Caligo

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Ecdysozoa
Cladus: Panarthropoda
Phylum: Arthropoda
Subphylum: Hexapoda
Classis: Insecta
Cladus: Dicondylia
Subclassis: Pterygota
Cladus: Metapterygota
Infraclassis: Neoptera
Cladus: Eumetabola
Cladus: Endopterygota
Superordo: Panorpida
Cladus: Amphiesmenoptera
Ordo: Lepidoptera
Subordo: Glossata
Cladus: Coelolepida
Cladus: Myoglossata
Cladus: Neolepidoptera
Infraordo: Heteroneura
Cladus: Eulepidoptera
Cladus: Ditrysia
Cladus: Apoditrysia
Cladus: Obtectomera
Superfamilia: Papilionoidea

Familia: Nymphalidae
Subfamilia: Morphinae
Tribus: Brassolini
Subtribus: Brassolina
Genus: Caligo
arisbe Species Group
Caligo martia

Species (3): C. arisbe – C. martia – C. oberthurii
atreus Species Group

Species (2): C. atreus – C. uranus
beltrao Species Group
Caligo beltrao

Species (1): C. beltrao
eurilochus Species Group

Species (9): C. bellerophon – C. brasiliensis – C. eurilochus – C. idomeneus – C. illioneus – C. prometheus – C. suzanna – C. telamonius – C. teucer
oileus Species Group

Species (4): C. oedipus – C. oileus – C. placidianus – C. zeuxippus
unknown Species Group

Species (2): C. euphorbus – C. superbus
Name

Caligo Hübner, 1819
Synonyms

Hamadryas Mikan, 1821 [ junior homonym ]
Pavonia Godart, 1824
Aerodes Billberg, 1920

Type species: Papilio eurilochus Cramer, 1775
References

Brévignon, C. 2005: Description de nouveaux Brassolinae provenant de Guyane française. (Lepidoptera: Nymphalidae). Lambillionea, 105(2) (Tome II): 314–318. Reference page.
Lamas, G. 2004. (ed.) Checklist: Part 4A. Hesperioidea - Papilionoidea. In Heppner, J.B. (ed.) Atlas of Neotropical Lepidoptera. Vol.5A, Pt.4A. Assn. for Tropical Lepidoptera/Scientific Publishers, Gainesville. 439pp. Reference page.

The owl butterflies are species of the genus Caligo and are known for their huge eyespots, which resemble owls' eyes. They are found in the rainforests and secondary forests of Mexico, Central and South America.

Owl butterflies are very large, 65–200 mm (2.6–7.9 in), and fly only a few meters at a time, so avian predators have little difficulty in following them to their settling place. However, the butterflies preferentially fly in dusk, when few avian predators are around.[1] The Latin name may possibly refer to their active periods; caligo means darkness.

Some owl butterflies form leks in mating behavior.[2]

Species

Listed alphabetically within groups:[3]

There are some twenty species in this genus, which can be divided into six groups that might constitute subgenera. Some species are of uncertain placement with regard to these groups, however:

C. eurilochus species group
Caligo bellerophon Stichel, 1903
Caligo brasiliensis (C. Felder, 1862) – Brazilian owl, almond-eyed owl[4]
Caligo eurilochus (Cramer, [1775]) – forest giant owl
Caligo idomeneus (Linnaeus, 1758) – Idomeneus giant owl
Caligo illioneus (Cramer, [1775]) – Illioneus giant owl
Caligo memnon (C. & R. Felder, [1867]) – giant owl, pale owl
Caligo prometheus (Kollar, 1850)
Caligo suzanna (Deyrolle, 1872)
Caligo telamonius (C. & R. Felder, 1862) – yellow-fronted owl[4]
Caligo teucer (Linnaeus, 1758) – Teucer giant owl
C. arisbe species group:
Caligo arisbe Hübner, [1822]
Caligo martia (Godart, [1824])
Caligo oberthurii (Deyrolle, 1872)
C. atreus species group:
Caligo atreus (Kollar, 1850) – yellow-edged giant owl
Caligo uranus Herrich-Schäffer, 1850 – yellow-bordered owl[4]
C. oileus species group
Caligo oedipus Stichel, 1903 – boomerang owl[4]
Caligo oileus C. & R. Felder, 1861 – Oileus giant owl
Caligo placidianus Staudinger, 1887 – placid giant owl
Caligo zeuxippus Druce, 1902
C. beltrao species group
Caligo beltrao (Illiger, 1801) – purple owl
incertae sedis
Caligo euphorbus (C. & R. Felder, 1862) – Euphorbus giant owl
Caligo superbus Staudinger, 1887

Caligo idomeneus - MHNT

Caligo teucer - MHNT

Caligo oedipus

Caligo telamonius
in Costa Rica

Functions of the wing pattern
Close-up of a Caligo wing

The underwing pattern is highly cryptic. It is conceivable that the eye pattern is a generalized form of mimicry. It is known that many small animals hesitate to go near patterns resembling eyes with a light-colored iris and a large pupil, which matches the appearance of the eyes of many predators that hunt by sight.[5]

According to the Batesian mimicry theory the pattern on the wings of Caligo resemble the head of a predator like a lizard or an amphibian. It should deter predators while resting, feeding, mating, or emerging from the pupa.

The role of eyespots as antipredator mechanisms has been discussed since the 19th century. Several hypotheses are suggested to explain their occurrence.[6] In some butterflies, particularly Satyrinae (such as the gatekeeper butterfly and the grayling), it has been shown that ocelli (eyespots) serve as a decoy, diverting bird attack away from the vulnerable body, and towards the outer part of the hindwings or the forewing tip.

Research of Stevens et al. (2008), however, suggests that eyespots are not a form of mimicry and do not deter predators because they look like eyes. Rather the conspicuous contrast in the patterns on the wings deter predators.[7] In this study, however, the influence of surrounding forms, like the head region of a predator, was not tested. Also the question why animals evolved such complex imitations of other species is left unanswered.
References

André V. L. Freitas; Woodruff W. Benson; Onildo J. Marini-Filho; Roberta M. de Carvalho (1995). "Territoriality by the dawn's early light: The neotropical owl butterfly Caligo idomenaeus (Nymphalidae: Brassolinae)" (PDF). Journal of Research on the Lepidoptera. 34 (1–4): 14–20. Archived from the original (PDF) on 2016-03-03. Retrieved 2009-10-15.
Robert B. Srygley & Carla M. Penz (1999). "Lekking in neotropical owl butterflies, Caligo illioneus and C. oileus (Lepidoptera: Brassolinae)". Journal of Insect Behavior. 12 (1): 81–103. doi:10.1023/A:1020981215501. S2CID 30918158.
"Caligo Hübner, [1819]" at Markku Savela's Lepidoptera and Some Other Life Forms
Glassberg, J. (2007). A Swift Guide to the Butterflies of Mexico and Central America. Sunstreak Books. p.132.
Sebastiano De Bona, Janne K. Valkonen, Andrés López-Sepulcre, Johanna Mappes (2015). "Predator mimicry, not conspicuousness, explains the efficacy of butterfly eyespots". Proceedings of the Royal Society B: Biological Sciences. 282 (1806): 20150202. doi:10.1098/rspb.2015.0202. PMC 4426626. PMID 25854889.
Martin Stevens (2005). "The role of eyespots as anti-predator mechanisms, principally demonstrated in the Lepidoptera". Biological Reviews. 80 (4): 573–588. doi:10.1017/S1464793105006810. PMID 16221330. S2CID 24868603.

Martin Stevens, Chloe J. Hardman & Claire L. Stubbins (2008). "Conspicuousness, not eye mimicry, makes "eyespots" effective antipredator signals". Behavioral Ecology. 19 (3): 525–531. doi:10.1093/beheco/arm162.