Juice delicious

Juice delicious
Yellow-bellied juice tasty
Systematics
Class : Birds (aves) Order : Woodpecker birds (Piciformes) Family : Woodpeckers (Picidae) Subfamily : Real woodpeckers (Picinae) Genre : Juice delicious
Scientific name
Sphyrapicus
Baird , 1858

The Saplecker ( Sphyrapicus ) form a genus of small to medium-sized woodpeckers in the family of the woodpeckers (Picidae). The genus includes four species whose occurrence is restricted to North America. The Saftlecker, in English sapsuckers get their name from the special, specialized way in which they obtain part of their food.

The yellow-bellied sap-lickers , the red-naped sap-lickers and the fiery-head sap-lickers form the superspecies Sphyrapicus varius ; until 1983 they were grouped together in a single type. The fourth species, the pine sap liqueur , has a clear genetic distance from the varius group. Where the distribution limits of the individual species of the S. varius group overlap, hybrids appear that show the characteristics of the parent species in different degrees of clarity and gradation.

Saftlecker colonize different tree communities, especially in western North America. Only the distribution area of ​​the yellow-bellied juice lick also reaches the North American east coast. They are resident birds , short-range or medium-range migrants . Their occurrences extend vertically from sea level to near the regional tree lines. Outside of the breeding season, they mainly feed on tree sap, which they obtain from mostly small sap holes cut into the wood. Insects are the main food during the breeding season. Insects are also the rearing food for the young.

The genus Sphyrapicus was separated from a genus Picus in 1858 by Spencer Fullerton Baird , in which many different species of woodpecker and genera were united. The generic epithet is formed from the Greek σφύρα (hammer, chisel) and Latin picus (woodpecker).

None of the four species currently appear in an endangerment category. Their population is considered to be largely stable, and regionally they are frequent breeding birds.

features

Sphyrapicus ruber

Sphyrapicus nuchalis

Sphyrapicus thyroideus

Small to medium-sized woodpeckers are sap-loving. Yellow-bellied juices and red-naped juices are the two smallest species with a maximum body length of 21 centimeters. The Feuerkopf-Saftlecker is only slightly larger. At 23 centimeters, the pine sap delicious just about the size of the great spotted woodpecker . All sap eaters are slender and easily built birds. They are much lighter than woodpeckers of comparable size such as the middle or great spotted woodpecker . The weight of the woodpeckers from the S. varius group is between 36 and 62 grams, the pine sap tasty weighs a maximum of 64 grams.

Woodpeckers of the S. varius  group are quite similar to one another in terms of the color of their body plumage. The upper side is essentially black with white inclusions of varying degrees, the belly on a gray-white background with dark dashed lines or drawn like an arrowhead. The upper part of the abdomen is light yellow in the case of the yellow-bellied juice lick, and pale reddish in the case of the fire-headed juice lick. The elongated white wing field typical of the genus is the only characteristic that all four species have in common. The coloring of the head, throat and breast plumage is very different, especially the red components vary considerably from species to species. The yellow-bellied juice tick shows the least red, most of the fire-head juice tick, in which the entire head, the neck and throat and the chest area are colored red. Males and females of the fire-headed sap litter are largely monomorphic, in the other two species the sexual dimorphism is limited to the color of the head, especially the distribution of the red components. Differences in size and weight between the sexes are marginal.

Of these three types of sap lickers, the males of the pine sap lickers differ considerably. The head and top of these are essentially black, only the throat is red. The male's belly is yolk yellow. The color dimorphism is so pronounced that for a long time males and females were mistaken for representatives of different species. Aside from their different sizes, females are very similar to female Gilaspeckers .

All juice treats are zygodactyl . They have a broad, chisel-like pointed, mostly slate-gray beak at the base. The iris of the eyes is dark brown, the featherless area of ​​the legs and toes are gray.

Vocalizations

Juice lovers are acoustically very present, especially in the periods of courtship and territorial establishment. They have a number of different species-typical calls. Characteristic for all juice lovers is the drumming, which starts with a fast drum roll and ends with a few, irregular single beats.

behavior

Activity and rest

Like all woodpeckers, juice lovers are diurnal. Your activity phase corresponds to the brightness of the day. The woodpeckers from the varius group spend the night clinging to the trunk under a strong branch, while the pine sap delicacies in natural tree hollows or their own sleeping hollows. During the day, the woodpeckers take long breaks in activity, especially around lunchtime, which they doze off or take care of their plumage.

Move

Male yellow-bellied juice tasty while eating berries

All juice lovers hop on both legs, clinging to the trunk or branch surface both vertically and horizontally on trunks and branches. Especially during courtship and in agonistic situations, they jump up the trunk in a screwy manner. To harvest fruits or berries, they also cling to very thin branches. The flight is the typical arched woodpecker flight with a series of strong, fast wing beats in the upward phase and fully applied wings in the downward phase. The flight of the juice-lovers is quick and agile; with skillful, quick turns, they can prey on insects in flight.

Comfort behavior

Juice lovers spend a lot of time caring for their plumage. They frequently shake and ruffled their plumage and pull individual feathers, especially the wings and tail, through their beak. They also use their beak to organize the rest of the accessible feather areas. Water bathing was only rarely observed in woodpeckers of the varius group; pine sap lovers seem to do this more frequently. Sunbathing is a frequent comfort act for all four species: they turn their backs to the sun, fluff their feathers and slightly spread their wings. Active canning was observed in the pine sap litter .

Agonistic behavior

All sap lovers are territorial, at least in the summer months, resident woodpeckers throughout the year. The territory is marked and delimited by rows of drums and sightseeing flights. Saftlecker defend the immediate cave environment and some important food trees against conspecifics and against food and cave competitors. They are able to drive away much larger species, such as the helmeted woodpecker . The potential for aggression is greatest in the pre-breeding season and while the nestlings are being raised. During this time male conspecifics, but also with another type of juice delicacy, can have violent contact fights. Most of the time, threatening gestures accompanied by loud series of calls, such as raising the head, breast and crown plumage, swinging the head horizontally and moving the head vertically up and down, are sufficient. Mild agonistic behaviors are also part of courtship and are observed in the mutual behavior of couples. Outside the breeding season, sap lovers live solitary. Occasionally, small temporary groups are formed during the migration and in winter quarters.

During the nestling period, juice lovers also try to drive larger predators out of the nest environment by loud screaming and direct attacks. Otherwise they are largely calm towards their enemies, either remaining quiet and clinging closely to the trunk, or trying to flee unnoticed.

Distribution and habitat, migrations

Distribution and hybridization zones of the S. varius superspecies

With the exception of a small, isolated brood occurrence of the pine sap litter in Baja California, the brood distribution of the sap litter is limited to the states of Canada and the USA . The greatest biodiversity is in the mountainous regions of north-western North America, where all four species occur, mostly in clearly separated areas. By far the largest breeding area is occupied by the yellow-bellied sap licker, which is the only one of the sap licker species to reach the North American east coast. It is also the most northerly occurring species , with breeding grounds in central Alaska . The southernmost breeding occurrences are those of the red-necked sap lick in northwest Texas . The smallest area inhabits the pine sap licker. The yellow-bellied and the fire-head juice lickers are distributed vertically from sea level to around 3000 meters, the red-naped juice lickers from around 300 meters to 3000 meters. The pine sap licker is a submontane or montane species. Its breeding grounds are not less than 800 meters in the north, in the central part of its breeding area mostly over 1500 meters and reach up to the tree line.

The habitats of the yellow-bellied sap litter are forests with different compositions, such as mixed forests of different conifer species with poplar , birch , willow and - especially in the east - hickories , occasionally also agriculturally used, loosely tree-covered areas and larger parks. The Feuerkopf-Saftlecker and the Kiefernsaftlecker are more likely to inhabit pure coniferous forests, the Red-necked Saplecker prefers deciduous forests and mixed deciduous forests, but occasionally also occurs in open stands of yellow pine . Poplars play an excellent role for all types of sap-delicious, both as a food and as a cave tree. Standing dead wood is also essential for some to create the nesting caves.

The winter distribution of the yellow-bellied sap lick includes the southeastern area of ​​the USA, Mexico, Central America to northern Panama and many of the West Indies . Red-necked juices hibernate in southern areas of the breeding area or migrate to central Mexico, in exceptional cases to Guatemala and Honduras , to Baja California or the southern California Pacific coast. Pine sap lickers spread to lower-lying areas or move relatively small-scale southwards, fire head sap lickers are mostly resident birds .

Hybridization Zones and Hybrids

The breeding areas of Kiefernsaftlecker, Feuerkopf-Saftlecker and Rotnacken-Saftlecker touch each other or overlap in many regions. Feuerkopf sap lickers and pine sap lickers also colonize the same forest types. Wherever the woodpeckers appear sympatric, they keep the same territorial distances as to other species. Hybrids of woodpeckers from the varius group with the pine sap litter appear to occur, but are extremely rare.

The breeding areas between the Feuerkopf- and Rotnacken-Saftlecker overlap on their eastern and western limits of distribution. In the entire area of ​​this contact zone, hybrids are found in which the plumage characteristics of both parents mix. In mixed couples, in most cases the male is a fire-headed sap eater. In the contact zones the proportion of macroscopically identifiable hybrids of the first or a subsequent generation is very high at 32%. Hybrids seem to have no impairment in terms of physical fitness, and their breeding success does not differ from that of conspecific pairs. However, finding a partner may be more difficult for hybrids.

In northern British Columbia the breeding areas of the fire head and yellow-bellied sap litter overlap , in southern Alberta those of the yellow-bellied sap litter and the red-necked sap litter overlap . Hybrids are also found in these significantly smaller contact areas.

Food and subsistence

Female yellow belly sap sap sap while drinking tree sap

Feuerkopf-Saftlecker while drinking juice

Saftlecker, in English sapsuckers , get their name from the special, specialized way in which they obtain part of their food. For many woodpeckers, tree sap forms part of their diet, but the sap-eaters have specialized in this way of acquiring food.

Tree sap is an essential part of the diet throughout the year, only during the breeding season do all types of sap luscious feed mainly on insects, primarily ants , but also other arthropods such as flies , wasps , beetles , cicadas and spiders . The young are fed with insects. Occasionally it has been observed that the insect prey was dipped in tree sap prior to feeding. Other important nutritional components are bark and various fruits and berries. Quantitative analyzes are not meaningful, as the tree sap leaves the stomach very quickly, so its proportion cannot be determined. On an annual average, the energy coverage through tree sap is likely to be around 20%, but increases seasonally to 100%

The insect food can be obtained by searching the stem and branch surfaces, by poking and drilling, and occasionally also by removing larger pieces of bark. Above all, however, they collect those insects that were attracted to the sap holes. Flying insects are also captured in flight in the form of flycatchers . Feeding tunnels of wood-dwelling insects or insect larvae do not chop sap-leavers free.

Saplecker create sap holes in a variety of woody plants, but deciduous trees such as birch , poplar , willow , elm , oak , maple and hickory, as well as conifers such as yellow pine, coastal pine , Jeffrey pine , Douglas fir , Western American hemlock , rocky mountain fir and purple are preferred Fir tree . Yellow-bellied sap-tickers and red-necked sap-tickers prefer deciduous trees, the other two species conifers. Juice lovers create two different types of sap holes: Outside the growing season they punch round or oval holes that are driven into the wood. These holes are usually arranged radially. During the growing season, the sap holes are significantly flatter and larger, often almost rectangular and mostly lie one below the other. Trees with higher sugar content are preferred to those with greater sap flow.

The daily energy requirement of a yellow-bellied juice liqueur weighing around 46 grams is around 85 kilojoules . For this he needs 300  milliliters of tree sap with 1.9% sugar. With an average sap flow, this amount could produce four sap holes in an hour. However, the sugar content of the tree sap is significantly higher during the growing season, so that the amount of liquid necessary to cover the energy requirement is reduced accordingly.

Breeding biology

All juice treats become sexually mature at just under one year of age and usually breed for the first time at this age. They lead a largely monogamous seasonal partnership. Reparations of last year's partners occur relatively often due to the great loyalty of both sexes. The partnership is characterized by mutual distance and never-ending aggression. Saftlecker breed once a year. Only if the clutch is lost early do all species start a replacement brood.

Courtship and cave construction

The courtship of all species begins in the last third of March and reaches its peak in the first half of April. It contains the elements typical for many species of woodpecker, such as loud calls, drums, showing cave and food trees, sightseeing flights, screwy trunk climbing and chases. Many elements of the courtship ritual are also agonistic behaviors.

Every year, juice lovers create a new breeding cave, often in the same tree as the previous year. A large number of vital or dead deciduous and coniferous trees can be used as nesting trees. Only the Feuerkopf-Saftlecker breeds almost exclusively in dead trees or in dead areas of still living trees; the other species prefer to make their burrows in living poplars or birches, or, if these are not available, in severely damaged or already dead pines. The American quivering poplar is particularly popular as a nesting tree , especially if it has already become easier to work with due to fungal attack.

The main work of cave construction is done by the males. The participation of the females varies greatly from person to person and can also be omitted entirely.

Clutch and young rearing

The egg-laying of the yellow-bellied sap-lick does not begin until mid-May, that of the other three species in the last week of April, and even earlier in the case of populations breeding very south. The clutch size is quite uniform and averages around 4 - 5 pure white, oval eggs for all species, which are laid every day. Both parents breed in roughly equal parts, as in most woodpeckers always the male at night. The incubation period is about 12-13 days. Both parents farm and feed the young. After about 25-28 days, the young fly out and are immediately lured to sap trees by their parents. Young juice lovers become largely independent of their parents after just a few days.

In-depth studies on the dismigration of young woodpeckers are still pending, but the results of smaller series of studies indicate that subadult sap-lickers often return to the immediate, or at least to the immediate vicinity of the place of birth after their first winter.

Breeding success and life expectancy

There are only a few data on breeding success from relatively small, unrepresentative series of studies. 87 young fled from 32 yellow-bellied juicy nests (2.72 / nest). In Nevada, 77% of one-year-old breeding partners with at least one fully fledged boy had breeding success, on the other hand 92% of three-year-old parents brought at least one young to fly. Relatively high escape rates of an average of over three young per clutch were determined for the pine sap delicacies. There is also a lack of data on life expectancy. The maximum age of sap delicacies found was over six years. Mortality is highest in the first few weeks of life. Only a maximum of a quarter of the young birds live to be one year old.

Systematics

The genus Sphyrapicus was introduced by Spencer Fullerton Baird in 1858. He gave the red-naped sap lickers first described together with John Cassin , the Melanerpes (or Picus ) thyroideus (= female of the pine sap lickers) first described by Cassin and the yellow-bellied sap lickers with the species epithet that is still in use today. He understood the fire head sap litter as a subspecies of the red neck sap litter. Robert Ridgway in 1914 in The Birds of North an Middle America understood S. ruber and S. nuchalis as subspecies of S. varius , so that in his case the genus Sphyrapicus contained two species, Sphyrapicus varius and S. thryoideus . It was known since 1873 that the woodpecker species previously known as Picus williamsonii were the males of S. thyroideus . The Ridgways classification lasted until 1983. In particular, the research work of Ned K. Johnson and Robert M. Zink resulted in S. nuchalis and S. ruber being given species rank.

The genus Sphyrapicus is the sister genus of Melanerpes . The genus apparently split into two lines very early on, one comprising the yellow-bellied sap licker ( Sphyrapicus varius ), the fire-head sap licker ( Sphyrapicus ruber ) and the red-naped sap licker ( Sphyrapicus nuchalis ) and a second with the pine sap licker ( Sphyrapicus thyroideus ) as the only representative.

German name	Scientific name	distribution	Hazard level Red List of IUCN	Remarks	image
Yellow-bellied juice tasty	Sphyrapicus varius ( Linnaeus , 1766)		( Least Concern - not at risk)	monotypical From central Alaska east to Newfoundland , south to southern Canada or northern USA
Red-neck juice tasty	Sphyrapicus nuchalis S. F. Baird , 1858		( Least Concern - not at risk)	monotypically Rocky Mountains from British Columbia to Arizona and northwest Texas
Fire head juice tasty	Sphyrapicus ruber ( Gmelin , 1788)		( Least Concern - not at risk)	2 subspecies: Alaska Fire Head Juice Licker ( S. r. Ruber ( Gmelin , 1788)) Californian Fire Head Juice Licker ( S. r. Daggetti Grinnell , 1901) Close to the Pacific from Southern Alaska to Southern California
Pine sap delicious	Sphyrapicus thyroideus ( Cassin , 1852)		( Least Concern - not at risk)	2 subspecies: S. t. thyroideus ( Cassin , 1852) S. t. nataliae ( Malherbe , 1854) Heavily fragmented in the Rocky Mountains and the Cascade Mountains

Enemies

Adult sap-lickers are mainly preyed on by birds of prey such as the round-tailed cattle , the corner- tailed cattle or the hawk , they also fall prey to owls, especially the barred owl . Resting and brooding birds, young birds and eggs belong to the prey spectrum of martens , squirrels , black bears and raccoons , as well as tree-climbing snakes, especially Pituophis catenifer and the mountain garter snake . The house wren was observed as an often successful cave competitor ; the significantly smaller bird destroys juicy clutches and builds its own nest over it.

Existence and endangerment

According to BirdLife International, none of the four species is currently threatened. However, there are no supra-regional quantitative surveys for all four species. With the exception of regional declines in populations mainly caused by forestry measures, such as the yellow-bellied sap lick in the Appalachian Mountains , the population of species from the varius group is largely stable at a high level and probably higher in many places than before the European colonization of North America. In ideal habitats, up to 28 breeding pairs of the Feuerkopf sap litter per 100 hectares were found. The population of the pine sap lick fell regionally by up to 60% in the period between 1984 and 1993, but currently seems to remain stable at a lower level. It is classified by nature conservation authorities in Oregon and Utah as a sensitive species (= structure- sensitive species ). All juice treats in the United States and Canada are protected by the Migratory Bird Treaty Act .

Sap leaks can tolerate disturbances at the breeding site and certain forestry interventions in their habitat, as long as trees for the nesting hole and sap trees are preserved. Yellow-bellied sap-lovers have even benefited by taking advantage of new habitats at forest edges, clearings and in more open forest areas. Saftlecker react sensitively to the large-scale harvest of poplars for veneer production and the production of chopsticks, fire-head and pine juice treats also to the removal of dead wood from commercial forests. Direct persecution through shooting and poisoning, which for a long time had the effect of reducing the population in the fruit-growing areas of the east and in California, no longer plays a role today.

Individual evidence

1. ↑ James A. Jobling: The Helm Dictionary of Scientific Bird Names. Helm, London 2010, ISBN 978-1-4081-2501-4 , p. 362.
2. ↑ Winkler et al. (1995) pp. 220-225.
3. ↑ Dobbs et al. (1997) Introduction
4. ↑ Drumming Feuerkopf-Saftlecker (MP3; 702 kB)
5. ↑ Drums and shouts of pine sap delicious (MP3; 937 kB)
6. ↑ Dobbs et al. (1997) Behavior / Sleeping, Roosting, Sunbathing
7. ↑ Dobbs et al. (1997) Behavior / Preening, ...
8. ↑ Walters et al. (2002) Yellow-bellied Sapsucker - Social And Interspecific Behavior / Nonpredatory Interspecific Interactions
9. ↑ Walters et al. (2002) Red-breasted Sapsucker - Agonistic Behavior / Physical Interactions
10. ↑ Walters et al. (2002) Red-breasted Sapsucker - Spacing
11. ↑ McCarthy (2006) p. 110.
12. ^ Ned K. Johnson and Carla Bowan Johnson: Speciation in Sapsuckers (Sphyrapicus): II. Sympatry, Hybridization an Mate Preference in S. ruber dagetti and S. nuchalis. The Auk 1985, Vol. 102, p. 13.
13. ↑ McCarthy (2006) p. 110.
14. ^ Ned K. Johnson and Carla Bowan Johnson: Speciation in Sapsuckers (Sphyrapicus): II. Sympatry, Hybridization an Mate Preference in S. ruber dagetti and S. nuchalis. The Auk 1985, Vol. 102, p. 13.
15. ↑ Saftlecker hybrids pdf. engl. ( Memento of the original from June 26, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. 
16. ↑ Walters et al. (2002) Yellow-bellied Sapsucker - Parental Care / Feeding
17. ↑ Walters et al. (2002) Red-breasted Sapsucker - Diet / Quantitative Analysis
18. ↑ Walters et al. (2002) Yellow-bellied Sapsucker - Metabolism and Temperature Regulation
19. ↑ Walters et al. (2002) Yellow-bellied Sapsucker - Feeding / Food Capture and Consumption
20. ↑ Walters et al . (2002) Yellow-bellied Sapsucker - Behavior / Individual Distance
21. ↑ Walters et al . (2002) Red-breasted Sapsucker - Range / Initial Dispersal From Natal Site
22. ↑ Walters et al . (2002) Yellow-bellied Sapsucker - Demography and Populations / Annual And Lifetime Reproductive Success
23. ↑ Walters et al . (2002) Red-breasted Sapsucker - Demography and Populations / Proportion Of Total Females That Rear At Least One Brood To Nest-Leaving Or Independence
24. ↑ Dobbs et al . (1997) Demography and Populations
25. ↑ Walters et al . (2002) Red-breasted Sapsucker - Demography and Populations / Life Span And Survivorship
26. ↑ Bulletin of the United States National Museum No. 50 (1914) p. 272 ​​ff. (PDF; 88.0 MB)
27. ^ Dobbs (1997) Introduction .
28. ^ Ned K. Johnson and Robert M. Zink: Speciation in Sapsuckers (Sphyrapicus). Genetic Differentiation . The Auk 100 (1983) pp. 871-884.
29. ↑ Brett W. Benz, Mark B. Robbins, A. Townsend Peterson: Evolutionary history of woodpeckers and allies (Aves: Picidae): Placing key taxa on the phylogenetic tree. In: Molecular Phylogenetics and Evolution 40 (2006): pp. 389-399; P. 394 ff.
30. ^ Ned K. Johnson and Robert M. Zink: Speciation in Sapsuckers (Sphyrapicus). Genetic Differentiation . The Auk 100 (1983) p. 871.
31. ↑ Sphyrapicus varius in the IUCN Red List of Threatened Species 2016.3. Posted by: BirdLife International, 2016. Retrieved February 8, 2017.
32. ↑ Sphyrapicus nuchalis in the Red List of Threatened Species of the IUCN 2016.3. Posted by: BirdLife International, 2016. Retrieved February 8, 2017.
33. ↑ Sphyrapicus ruber in the Red List of Threatened Species of the IUCN 2016.3. Posted by: BirdLife International, 2016. Retrieved February 8, 2017.
34. ↑ Sphyrapicus thyroideus in the IUCN Red List of Threatened Species 2016.3. Posted by: BirdLife International, 2016. Retrieved February 8, 2017.
35. ↑ Dobbs et al. Predation
36. ↑ data sheet Sphyrapicus varius - BirdLife international pdf engl.
37. ↑ Data sheet Sphyrapicus nuchalis - BirdLife international pdf engl.
38. ↑ data sheet Sphyrapicus ruber - BirdLife international pdf engl.
39. ↑ Data sheet Sphyrapicus thyroideus - BirdLife international pdf engl.
40. ↑ Walters et al. (2002) Yellow-bellied Sapsucker - Population Status / Trends
41. ↑ Walters et al. (2002) Red-breasted Sapsucker Management
42. ↑ Dobbs et al. (1997) Population Status / Trends

literature

• Eugene M. McCarthy: Handbook of Avian Hybrids of the World . Oxford University Press 2006, ISBN 0-19-518323-1 , p. 110.
• Robert C. Dobbs, Thomas E. Martin, Courtney J. Conway: Williamson's Sapsucker (Sphyrapicus thyroideus) . In: A. Poole (Ed.): The Birds of North America Online. Cornell Lab of Ornithology, Ithaca. (Retrieved from The Birds of North America Online 1997 )
• Eric L. Walters, Edward H. Miller, Peter E. Lowther: Yellow-bellied Sapsucker (Sphyrapicus varius). In: A. Poole (Ed.): The Birds of North America Online. Cornell Lab of Ornithology, Ithaca 2002.
• Eric L. Walters, Edward H. Miller, Peter E. Lowther: Red-breasted Sapsucker (Sphyrapicus ruber). In: A. Poole (Ed.): The Birds of North America Online. Cornell Lab of Ornithology, Ithaca. (Retrieved from The Birds of North America Online 2002 )
• Hans Winkler , David A. Christie, David Nurney: Woodpeckers. A Guide to the Woodpeckers, Piculets, and Wrynecks of the World. Pica Press, Robertsbridge 1995, ISBN 0-395-72043-5 , pp. 68-69 and 220-225.
• Hans Winkler: Family Picidae (Woodpeckers) In: Elliott and Sargatal del Hoyo (eds.): Handbook of the Birds of the World. Volume 7: Jacamars to Woodpeckers. Lynx Ediciones, Barcelona 2002, ISBN 84-87334-37-7 , pp. 274-419 and 452-453.

Web links

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