Owl butterfly
1828507
215541848
2008-05-28T17:39:53Z
200.172.123.196
{{Taxobox
| name = Owl butterflies
| image = Caligo Memnon Owl Butterfly.jpg
| image_width = 250px
| image_caption = ''[[Caligo memnon]]''
| regnum = [[Animal]]ia
| phylum = [[Arthropod]]a
| classis = [[Insect]]a
| ordo = [[Lepidoptera]]
| unranked_familia = [[Rhopalocera]]
| superfamilia = [[Papilionoidea]]
| familia = [[Nymphalidae]]
| subfamilia = [[Morphinae]]
| tribus = [[Brassolini]]
| genus = '''''Caligo'''''
| genus_authority = [[Hübner]], 1819
| type_species = ''Papilio eurilochus''
| type_species_authority = [[Pieter Cramer|Cramer]], 1775
| diversity = c.20 species
| diversity_link = Caligo
| subdivision_ranks = [[Species]]
| subdivision =
*''C. eurilochus'' species-group
**''[[Caligo eurilochus|C. eurilochus]]''
**''[[Caligo idomeneus|C. idomeneus]]''
**''[[Caligo illioneus|C. illioneus]]''
**''[[Caligo memnon|C. memnon]]''
**''[[Caligo prometheus|C. prometheus]]''
**''[[Caligo teucer|C. teucer]]''
*''C. arisbe'' species group:
**''[[Caligo arisbe|C. arisbe]]''
**''[[Caligo martia|C. martia]]''
**''[[Caligo oberthurii|C. oberthurii]]''
*''C. atreus'' species group:
**''[[Caligo atreus|C. atreus]]''
**''[[Caligo uranus|C. uranus]]''
*''C. oileus'' species-group
**''[[Caligo oedipus|C. oedipus]]''
**''[[Caligo oileus|C. oileus]]''
**''[[Caligo placidianus|C. placidianus]]''
**''[[Caligo zeuxippus|C. zeuxippus]]''
*''C. beltrao'' species-group
**''[[Caligo beltrao|C. beltrao]]''
*''[[incertae sedis]]''
**''[[Caligo euphorbus|C. euphorbus]]''
**''[[Caligo superbus|C. superbus]]''
}}
'''Owl butterflies''', of which there are around 20 different [[species]], are members of the genus '''''Caligo''''', in the [[brush-footed butterfly]] [[family (biology)|family]] [[Nymphalidae]]. They are found in the [[rainforest]]s and [[secondary forest]]s of [[Mexico]], [[Central America|Central]] and [[South America]].
[[Image:Owl Butterfly Two.JPG|thumb|left|200px|Underwing and upperwing pattern]]
The common name is derived from the presence of large "eyespots" ([[ocelli]]) on the underside of the hindwings. To a human observer of dead butterflies pinned up in a collection, owl butterflies' underwings resemble the head of an [[owl]] when the butterfly is held head down. It was speculated that the ocelli are "false eyes" to scare smaller birds that attempt to prey on the butterfly.
There is no evidence that the function of the ocelli is to resemble an owl. The position in which the owl-like appearance occurs is not generally assumed by the butterfly in life. In its resting position, ''Caligo'' [[butterflies]] settle down with closed wings like most butterflies, showing only one of the eyespots, and do not look owl-like.
The actual significance of the ocelli remains elusive (Stevens 2005). In some butterflies, particularly [[Satyrinae]] (such as the [[Gatekeeper Butterfly]] and the [[Grayling (butterfly)|Grayling]]), it has been shown that ocelli serve as a decoy, diverting bird attack away from the vulnerable body, and towards the outer part of the hindwings or the forewing tip. Owl butterflies have been observed with large chunks missing from their hindwings{{Fact|date=June 2007}}. On the other hand, decoy ocelli are almost always small and located near the margin of the wing, where the damage caused by a bird's beak would interfere little with the butterfly flying and going about its life. The position and size of the owl butterflies' ocelli makes them a decidedly suboptimal decoy, as they are far too close to the [[abdomen]] in resting position to ensure no substantial damage is inflicted by a bird snapping at them.
[[image:Caligo eurilochus 3 Richard Bartz.jpg|thumb|left|200px|[[Caligo eurilochus]]]]
The underwing pattern is highly [[crypsis|cryptic]]. Caligos typically rest on tree trunks and large branches, and at least to human observers, when seen from a distance, the eyespot and the surrounding dark area do not compromise their superb camouflage. As many birds are able to see in the [[ultraviolet]], more research is needed to determine how the eyespot pattern is perceived by the actual predators. In any case, at fairly close range the most visible thing about a resting owl butterfly is certainly a dark patch containing a single "false eye".
Owl butterflies are very large, and fly only a few metres at a time, so avian predators have little difficulty in following them to their settling place. However, the butterflies preferentially fly around dusk, when few avian [[predators]] are around (Freitas et al., 1995). Indeed, their main predators are apparently{{Fact|date=September 2007}} small [[lizard]]s such as ''[[Anolis]]''. It has been suggested{{Fact|date=September 2007}} that the hindwing underside pattern actually resembles the head of a large ''[[Hyla]]'' tree frog, which prey on ''Anolis''. This theory remains to be tested. It is known that many small animals hesitate to go near patterns resembling eyes with a light-colored [[iris (anatomy)|iris]] and a large [[pupil]], which matches the appearance of the eyes of many predators that hunt by sight{{Fact|date=September 2007}}. Thus, it is conceivable that the eye pattern is a generalized form of [[automimicry]] that would buy the butterfly time to escape from an approaching predator.
Some owl butterflies form leks in mating behavior (Srygley & Penz, 1999).
== Common names of some ''Caligo'' species ==
* ''Caligo euphorbus'' - Euphorbus Giant Owl
* ''Caligo eurilochus'' - Forest Giant Owl
**''Caligo eurilochus mattogrossensis'' - Forest Giant Owl
**''Caligo eurilochus livius'' - Forest Giant Owl
* ''Caligo idomeneus'' - Idomeneus Giant Owl
* ''Caligo idomeneus idomenides'' - Idomeneus Giant Owl
* ''Caligo illioneus'' - Illioneus Giant Owl
* ''Caligo oileus'' - Oileus Giant Owl
* ''Caligo placidianus'' - Placid Giant Owl
* ''Caligo teucer'' - Teucer Giant Owl
Source: Garwood, K. M., Lehman, Carter, W., & Carter, G. (2007). ''Butterflies of Southern Amazonia''. Mission, Texas: Neotropical Butterflies.
==References==
* Freitas, A. V. L., Benson, W. W., Marini Filho, O. J., & Carvalho, R. M. (1995). Territoriality by the dawn's early light: The neotropical owl butterfly ''Caligo idomenaeus'' (Nymphalidae: Brassolinae). ''Journal of Research on the Lepidoptera, 34''(1-4), 14-20.
* {{aut|Stevens, Martin}} (2005): The role of eyespots as anti-predator mechanisms, principally demonstrated in the Lepidoptera. ''[[Biological Reviews|Biol. Rev.]]'' ''80''(4): 573–588. <small>{{doi|10.1017/S1464793105006810}}</small> (HTML abstract)
* Srygley, R. B., & Penz, C. M. (1999). Lekking in neotropical owl butterflies, ''Caligo illioneus'' and ''C. oileus'' (Lepidoptera: Brassolinae). ''Journal of Insect Behavior, 12''(1), 81-103.
==External links==
*[http://www.richard-seaman.com/Insects/TrinidadAndTobago/Butterflies/OwlButterfly/ Pictures of an owl butterfly]
*[http://www.boldsystems.org/views/taxbrowser.php?taxid=7107 Taxonomy Browser] Upperside and underside photographs.
[[Category:Morphinae]]
[[de:Bananenfalter]]
[[es:Caligo]]
[[nl:Uilvlinder]]
[[pt:Borboleta-coruja]]