PICIDAE

The avian family 'Picidae' includes the woodpeckers, piculets and wrynecks. Members of this family are found worldwide, except for Australia, Madagascar, and the extreme polar regions. Most species live in forests or woodland habitats, although a few species are known to live in desert areas.
The Picidae is just one of the eight families in the order Piciformes. Members of the order Piciformes, such as the jacamars, puffbirds, barbets, toucans and honeyguides, have traditionally been thought to be very closely related to the woodpeckers, piculets and wrynecks. Recent molecular studies have strengthened this view.
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There are about over 200 species and about 30 genera in this family (for the full species list, see Woodpecker). Many species are threatened or endangered due to loss of habitat or habitat fragmentation. Two species of woodpeckers, the Ivory-billed Woodpecker and the Imperial Woodpecker, have been considered extinct for about 30 years (there has been some controversy recently whether these species still exist).
The smallest woodpecker is the Bar-breasted Piculet, at 7 g and 8 cm (3.2 inches). The largest woodpecker was the Imperial Woodpecker, at an average of 58 cm (23 inches) and probably over 600 g (1.3 lbs). The Ivory-billed Woodpecker is (or was) slightly smaller at 50 cm (20 inches) and a weight of 500 g (1.1 lbs). If both the Ivory-billed and Imperial Woodpeckers are indeed extinct, the largest extant woodpecker is the Great Slaty Woodpecker of Southeast Asia, at about 50 cm (20 inches) and 450 g (1 lb). Most species possess predominantly white, black and brown feathers, although many piculets show a certain amount of gray and olive green. In woodpeckers, many species exhibit patches of red and yellow on their heads and bellies. Although the genders of a species tend to look alike, male woodpeckers will have brighter reds and yellows than the females.
Members of the family Picidae have strong bills for drilling and drumming on trees and long sticky tongues for extracting food. Woodpecker bills are typically longer, sharper and stronger than the bills of piculets and wrynecks, however their morphology is very similar. Due to their smaller bill size, many piculets and wrynecks will forage in decaying wood more often than woodpeckers. The long sticky tongues, which possess bristles, aid these birds in grabbing and extracting insects deep within a hole of a tree.
Woodpeckers, piculets and wrynecks all possess zygodactyl feet. Zygodacytl feet consist of four toes, two facing frontward and two facing back. This type of foot arrangement is good for grasping the limbs and trunks of trees. Members of this family can walk vertically up a tree trunk, which is beneficial for activities such as foraging for food or nest excavation.
The diet of these birds consists mainly of insects, such as ants and beetles, nuts, seeds, berries, some fruit and sap. Species may feed generally on all of these, or may specialize on one or two.
All members of the family Picidae nest in cavities. Woodpeckers and piculets will excavate their own nests, but wrynecks will not. The excavated nest is usually only lined from the wood chips produced as the hole was made. Many species of woodpeckers excavate one hole per breeding season, sometimes after multiple attempts. It takes around a month to finish the job. Abandoned holes are used by many other birds and animals, such as flying squirrels.
Members of Picidae are typically monogamous. A pair will work together to help build the nest, incubate the eggs and raise their altricial young. However, in most species the male does most of the nest excavation and takes the night shift while incubating the eggs. A nest will usually consist of 2-5 round white eggs. Since these birds are cavity nesters their eggs do not need to be camouflaged and the white color helps the parents to see them in dim light. The eggs are incubated for about 11-14 days before the chicks are born. It takes about 18-30 days before the young are ready to leave the nest.
Picidae species can either be sedentary or migratory. Many species are known to stay in the same area year around while others, such as the Eurasian Wryneck and the Yellow-bellied Sapsucker, travel great distances from their breeding grounds to their wintering ground.

Contents

Systematics and evolution

Prehistoric taxa

Subfamily Nesoctitinae: Antillean Piculet

References

Systematics and evolution

The phylogeny has been updated according to new knowledge about convergence patterns and evolutionary history (Benz ''et al.'', 2006; Moore ''et al.'', 2006). Most notably, the relationship of the picine genera has been largely clarified, and it was determined that the Antillean Piculet is a surviving offshoot of proto-woodpeckers.
The evolutionary history of this group is not well documented, but the known fossils allow some preliminary conclusions: the earliest known modern picids were piculet-like forms of the Late Oligocene (c. 25 mya). By that time, however, the group was already present in the Americas and Europe, and it is hypothesized that they actually evolved much earlier, maybe as early as the Early Eocene (50 mya). The modern subfamilies appear to be rather young by comparison; until the mid-Miocene (10-15 mya), all picids seem to have been small or mid-sized birds similar to a mixture between a piculet and a wryneck. An enigmatic form based on a coracoid found in Pliocene deposits of New Providence, Bahamas, has been described as ''Bathoceleus hyphalus'' and probably also is a woodpecker (Cracraft & Morony, 1969).
Prehistoric forms of the extant genera are treated in the corresponding genus articles.

Prehistoric taxa

'Basal'

★ Genus ''Palaeopicus'' (Late Oligocene of France)

'Not assigned to subfamily'

★ Picidae gen. et sp. indet. (Middle Miocene of New Mexico, USA)

★ Picidae gen. et sp. indet. (Late Miocene of Gargano Peninsula, Italy)
===Subfamily Jynginae: Wrynecks===

★ Genus ''Jynx'' (2 species)
===Subfamily Picumninae: Piculets===
Genus ''Picumnus'' - American Piculets (c.27 species)
Genus ''Verreauxia'' - African Piculet (sometimes included in ''Sasia'')
Genus ''Sasia'' - Asian Piculets (2 species)

Subfamily Nesoctitinae: Antillean Piculet

★ Genus ''Nesoctites'' - Antillean Piculet
===Subfamily Picinae: Woodpeckers===
'Unassigned fossil forms'

★ Genus ''Palaeonerpes'' (Ogalalla Early Pliocene of Hitchcock County, USA) - possibly dendropicine

★ Genus ''Pliopicus'' (Early Pliocene of Kansas, USA) - possibly dendropicine

★ cf. ''Colaptes'' DMNH 1262 (Early Pliocene of Ainsworth, USA) - malarpicine?

'Tribe Dendropicini'

★ Genus ''Melanerpes'' (some 22 species)

★ Genus ''Sphyrapicus'' - sapsuckers (4 species)

★ Genus ''Xiphidiopicus'' - Cuban Woodpecker (Placement in Dendropicini tentative)

★ Genus ''Dendropicos'' (15 species)

★ Genus ''Dendrocopos'' (21 species)

★ Genus ''Picoides'' (presently 12 species; maybe only 3 belong here) - this genus is in need of revision (Moore ''et al.'', 2006). See the genus article for more.

★ Genus ''Veniliornis'' (14 species)

'Tribe Malarpicini'

★ Genus ''Campethera'' (12 species)

★ Genus ''Geocolaptes'' - Ground Woodpecker

★ Genus ''Dinopium'' - malarpicine flamebacks (4 species)

★ Genus ''Meiglyptes'' (3 species)

★ Genus ''Hemicircus'' (2 species; placement in Malarpicini tentative)

★ Genus ''Micropternus'' - Rufous Woodpecker (formerly in ''Celeus'')

'Tribe Picini'

★ Genus ''Picus'' (c.15 species)

★ Genus ''Mulleripicus'' (3 species)

★ Genus ''Dryocopus'' (7 species)

★ Genus ''Celeus'' (11 species)

★ Genus ''Piculus'' (7 species)

★ Genus ''Colaptes'' - flickers (about one dozen species)
'Tribe Megapicini'

★ Genus ''Campephilus'' (11 species, 2 possibly recently extinct)

★ Genus ''Chrysocolaptes'' - megapicine flamebacks (2 species)

★ Genus ''Reinwardtipicus'' - Orange-backed Woodpecker

★ Genus ''Blythipicus'' (2 species)

★ Genus ''Gecinulus'' (2 species; placement in Megapicini tentative)

★ Genus ''Sapheopipo'' - Okinawa Woodpecker (Placement in Megapicini tentative)

References

★ 'Benz', Brett W.; Robbins, Mark B. & Peterson, A. Townsend (2006): Evolutionary history of woodpeckers and allies (Aves: Picidae): Placing key taxa on the phylogenetic tree. ''Molecular Phylogenetics and Evolution'' '40': 389–399.

★ 'Cracraft', Joel & 'Morony', John J. Jr. (1969): A new Pliocene woodpecker, with comments on the fossil Picidae. ''American Museum Novitates'' '2400': 1-8. PDF fulltext

★ 'Johansson', U. S. & 'Ericson', G. P. (2003): Molecular support for a sister group relationship between Pici and Galbulae (Piciformes sensu Wetmore 1960). ''Journal of Avian Biology'' '34': 185-197. PDF fulltext

★ 'Koenig', W. D. & 'Haydock', J. (1999): Oaks, acorns, and the geographical ecology of acorn woodpeckers. ''J. Biogeogr.'' '26'(1): 159-165. (HTML abstract)

★ 'Lemaitre', J. & 'Villard', M. A. (2005): Foraging patterns of pileated woodpeckers in a managed Acadian forest: a resource selection function. ''Canadian Journal of Forest Research'' '35'(10): 2387-2393. HTML abstract

★ 'Michalek', K. G. & 'Winkler', H. (2001): Parental care and parentage in monogamous great spotted woodpeckers (''Picoides major'') and middles spotted woodpeckers (''Picoides medius''). ''Behaviour'' '138'(10): 1259-1285. (HTML abstract)

★ 'Moore', William S.; Weibel, Amy C. & Agius, Andrea (2006): Mitochondrial DNA phylogeny of the woodpecker genus ''Veniliornis'' (Picidae, Picinae) and related genera implies convergent evolution of plumage patterns. ''Biol. J. Linn. Soc.'' '87': 611–624. PDF fulltext

★ 'Stark', R. D.; Dodenhoff, D. J. & Johnson, E. V. (1998): A quantitative analysis of woodpecker drumming. ''Condor'' '100'(2): 350-356. PDF fulltext

★ 'Villard', P.; Cuisin, J. & Karasov, W. H. (2004). How do woodpeckers extract grubs with their tongues? A study of the Guadeloupe woodpecker (''Melanerpes herminieri'') in the French Indies. ''Auk'' '121': 509-514. DOI:10.1642/0004-8038(2004)121[0509:HDWEGW]2.0.CO;2 HTML abstract

★ 'Webb', Daniel Matthew & 'Moore', William S. (2005): A phylogenetic analysis of woodpeckers and their allies using 12S, Cyt ''b'', and COI nucleotide sequences (class Aves; order Piciformes). ''Molecular Phylogenetics and Evolution'' '36': 233-248. PDF fulltext

★ 'Wiebe', K.L. & 'Swift', T. L. (2001): Clutch size relative to tree cavity size in northern flickers. ''Journal of Avian Biology'' '32'(2): 167. (HTML abstract)

★ 'Wiktander', U.; Olsson, O. & Nilsson, S.F. (2000) Parental care and social mating system in the lesser spotted woodpecker ''Dendrocopos minor''. ''Journal of Avian Biology'' '31'(4): 447. (HTML abstract)

★ 'Yom-Tov', Y. & 'Ar', A. (1993): Incubation and fledging durations of woodpeckers. ''Condor'' '95'(2): 282-287. PDF fulltext