Iberian grubs

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Iberian grubs
Iberian shrug in the pseudo-steppe near Castro Verde (Portugal)

Iberian shrug in the pseudo-steppe near Castro Verde (Portugal)

Systematics
Order : Passerines (Passeriformes)
Subordination : Songbirds (passeri)
Superfamily : Corvoidea
Family : Shrike (Laniidae)
Genre : Real strangler ( Lanius )
Type : Iberian grubs
Scientific name
Lanius meridionalis
Temminck , 1820

The Iberian shrike ( Lanius meridionalis ), previously the southern shrike , is a member of the genus Lanius within the family of the shrike (Laniidae).

The rather large, gray-white-black, long-tailed strangler species occurs on the Iberian Peninsula and on the southern French Mediterranean coast and its hinterland. The species remains in the breeding area even during the winter months. The Iberian shrike is primarily a hide hunter that feeds primarily on large insects and small vertebrates .

Taxonomically the entire Lanius excubitor / Lanius meridionalis complex is complicated. Originally the species was thought to be conspecific with Lanius excubitor , to which it is closely related. Studies carried out towards the end of the 20th century revealed a clear genetic distance between individuals from Central Europe , Northern Asia and North America and those from Spain , the Canary Islands , Africa, the Middle East and Central Asia . This led to the separation between northern gray shrike and southern gray shrike . Finally, the work of Olsson et al. (2010) and Peer et al. (2011) on a far-reaching re-evaluation of the taxonomic situation, as a result of which, among other changes, the Iberian shrike resulted as a monotypical species.

The population of the Iberian grubber has declined continuously since 1970 and has only started to stabilize at a lower level since 2010. Due to this decline, the HBW and the IUCN rate the endangered status as vulnerable . The upgrade from least concern (not at risk) to vulnerable (at risk) took place at the end of 2017.

Appearance

Adult Iberian shrike. The over-eye stripe relevant to the determination is clearly visible

The Iberienraubwürger is a good star big gray, white and black colored, long-tailed little acting typical shrikes . Its total length (beak to tail tip) is about 24 centimeters. The weight fluctuates between 48 and 93 grams depending on the season and nutritional status. Adult males are the largest and heaviest, and female yearlings are the smallest and lightest. Overall, however, the sexual dimorphism remains low in terms of coloration and is also marginal in terms of weight and size.

The head, neck, coat, back and rump are lead gray, with the vertex and neck being the darkest. The typical black face mask runs from the base of the beak over the eyes to behind the ear covers . It is bordered by a fine, white stripe over the eyes to just above the eyes. The cheeks are white, the throat light gray. The shoulders are white, the wings and inner control springs are black, the outer ones white. The white shoulder color and the black wings create a striking black and white contrast. The base of the inner arm wings is white; this creates a white wing field that is always visible when the bird is sitting, and a clear sickle-shaped mark when it is in flight. All arm wings and the inner hand wings are bordered in white, a feature that is rather indistinct when the bird is sitting, and somewhat more noticeable when it is flying. The throat is white, the chest and belly are tinged with pink, most intense on the flanks. The rump and tail-coverts are dirty white. The tail is clearly stepped, a feature that is particularly noticeable in the flying bird. Eyes, hooked bills and legs are black. The flight is slightly undulating, powerful and fast. The white shoulder markings and white wing bands as well as the stepped white outer feathers of the tail are striking. Females have the same color distribution as males. Sometimes their coloring is somewhat duller and the white components smaller and less clear. Young birds are also similar, but much paler in color; on the underside a fine, dark line can sometimes be seen; the face mask is brown and incomplete.

Mauser

Soon after flying out, young birds molt their body plumage, sometimes also some outer wings. They change to adult plumage in early first spring. This is followed by a complete post-breeding moult between June and October and an only slightly noticeable moult of the head and body plumage between February and April.

voice

The rather soft singing consists of lined-up croaking-screeching calls and snarling, very fine, long-lasting whistles and short, melodious, trilling phrases that are recited in a chatting-gossiping manner. Singing elements from other songbirds are occasionally interspersed in this extremely varied repertoire. In threatening situations, a loud, glaring, repeated screeching can be heard, in which some authors recognize meowing sound components. Also bill squires and wing clapping can be heard.

distribution and habitat

Tree pastures in southern Spain - a typical habitat of the species
Distribution area of ​​the Iberian shrike
gray-brown: breeding area and year-round occurrence
ocher: non-breeding and non-breeding season occurrences

The breeding areas of the Iberian shrike are mostly on the Iberian Peninsula; In addition, the species occurs on the Mediterranean coast of France and its hinterland northeast to just before Antibes , in the interior approximately to the central regional nature park of Monts d'Ardèche . The extreme southern tip of Spain is not populated , as is a strip of different widths on the northern Atlantic coast , from Galicia in the west to Pais Vasco in the east, as well as the regions of the provinces of Navarra , Aragon and Catalonia near the Pyrenees . On the Portuguese Atlantic coast, the species is absent in a strip of different widths, for example from Lisbon northwards to Porto .

Garigue in the south of France

In winter all parts of Spain are populated except for the extreme south; in France, the winter spread extends to the Atlantic coast south of Bordeaux . The coastal section in Portugal remains uninhabited even in winter. In this area of ​​distribution, the Iberian shrike is able to colonize a multitude of different, but mostly dry and open, landscape types if, in addition to sufficient food, the essential requirements of a suitable breeding territory, such as sparsely distributed trees, dense bushes and (preferably thorny) undergrowth, as well as barren or missing soil vegetation are offered. The presence of Phillyrea angustifolia , different species of Rubus , Prunus , Crataegus , as well as Quercus ilex or Quercus coccifera is important for a good breeding territory. In France these are mainly sparse tree-covered maquis and scrubby garigue , on the Iberian Peninsula dehesas , short-grass tree pastures with Quercus coccifera , next to them vacant fallow land, bushes and hedges on the edge of fields and paths, regions in which migratory cattle are raised, however also cultivated land, vineyards and orchards. The Iberian shrike is a type of low and middle elevations, it does not occur in montane areas. The highest evidence of breeding is around 1200 meters. Settlement density and size of the breeding territories depend on many factors and accordingly vary greatly from region to region. In good habitats, the size of the breeding grounds is between 10 and 25  hectares , but often only one breeding pair is found per 100 hectares. In another study in northwestern Spain, 42 nests were found in the 72 km² study area. After the breeding season, Delgado et al. the largest area density with 1 area on 0.5 km² on the edge of grain fields.

In France, the occurrences of L. excubitor excubitor and L. meridionalis are separated due to the different habitat preferences, so that no hybrids have been known to date .

hikes

The species is largely sedentary. When migrations take place, they remain small-scale. Females leave the breeding ground after brooding; Males usually stay in it and only leave it if they were dissatisfied with its quality, or could not maintain it. Overall, the willingness of the females to migrate is somewhat greater. In winter, regions that are not suitable as breeding areas are also sought out. In Spain these are mainly northern parts of the country, in France small-scale train movements lead to the west. Few individuals appear to be flying south, across the Strait of Gibraltar . There are 6 records from Morocco , all from 2016. Nothing is known about the dismigration of young birds.

Food and subsistence

Like all stranglers, the Iberian shrike is an opportunistic hunter who strikes the prey that can be reached with the least amount of energy. The range of its prey is correspondingly variable. It changes regionally as well as seasonally. In terms of the number of prey animals, insects predominate everywhere . In terms of biomass , vertebrates can become very important, at least regionally . In an extensive study in two sample areas in southern Spain, 329 vaults were analyzed. Invertebrates made up 90.5% of the prey. The remaining 9.5% were vertebrates, mostly small lizards . However, this made up 66.3% of the consumed biomass. It was also noticeable in this study that ants were almost completely avoided and only swarming sex animals were occasionally eaten. An analysis carried out in the south of France produced other results: there insects made up 63.3% of the biomass, of which more than a third was made up of beetles; Vertebrates made up only 21% of the biomass. In general, stranglers that breed at higher altitudes seem to strike vertebrates, especially small songbirds, more frequently, both during the breeding season and outside of it, than stranglers in the lowlands

The western ore sneak is an important prey animal.

Crickets , mole crickets , grasshoppers and dung beetles dominate the insects . Hymenoptera , especially large bumblebees , also play an important role in summer . As large specimens as possible are preferred. Occasionally arachnids and centipedes are also preyed on . On vertebrates, the Iberian shrike hits mainly reptiles , especially small lizards, small snakes and skinks , here especially Chalcides striatus . Warm-blooded animals such as small songbirds or small mammals are only caught occasionally; Above all, the remains of house shrews , forest mice and various types of field mice were regularly found in the ridges.

The Iberian shrike is a distinct hide hunter . From a control room, usually at a height of around 2 to 3 meters (e.g. outer branch of a tree or higher bush, rock formation, pasture fence or telephone line), he observes the environment, especially the ground. A very good view of the ground is a prerequisite for this preferred, energy-saving hunting method. Although the species can spot prey at 100 meters and more, the most effective radius in which most successful prey flights take place is less than 30 meters. If it spies a suitable prey, it glides off the hide without flapping its wings and hits it on the ground. He eats smaller prey on the spot, he carries larger prey to a feeding place or deposits them in one of his spear places , which he maintains in his territory. The prey stored there is gradually consumed, usually within 9 days; however, only 62% of the prey stored there is actually used. The seats are changed several times an hour. Air hunting from a shaking out dominated L. meridionalis too, but this hunting technique applies to more rare.

Behavior and Breeding Biology

Like all stranglers, L. meridionalis is diurnal. Iberian shrike live in seasonal pairs during the breeding season, outside of this solitary . The activity span lasts approximately from sunrise to sunset. During this time, especially during the hot midday hours, extended rest phases are taken, which also serve to care for the plumage. Both sexes are strictly territorial; they do not tolerate any conspecifics and no other stranglers in the area, mostly other food competitors are also driven away; Contact fights between conspecifics were observed; The breeding pair tries to keep potential nest robbers, especially crows and jays , away from the territory by attacks. The territory is mainly marked by low, conspicuous sightseeing flights; Furthermore, sitting upright in exposed places, especially at the territorial boundaries, serves to delimit the territory. The territoriality is greatest in the pre-breeding season and breeding season; Outside the breeding season, only individual important places within the territory, such as waiting areas, hiding places or spit-kitchens, are guarded and maintained. Females leave the territory after the breeding season; their loyalty to their breeding site is low, so that annual new pairings are the rule. Males, on the other hand, hold on to their chosen territory whenever possible, sometimes for many years. At the end of January and beginning of February the females migrate back into the male territories and pair formation and nest building begin. Iberian shrike breed once a year, mostly yearlings already brood for the first time. Due to the frequent loss of clutch caused by predation , lack of food or the effects of the weather, the species is often forced to replace the clutch.

Courtship and pairing begins in southern Spain as early as the end of January and later in the north. Fresh clutches can be found in Spain between March and June. In southern France, the peak of the laying period is between the beginning of April and the beginning of May. Both adult birds build the nest; it is a rather messy bowl made of grass, twigs and also green parts of plants, often camouflaged on the outside with leaves of Echium plantagineum and other green plants. It is relatively low (average height in Spain 1.1 meters) in various bushes and trees, but preferably in dense, thorny bushes, especially blackberries . The nest distances are usually very large; Panov documents distances between 710 and 938 meters, Moreno-Rueda  et al. (2016) determined an average of 1.67 kilometers.

The western lizard snake is an important nest predator.

The clutch consists of 2 - 7 (4 - 6) bluish green eggs with irregularly distributed olive-brown spots; they measure on average 27.3 x 19.6 mm; they are placed at daily intervals and mostly incubated by the female for 17 to 18 days. During this time and in the first few days after hatching, the male takes care of the female and chick alone, after which both parents feed the nestlings. The nestling period lasts 16–19 days. Older nestlings are occasionally lured out of the nest when the nest is disturbed and taken care of outside of it (usually in dense bushes on the ground). After flying out, the tour takes a little longer than a month until the young birds leave their parenting area.

The breeding success of the species seems to be subject to strong fluctuations according to previous studies. In general, it was observed that seasonally early broods and clutches that were laid out in as dense, thorny scrub as possible had the highest escape rate. Surprisingly, a study carried out in 2016 in an agriculturally used distribution area in southeastern Spain ( province of Granada ), in which the population density of the species had declined sharply, produced the most positive results. Both breeding success and the exit rate were high. At least one young bird flew out of 83% of the nests. Other studies show less encouraging results; in a population in the area of Toro ( province of Zamora ), at least one young bird flew out of only 38% of the nests. The main reasons for unsuccessful breeding are climatic influences and the associated lack of food, disturbances at the breeding site and predation by a number of nest predators, such as the western lizard snake , garden dormouse , in southern France also dormouse , red fox and various crows , especially the magpie . In some regions the clutch loss caused by predation can amount to almost half of the clutch.

Systematics

The species was first described by Coenraad Jacob Temminck in 1820. As habitat he indicated central Italy, Dalmatia , central France, the edge of the Mediterranean and Spain. In the same year Temminck seems to have assigned L. meridionalis to L. excubitor , a view that persisted until shortly before 2000. This assessment was concretized in 1959 by Charles Vaurie , who divided the entire Lanius excubitor complex into a north and a south group. This separation is also clearly emphasized in the HBV in 1993. However, this assessment did not have any taxonomic consequences for the time being. In 2000, the two groups were first separated by James F. Clements into two polytypic species, Lanius excubitor - northern gray shrike and Lanius meridionalis - southern gray shrike. This assessment was gradually followed by all authorities, until 2010 through the work of Olsson et al. the discussion was rekindled. Although the result of the work allowed multiple interpretations and although the authors that the taxonomic situation in this species as a circle conundrum designated = mystery, even gave up proposals with regard to taxonomic changes, scheme was Lanius excubitor - superspecies largely redesigned. Among other profound changes affecting Lanius excubitor and Lanius sphenocercus , all subspecies of the southern gray shrike were added to L. excubitor . The species, which was previously polytypic with up to 10 subspecies, became monotypic; consequently, the corresponding trivial names were also adapted (Southern Gray Shrike> Iberian Gray Shrike // Südlicher Raubwürger> Iberienraubwürger)

Persistence and Threat

At the end of 2017, the risk assessment was upgraded from LC = least concern (not endangered) by two levels to VU = vulnerable (endangered). The main reason for this was the systematic reassessment that the previously polytype species had on Lanius meridionalis s.str. limited. In contrast to most of the other subspecies previously assigned to this species, the population of Lanius meridionalis s.str. declined very much since the 1970s. Although the total population is still high with an estimated 372,150 - 656,150 breeding pairs, and the species is not rare, at least regionally, the Spanish bird monitoring system recorded a decrease of 60% between 1998 and 2016. The majority of this decrease occurred before 2010; Since then, individual populations have shifted, but the total population has remained more or less stable. Besides the main occurrences in Spain, which make up about 95% of the total population, 1500 breeding pairs live in southern France. No new data are available from Portugal, an earlier estimate (2000) put the maximum population at 100,000 breeding pairs, but from today's perspective this figure is probably far too high. The reasons for the decline are not clear. In particular, the intensification of agriculture and the increased input of pesticides are having a negative impact. The extensive abandonment of migratory livestock farming, as a result of which habitats that were previously usable for the species are overgrown and thus unusable, should also play a not insignificant role. However, since the population density of the species also decreased in regions in which these negative influences were hardly effective, other reasons for the negative population dynamics must also be decisive. The low breeding success does not seem to be a major factor, because the populations are also thinning out where the species achieves excellent reproduction rates. What is striking, however, is the very high mortality, especially of young birds, the cause of which is largely unknown. However, a comparatively high exposure to various blood parasites was found in young birds; The extent to which this stress affects the fitness of individuals has not yet been conclusively clarified.

literature

  • Tony Harris, Kim Franklin: Shrikes & Bush-Shrikes. Including wood-shrikes, helmet-shrikes, flycather-shrikes, philentomas, batises and wattle-eyes. Christopher Helm, London 2000, ISBN 0-7136-3861-3 .
  • Norbert Lefranc, Tim Worfolk: Shrikes. A Guide to the Shrikes of the World. Pica Press, 1997, ISBN 1-4081-3505-1 .
  • Reuven Yosef & International Shrike Working Group (2018): Emins's Shrike (Lanius gubernator). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, DA & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/60474 on August 28, 2018).
  • Evgenij N. Panov: The True Shrikes (Laniidae) of the World - Ecology, Behavior and Evolution. Pensoft Publishers, Sofia 2011, ISBN 978-954-642-576-8 .
  • Urs N. Glutz von Blotzheim (Hrsg.): Handbook of the birds of Central Europe. Edit and a. by Kurt M. Bauer and Urs N. Glutz von Blotzheim. 2nd Edition. Teilband 13/2, Aula-Verlag, Wiesbaden 1985 ff., ISBN 3-89104-535-2 , pp. 1262-1328.

Individual evidence

  1. ↑ Urban Olsson, Per Alström, Lars Svensson, Mansour Aliabadian, Per Sundberg: The Lanius excubitor (Aves, Passeriformes) conundrum — Taxonomic dilemma when molecular and non-molecular data tell different stories. In: Molecular Phylogenetics and Evolution. Volume 55, No. 2, 2010, pp. 347-357.
  2. ^ Brian D. Peer, Carl E. Mc Intosh, Michael J. Kuehn, Stephen I. Rothstein and Robert C. Fleischer: Complex biogeographic History of Lanius Shrikes and its Implication for the Evolution of Defenses of Avian Brood Parasitism. In: The Condor. Volume 113, No. 2, 2011, pp. 385-394.
  3. ↑ a b c d e f g h i j k l m n o p Reuven Yosef & International Shrike Working Group: Iberian Gray Shrike (Lanius meridionalis). In: J. del Hoyo, A. Elliott, J. Sargatal, DA Christie, E. de Juana (eds.): Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona 2018. (downloaded from http://www.hbw.com/node/60483 on August 31, 2018).
  4. ↑ a b c Lanius meridionalis in the IUCN Red List of Threatened Species 2018.1. Listed by: BirdLife International, 2018. Retrieved August 28, 2018.
  5. ↑ Photo: Adult male
  6. ↑ F. Gutierrez-Corchero, F. Campos, M. Ángeles Hernandez, Ana Amezcua: Biometrics of the Southern Gray Shrike Lanius meridionalis in relation to age and sex. In: Ringing & Migration. Volume 23, 2007, pp. 141–146 ( PDF file; English )
  7. ^ T. Harris, K. Franklin: Shrikes & Bush-Shrikes ... 2000, p. 155.
  8. ^ Evgenij N. Panov: The True Shrikes (Laniidae) of the World - Ecology, Behavior and Evolution. Pensoft Publishers, Sofia 2011, ISBN 978-954-642-576-8 , p. 240.
  9. ↑ T. Harris, K. Franklin: Shrikes & Bush-Shrikes ... 2000, pp. 155-156.
  10. ^ T. Harris, K. Franklin: Shrikes & Bush-Shrikes ... 2000, p. 156.
  11. ↑ Voice examples. Attention: Only examples from the Iberian Peninsula and from the south of France relate to the present species
  12. ^ IUCN distribution map
  13. ↑ a b c d e T. Harris, K. Franklin: Shrikes & Bush-Shrikes… 2000, p. 157.
  14. ^ Evgenij N. Panov: The True Shrikes (Laniidae) of the World - Ecology, Behavior and Evolution. Pensoft Publishers, Sofia 2011, ISBN 978-954-642-576-8 , p. 244.
  15. ^ A b Francisco Campos and Raúl Martín: Spatial and temporal distribution of Southern Gray Shrikes Lanius meridionalis in agricultural areas. In: Journal of Bird Study. Volume 57, 2010 - Issue 1. doi : 10.1080 / 00063650903431654 (PDF file; English).
  16. ^ A. Delgado, F. Moreira: Bird assemblages of an Iberian cereal steppe. In: Agriculture, Ecosystems and Environment Volume 78, 2000, pp. 65-76 ( PDF file; English ).
  17. ↑ Urs N. Glutz von Blotzheim (ed.): Handbook of the birds of Central Europe. Edit and a. by Kurt M. Bauer and Urs N. Glutz von Blotzheim. 2nd Edition. Part 13/2, Aula-Verlag, Wiesbaden 1985 ff., ISBN 3-89104-535-2 , p. 1266.
  18. ↑ a b c José A. Hódar: Diet composition and prey choice of the Southern Gray Shrike (L. meridionalis) in south eastern Spain: The importance of vertebrates in the diet. In: Ardeola. Volume 53, No. 2, 2006, pp. 237-249 ( PDF file; English ).
  19. ^ Evgenij N. Panov: The True Shrikes (Laniidae) of the World - Ecology, Behavior and Evolution. Pensoft Publishers, Sofia 2011, ISBN 978-954-642-576-8 , pp. 263-265.
  20. ↑ Photo: L. meridionalis with a speared mouse
  21. ^ Evgenij N. Panov: The True Shrikes (Laniidae) of the World - Ecology, Behavior and Evolution. Pensoft Publishers, Sofia 2011, ISBN 978-954-642-576-8 , pp. 234-235.
  22. ^ Evgenij N. Panov: The True Shrikes (Laniidae) of the World - Ecology, Behavior and Evolution. Pensoft Publishers, Sofia 2011, ISBN 978-954-642-576-8 , pp. 252-254.
  23. ^ Evgenij N. Panov: The True Shrikes (Laniidae) of the World - Ecology, Behavior and Evolution. Pensoft Publishers, Sofia 2011, ISBN 978-954-642-576-8 , pp. 252 and 253.
  24. ^ A b c T. Harris, K. Franklin: Shrikes & Bush-Shrikes ... 2000, p. 158.
  25. ^ Evgenij N. Panov: The True Shrikes (Laniidae) of the World - Ecology, Behavior and Evolution. Pensoft Publishers, Sofia 2011, ISBN 978-954-642-576-8 , p. 254.
  26. ↑ a b c d e f g h G. Moreno – Rueda et al .: Breeding ecology of the southern shrike, Lanius meridionalis, in an agrosystem of south – eastern Spain: the surprisingly excellent breeding success in a declining population. In: Animal Biodiversity and Conservation 39.1, 2016 ( PDF file; English ).
  27. ^ Coenraad Jacob Temminck: Manuel d'ornithologie, ou, Tableau systématique des oiseaux qui se trouvent en Europe: précédé d'une analyze du système général d'ornithologie, et suivi d'une table alphabétique des espèces . 2nd Edition. tape 1 . H. Cousin, Paris, p. 143-144 ( biodiversitylibrary.org - 1820-1840).
  28. ↑ Author's note: So some subspecies that are now included in L. excubitor have not yet been recognized. It is doubtful whether birds from the great shrike complex actually occurred in central Italy at that time. Today no gray shrike breed in Italy
  29. ^ Evgenij N. Panov: The True Shrikes (Laniidae) of the World - Ecology, Behavior and Evolution. Pensoft Publishers, Sofia 2011, ISBN 978-954-642-576-8 , p. 233.
  30. ↑ Urs N. Glutz von Blotzheim (ed.): Handbook of the birds of Central Europe. Edit and a. by Kurt M. Bauer and Urs N. Glutz von Blotzheim. 2nd Edition. Teilband 13/2, Aula-Verlag, Wiesbaden 1985 ff., ISBN 3-89104-535-2 , pp. 1262-1266.
  31. ↑ a b Urban Olsson, Per Alström, Lars Svensson, Mansour Aliabadian, Per Sundberg: The Lanius excubitor (Aves, Passeriformes) conundrum — Taxonomic dilemma when molecular and non-molecular data tell different stories. In: Molecular Phylogenetics and Evolution. Volume 55, No. 2, 2010, pp. 347-357.
  32. ↑ James F. Clements: Birds of the World. A checklist. 5th edition. Ibis, Vista 2000, ISBN 0-934797-16-1 .
  33. ↑ Original quote: However, because of the disagreement between the mitochondrial and non-molecular data, we refrain from proposing any revised classification.
This article was added to the list of excellent articles on September 20, 2007 in this version .