Preferring colder climates and higher elevations, the spotted the nutcracker ranges from Scan- dinavia across northern Europe and as far as eastern Asia. It occupies coniferous forest Nutcracker (pine, fir and spruce) as well as mixed conifer and birch forest. A bird that shares its name with the famous Russian ballet that begins as night falls on Christmas Eve, the nutcracker has one of the most remarkable memories in the animal kingdom. Nutcracker dolls were originally The nutcracker gets its name given as gifts and are associated from its unusual ability to crack with the Christmas season in Ger- open hard shells, with the help of an interlocking ridge on the many. Modern versions are most- inside of its beak. Larger, ly decorative and unable to crack harder nuts are wedged into nuts as efficiently as their avian a crevice or held in the claws before being pecked open. counterparts! The spotted nutcracker feeds Each nutcracker must hoard enough seeds, on pine nuts and hazelnuts, nuts and other edibles to see it through the which are among the most winter. Each cache is carefully disguised energy-rich seeds in its habitat. with layers of bark, lichen, moss and other In autumn, the birds extract natural camouflage. pine nuts from the ripened When the cold weather arrives, nutcrackers cones, stow them in large turn from hiding to seeking. Studies have numbers in special pouches shown that they have a remarkable memo- under their tongues and carry ry and can remember where to find most of them to carefully-selected the seeds they’ve hidden, even when seve- storage places where they are ral feet of snow cover makes the surroun- then buried. A single bird can dings unrecognisable. Any forgotten seeds bury tens of thousands may eventually sprout to become part of of seeds per year. the forest of the future - making nutcrac- kers an important means by which Eurasian coniferous forests rejuvenate and spread. Research has demostrated that nutcrackers hide seeds in areas where they are least likely to germinate—such as heavily shaded spots or areas with low soil moisture - to maximises the ‘shelf life’ of the deposited food. However, pine trees don’t need lots of successful germinations to maintain healthy populations,as they can live for hundreds of years. Nutcrackers have a highly sophistica- ted spatial memory, which allows them to recall landmarks, such as trees, to pinpoint the locations of their food caches. Their hippocam- pus (the part of the brain associated with spatial memory), continues to produce neurons into adulthood, meaning that the nutcracker’s memory improves with age, unlike ours. Nutcrackers are corvids. That In times of famine, populations move to means they’re in the same a new habitat in mass movements family as crows, jays, ravens called invasions. Invasions have and magpies. Corvids are occurred in Europe some 25 times in the among the most intelligent last 250 years, since the first record in birds that have been studied, 1753. In 1968, during one of the largest with a brain-to-body mass ratio scale invasions, nutcrackers from equal to that of great apes and Siberia were recorded in Belgium and cetaceans, and only slightly Britain,with a few individuals getting as lower than humans. far as Portugal and North Africa. The spotted nutcracker reaches Nutcrackers favour high altitudes; the western limits of its range some live in the Himalayas at in Euope, but across the above 13,000 feet! Atlantic the Clark’s nutcracker - a separate species with broadly similar habits - makes its home in the pine forests of western North America [Left] While stored seeds and nuts should carry the nutcrac- ker through the winter, it may source other food when hungry (in this case, reindeer meat at a herder’s camp). [Right] During the summer and autumn months, when seeds and nuts are out of season, nut- crackers supplement their diet with berries and insects. Some species of pine have cones that do not open when the seeds are ripened. These pines rely upon animals such as nutcrackers to break open the cones and disperse their seeds. The way nutcrackers disperse and store pine seeds provides the pine with a better planting mechanism than simply dropping it seeds on the ground. KRAAAAK! Spotted nutcrackers breed The nutcracker’s call is simi- KRAAAAK! between March and May, lar to that of the Eurasian jay. depending on their geographic It is described as a harsh, dry location. The young are fed at ‘kraaaak’- sometimes repea- the nest by both parents for ted as a quick rattle. It also has about three weeks, begging a song consisting of various for food with a goat-like bleat. piping, whistling, squeaking They stay with their parents for and clicking sounds. a further three months after fledging. Spotted nutcrackers can breed even when snow is still covering the ground, thanks to their supply of cached seeds, which enables them to feed their chicks when other food is scarce. Nutcrackers range from 32–38 cm in length (from tip of beak to tip of tail) and have a wingspan ranging from 49–53 cm. Nutcrackers rarely leave their home ranges, unless they need to search for new food supplies. Failures in pine seed production sometimes occur, usually after several seasons of good seed production, which in turn builds up the nutcracker population and increases competition for food. Traditionally, the nutcracker has been thought of as a territorial species, but recent research has challenged this view. Rather than maintaining territories, at least some popu- lations have home ranges that overlap. The birds have been shown to tolerate interlopers on their home range, possibly because each nutrcracker’s food store is known only to its Nutcrackers are strong and may owner. However, if a visiting act aggressively towards each bird tries to take food from other if they feel their food another’s home range, the supply is being threatened. resident bird may respond by attacking it. Contact: [email protected] +44 (0)117 911 4675 All photos © naturepl.com.