Canary slackers

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Canary slackers
Canary Wharf (Saxicola dacotiae), male in the first winter

Canary Wharf (Saxicola dacotiae) ,
male in the first winter

Systematics
Order : Passerines (Passeriformes)
Subordination : Songbirds (passeri)
Family : Flycatcher (Muscicapidae)
Subfamily : Schmätzer (Saxicolinae)
Genre : Meadow treacher ( Saxicola )
Type : Canary slackers
Scientific name
Saxicola dacotiae
( Meade-Waldo , 1889)

The Canary Wharf ( Saxicola dacotiae ) is a songbird species from the flycatcher family (Muscicapidae). It only occurs on the Canary Island of Fuerteventura . According to an estimate from 2006, the total population is estimated at around 14,000 individuals, according to another from 2010 at 550–950 breeding pairs. The species is listed by the IUCN due to its limited distribution on the warning list (near threatened) .

female

description

The Kanarenschmätzer is with 11-12.5 cm body length slightly smaller than a robin . It closely resembles the stonechat and has often been viewed as a subspecies of the same.

The head of the adult male is predominantly blackish in color. This contrasts with a very fine, white stripe above the eyes and a wide white collar that is interrupted in the neck and extends over the sides of the neck down to the white throat. The orange color of the breast is less extensive than that of the stonechat, the sides of the breast are broader white. The color runs towards the belly into the white of the rest of the underside. The rump is grayish brown in color, slightly lighter and tinged orange towards the tail; otherwise the rest of the top is very similar to that of the stonechat. The predominantly blackish color of the back is interspersed with cinnamon-brown feather fringes, which make the bird appear brownish in its fresh plumage, but wear off over time. The wings of the hand and arm are brown with narrow cinnamon-brown edges on the outer flags. The upper wing ceilings are black with light to cinnamon-brown lace hems. The inner large arm covers as well as the middle and inner middle arm covers are partially colored white and form a white transverse band at the base of the wing, which can also be partially seen when the wing is folded. The control feathers are black with cinnamon brown edges. Legs and feet are black.

The female is dashed dark brown-blackish on top. The rump is grayish. The beige-brown stripe above the eyes is often only weakly pronounced. The underside is brownish beige. In the fresh plumage, the upper side looks lighter and grayish, the underside is warmer beige-brown and the rump is yellowish-brown.

Birds in juvenile plumage resemble females in fresh plumage with yellowish-brown dots on the top and blackish speckles on the chest.

voice

The song resembles that of the stonechat. It can be described as a rough bik bisi bisiu , but it is often greatly varied. With singing flights, a soft, lark-like liu and a hard, scratchy skriez are often woven in, which are often strung together , for example as liu liu liu skriez . A gentle, high- pitched sees or suiet is described as an alarm and contact call, and a hard chapp as a call when there is great excitement . Both are also combined, especially on the nest. In the case of extreme excitement, a faint scratching call can also be heard.

Distribution and existence

The Canary Wharf is endemic to Fuerteventura and is a resident bird there . By 1913 there was said to have been a breeding population on Alegranza and Montaña Clara (north of Lanzarote ). However, this assumption is very uncertain. It is more likely that it was a temporary settlement after good breeding successes and subsequent dismigration from Fuerteventura. It is documented that the population there was at a low point between 1902 and 1904, but had reached a maximum again in 1914.

The stock estimates that have been published in several years since 1985 differ greatly from one another, which is probably less due to changes in stocks than to different recording methods. In 1985 the population was estimated at 650–850 breeding pairs, in 2005/2006 at 14,436 individuals. In 2008 1035 birds were counted, which probably underestimates the actual population due to the method used. Other authors therefore assumed 550–950 breeding pairs in 2010.

Presumably, the population is generally subject to significant, weather-related fluctuations. Particularly dry years are likely to have a very negative effect; after successive years with extensive rainfall, the population may increase significantly again. The strongly increasing tourist use of the island has negative influences, even if this development has slowed down a bit recently. The development of new building land for hotel complexes, golf courses or industrial areas and the increasing desertification due to increasing water consumption are destroying suitable habitats in many places. Further negative factors are the extensive grazing of the landscape with goats or other farm animals and the increased risk of predation from introduced mammals. In the vicinity of localities these are often house cats , elsewhere house rats , Atlas squirrels and North African hedgehogs ( Atelerix algirus ) play a role as nest robbers. The effects of these factors on breeding success have hardly been researched.

In Spain the species is listed as "critically endangered" on the national red list. By 2010, it was by the IUCN as endangered also (endangered) considered in 2011 but despite negative population trends on the early warning list (near threatened) reset.

habitat

The Kanarenschmätzer populates rocky slopes with shrubby vegetation, which typically consists of shrub lettuce ( Launaea arborescens ), worm-shaped brine ( Salsola vermiculata ) and blue boxthorn ( Lycium intricatum ), sometimes also blunt-leaved tobacco ( obtotusifolia ) or spurge ( Euphorbia, obtusifolia ) Oleander-leaved Kleinie ( Kleinia neriifolia ) consists. The species can also be found on the edges of overgrown lava fields (“malpaíses”) , stream beds (“barrancos”) with tamarisk vegetation , in cultivated land, on fallow land and in overgrown gardens. For food, only scree slopes or stony stream beds are sought, but lava fields or sand dunes are avoided. Habitats with isolated, high bushes and relatively large boulders, relatively steep slopes, a lot of grass and little debris are preferred.

nutrition

The diet consists of invertebrates such as caterpillars, ants , parasitic wasps , flies , centipedes , beetles and spiders . Locusts , butterflies and flies are fed to the nestlings . When foraging for food, the bird usually sits in a low control room and comes down to the ground in short catches. Sometimes flying insects are also captured or prey jumping on the ground is pursued.

Reproduction

The start of the breeding season correlates with the time and extent of winter rainfall. It is sometimes in January, but mostly between mid-February and the end of March. Dependent boys were observed in some cases as late as May. Two annual broods are rare and probably only occur after particularly humid winter months. Some observations suggest that some pairs may cooperate during the breeding process. For example, the young were looked after by strange birds of both sexes or accompanied after they had fled.

The nest is built by the female and is a solid bowl that stands on the ground between stones or rocks, in cactus thickets, under bushes or tufts of grass, at the foot of walls or in the rubble of stream beds and is not infrequently covered by overlying structures such as rocks or bushes . It consists of grass, plant stems or fibers. Brine is often used. The upholstery is made of wool or goat hair.

The clutch consists of 2–5, but mostly 4 eggs of about 18 × 14 mm in size, the surface of which is smooth and shiny. They are dull greenish blue in color and speckled finely reddish brown. The mottling often condenses on the blunt pole. Incubation is the sole responsibility of the female, begins after the last egg and lasts 13–15 days.

The nestling period lasts 16-18 days. It is unclear how long the young birds will be cared for after they have fled. In one case, the young of a second brood hatched just 23 days after the first one left.

Systematics

For a long time, the canary slacker was considered a subspecies of the stonechat (then Saxicola torquatus ). However, studies of mitochondrial DNA revealed that this complex can be broken down into several types. The Canary Wharf is a sister taxon to the European Stonechat ( Saxicola rubicola ), while the two as a group are closely related to the Siberian Stonechat ( Saxicola maura ). The African stonechat ( Saxicola torquatus , the previous nominate form ), however, is more closely related to the Réunion blackthroat ( Saxicola tectes ). The Canary Wharf is believed to have emerged from a population of European stonechats from Europe or North Africa. The separation probably took place about 1.3-1.7 million years ago.

The Canary Treasure was first described in 1889 by Edmund Meade-Waldo as Pratincola dacotiae . The type specimen came from Fuerteventura. In 1913 several specimens were collected on the islands of Montaña Clara and Alegranza off Lanzarote and described by David Armitage Bannerman as a subspecies murielae . It can be assumed, however, that this was not a separate breeding population, but rather birds that were temporarily flown in from Fuerteventura. The species is therefore considered to be monotypical .

literature

  • Nigel Collar, Arnau Bonan: Fuerteventura Stonechat (Saxicola dacotiae). In: Josep del Hoyo , Andrew Elliott, David Christie: Handbook of the Birds of the World . Volume 10: Cuckoo-shrikes to Thrushes. Lynx Edicions 2005 (Revision 2013), p. 783.
  • Juan Carlos Illera: Habitat selection by the Canary Islands stonechat (Saxicola dacotiae) (Meade-Waldo, 1889) in Fuerteventura Island: a two-tier habitat approach with implications for its conservation , Biological Conservation 97, 2001, pp. 339–345, ( PDF , 181 kB)

Individual evidence

  1. ↑ a b c d e f g h i j Collar (2005), see literature
  2. ↑ a b BirdLife species factsheet , accessed on October 10, 2013
  3. ↑ Illera (2001), p. 342, see literature
  4. ↑ a b C. Harrison, P. Castell, H. Hoerschelmann: Young birds, eggs and nests of the birds of Europe, North Africa and the Middle East , Aula Verlag, Wiebelsheim 2004, ISBN 3-89104-685-5 , pp. 206/345
  5. ↑ Michael Wink, Hedi Sauer-Gürth, Eberhardt Gwinner: Evolutionary relationships of stonechats and related species inferred from mitochondrial-DNA sequences and genomic fingerprinting . British Birds 95, 2002, pp. 349–355, ( PDF )

Web links

Commons : Kanarenschmätzer  - Collection of images, videos and audio files