Breeding takes place generally north of50° northern latitude in northern Europe andAsia. Most populationsmigrate south in winter totemperate regions.[2] The great grey shrike is carnivorous, withrodents making up over half its diet.
The species was firstscientifically described byCarl Linnaeus in his 1758 edition ofSystema Naturae under the currentbinomial name. His description isL[anius] cauda cuneiformi lateribus alba, dorso cano, alis nigris macula alba – "a shrike with a wedge-shaped white-bordered tail, back grey, wings black with white spot".[3] At that time, none of the other grey shrikes – including thelesser grey shrike (L. minor), for which the description of the tail pattern is incorrect and which some authors already recognized as distinct – were considered separate species by Linnaeus, but that was to change soon.
Linnaeus' binomial name replaced the cumbersome and confusing descriptive names of the earliernaturalist books he gives as his sources: in his ownFauna Svecica he named itampelis caerulescens, alis caudaque nigricantibus ("light-bluewaxwing, wings and tail blackish"), while it is calledpica cinerea sive lanius major ("ash-greymagpie or greater shrike") byJohann Leonhard Frisch, who in his splendid colour plate confused male and female. But most authors cited by Linnaeus –Eleazar Albin,Ulisse Aldrovandi,John Ray andFrancis Willughby – called itlanius cinereus major or similar, which is a near-literal equivalent of the common name "great grey shrike". Thetype locality of Linnaeus is simply given asEuropa ("Europe").[4]
The scientific name of the great grey shrike literally means "sentinel butcher":Lanius is the Latin term for a butcher, whileexcubitor is Latin for a watchman or sentinel.[5] This refers to the birds' two most conspicuous behaviours – storing food animals by impaling them on thorns, and using exposed tree-tops or poles to watch the surrounding area for possible prey. Use of the former byConrad Gessner established the quasi-scientific termlanius for the shrikes. Linnaeus chose hisspecific name because the species "observes approachinghawks and announces [the presence] of songbirds"[6] as he put it. This habit was also put to use infalconry, as fancifully recorded byWilliam Yarrell later.[7] The common English name "shrike" is fromOld Englishscríc, "shriek", referring to the shrill call.[8]
Ulisse Aldrovandi,Conrad Gessner,John Ray andFrancis Willughby also reported oldfolk names, mainly fromGermanic languages:Wereangel orWierangel from thePennines of England (where the bird was noted as avagrant) as well asWarkangel, Werkengel orWurchangel in various German dialects (e.g. around Frankfurt and Strasbourg) probably mean "choking angel" (cf.Standard GermanWürgeengel). These names are unlikely to significantly pre-date the times ofSaint Boniface (c. 700 AD) because of their Christian connotation; the relatedWerkenvogel ("choking bird") might, however, do so. The English version, having becomewariangle orweirangle, was eventually transferred to the nativered-backed shrike (L. collurio) and lingered on into modern times in Yorkshire. Along the upper Rhine, between Strasbourg and Heidelberg for example,Linkenom is attested; its origin is unclear.Low GermanNeghen-doer andMiddle GermanNünmörder were also used; this has today evolved intoNeuntöter and specifically means the red-backed shrike, but could in earlier times refer to any nativeLanius. It literally means "killer of nine [prey animals]" and refers to the food caches.
Afalconer's name for the great grey shrike wasmattages(s)(e), which is related tomat'agasse from the western Alps. These terms may mean "magpie killer", due to their use for luring carnivorous birds to hunters – but perhaps more likely "killer magpie", considering that the bird was believed to be a peculiar sort of magpie by Johann Leonhard Frisch and others, and that another vernacular English name was "murdering pie".Shrike, meanwhile, is of Germanic origin also and dates back at least toMiddle orEarly Modern Englishschricum. This is related to such words as Norwegian and Swedishskrika ("shriek,skrike"), GermanSchrei ("scream") or Icelandicshrikja ("shrieker"). But it seems to have become the dominant term only in rather recent times, for as late as the 18th century, the species was still widely known as "greater butcher-bird" in English, just like it was known as theboucher ("butcher") in theFrench Jura. In Norway a vernacular name for the bird isvarsler.[9] A whimsical name – presumably from Scotland or nearby England – was "white wisky John" in reference to its wavy and somewhat unelegant flight, during which its large areas of lightplumage are conspicuous.[10]
The "grey shrike" is also sometimes named "gray shrike."[11]
The shrikefamily (Laniidae) is a member of theCorvoidea, the most ancient of the four large songbirdsuperfamilies. Among its superfamily, the closest relatives of the Laniidae are probably theCorvidae (crows and allies). Little reliable data exists on its evolution; certainly (even though the supposed ancestral shrike"Lanius" miocaenus might not belong in the Laniidae, and probably does not belong in the same genus asL. excubitor) the genus dates back toMiocene times. ALaniusfossil from theLate MioceneTurolian age, c. 6 million years ago, has been found atPolgárdi, Hungary. Its relationship to the modern species is unclear. However, all things considered, the grey shrike lineage probably represents theHolarcticsister to the African radiation of fiscal shrikes. These two seem to have originated in a west- or southwestward expansion from the genus' origin, which (considering thebiogeography of livingLanius lineages) was probably somewhere between Asia Minor and central Asia. At the time of the Polgárdi fossil, it is rather likely that the grey shrikes were a distinct lineage already; given that they and the fiscals generally followBergmann's Rule, the smallish fossil makes an unlikely ancestor to the large grey shrikes even when taking into account the somewhat warmer Miocene climate.[12]
The grey shrikesuperspecies consists ofL. excubitor and itsparapatric southern relatives. As mentionedabove, the other members of this group are theIberian grey shrike (L. meridionalis), thesteppe grey shrike (L. pallidirostris), theChinese grey shrike (L. sphenocerus) and theloggerhead shrike (L. ludovicianus). The centre of this group's radiation is probably in the eastern Mediterranean region, and the southern grey shrike represents thebasalmost form. The other three only diverged during the expansion into temperate regions. This must have happened fairly recently, becauselineage sorting is not complete in the grey shrikes, and most of the present-day habitat ofL. excubitor was uninhabitable during much of theQuaternary glaciation. Because of thephylogenetic uncertainties surrounding this close-knit group in the absence of a good fossil record, some refrain from splitting them up into distinct species; most modern authors do so however.[1][13]
Lanius excubitor excubitor (includingmelanopterus – which mayintergrade withsibiricus – andgalliae) – breeds in temperate tosubarctic continental Europe and northwest Siberia
Medium grey above, pale grey hue below; some white on primaries and sometimes secondaries
Lanius excubitor homeyeri – breeds in southeast Europe and southwest Siberia
Lighter grey thanexcubitor above, dull white below; more white on primaries and secondaries
Lanius excubitor koenigi – endemic to the Canary Islands
Lanius excubitor algeriensis – coastal northwestern Africa
Lanius excubitor elegans – Eastern Morocco, northeastern Mauritania and northwestern Mali to northeastern Sudan, Egypt and southwestern Israel
Lanius excubitor leucopygos – central and southern Mauritania to southern Chad and central Sudan
Lanius excubitor aucheri – east-central Sudan to northwestern Somalia northwest to Iraq and Iran
Lanius excubitor theresae – southern Lebanon and northern Israel
Lanius excubitor buryi – endemic to Yemen
Lanius excubitor uncinatus – endemic to Socotra
Lanius excubitor lahtora – Pakistan through central India and southern Nepal to western Bangladesh
Lanius excubitor pallidirostris (Steppe grey shrike) – Central Asia and parts of northern China, Iran, Afghanistan and Pakistan
An adult great grey shrike is a medium-sized passerine about as large as a bigthrush, measuring from 22 to 26 cm (8.7 to 10.2 in) long. It typically weighs around 60 to 70 g (2.1 to 2.5 oz), although somesubspecies are noticeably smaller or larger, and even in thenominate subspecies adult weights between 48 and 81 g (1.7 and 2.9 oz) are recorded. The wings are around 11.4 cm (4.5 in) and the tail around 10.9 cm (4.3 in) long in the nominate subspecies, its bill measures about 23 mm (0.91 in) from tip to skull, and thetarsometatarsus part of its "legs" (actually feet) is around 27.4 mm (1.08 in) long.[15] Wingspan can range from 30 to 36 cm (12 to 14 in).[16]
Adult male (top) and femaleL. e. excubitor with fledging young (bottom)
The general colour of the upperparts is pearl grey, tinged brownish towards the east of its Eurasian range. The cheeks and chin as well as a thin and often hard-to-see stripe above the eye are white, and a deep black mask extends from thebeak through the eye to theear coverts; the area immediately above the beak is grey. The scapulars (shoulder feathers) are white, and the wings are black with a white bar made up by the bases of the primaryremiges, continuing slightly offset onto the bases of the secondary remiges in some regions. The tail is black, long, and pointed at the tip; the outerrectrices have white outervanes. The underparts are white, slightly tinged with grey in mostsubspecies. In particular the breast is usually darker and sometimes browner than the rest of the light underside, and may appear as an indistinct band between the lighter belly and white throat. In the subspecies around theNorth Pacific in particular and in females elsewhere too, there may be faint brownish bars on the breast. The bill is large and hooked at the tip and coloured nearly black, but pale at the base of the undermandible (though the extent variesseasonally). The legs and feet are blackish.[17]
Males and females are about the same size, and do not differ conspicuously in appearance except by direct comparison. In the female the underparts are greyer and are usually visibly barred greyish-brown, and the white wing and tail markings are characteristically less in extent (though this is rarely clearly visible except in flight).Fledged young birds are heavily tinged greyish-brown all over, with barring on the upperside and indistinctbuffy-white markings. The tips of the tertiary remiges and thewing coverts are also buffy, with a black band in the latter. In the North American subspeciesborealis, the fledglings are tinged quite brown indeed on upperside and wings, and have sharp and dark underside bars. In Eurasia, fledglingsmoult into a female-like plumage with the tertiary bars usually remaining in autumn. Across its range, the young acquire the adult plumage in their first spring.[18]
The male'ssong consists of short pleasant warbling strophes, interspersed with fluid whistles. The individual phrases may go liketu-tu-krr-pree-pree ortrr-turit trr-turit.... To announce that it has become aware of someone straying into itsterritory – be it a female or male of its species or a largemammal – it gives long shrill raspy whistles liketrrii(u) or(t')kwiiet. To announce to females, it often mixes these whistles with a strophe of song. A softer whistle goes liketrüü(t). These whistles are also used in duets between mates in winter and neighbours in the breeding season. Various contact calls have been described aschlie(p),gihrrr,kwä orwuut. These are frequently heard during courtship, interspersed with song phrases as the harsh whistles are in pre-courtship. The song becomes softer and more warbling as the male shows the female around his territory, and at potential nest sites the male gives a lively chatter containing flutingtli-tli,prrr trills andkwiw...püh calls.[19]
When disturbed, its alarm note is a harshjay-likek(w)eee,greee orjaaa, often repeated twice. The more excited the birds become, the higher and faster the calls get, viachek-chek-chek to a rattletrr-trr-trr or an explosiveaak-aak-aak. Abird of prey alert is given with a whistlebreezeek.Knuk calls are given by adults confronted with a potential threat to their young. To beg for food – young to adults or mates to each other – rows ofwaik calls are given. This species sometimes tries to attract small songbirds bymimicking their calls, so it may attempt to catch them for food.[20]
TheIberian grey shrike (L. meridionalis) was formerly included in the great grey shrike assubspecies. It occurs in south western Europe (Iberian Peninsula and France). It prefers differenthabitat – lightly wooded grassland in the great, morearidshrubland in the southern grey shrike – and where the species' ranges overlap, they do nothybridize at present (though they may have done so in pastmillennia).[21]
Elsewhere, theparapatric relatives of theL. excubitor are theChinese grey shrike (L. sphenocerus) fromEast Asia and thenorthern shrike (L. borealis) andloggerhead shrike (L. ludovicianus) from North America. The northern grey shrike issympatric in winter quarters with each of its three close relatives at the north of their range. Their overall colouration is – apparentlyplesiomorphically – shared insub-Saharan Africa by the somewhat more distantly relatedgrey-backed fiscal (L. excubitoroides) which is found from theSahel eastwards, andMackinnon's fiscal (L. mackinnoni) of theCongo Basin region. Thelesser grey shrike (L. minor,Balkans to Central Asia) seems to be quite distinct indeed and issympatric with the grey shrikesuperspecies between Eastern Europe and Central Asia; it may be more closely related to the small brown shrikes and resemble the bold, aggressive and hard-to-catch grey shrikes because ofBatesian mimicry.[22]
The Iberian grey shrike is clearer and usually darker grey above, and not tinged grey but often decidedly pinkish on the belly and particular breast; the white "eyebrow" extends to over the beak, which has typically a larger pale base. The barring pattern is less developed at all ages, hardly ever present even in females, and slighter in the otherwise very similarfledglings.[23]
East AsianL. excubitor are barely sympatric with the Chinese grey shrike. The latter is larger and generally differs from the northern species as the southern does, and in addition has much larger white areas in wings and tail.[24]
The loggerhead shrike is hard to distinguish, but the proportion of the head to the beak (which seems stubby inL. ludovicianus by comparison and is all-dark) is usually reliable. Indeed, the wordloggerhead refers to the relatively larger head of the southern species.[25]
The lesser grey shrike is a smaller and comparatively short-tailed bird. It can best be recognized by the rather large black area above the bill, almost reaching to the forehead and without a white stripe above it. In flight, the wide instead of pointed black tail end ofL. minor is characteristic. The African species are completelyallopatric withL. excubitor; they lack white scapulars (grey-backed fiscal) or wingspots (Mackinnon's fiscal) and differ in some other details, particularly the tail pattern.[26]
Generally, its breeding range is found in Eurasia and northern Africa. In the high mountains of theAltai-Tian Shan region, it ranges south perhaps as far as42° northern latitude. Its northern limit is generally70° northern latitude. It is only found as avagrant inIceland, theBritish Isles, the Mediterranean region (excluding theIberian Peninsula and perhapsRomania but includingCyprus), andKorea. There do not appear to be breeding records from the entireKamchatka Peninsula; in Switzerland, the present dayNetherlands and southern Germany small populations were found in the mid-20th century but have declined or even disappeared since then.[27]
Except for thesubspeciesbianchii which is largely all-year resident, and subspeciesexcubitor in the temperate European parts of its range with their mildmaritime climate, the species is a short-distancemigrant. The migrations are triggered by scarcity of food and therefore, according to prey population levels, the winter range might little extend south beyond the breeding range, or be entirelyparapatric to it. The populations of the Central Asian mountains mostly migrate downslope rather than southwards. Females are more prone to migration than males; they do not appear to migrate, on average, longer or shorter distances than males, and consequently are the dominant sex in many parts of the winter range. Birds leave for winter quarters a more or less short time after breeding – July to October, with most birds staying to September – and return to nest mainly in March/April, but some only arrive in May. In recent decades, the number of birds remaining on the breeding grounds all year has been noted to increase e.g. inFennoscandia, whereas for exampleborealis seems to be as rare a winter visitor in northernOhio as it was a century ago.[2][28][29]
The preferredhabitat is generally opengrassland, perhaps withshrubs interspersed, and adjacent lookout points. These are normally trees – at forest edges in much of the habitat, but single trees or small stands at thetaiga-tundra border. Insteppe, it will utilize any isolated perch, be it fence posts,power lines or rocks. In general, some 5–15 perching sites perhectare habitat seem to be required. It avoids low grassland with no lookouts and nesting opportunities (trees or large shrubs), as well as dense forest with no hunting ground. Apart from grassland, the birds will utilize a variety of hunting habitats, includingbogs,clearings or non-industrially farmedfields. Breeding birds appear to have differentmicrohabitat desires, but little detail is known yet.[30]
Perching sites are important features of great grey shrike habitat
This species isterritorial, but likes to breed in dispersed groups of a good half-dozen adults. It is not known to what extent the birds in such groups are related. In the temperate parts of its range, groups are perhaps 5 km (3.1 mi) apart, while individual territories within each group may be as small as 20 ha (49 acres) but more typically are about twice that size. In less hospitable climes, territories may be more than 350 ha (1.4 sq mi). Throughout the breeding season, in prime habitat, territories are held by mated pairs and single males looking for a partner. In less productive habitat, "floaters" hold territories moreephemerally. This leads to shifts inpopulation density between regions, as "floaters" move between groups of territorial birds in search of a bountiful unclaimed territory to settle down and/or a partner to mate with. On the wintering grounds, pairs separate to account for the lower amount of food available at that time, but if both members migrate they tend to have their wintering grounds not far apart. As it seems, once an individual great grey shrike has found a wintering territory it likes, it will return there subsequently and perhaps even try to defend it against competitors just like a summer territory. Throughout the year, the birds regularly but briefly move through a range up to three times larger than their territory; this is tolerated by territory owners in winter more easily than in summer, and the parts of Europe where all-year residents and winter visitors co-occur typically have population densities around eight[verification needed] birds/km2 (about thirty[verification needed] per square mile) and occasionally more in winter.[31]
An alertL. e. excubitor perching on a wire inLasy Janowskie, Poland
Before and after the nesting season, groups of breeding birds will sometimes initiate gatherings; these seem to occur at the boundary of the group's combined range or in the unclaimed land separating it from neighbouring groups. The initiation signal is a conspicuous display flight given by a bird surveying its territory: it spirals tens of meters/yards high into the air, usually briefly does a fluttering hover at the top of the spiral, and then glides down. Group neighbours will respond by performing the same type of flight, and eventually about half the group's members will depart to the meeting location where they will spend several tens of minutes – sometimes more than an hour – chattering, calling, duetting, and excitedly moving about the meeting site (which typically is some small tree or shrubbery). In winter, birds will often assemble in small groups and roost together, particularly to keep warm during the night; this is apparently not initiated with a specific assembly display however.[32]
The flight of the great grey shrike is undulating and rather heavy, but its dash is straight and determined. It is, as noted above, also capable ofhovering flights, which last briefly but may be repeated time after time because of the birds' considerable stamina. It will usually stay low above the ground in flight, approaching perches from below and landing in an upward swoop. In social interactions, birds signal an aggressive stance by a bold upright posture, fanning and then flicking the tail and eventually the wings also as the bird gets more excited. It signals its readiness to strike at an intruder by shifting to ahorizontal pose and fluffing its feathers, raising them into a smallcrest along the top of the head. Birds appeaseconspecifics by head-turns away from them (if close by), or by imitating the crouching fluttering pose and calls given byfledglingsbegging for food (if sitting father apart). Thesubmission gesture to prevent an imminent attack by a conspecific is pointing thebeak straight up.[33]
Fledgelings moult part of their juvenile plumage before their first winter, and the rest in spring. Adults moult on their breeding grounds before going on migration, or before the depth of winter if they are resident. Sometimes adults also seem to moult some feathers before attempting to breed. As moult requires a considerable investment of energy, some significantevolutionary benefits to offset this are likely. Reducing feather wear andparasite load, moulting can make a bird more physically attractive and healthy, and may thus increase its chance of successful reproduction. The phenomenon is not well understood, however.[2]
Occasionally, animals as large as a youngstoat (Mustela erminea) are killed and eaten by great grey shrikes
The great grey shrike eats smallvertebrates and largeinvertebrates. To hunt, this bird perches on the topmost branch of a tree,utility pole or similar elevated spot in a characteristic upright stance some metres/yards (at least one and up to 18 m/20 yd) above ground. Alternatively, it may scan the grassland below from flight, essentially staying in one place during prolonged bouts of mainly hovering flight that may last up to 20 minutes. It will drop down in a light glide forterrestrial prey or swoophawk-like on a flyinginsect. Small birds are sometimes caught in flight too, usually by approaching them from below and behind and seizing their feet with the beak. If no prey ventures out in the open, great grey shrikes will rummage through the undergrowth or sit near hiding places and flash their white wing and tail markings to scare small animals into coming out. As notedabove, it will sometimesmimic songbirds to entice them to come within striking distance.[32]
Typically, at least half the preybiomass is made up from smallrodents from theCricetidae (voles,lemmings) andMurinae (Eurasian mice and sometimes young Eurasianrats).Shrews, songbirds, other passerines,[34]lizards, andfrogs andtoads (typically astadpoles) make up most of the remaining vertebrate prey. Birds are generally of little importance however, except in spring when male songbirds are engaged incourtship display and often rather oblivious of their surroundings, in late summer when inexperiencedfledglings abound, and in winter when most small mammalshibernate. Occasionallybats,newts andsalamanders, and evenfish are eaten. Prey animals may exceptionally be almost as large as the birds themselves, for example chicks of thewillow ptarmigan (Lagopus lagopus) or a youngstoat. Largearthropods are the second-most important prey by quantity, though not by biomass; in the latter respect they are only a bit more important than birds, except as food fornestlings where they usually form a substantial part of the diet. Most important among invertebrate prey areinsects, especiallybeetles (e.g.ground beetles,dung beetles,rove beetles, anddarkling beetles),[35]crickets andgrasshoppers, andbumblebees andwasps. Invertebrate prey of minor importance arespiders andscorpions,crayfish andisopods,snails, andoligochaete worms.Carrion andberries are rarely if ever eaten; though it might occasionally plunder songbird nests this is not well documented and it is not known to eateggs.[31][36]
Prey is killed by hitting it with the hooked beak, aiming for the skull in vertebrates. If too large to swallow in one or a few chunks, it is transported to a feeding site by carrying it in the beak or (if too large) in the feet. The feet are not suited for tearing up prey, however. It is rather impaled upon a sharp point –thorns or the barbs ofbarbed wire – or wedged firmly between forkingbranches. Thus secured, the food can be ripped into bite-sized pieces with the beak. Orthoptera that the birds have recognized as containing noxious chemicals are left impaled in the larder for several days, until the chemicals that usually deter predators have been degraded. Great grey shrikes have also been observed to impalecommon toads (Bufo bufo) andskin them – by ripping open the back skin and pulling it over the head – to avoid contamination of the meat by the toxic skin secretions. Large bones and similar inedible parts of prey animals are usually not ingested, but smaller ones such as tiny bones or theelytra of beetles are eaten and laterregurgitated aspellets.[32][36]
The basicmetabolic rate of the great grey shrike is around 800milliwatts, or somewhat more than 11 milliwatts per gram ofbody mass. An adult of this species needs about 50 g (1.8 oz) of prey a day, probably somewhat more in winter. Under most circumstances, this would thus translate to one or tworodents, one or two additional vertebrate prey animals (including rodents), and up to a single vertebrate prey item's worth of invertebrates. Surplus food may be impaled for storage. These "larders" are typically around 1 m (3.3 ft) above ground and can be found anywhere within the birds' territory, but tend to be rather in the general vicinity of nest sites than far away from them.[32][37]
Great grey shrikes breed during the summer, typically once per year. In exceptionally good conditions, they raise two broods a year, and if the firstclutch is destroyed before hatching they are usually able to produce a second one. Theirmonogamouspair bond is strong during the breeding season and loosens over winter; birds often choose a different mate than the year before. To seek out potential mates, males will venture outside their breeding territories. If a female thus encountered finds a male to her liking, she will visit to see whether they get along well and inspect the nesting sites he can offer. Thecourtship period is generally longer than in theIberian grey shrike (L. meridionalis), usually starting about March and lasting to April/May. At first, the female rebuffs the male, only allowing him to feed her. Males give increasingly vocal displays and show off the white markings of the wings in flight and of the tail by fanning it and turning away from the female. He also occasionally turns to sit at a right angle to her. Eventually, the female will join in the male's displays, and the songs will become duets. To feed females and to show off their hunting prowess, males will make their food caches in conspicuous places during this time. When presenting nesting sites, males give the variety of calls describedabove and jerk their head and fanned tail.[38]
Nestingfieldfares (Turdus pilaris) and great grey shrikes apparently cooperate to protect their offspring frompredators
Copulation is typically initiated by the male bringing an attractive prey item to the female. With both giving begging calls, they approach until they are side by side. The male then raises and swings his body left and right a few times, and passes the prey to the female, followed by the actual copulation. The gatherings of neighbour groups (seeabove) cease when nesting is underway, and when the eggs are nearly ready to lay, the male guards his partner closely, perching higher than her to watch for threats and frequently feeding her. This apparently ensures her physical well-being rather than preventingextra-pair copulations, as neighbouring males will stray through each other's territory to snatch a quick fling with the resident females. In this, they have almost a one-in-three chance of success, and consequently the average grey shrike nest is very likely to contain offspring of more than one male. Females may deposit their eggs in neighbours' nests, but this seems to occur more rarely; in general, mated females are fairly reclusive after their eggs have started developing. A fullclutch of eggs can be produced by a female in about 10–15 days.[38]
Nests are built in April or May more than 1 m (3.3 ft) above ground in trees. This height varies according to habitat, but while nests have been found almost 40 m (44 yd) up, most are 2–16 m above ground. Presence ofmistletoes orvines likecommon ivy (Hedera helix) on side branches near the trunk (where nests are preferentially built) will make a tree markedly more attractive.Fieldfares (Turdus pilaris) nesting in the vicinity will also increase the desirability of nest sites to great grey shrikes, which moreover often refuse to prey upon thesethrushes' nestlings though the opportunity is there. Apparently, the two species are more efficient in spotting potential nest predators – in particularcorvids – early on andmobbing them off cooperatively than either is on its own. Otherwise, there is no clear preference for particulartaxa of nesting trees, provided they are sufficiently dense.Conifers seem to have become more popular with EuropeanL. excubitor in recent decades, but a diversity ofdeciduous trees is used just as well. Far more rarely, large and especiallythorny shrubs are used for nesting. The actual nesting site is chosen by the male; the courtship visits of the female are mainly to form and strengthen the pair bond. Also, though the partners build the nest together, the male collects most of the nesting material. Thecup nest is quite sizable, measuring 20–28 cm (7.9–11.0 in) in outer diameter. Its body is constructed of coarse vegetable material – mainly large twigs and chunks ofmoss, though bits of fabric and rubbish may be added. The interior cup is 8–12 cm (3.1–4.7 in) in diameter and 10–15 cm (3.9–5.9 in) deep; it is lined with fine twigs and roots,lichen, hair and feathers. Building a nest from scratch takes a pair one to two weeks, but if nests of the previous year in good locations remain usable, they are repaired rather than discarded.[39]
Unlikereed-warblers (Acrocephalus), the great grey shrike seems to haveout-evolved thecommon cuckoo (Cuculus canorus) for the time beingEggs fromMénil-en-Xaintois (France) atMHNTCuculus canorus canorus in a spawn ofLanius excubitor -MHNTLanius excubitor elegans -MHNT
Laying usually takes place in May. The clutch numbers three to nine eggs, typically around seven, with North American clutches tending to be larger on average than European ones. If a second clutch is produced in one breeding season, it is smaller than the first one. The eggs have a white background colour, usually with a grey hue and sometimes with a blue one; they are patterned with blotches of yellowish- to reddish-brown and purplish-grey, often denser around the blunt end. They measure around 26 mm (1.0 in) in length and 19.5 mm (0.77 in) in width.Incubation takes around 16 days but may be closer to three weeks for large clutches; it is generally done only by the female. While the male may briefly take over incubating, his task during this time is to provide food. Thealtricialnestlings hatch naked, blind and pink-skinned, weighing c. 4 g (0.14 oz); their skin turns darker after a few days. The inside of their beak is pink and they probably lack spots or other prominent marks; the wattles at the corners of the mouth are yellow as in manypasserines. As the nestlings grow, the female broods them, and later on assists in providing food. The youngfledge after 2–3 weeks, typically in late June or early July; they become independent of their parents about 3–6 weeks later. Sometimes, a parent will single out particular fledglings (possibly the weakest ones) and focus their care and feeding on these during this time. Other adults have occasionally been recorded assisting in feeding a pair's offspring; it is not clear whether thesehelpers at the nest are offspring of previous years, or unrelated non-breeding "floaters" or breeding neighbours.[37][39]
Common cuckoos (Cuculus canorus) have been noted as regularbrood parasites ofL. e. excubitor in the past; for reasons unknown this has ceased since the late 1970s or so. It may well be that the cuckoo'sgens laying eggs similar to those of the great grey shrike has becomeextinct. Amongpredators of eggs and nestlings,corvids (Corvidae) – extremely close relatives of the shrikes (Laniidae) as it happens[40] – are most significant.[39]
Usually more than half of all nests manage to hatch at least one young, and around three-quarters of all eggs laid hatch, suggesting that if eggs are lost before hatching, it usually is the entire clutch. Half to three-quarters of the hatched young successfully fledge under most circumstances. They will become sexually mature in their first spring and often attempt to breed right away. On average, great grey shrikes get a chance at four breeding attempts during their life, with most birds in the wild getting eaten by abird of prey orcarnivorousmammal or dying of other causes before the end of their fifth winter. Raptorial birds are the main threat to shrikes after fledging, with regular predators including species as small aslittle owls (which are close to the same size as the shrike).[41] The maximum documented lifespan, however, is 12 years.[37][42]
As remarkedabove, the great grey shrike has apparently becomeextinct as a breeding bird in Switzerland and theNetherlands. Overall, its stocks seem to be declining in the European part of its range since the 1970s. The increase and decline seem to be reactions to changing land use, with an increase as the number of agricultural workers declined after World War II and land fellfallow, declining again whenland consolidation (see e.g.Flurbereinigung) had seriously depleted the number ofhedgerows and similar elevated growth formerly common amidst the agricultural landscape. For such apredatory bird, the indiscriminate use ofpesticides (which will accumulate in adult carnivores and inhibit breeding success) around the 1960s probably had a detrimental influence on stocks too.[30]
Altogether, the great grey shrike is common and widespread and not considered athreatened species by theIUCN (though they still includeL. meridionalis inL. excubitor). Wherever it occurs, its numbers are usually many hundreds or even thousands per country. Its stronghold is the region around Sweden, where at least almost 20,000, perhaps as many as 50,000 were believed to live in the late 20th century. However, in some countries it is not robustly established; inEstonia only a few hundred are found, with less than 200 in Belgium and some more or less than 100 inLatvia andLithuania, respectively. The 10 birds or so in Denmark might disappear because of a few years of adverse circumstances. By contrast, inLuxembourg plentiful high-quality habitat is found; though the number of great grey shrikes in this tiny country is necessarily limited, the averagepopulation density there is 25 times as high as in Lithuania.[1][30]
Aldrovandi, Ulisse (Ulyssis Aldrovandus) (1646):De alio laniorum genera majore Ornithologi ["Of the other kind of shrike, called the Greater by ornithologists"].In: Ornithologia (3rd ed., Vol. 1): 389 [in Latin]. Nicolò Tebaldini, Bologna ("Bononia").
Antczak, Marcin; Hromada, Martin; Tryjanowski, Piotr (2005). "Frogs and toads in the food of the Great Grey Shrike (Lanius excubitor): larders and skinning as two ways to consume dangerous prey".Anim. Biol.55 (3):227–233.doi:10.1163/1570756054472836.
Clement, Peter; Worfolk, Tim (1995). "Southern and eastern Great Grey Shrikes in northwest Europe".Birding World.8 (8):300–309.
Frisch, Johann Leonhard (1720):Der V.ten Hauptart II.te Abtheilung, Viererley Arten Aelstern – II.te Platte ["Second division of the fifth primary species, the four species of magpies – Plate 2"].In: Vorstellung der Vögel in Teutschland, und beyläuffig auch einiger fremden, mit ihren natürlichen Farben, etc. (Vol. 5): plate 55 [German with Latin and French captions]. F.H.Frisch, Berlin ("Berolinum").
Harris, Tony & Franklin, Kim (2000):Shrikes & bush-shrikes: including wood-shrikes, helmet-shrikes, flycatcher-shrikes, philentomas, batises and wattle-eyes.Christopher Helm, London.ISBN0-7136-3861-3
Linnaeus, Carl (1758): 43.2.Lanius excubitorArchived 2017-06-13 at theWayback Machine. In:Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis (10th ed., Vol. 1): 94 [in Latin]. Lars Salvius, Stockholm ("Holmius").
Ray, John (Joannis Raii) (1713): A. 3.Lanius seu Collurio cinereus major. In:Synopsis methodica avium & piscium: opus posthumum, etc. (Vol. 1) [in Latin]. William Innys, London.
Sangster, George; Knox, Alan G.; Helbig, Andreas J.; Parkin, David T. (2002). "Taxonomic recommendations for European birds".Ibis.144 (1):153–159.doi:10.1046/j.0019-1019.2001.00026.x.
Keller; Herrado; Voříšek (2020).European Breeding Bird Atlas 2: Distribution, Abundance and Change. Barcelona: European Bird Census Council & Lynx Editions.
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