Siberian Red-Tailed Shrike or Butcher-Bird
Lanius cristatus cristatus L.
Habitational status: Breeds and migrates throughout nesting range.
Timetable: In Indochina appears at winter quarters in second third of September, flying out in late April, some lingering until early May (Olivier, 1944). In northern Thailand first however appear as early as late August, with last departing in first 5 days of May; sometimes appear only in January or February (Deignan, 1945). Arrives at nesting areas relatively late: at Tomsk in late May, in Altais, along Kolyma, in Anadyr, apparently only in early June, at Krasnoyarsk about June 1; in Chita Region common in late May (Pavlov, 1948), with similar dates probably also applying to Kamchatka (Dybovskii). In northwest Mongolia arrives about May 24-26, large-scale flights in late May (Kozlova, 1930). Departs at various times in late August and finishes in first half of September. Departs in parties of 10-15 (Tugarinov and Buturlin, 1911).
Biotope: In general similar to European form, but in contrast does not avoid true forests and frequently -- at least in central and West Siberia - occurs in mountains. In Altai Mountains rises to heights of 1800m (Sushkin, 1938). In north of range in river valleys and willow beds. In other regions in coniferous and mixed stands of open woodlands, in burns and fellings, etc. In Kamchatka in light poplar and birch tracts (but not conifers).
Numerical status: Common, but sporadically distributed.
Breeding: Data fragmentary. Beginning of breeding period in second half of June. Fledglings in Minusinsk wooded steppe and in Altais only in late July (July 24; Sushkin, 1938); Johansen (1944) obtained subfledgling in Salair on July 17. In Kamchatka in mid-July, at Chapina, observations of incubating birds, flighted juveniles and Kozyrevka on August 12 (Bergman, 1934). In Chita Region nests found on ground or in bushes of willow, dwarf birches and hawthorns. Nests constructed of stems and blades of previous year's grass crop, with 6-7 eggs per clutch, color of eggs as in European form. Eggs laid once daily. On June 14 1 nest contained 1 egg, complete clutch in this nest of 6 eggs on June 19. Incubation begins with last egg. In another nest on June 24 were 7 incubated eggs. Nest constructed by female (Pavlov, 1948). Around Krasnoyarsk nests lie most frequently in shrubbery, some 70-150 cm above ground, of plant scraps, with external layer of twigs, bark, thick stalks, etc.; lining of grass blades, roots and horsehair. Number of eggs 5-8, ground color most often white-greenish. Egg sizes (18) 21.0 - 24.8 X 16.3 - 18.3, have 22.8 X 7.3 mm (Tugarinov and Buturlin, 1911). Juveniles hatch in early July and soon leave nest, hiding in grass in case of danger (Tugarinov and Buturlin, 1911). At Krasnoyarsk 5 fresh eggs found on 18 June 1928, incubated clutch until late June (Yudin, 1952). In Zoological Museum of Moscow University are following juveniles: fully grown, obtained in Slyudyanka, Irkutsk District, 27 July 1912; similarly from Sosnovka, northern Baikal, 7 August 1923; with still-growing wings and tail from vicinity of Olekminsk from July 29; very small, just putting on feathers, from 8 July 1907, from same place, at Malaya Cherepanikha River, and another from same place fully- grown, 18 July 1908; juvenile fram Pokhodsk, lower Kolyma, with growing tail and wings, 9 August 1903.
Molt: As in nominal form in general. Replacement of feathering of juveniles recorded in August. End of full molt in adult in Thailand in April or even early May (Deignan, 1945).
Diet: Primarily insects, particularly beetles, also grasshoppers (Pavlov, 1 9 48). De ta ils uncla r ified.
Size and Structure: Wing formula generally 3 > 4 > 5 > 2 > 6, sometimes 4 > 3 or 6 > 2. Tip of wing, according to Shtegman, 22 - 27mm. Tail with narrow rectrices, more rounded than in western group of subspecies (collurio--phoenicuroides -- isabellinus)- difference between middle and extremic rectrices 20-25 mm (in western forms 8 -15 mm). Beak powerful with sharper hook, length about 14-15 mm, Length of tail about 75-85 mm; tarsometatarsus about 25 mm. Wing 80-90, tip of wing (according to Shtegman) 22 -27 mm.
Coloration: Similar to dark individuals of Turkestan birds (L. c. phoenicuroides), but upperparts grayish brown, head russet brown, forehead and superciliaries pure white, tail yellowish brown; wings gray- brown, lacking speculum; underparts ocher, paler than in Turkestan form; throat white. Female resembles male, but general tone duller, sometimes with vestiges of undulant barring abdominally, particularly at sides of breast. Iridea brown, bill black, feet leaden gray. Juveniles in first plumage have feathers relatively darker, rufous brown, with well developed barring abdominally. Juvenal plumage grayish brown above, ocher below, with black wavy barring.