Sciurus vulgaris, Linnaeus, 1758
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publication ID |
https://doi.org/ 10.5281/zenodo.6840226 |
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DOI |
https://doi.org/10.5281/zenodo.6822965 |
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persistent identifier |
https://treatment.plazi.org/id/064D0660-FFED-ED11-FA69-F477F66FFD1D |
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treatment provided by |
Diego |
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scientific name |
Sciurus vulgaris |
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Eurasian Red Squirrel
French: Ecureuil d’Eurasie / German: Eurasisches Eichhérnchen / Spanish: Ardilla roja de Eurasia
Taxonomy. Sciurus vulgaris Linnaeus, 1758 View in CoL ,
“in Europae arboribus.” Restricted by O. Thomas in 1911 to Uppsala, Sweden.
Twenty-two subspecies are recognized.
Subspecies and Distribution.
S. v. imlgans Linnaeus, 1758 — S Scandinavia. S. ıı. alpmus Desmaresl, 1822 - Iberian Peninsula, S France, and Italy. S. v. allaıcıu Screbrennikov, 1928 - Altai of E Russia, N Mongolia, and NW China. S. v. anadyrrmzs Ognev, 1929 - Far N Russia across Siberia. S. u. aıctıcus Trouessart, 1906 - Boreal Siberia lo the Lena River (Russia). S. v. balcanıcus Heinrich, 1936 - E Balkan Peninsula. S. v. chiliensis Sowerby, 1921 — E China.
S. v. cinerea Hermann, 1804 — C Europe.
S. v. dulkeiti Ognev, 1929 — Amur Region of E Siberia to include Shantar Is (Russia).
S. v. exalbidus Pallas, 1779 — W Siberia E of the Ob River (Russia).
S. v. fedjushini Ognev, 1935 — Belarus, Lith- uania, Latvia, and Estonia.
S. v. formosovi Ognev, 1935 — NW Russia.
S. v. fusconigricans Dwigubski, 1804 — Mon- golia and China.
S. v. leucourus Kerr, 1792 - Great Britain and Ireland.
S. u. lilaeus Miller, 1907 - W Balkan Peninsula.
S. v. mantchumw Thomas, 1909 - NE China and Korean Peninsula.
S. u. manensr Matschie. 1901 - W Siberia to W of the Ob River, Russia.
S. v. ogvmıı Migulin, 1928 - W Russia.
S. v. mimtıs Thomas, 1906 - Hokkaido 1 (Iapan).
S. v. mpalns Thomas, 1907 - Sakhalin (Russia).
S. v. ulmımwııs Migulin, 1928 - Ukraine.
S. v. vanus Gmelin. 1788 - N Scandinavia. View Figure
Introduced populations of unknown subspecies were reported for Crimea (Ukraine), E Anatolia (Turkey), the Caucasus (Georgia, Armenia, and Azerbaijan), several parts of Kazakhstan and Kyrgyzstan S of the original native distribution, Japan (Tokyo), and Saint Kitts and Nevis Is in the Caribbean.
Descriptive notes. Head-body 206-250 mm,tail 150-205 mm; weight 235-480 g. The Eurasian Red Squirrel has uniformly dark dorsum, with color varying from dark red, black, brown, gray to bluish. Often ears, legs, and hips have suffusion of red. Ear tufts are pronounced in winter and reduced in summer. Venter is cream to white. Tail is most often same color as dorsum, butit can be lighter in shade, occasionally black or nearly white in some subspecies. Melanism is common, especially in mainland, boreal, and montane populations. Subspecies are not well defined and lack a thorough distribution-wide assessment. Nominate vulgaris is smallish, has reddish dorsum, and lacks dark phase. Subspecies alpinus is intense russet-brown over dorsum. Subspecies altaicus is highly variable and includes extremely dark variants. In winter, anadyrensis has tinge of chestnutin its grayish dorsal pelage. Subspecies arcticus has reddish to bay dorsum and a white venter. Subspecies balcanicus is more brownish form. Subspecies chiliensis is black across dorsum and tail, with varying amounts of reddish. Subspecies dulkeiti has black or black-chestnut dorsum and black tail throughout the year. Subspecies exalbidus is pale buff-gray in winter, with light gray tail. Subspecies fedjushini has rich dark reddish brown dorsum, with dark chestnut or red tail. Winter pelage offormosovi is gray, with chestnut tail. Subspecies fuscoater is bright red, with white venter. Subspecies fusconigricans is usually dark chestnut or black-chestnut in summer and dark black to bluish gray in winter, with small white patch on venter. Subspecies leucourus has reddish dorsum, with tail that often fades to white in summer. Subspecies lilaeus is generally brownish form. Subspecies mantchuricus has black tail year-round, and dark gray winter pelage. Subspecies martens: has chestnuttail, with pale gray winter pelage and yellow buff on hips in summer. Subspecies ognevi is smallish, with highly variable color, but winter pelage is often light gray, with tinge of buff. Subspecies orientis is endemic to Hokkaido, with gray dorsum and white venter. Subspecies rupestris has black or black-chestnut dorsum, with black tail throughout the year. Subspecies ukrainicus has dorsum and tail that retain much of their reddish brown color in winter. Subspecies varius has light bluish gray dorsum in winter, with dark chestnutto red tail. Chromosomal complementis 2n = 40 and FN = 70.
Habitat. Coniferous, deciduous, and mixed forests and parklands from sea level to subalpine forests within the great mountains of Europe and northern Asia. The Eurasian Red Squirrel can be found in urban and suburban areas, conifer plantations, and secondary forests at generally lower densities. It is uncommon in fragmented and discontinuous forests.
Food and Feeding. The Eurasian Red Squirrel is primarily herbivorous and forages in the canopy and on the ground throughout the year. It feeds heavily on tree seeds, especially those of conifers, but also eats other plant tissues including fruits, buds, flowers, shoots, herbs, bark, and sap. Hypogeous and epigeous fungi, lichens, insects, larvae, bird eggs, avian nestlings, bones, and scavenged carcasses are consumed on occasion. A conspicuous behavior is the autumnal scatterhoarding of pinecones and seeds of low perishability and to lesser amounts acorns and other nuts to serve as winter food store. Hoarding activities are more common in deciduous forests compared with coniferous forests. Squirrels collect tree seeds near parent trees, disperse to distant sites, and bury in the soil. These behaviors serve to decrease loss of this critical food source to other seed predators such as birds that forage primarily be sight. Caches are recovered throughout winter and spring using a combination of spatial memory and olfactory cues; however, spatial memory of the Eurasian Red Squirrel appears less acute than that of the introduced Eastern Gray Squirrel (S. carolinensis). Fungi are also cached in branches of trees and permitted to dry for storage. Success in recovery of caches increases probability of survival and augments reproductive success.
Breeding. Breeding season occurs in December—August. Males track females’ reproductive condition throughout the year by following them and sniffing their genitalia. As with all known tree squirrels, estrus lasts for a few hours on a single day during a breeding season. Males congregate near a female’s nest in the morning on her day of estrus, and as many as twelve males will pursue her throughout the day. Dominant males are able to obtain the majority of mating, which occur along tree trunks, in branches, on the ground, or in dens. Copulation lasts less than 30 seconds. Litters of 1-6 young are born in tree cavities or leaf nests most frequently in February-April and
May-August. Individuals in good body condition and high dominance rank have the greatest reproductive success. Adult females typically produce a single litter each year, but some females produce a second litter. Young emerge from the nest after 6-7 weeks and are weaned at 8-12 weeks of age. Adult size is achieved at c.1 year. Most individuals do not reproduce until at least 10-11 months of age, and many will not do so until almost two years old. Lifetime reproductive success for adult females averages c.5 five young/lifetime but varies greatly from one to eleven young. Natal dispersal occurs soon after weaning, and all males and females leave their natal areas.
Activity patterns. Eurasian Red Squirrels are diurnal and active throughout the year. Activity is distinctly bimodal in summer, with early morning and late afternoon-early evening peaks in activity and midday lull. Winter activity is unimodal and focused during the relative warmth of midday. During periods of extreme inclement weather, Eurasian Red Squirrels may enter short periods of torpor in their nests.
Movements, Home range and Social organization. The Eurasian Red Squirrel nests in cavities or constructs spherical dreys from leaves, pine needles, and twigs placed high in the canopy. It is relatively solitary; however, several adults will share a nest at night, especially in cold months in winter and spring. Multiple individuals will also feed at concentrated food sources, with interactions that are at best tolerance but often agonistic. Individuals will scent-mark trees with their cheek glands on occasion while moving through the forest. Home range overlap is modest, especially among females, which often defend core areas especially during lactation. Home ranges are 6-2-31-4 ha for males and 2:4-19-7 ha for females. Extreme home ranges as large as 47 ha have been reported in high-elevation forests. Vocalizations are primarily alarm calls that start as intermediate-pitched barks or chucks that will escalate to long highpitched whines if threat level is high or remains unabated;tail flagging also appears to increase with threat level.
Status and Conservation. Classified as Least Concern on The IUCN Red List. Population trend of the Eurasian Red Squirrel is decreasing. Subspecies leucourus is considered to be in critical decline in the British Isles. The Eurasian Red Squirrel is considered near threatened in Mongolia and Croatia and vulnerable in Poland and China. This large-bodied squirrel is hunted or trapped for food and pelts in many parts ofits distribution. Serious conservation concerns for populations in countries such as Mongolia exist due to harvest. The Eurasian Red Squirrelis often valued in parks and urban areas as an aesthetically appealing synanthrope. The Eurasian Red Squirrel is frequently considered a pest in gardens, orchards, or other agricultural lands because they pilfer crops. Furthermore, their habit of occasionally stripping bark to obtain cambium retards tree growth and reduces vitality. This behavior is rarely a problem in areas of native distribution, but the introduced Eastern Gray Squirrel causes excessive damage. The Eastern Gray Squirrel has rapidly spread in Great Britain and Ireland, with concomitant decline in the distribution and abundance of the Eurasian Red Squirrel. Eastern Gray Squirrels occur at higher densities in broadleaf forests and form kin clusters of related females, nest in large groups, digest acorns more efficiently, and accumulate fat more quickly than Eurasian Red Squirrels in some habitats. The Eastern Gray Squirrel also pilfers caches of the Eurasian Red Squirrel, decreases summer breeding, and limits juvenile recruitment of the declining native. Furthermore, the Eastern Gray Squirrel harbors poxvirus without pathology; however, the virus is extremely virulent and nearly always fatal to Eurasian Red Squirrels. Furthermore, the Eurasian Red Squirrel demonstrates extreme sensitivity to fragmentation of their habitat. Combination of habitat loss and associated fragmentation constitutes a significant threat to the Eurasian Red Squirrel in many regions. Long-term conservation strategies will require wise and large-scale forest management efforts; such efforts are underway in northern England and Scotland. Restoration of native predators also provides some optimism for recovery of populations.
Bibliography. Everest et al. (2014), Grill et al. (2009), Gurnell (1987), Liu Zhu etal. (2014), Lurz et al. (2005), Ognev (1963), Romeo et al. (2015), Sainsbury et al. (2008), Sheehy & Lawton (2014), Teangana et al. (2000), Thomas (1911c¢), Thorington et al. (2012), Wauters & Casale (1996), Wauters & Dhondt (1989, 1992), Wauters, Bertolino et al. (2005), Wauters, Casale & Dhondt (1994), Wauters, Lurz & Gurnell (2000), Wauters, Matthysen & Dhondt (1994), Wauters, Tosi & Gurnell (2002), Wauters, Verbeylen et al. (2010), Wauters, Vermeulen et al. (2007), Zong Cheng et al. (2014).
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