti­vated areas with groups of trees, and parks or gar­dens with ma­ture trees.

Scops owls can be found in a wide range of el­e­va­tions, from low-ly­ing areas to moun­tains, rang­ing from 65 to 3764 me­ters above sea level. (Denac, 2009; March­esi and Ser­gio, 2005; Mar­tinez, et al., 2007; Mikkola, 2012; Wink, et al., 2008)

• Habitat Regions
• temperate
• terrestrial

• Terrestrial Biomes
• savanna or grassland
• scrub forest
• mountains

• Other Habitat Features
• suburban
• agricultural

• Range elevation

  65 to 3764 m

  213.25 to 12349.08 ft

Phys­i­cal De­scrip­tion

The Eurasian scops owl has a mass of 60-135 grams with the fe­males typ­i­cally weigh­ing 15-25 grams more than the males. The wingspan ranges from 50-64 cen­time­ters and the length ranges from 16-21 cen­time­ters for both male and fe­male. It has rel­a­tively long wings and a short tail. Mostly liv­ing in trees, the scops owl is able to cam­ou­flage well with its grey­ish-brown feath­ers. The plumage looks like the bark of a tree, with black­ish streaks.

The owl has small ear tufts, vis­i­ble when on alert. The eyes are a bright yel­low while the bill is grey. The scops owl is feath­ered to the base of the grey toes that have dark-tipped grey-brown claws.

The downy chick is whitish. As it grows, the ju­ve­nile scops owl tends to re­sem­ble the adult, but the feath­ers are fluffier and have dis­tinct pat­tern mark­ings on the crown, upper back and breast. (Mikkola, 2012; Wink, et al., 2008)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• female larger

• Range mass

  60 to 135 g

  2.11 to 4.76 oz

• Range length

  16 to 21 cm

  6.30 to 8.27 in

• Range wingspan

  50 to 64 cm

  19.69 to 25.20 in

Re­pro­duc­tion

On its re­turn from its win­ter home, the mi­gra­tory male will begin to sing on calm nights. The non-mi­gra­tory males will start singing in Feb­ru­ary. Once a fe­male re­sponds, the pair will begin a duet and cop­u­la­tion fre­quently oc­curs there­after. After cop­u­la­tion, the male will fly off in search of a po­ten­tial nest­ing site. Once a cav­ity has been found, the male will sing from the open­ing, call­ing to the fe­male. The fe­male will come and in­spect the po­ten­tial nest be­fore ac­cept­ing the cav­ity. The scops owls are typ­i­cally monog­a­mous, but have also been seen to dis­play polyg­yny, where the male will have more than one fe­male part­ner. The pair will work to­gether to care for the young and de­fend the nest from in­trud­ers. (Blanco, et al., 2002; Wink, et al., 2008)

• Mating System
• monogamous
• polygynous

Eu­ro­pean scops owls breed once a year be­tween April through Au­gust. Nests can be found in nat­ural cav­i­ties found in trees, rocks or walls, holes in trunks or large branches from wood­peck­ers, or even under roofs. Nest-boxes also have been ac­cepted. The fe­males can lay up to six eggs per brood, but usu­ally pro­duces an av­er­age of three to four eggs. Fe­males begin lay­ing eggs in late April, di­rectly at the base of the tree cav­ity, at two day in­ter­vals. In­cu­ba­tion will begin after the sec­ond egg. The males will bring food to the fe­males while she is in­cu­bat­ing. Both sexes pro­tect the nest from in­trud­ers using vocal de­fense. The eggs will begin to hatch asyn­chro­nously over two to four days, after 20 to 31 days of in­cu­ba­tion. Brood re­duc­tion usu­ally oc­curs as a re­sult of com­pe­ti­tion be­tween sib­lings. The male and fe­male will feed and care for the brood for four to five weeks. Three to four weeks after hatch­ing, the fledg­lings will be able to leave the nest and climb into trees or bushes using its bills and claws, and flut­ter­ing with their wings, and will be­come in­de­pen­dent around four to five weeks old. Sex­ual ma­tu­rity for both sexes is reached at ten months of age.

In a study com­pleted by Blanco et al. (2002), 94% of the first-hatched chicks from first-laid eggs were male. Ev­i­dence that fe­males may ad­just the sex ratio of their off­spring has in­creased since mol­e­c­u­lar tech­niques for sex­ing nestlings have begun. A re­la­tion­ship has been found be­tween ovu­la­tion order and egg sex. The scops owl is slightly size-di­mor­phic, as the fe­males are born larger than the males, and there­fore take more en­ergy to raise. The sex ma­nip­u­la­tion most likely oc­curs dur­ing egg pro­duc­tion, as ma­nip­u­la­tion after hatch­ing would be risky and ex­pen­sive in re­sources. This may be achieved by plac­ing the ini­tial egg in the de­sired di­rec­tion, or due to the changes in hor­mones in the fe­male be­fore and after the first-laid egg. (Blanco, et al., 2002; Ga­le­otti and Sac­chi, 2001; Ga­le­otti, et al., 1997; Mar­tinez, et al., 2007; Mori, et al., 2014; Wink, et al., 2008)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• oviparous

• Breeding interval

  European scops owls breed once yearly

• Breeding season

  April-August

• Range eggs per season

  2 to 6

• Average eggs per season

  3-4

• Range time to hatching

  20 to 31 days

• Range fledging age

  3 to 4 weeks

• Range time to independence

  4 to 5 weeks

• Average age at sexual or reproductive maturity (female)

  10 months

• Average age at sexual or reproductive maturity (male)

  10 months

Parental in­vest­ment be­gins after the pair has ap­proved a nest­ing site. The pair will begin de­fend­ing their ter­ri­tory with vocal calls, and can be seen near the nest­ing site every night. After the fe­male lays the eggs, she alone will in­cu­bate, while the male will bring food to the nest. After hatch­ing, the fe­male will brood and feed the young for 18 days be­fore leav­ing the nest to help the male bring in food. The young are cared for, fed, and pro­tected by both par­ents until about four to five weeks old, when they are con­sid­ered in­de­pen­dent. (Blanco, et al., 2002; Wink, et al., 2008)

• Parental Investment
• altricial
• male parental care
• female parental care
• pre-hatching/birth
  • provisioning
    • male
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • male
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • male
    • female
  • protecting
    • male
    • female

Lifes­pan/Longevity

In a study by Boano and Sil­vano (2015), the max­i­mum age for the scops owl in the wild was 6 years and 8 months. In the study, a long-term mark-and-re­cap­ture ap­proach es­ti­mated the adult sur­viv­abil­ity. In cap­tiv­ity, in­di­vid­u­als can live up­wards of 12 years. (Boano and Sil­vano, 2015; Frans­son, et al., 2010; Mikkola, 2012)

• Range lifespan
  Status: wild

  6.7 (high) years

• Range lifespan
  Status: captivity

  >12 (high) years

Be­hav­ior

Eu­ro­pean scops owls are typ­i­cally soli­tary birds, but can form loose colonies. The owls will monog­a­mously pair dur­ing the breed­ing sea­son and polyg­yny can occur in rare in­stances. Once paired, both sexes will de­fend the ter­ri­tory through duet­ted vocal dis­plays against the in­truder. The egg-lay­ing and in­cu­ba­tion pe­riod will begin in late May to early July, and parental care will con­tinue through July and Au­gust. They cre­ate nests in cav­i­ties of old trees and build­ings.

The scops owls are noc­tur­nal, most ac­tive from after sun­set to mid­night. Both sexes are vocal and have sim­i­lar calls, while pitch for the fe­males is higher than the males. When there are preda­tors nearby, the owls will call out to alarm and alert oth­ers. Dur­ing the day, they can cam­ou­flage them­selves by con­ceal­ing their bod­ies against the bark of the tree. If ap­proached by a preda­tor, the owls can en­hance their cam­ou­flage, by stretch­ing their body and sway­ing back and forth to im­i­tate a branch.

These owls that live in the same vicin­ity as the lit­tle owl (Athene noc­tua) use this species’ alarm call as a warn­ing sign and to pro­vide greater pro­tec­tion. They will roost near the trunk of the tree or in tree cav­i­ties where their cam­ou­flage is most ef­fec­tive. The owl will perch in trees, near the roost­ing site, be­fore swoop­ing down to catch prey, typ­i­cally in­sects.

The ma­jor­ity of the in­di­vid­u­als will mi­grate to sub-Sa­ha­ran Africa dur­ing the win­ter due to de­creas­ing tem­per­a­tures, while some pop­u­la­tions have been found to re­main in cen­tral and south­ern Italy based on the mod­er­ate tem­per­a­tures year-round. The owls will re­turn to their breed­ing habi­tat in late March. ("Com­mon scops-owl (Otus scops)", 2015; Ga­le­otti and Sac­chi, 2001; Ga­le­otti, et al., 1997; Mar­tinez, et al., 2007; Wink, et al., 2008)

• Key Behaviors
• arboreal
• flies
• nocturnal
• motile
• migratory
• solitary
• territorial

Home Range

Mar­tinez et al. (2007) de­scribed the home range of the Eu­ro­pean scops owl as a 30-hectare area sur­round­ing the nest. The size of the core area is only 35 per­cent of the home range, a 10.5-hectare cir­cu­lar plot. (Mar­tinez, et al., 2007)

Com­mu­ni­ca­tion and Per­cep­tion

The hoot of the male Eu­ro­pean scops owl is a sin­gle syl­la­ble that lasts around 0.2 to 0.4 sec­onds and is re­peated every two to three sec­onds for tens of min­utes. The av­er­age fre­quency ranges from 1150 to 1450 Hertz. A fe­male hoot is sim­i­lar to that of the male, but is slightly higher pitched. When the scops owl is alarmed, both sexes will emit a loud and pierc­ing call, to alert oth­ers of the dan­ger.

The owl re­lies on ex­cel­lent hear­ing in order to hunt. An east­ern screech owl Otus asio in the same genus is able to de­tect and catch prey by hear­ing alone, so it is as­sumed that this is the same for the scops owl. The vi­sual ca­pa­bil­i­ties of the owl is poor. In typ­i­cal low light con­di­tions, these owls can only de­tect large ob­jects. (Drag­onetti, 2012; Hardouin, et al., 2009; Mar­tin, 2008; Mikkola, 2012; Wink, et al., 2008)

• Communication Channels
• visual
• tactile
• acoustic

• Other Communication Modes
• duets

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

The Eu­ro­pean scops owl is noc­tur­nal and mostly ac­tive be­tween sun­set and mid­night. It is in­sec­tiv­o­rous, prey­ing mostly on in­sects such as moths, grasshop­pers, ci­cadas, and bee­tles. Earth­worms and spi­ders are also eaten, as well as small ver­te­brates such as geckos, frogs, small birds, like the great tit (Parus major), or mice. Small birds and mam­mals make up only one per­cent of the scops owl diet.

The scops owl will swoop down and cap­ture in­sects using the beak. For slightly larger prey, the owl will swoop down from a perch and seize the ver­te­brate with the talons, and hold it in the toes of a raised foot while being con­sumed. (March­esi and Ser­gio, 2005; Mikkola, 2012; Wink, et al., 2008)

• Primary Diet
• carnivore
  • eats terrestrial vertebrates
  • insectivore
  • vermivore

• Animal Foods
• birds
• mammals
• amphibians
• reptiles
• insects
• terrestrial worms

Pre­da­tion

The tawny owl (Strix aluco) preys upon the Eu­ro­pean scops owl. This preda­tor may limit the dis­tri­b­u­tion that the scops owl is found, as the tawny owl is mainly a wood­land species, push­ing the scops owl to more grass­land areas. Ser­gio et al. (2009) com­pleted a study of the scops owl vo­cal­iza­tions, and found that tawny owls will try to am­bush un­sus­pect­ing in­di­vid­u­als. Hu­mans (Homo sapi­ens) are also thought to be a threat to the owl, as hunt­ing con­tin­ues along the mi­gra­tion routes in Italy and Malta. ("Otus scops", 2015; Ser­gio, et al., 2009)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • Strix aluco, tawny owl
  • Homo sapiens, humans

Ecosys­tem Roles

Eu­ro­pean scops owls are sec­ondary con­sumers be­cause they prey on in­sects and small ver­te­brates.

Cryp­tosporidio­sis, an oc­u­lar and res­pi­ra­tory dis­ease as­so­ci­ated with a par­a­sitic pro­tist (Cryp­tosporid­ium bai­leyi), has been found in scops owl fledg­lings born in the wild. In­fec­tion can occur due to in­hala­tion of the par­a­site. The fledg­lings de­velop necrotic plaques in their oral cav­i­ties, as a re­sult of a round­worm (Gongy­lonema). The in­fec­tion can af­fect the jaw­bone and lead to star­va­tion and death if not dis­cov­ered and prop­erly treated.

Par­a­sitic round­worms (Cen­trorhynchus alu­co­nis, Dis­phar­ynx na­suta, Syn­hi­man­tus affi­nis, Skr­jabinura spi­ralis, Sub­u­lura, and Choan­o­tae­nia lit­to­riae) have been found in scops owls in south­ern Italy. The pre­dom­i­nantly found species of round­worm was Syn­hi­man­tus affi­nis. These par­a­sites are likely ac­quired through in­ges­tion of in­fected prey.

A re­cently dis­cov­ered round­worm, (Sub­u­lura mackoi), has been found in the owl's colon and cae­cum.

Sero­log­i­cal tests have also re­cently dis­cov­ered the par­a­sitic pro­to­zoan, Tox­o­plasma gondii, in the owl. (Barus, et al., 2013; Cabezón, et al., 2011; Es­peron, et al., 2013; Molina-Lopez, et al., 2010; San­toro, et al., 2012)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Eu­ro­pean scops owls are hunted along mi­gra­tion routes in Malta and Italy, though the rea­sons for hunt­ing are un­known. ("Otus scops", 2015)

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There is no re­ported neg­a­tive eco­nomic im­por­tance for the Eu­ro­pean scops owl.

Con­ser­va­tion Sta­tus

The Eu­ro­pean pop­u­la­tion of scops owls is es­ti­mated at 463,000 to 785,000 in­di­vid­u­als, and counts across the en­tire range have been ex­trap­o­lated to 812,000-1,380,000. The IUCN Red List has listed this species as "Least Con­cern" due to the large range, while local pop­u­la­tion trends are not known. A de­cline has been seen in this species in de­vel­op­ing areas, most likely a re­sult of loss or frag­men­ta­tion of habi­tat and re­duc­tion of in­sects through the use of pes­ti­cides. In­crease in tawny owl (Strix aluco) pop­u­la­tions may lead to de­crease in this species. Hunt­ing, along mi­gra­tion routes in Malta and Italy, may also im­pact the species. The loss of habi­tat and suit­able tree cav­i­ties has been reme­died in var­i­ous coun­tries through the im­ple­men­ta­tion of ar­ti­fi­cial nest-boxes. Other pro­posed con­ser­va­tion ac­tions in­clude lim­it­ing the amount of highly toxic pes­ti­cides that could build up in in­sec­ti­vores, and pre­serv­ing ma­ture trees where scops owls have pre­vi­ously been found.

Scops owls have an Ap­pen­dix II sta­tus under CITES. Ap­pen­dix II sta­tus species are not threat­ened with ex­tinc­tion presently, but may be­come so if trade is not reg­u­lated. Pro­tec­tions in­clude re­quir­ing ex­port per­mits to bring the species out of the coun­try, in a man­ner that will min­i­mize any risk of in­jury, dam­age to health or cruel treat­ment. No ev­i­dence in trade of scops owls has been found.

Scops owls hold no spe­cial sta­tus in the United States be­cause they do not live there. ("Otus scops", 2015)

• IUCN Red List

  Least Concern

• US Migratory Bird Act

  No special status

• US Federal List

  No special status

• CITES

  Appendix II

Con­trib­u­tors

Danielle Lat­tanze (au­thor), Rad­ford Uni­ver­sity, Cari Mc­gre­gor (ed­i­tor), Rad­ford Uni­ver­sity, Zeb Pike (ed­i­tor), Rad­ford Uni­ver­sity, Karen Pow­ers (ed­i­tor), Rad­ford Uni­ver­sity, April Tin­gle (ed­i­tor), Rad­ford Uni­ver­sity, Jacob Vaught (ed­i­tor), Rad­ford Uni­ver­sity, Genevieve Bar­nett (ed­i­tor), Col­orado State Uni­ver­sity.

Ref­er­ences

2015. "Com­mon scops-owl (Otus scops)" (On-line). Wild­screen Arkive. Ac­cessed Feb­ru­ary 28, 2016 at http://​www.​arkive.​org/​common-scops-owl/​otus-scops/​.

BirdLife In­ter­na­tional. 2015. "Otus scops" (On-line). The IUCN Red List of Threat­ened Species 2015: e.T22688643A80484352. Ac­cessed Jan­u­ary 28, 2016 at http://​www.​iucnredlist.​org/​details/​22688643/​0.

Barus, V., S. Masova, B. Koubkova, J. Sitko. 2013. Sub­u­lura mackoi n. sp. (Ne­ma­toda: Sub­u­luri­dae) and the zoo­geog­ra­phy of sub­u­lurids par­a­sitiz­ing birds. Helmintholo­gia, 50/1: 46-56.

Blanco, G., J. Davila, J. Lopez Sep­tiem, R. Ro­driguez, F. Mar­tinez. 2002. Sex-bi­ased ini­tial eggs favours sons in the slightly size-dim­porhic scops owl (Otus scops). Bi­o­log­i­cal Jour­nal of the Lin­nean So­ci­ety, 76/1: 1-7.

Boano, G., F. Sil­vano. 2015. Adult sur­vival prob­a­bil­ity in a re­cov­ered pop­u­la­tion of scops owls Otus scops. Ardea, 103/2: 145-153.

Cabezón, O., I. García-Bo­cane­gra, R. Molina-López, I. Marco, J. Blanco, U. Höfle, A. Mar­gal­ida, E. Bach-Raich, L. Dar­wich, I. Echev­er­ria, E. Obón, M. Hernández, S. Lavín, J. Dubey, S. Almería. 2011. Seropos­i­tiv­ity and risk fac­tors as­so­ci­ated with Tox­o­plasma gondii in­fec­tion in wild birds from Spain.. PLoS ONE, 6/12: 1-7.

Denac, K. 2009. Habi­tat se­lec­tion of Eurasian scops owl Otus scops on the north­ern bor­der of its range, in Eu­rope. Ardea, 97/4: 535-540.

Drag­onetti, M. 2012. In­di­vid­u­al­ity in scops owl Otus scops vo­cal­iza­tions. Bioa­coustics, 16/2: 147-172.

Es­peron, F., M. Paz Mar­tin, F. Lopes, P. Ore­jas, L. Car­rero, M. Jesus Munoz, R. Alonso. 2013. Gongy­lonema sp. in­fec­tion in the scops owl (Otus scops). Par­a­sitol­ogy In­ter­na­tional, 62/6: 502-504.

Frans­son, T., T. Kolehmainen, C. Kroon, L. Jans­son, T. Wen­ninger. 2010. "EU­R­ING list of longevity records for Eu­ro­pean birds" (On-line). Ac­cessed March 17, 2016 at http://​www.​euring.​org/​data-and-codes/​longevity-list?​page=3.

Ga­le­otti, P., R. Sac­chi. 2001. Turnover of ter­ri­to­r­ial scops owls Otus scops as es­ti­mated by spec­tro­graphic analy­ses of male hoots. Jour­nal of Avian Bi­ol­ogy, 32/3: 256-262.

Ga­le­otti, P., R. Sac­chi, E. Perani. 1997. Co­op­er­a­tive de­fense and in­tra­sex­ual ag­gres­sion in scops owls (Otus scops): re­sponses to play­back of male and fe­male calls. Jour­nal of Rap­tor Re­search, 31/4: 353-357.

Hardouin, L., V. Bre­tag­nolle, P. Tabel, C. Bavoux, G. Bur­ne­leau, D. Reby. 2009. Acoustic cues to re­pro­duc­tive suc­cess in male owl hoots. An­i­mal Be­hav­iour, 78/4: 907-913.

March­esi, L., F. Ser­gio. 2005. Dis­tri­b­u­tion, den­sity, diet, and pro­duc­tiv­ity of the scops owl Otus scops in the Ital­ian Alps. Ibis, 147/1: 176-187.

Mar­tin, G. 2008. Sen­sory ca­pac­i­ties and the noc­tur­nal habit of owls (St­rigi­formes). In­ter­na­tional Jour­nal of Avian Sci­ence, 128/2: 266-277.

Mar­tinez, J., I. Zubero­goitia, J. Mar­tinez, J. Za­bala, J. Calvo. 2007. Pat­terns of ter­ri­tory set­tle­ment by Eurasian scops-owls (Otus scops) in al­tered semi-arid land­scapes. Jour­nal of Arid En­vi­ron­ments, 69/3: 400-409.

Mikkola, H. 2012. Owls of the World: A Pho­to­graphic Guide. Buf­falo, NY: Fire­fly Books.

Molina-Lopez, R., A. Ramis, S. Mar­tin-Vazquez, H. Gomez-Couso, E. Ares-Maza, S. Cac­cio, M. Leiva, L. Dar­wich. 2010. Cryp­tosporid­ium bai­leyi in­fec­tion as­so­ci­ated with an out­break of oc­u­lar and res­pi­ra­tory dis­ease in otus owls (Otus scops) in a re­ha­bil­i­ta­tion cen­tre. Avian Pathol­ogy, 39/3: 171-176.

Mori, E., M. Menchetti, F. Fer­retti. 2014. Sea­sonal and en­vi­ron­men­tal in­flu­ences on call­ing be­hav­ior of Eurasian scops owls. Bird Study, 61/2: 277-281.

San­toro, M., S. Mat­tiucci, G. Nascetti, J. Kin­sella, F. Di Prisco, S. Troisi, N. D’Alessio, V. Veneziano, F. Aznar. 2012. Helminth com­mu­ni­ties of owls (St­rigi­formes) in­di­cate strong bi­o­log­i­cal and eco­log­i­cal dif­fer­ences from birds of prey (Ac­cip­itri­formes and Fal­coni­formes) in South­ern Italy. PLoS ONE, 7/12: 1-13.

Ser­gio, F., L. March­esi, P. Pedrini. 2009. Con­ser­va­tion of scops owl Otus scops in the Alps: re­la­tion­ships with grass­land man­age­ment, pre­da­tion risk and wider bio­di­ver­sity. Ibis, 151/1: 40-50.

Seruca, C., R. Molina-Lopez, T. Pena, M. Leiva. 2012. Oc­u­lar con­se­quences of blunt trauma in two species of noc­tur­nal rap­tors (Athene noc­tua and Otus scops). Vet­eri­nary Oph­thal­mol­ogy, 15/4: 236-244.

Wink, M., K. Konig, F. Weick. 2008. Owls of the World. New Haven & Lon­don: Yale Uni­ver­sity Press.