Thenorthern nutcracker (Nucifraga caryocatactes), previously known asspotted nutcracker andEurasian nutcracker, is apasserine bird in the crow familyCorvidae. It is slightly larger than theEurasian jay but has a much larger bill and a slimmer looking head without any crest. The feathering over its body is predominantly chocolate brown with distinct white spots and patches. The wings and upper tail are black with a greenish-blue gloss.
The northern nutcracker is one of four species ofnutcracker currently accepted. Thesouthern nutcracker (Nucifraga hemispila) and theKashmir nutcracker (Nucifraga multipunctata) were formerly considered assubspecies of the northern nutcracker. The species complex was known by the English name "spotted nutcracker". The other member of the genus,Clark's nutcracker (Nucifraga columbiana), occurs in western North America.
The northern nutcracker was one of the many species originally described byCarl Linnaeus in his landmark 175810th edition ofSystema Naturae, and it still bears its original nameNucifraga caryocatactes.[2] The scientific name is areduplication;nucifraga is aNeo-Latin translation of GermanNussbrecher, "nut-breaker" based onLatinnucis "nut", andfrangere "to shatter",[3] andcaryocatactes based onGreek:karuon "nut", andkataseio "to shatter".[4] The common English namenutcracker first appears in 1693 in a translation of a German travel guide,[5][6] where it is a calque on the German nameNußknacker,[7] as the bird was not recorded in Britain until 1753.[4] Other Germanic languages have etymologically related names:Danish:nøddekrige;Dutch:notenkraker;Norwegian:nøttekråke;Swedish:nötkråka.
Northern nutcracker ranges from 32–38 cm in length (from tip of beak to tip of tail) and has a wingspan ranging from 49–53 cm. It is a dark brown, broad-winged, short-tailed corvid. Body plumage is mid-to-dark chocolate brown, heavily spotted with white on face, neck, mantle and underparts. It has a large white loral spot, a white eye-ring, blackish-brown cap extending onto the nape, dark blackish wings with a greenish-blue gloss, all white vent, and dark tail with white corners above and a white terminal band on the undertail. In flight, broad wings, white vent and short tail are noticeable; the flight undulating. The black bill is slender to stout and rather long, sharply pointed, and varies in size amongst races. The iris, legs and feet are black.[9]
Northern nutcracker call. Savoie, French Alps
The voice is loud and harsh, somewhat similar to that of theEurasian jay but slightly lower pitched and more on a single tone. It is described askraak-kraak-kraak-kraak.
APinus cembra cone stripped of its scales and seeds by a foraging nutcracker
The most important food resources for this species are the seeds (pine nuts) of variouspines (Pinus sp.), principally the cold-climate (far northern and high altitude) species ofwhite pine (Pinus subgenusStrobus) with large seeds:Swiss pine (P. cembra),Korean pine (P. koraiensis),Japanese white pine (P. parviflora,Macedonian pine (P. peuce),Siberian dwarf pine (P. pumila), andSiberian pine (P. sibirica). In some regions, where none of these pines occur, the seeds ofspruce (Picea sp.) andhazel nuts (Corylus sp.) form an important part of the diet too. The forms that take hazel nuts have thicker bills for cracking their hard shells, with a special ridge on the inside of the bill edge near the base. If the shell is too hard, it holds the nut between its feet and hacks at it with its bill like a chisel.[10]
A special adaptation is found in the tongue of the nutcracker. The tip of the tongue forks with two long pointed appendages which are keratinised into nail like surfaces. This is thought to help them handle and shell conifer seeds.[11]
Surplus seed is always stored for later use and it is this species that is responsible for the sowing of new trees of their favoured pines, including the re-establishment of the Swiss pine (Pinus cembra) over large areas in the Alps of central Europe where it had formerly been cleared by human overcutting.[10]
Variousinsects are also taken, and also smallbirds, their eggs and nestlings, smallrodents andcarrion such as roadkill. It digs outbumble bee andwasp nests avidly to get at the grubs.[10]
Nutcracker pairs stay together for life and their territory expands between 20 and 30 hectares. Nesting is always early in this species across its whole range, so as to make the best use of pine nuts stored the previous autumn. The nest is usually built high in a conifer (sometimes broadleaved trees are used) and usually on the sunny side. There are normally 2-4 eggs laid and incubated for 18 days. Both sexes feed the young which are usually fledged by about 23 days and stay with their parents for many months, following them to learn the food storage techniques essential for survival in their harsh environment.[10]
The northern nutcracker has an extensive range forming a broad swathe east–west fromScandinavia right across northern Europe,Siberia and to eastern Asia, includingJapan, inhabiting the hugetaigaconifer forests in the north.[10]
Disjunct populations occur in mountain conifer forests further south, in themountains of central and southeast Europe in theAlps, theCarpathians and theBalkan Peninsula mountains. See subspecies list above for race distributions. Some of the populations can be separated on bill size.[9]
This species has a large range, extending over 10,000,000 km2 globally. It also has a large global population, with an estimate of between 800,000-1,700,000 individuals in Europe.[12]
Northern nutcrackers are notmigratory, but will erupt out of range when a cone crop failure leaves them short of a food supply, the thin-billed eastern raceN. c. macrorhynchos being the most likely subspecies to do this.[9] Britain records very sporadic vagrants, but in 1968 over 300 nutcrackers visited Britain as part of a larger irruption into western Europe, probably due to a spell of early cold weather in Siberia.[4]
^Linnaeus, Carl (1758).Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata (in Latin). Holmiae. (Laurentii Salvii). p. 105.
^John Ray.A Collection of Curious Travels and Voyages.. Vol. II xi. 181.
^See, for example, Brehms Thierleben.Allgemeine Kunde des Thierreichs, Fünfter Band, Zweite Abtheilung: Vögel, Zweiter Band: Raubvögel, Sperlingsvögel und Girrvögel. Leipzig: Verlag des Bibliographischen Instituts, 1882. S. 446-450.
