''Acanthiza'' is a genus of

passeriform A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped') which includes more than half of all bird species. Sometimes known as perching birds, passerines generally have an anisodactyl arrangement of their t ...

birds, most endemic to

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, but with two species (''A. murina'' and ''A. cinerea'') restricted to

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

. These birds are commonly known as thornbills. They are not closely related to species in the hummingbird genera '' Chalcostigma'' and ''

Ramphomicron ''Ramphomicron'' is a genus of hummingbird in the family Trochilidae Hummingbirds are birds native to the Americas and comprise the Family (biology), biological family Trochilidae. With approximately 366 species and 113 genus, genera, they ...

'', which are also called thornbills. They are found primarily in

and have a thin long beak. Colloquially the thornbill is sometimes referred to as a “tit” by locals, but in reality the Australian continent lacks any true tits, albeit ''Acanthiza'' species do show some similarities with tits in their behavior. They have a similar role as small insect-eating birds with titmice and kinglets. Like tits, Thornbills live in small groups foraging amidst trees and shrubs, and feed in a similar manner.

Cooperative breeding Cooperative breeding is a social system characterized by alloparental care: offspring receive care not only from their parents, but also from additional group members, often called helpers. Cooperative breeding encompasses a wide variety of group s ...

is recorded from most species except the brown and Tasmanian thornbills. The habitat preferences of the group vary from dense forest to open saltbush and bluebush plains. ''Acanthiza'' follow a very characteristic undulating path when flying. Their

diet Diet may refer to: Food * Diet (nutrition), the sum of the food consumed by an organism or group * Dieting, the deliberate selection of food to control body weight or nutrient intake ** Diet food, foods that aid in creating a diet for weight loss ...

is formed essentially of little

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s and plant lice that these birds glean from foliage. They are also exceptional acrobats that are easily able to stay head downward like tits do. The

nest A nest is a structure built for certain animals to hold Egg (biology), eggs or young. Although nests are most closely associated with birds, members of all classes of vertebrates and some invertebrates construct nests. They may be composed of ...

of the ''Acanthiza'' is a large dome-shaped construction, completely enclosed except for a side hole, just like that of the

long-tailed tit The long-tailed tit (''Aegithalos caudatus''), also named long-tailed bushtit, is a common bird found throughout Europe and the Palearctic. The genus name ''Aegithalos'' was a term used by Aristotle for some European tits, including the long-tail ...

; however ''Acanthiza'' adds to it an additional room whose function is unknown. It is somewhat similar to the

Aegithalidae The bushtits or long-tailed tits are small passerine birds from the family (biology), family Aegithalidae, containing 13 species in three genera, all but one of which (''Psaltriparus'') are found in Eurasia. Bushtits are active birds with long t ...

in combining long incubation periods with highly synchronous hatching. This combination, normally impossible due to intense competition for food, occurs because parents and (usually) helpers can organise food supply in such a manner that sibling competition for food is virtually absent.Ricklefs, Robert E.
“SIBLING COMPETITION AND THE EVOLUTION OF BROOD SIZE AND DEVELOPMENT RATE IN BIRDS”
/ref> The number of

eggs An egg is an organic vessel in which an embryo begins to develop. Egg, EGG or eggs may also refer to: Biology * Egg cell, the female reproductive cell (gamete) in oogamous organisms Food * Eggs as food Places * Egg, Austria * Egg, Switzerland ...

usually ranges from two to four, and the incubation period is around twenty days with laying intervals of two days. The length of an adult bird is .

Species

The genus contains 14 species:

References

* Del Hoyo, J.; Elliot, A. & Christie D. (editors). (2006). Handbook of the Birds of the World. Volume 12: Picathartes to Tits and Chickadees. Lynx Edicions.

External links

Acanthiza fotos & videos
on the Internet Bird Collection {{Taxonbar, from=Q481671 Bird genera Taxa named by Nicholas Aylward Vigors Taxa named by Thomas Horsfield