Tyto

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Tyto
Temporal range: Late Miocene - Recent
Grass Owl adult.jpg
African grass owl, Tyto capensis
The "grass owls" are two rather long-legged species of Tyto.
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Tytonidae
Subfamily: Tytoninae
Genus: Tyto
Billberg, 1828
Species

About 20, see text

Synonyms

Lechusa Miller, 1956
Strix sensu auct. non Linnaeus, 1758 - preoccupied

The genus Tyto includes all barn owls (family Tytonidae) except for the bay owls (subfamily Phodilinae, genus Phodilus) - that is, the true barn owls, the grass owls and the masked owls collectively making up the subfamily Tytoninae. They are darker on the back than the front, usually an orange-brown colour, the front being a paler version of the back or mottled, although there is considerable variation even amongst species. Tyto owls have a divided, heart-shaped facial disc, and lack the ear-like tufts of feathers found in many other owls. Tyto owls tend to be larger than Bay-owls. The name tyto (τυτώ) is onomatopeic Greek for owl.

Throughout their evolutionary history, Tyto owls have shown a better capability to colonize islands than other owls. Several such island forms have become extinct, some long ago, but some in comparatively recent times. A number of insular barn-owls from the Mediterranean and the Caribbean were very large or truly gigantic species.

Systematics[edit]

Living and recently extinct species - and some notable subspecies - of barn owls are:

Early prehistoric extinctions[edit]

Known from ancient fossils

  • Tyto sanctialbani (Middle - Late Miocene of C Europe) - formerly in Strix, includes T. campiterrae
  • Tyto robusta (Late Miocene/Early Pliocene of Gargano Peninsula, Italy)
  • Tyto balearica (Late Miocene - Middle Pleistocene of WC Mediterranean)
  • Tyto mourerchauvireae (Middle Pleistocene of Sicily, Mediterranean)
  • Tyto jinniushanensis (Pleistocene of Jing Niu Shan, China)
  • Tyto sp. 1
  • Tyto sp. 2

Late prehistoric extinctions[edit]

Fossils of Tyto cavatica
Fossil of Tyto ostologa

Usually known from subfossil remains.
Melanesia:

Caribbean:

Mediterranean:

  • Maltese barn owl, Tyto melitensis (Malta) - formerly in Strix, possibly paleosubspecies of Tyto alba

Formerly placed in Tyto[edit]

A number of owl fossils were at one time assigned to the present genus, but are nowadays placed elsewhere. While there are clear differences in osteology between true owls and barn-owls, there has been parallel evolution to some degree and thus isolated fossil bones cannot necessarily be assigned to either family without thorough study. Notably, the genus Strix has been misapplied by many early scientists as a "wastebin taxon" for many owls including Tyto.[2]

  • "Tyto" antiqua (Late Eocene/Early Oligocene of Quercy? - Early Miocene of France) was a barn-owl of the prehistoric genus Prosybris; this taxon might be a nomen nudum as the species was originally described in Strix this requires confirmation.[3]
  • "Tyto" edwardsi (Late Miocene of Grive-Saint-Alban, France) was a strigid owl but has not yet been reliably identified to genus; it might belong into Strix or the European Ninox-like group[citation needed].
  • "Tyto" ignota (Middle Miocene of Sansan, France) was a strigid owl of unclear affinities; while it might belong into Strix this requires confirmation.[3]
  • "TMT 164", a distal left tarsometatarsus of a supposed Tyto from the Middle Miocene Grive-Saint-Alban (France) might also belong into Prosybris as it is similar to "Tyto" antiqua.[4]

Footnotes[edit]

  1. ^ a b Steadman (2006)
  2. ^ Mlíkovský (2002): p.217
  3. ^ a b Mlíkovský (2002)
  4. ^ Ballmann (1969)

References[edit]

  • Ballmann, Peter (1969): Les Oiseaux miocènes de la Grive-Saint-Alban (Isère) [The Miocene birds of Grive-Saint-Alban (Isère)]. Geobios 2: 157-204. [French with English abstract] doi:10.1016/S0016-6995(69)80005-7 (HTML abstract)
  • Bruce, M.D. (1999): Family Tytonidae (Barn-owls). In: del Hoyo, J.; Elliott, A. & Sargatal, J. (eds): Handbook of Birds of the World Vol. 5 (Barn-owls to Hummingbirds): 34-75, plates 1-3. Lynx Edicions, Barcelona. ISBN 84-87334-25-3
  • Mlíkovský, Jirí (2002): Cenozoic Birds of the World, Part 1: Europe. Ninox Press, Prague. ISBN 80-901105-3-8 PDF fulltext
  • Olson, Storrs L. (1985): Section IX.C. Strigiformes. In: Farner, D.S.; King, J.R. & Parkes, Kenneth C. (eds.): Avian Biology 8: 129-132. Academic Press, New York.
  • Steadman, David William (2006): Extinction and Biogeography of Tropical Pacific Birds. University of Chicago Press. ISBN 0-226-77142-3.