Crocidura russula
Creators: name: Mittermeier, Russell A.
name: Wilson, Don E.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Soricomorpha
Soricidae
Crocidura
Crocidura russula

description: 296. Greater White-toothed Shrew <i>Crocidura russula</i> <b>French:</b> Crocidure musette / <b>German:</b> Hausspitzmaus / <b>Spanish:</b> Musarana mayor <b>Other common names:</b> Greater Shrew, White-toothed Shrew <b>Taxonomy.</b> Sorex russulus Hermann, 1780, near Strasbourg, Bas Rhin, France. Many populations throughout Europe and Asia have been attributed to this species, although upon additional study, many of these are now attributed to C. suaveolens and C. gueldenstaedtii. Humans probably introduced the Canary Islands population of C. russula even though its size, ecology, and behaviors are distinct. This population was listed as a separate species (C. osorio) for many years before morphological and genetic data found it to be a peripheral population of C. russula and is thus treated as a synonym of subspecies russula. Crocidura pachyura was previously included under C. russula as C. r. ichnusae, although it was recognized as distinct based on morphological and genetic data. Additional research is still needed to further differentiate the two species. Crocidura russula seems to have originated in Africa and diversified into two lineages: one spreading into mainland Europe (some speculate that they were introduced by humans in ancient times; C. russula) and the other onto a few Mediterranean islands (Ibiza, Sardinia, and Pantelleria; C. pachyura). The forms cintrae, osorio, peta, and pulchra (all of which are treated as synonyms of russula here) have been recognized as distinct subspecies. Additional research into the biogeographical history and evolution of subspecies is needed. Two subspecies recognized. <b>Subspecies and Distribution.</b> C.r.russulaHermann,1780—W&amp;SWEuropeinGermany,Belgium,Netherlands,Luxembourg,N&amp;WSwitzerland,France,Spain,Portugal,andmanycloseoffshoreislands.ApopulationhasbecomeestablishedonGranCanariaIintheCanaryIs,althoughwhenthespecieswaslikelyintroducedisunresolved. C. r. yebalensis Cabrera, 1913 — NW Africa in N Morocco and N Algeria. The Greater White-toothed Shrew has also been recently reported in S Ireland, where it was likely recently introduced, probably representing the subspecies russula. They also seem to have made it to Scilly Is and the Channel Is, where they probably traveled by boat. <b>Descriptive notes.</b> Head-body 44-86 mm, tail 24-47 mm, ear 5-11 mm, hindfoot 10-14 mm; weight 5-16 g. The Greater White-toothed Shrew is medium-sized, with soft and moderately dense pelage. Dorsal fur is highly variable and ranges from reddish brown to grayish, being yellowish gray at the base. Ventral pelage is lighter and fades from dorsal pelage, being grayish white to gray. Feet are dark although somewhat lighter than dorsum. Tail is ¢.50% of head-body length, dark brown, and covered in long bristle hairs. Ears are relatively large and not concealed by pelage. The Greater Whitetoothed Shrew is said to be very similar to the Guldenstadt’s White-toothed Shrew (C. gueldenstaedtir) but is generally larger. Skull is elongated, and rostrum is narrow; antero-dorsal apex of rostrum is visible; third unicuspid is the same size as second and longer than parastyle of upper premolar. There are three unicuspids. Chromosomal complement has 2n = 42 and FN = 60 in Morocco. <b>Habitat.</b> Wide variety of habitats including shrubland (maquis), open habitats, forest edges with abundant ground vegetation, cultivated fields, urban areas, gardens, farms, mountainous areas, and land adjacent to rivers and streams at elevations less than 1000 m. The Greater White-toothed Shrew often favors old terraces with dry stonewalls. In northern Europe and at higher elevations, it is predominantly commensal, living near humans in houses and gardens. The Canary Islands population is found in remnant patches of humid laurel forests on Northern Grand Canary Island and in extensively managed farmlands. <b>Food and Feeding.</b> The Greater White-toothed Shrew eats a wide variety of invertebrate prey, primarily insects, although it is also known to eat earthworms, centipedes, spiders, snails, and slugs. Despite its small size, it occasionally eats young of other small mammals or small lizards, including geckos. Plant material is also found in diets. In Algeria, insects made up the largest proportion of diets, both in terms of biomass (48:9%) and individual prey items (122 out of 155 total food items in stomach contents); centipedes (29-7%) and lizards (14-9%) also made up notable proportions of biomass. They generally eat ¢.50% of their body weight each day. <b>Breeding.</b> The Greater White-toothed Shrew is monogamous and exhibits femalebiased dispersal, which is a rare for a mammal. It has a single breeding season and fertilization occurs directly after parturition. Breeding occurs in March-September (February-November in Mediterranean regions of Europe). Females can have up to four litters per year and up to eight in their lifetimes. Gestation lasts 28-33 days, and litters have 2-10 young. Males and females care for young, which is relatively unique among shrews. They both defend their territory and also forage for food, although males will more often stay with the nest while females forage. Males will stay with the female throughout all the litters she produces in a year and will even collect nest material. Young are weaned after 13-20 days, at which point they are independent and become sexually mature at 58 days for females and 84 days for males. One of the reasons for female dispersal is to avoid inbreeding; this dispersal might also be caused by local infiltration and migration to empty breeding sites. Females from the first litter in the season generally disperse prior to mating to avoid inbreeding with their siblings and father. All later litters usually do not reproduce until the following year, remaining close to their parental territory. Although females disperse, ¢.50% of them remain locally, and most males also stay close to their natal areas, increasing risk of inbreeding among siblings for those born later in the season. The Canary Islands population has a smaller litter size and lower metabolism than in mainland populations, possibly as a response to living in a warm and variable environment. Greater White-toothed Shrews have exceptionally long-life spans for a shrew, living up to four years in captivity. In the wild, they are only known to live c.18 months in most cases, rarely living to a second breeding season. <b>Activity patterns.</b> Greater White-toothed Shrews are terrestrial and forage by rummaging through leaf litter on the soil surface. They alternate bouts of activity with rest throughout the day and night, but activity peaks at dusk and dawn. Greater Whitetoothed Shrews tend to nest under stones and logs or in abandoned burrows of other small mammals. In winter, they share nests when they rest and enter torpor. They mainly use runways to get around but also use tunnels that have been excavated by other mammals. <b>Movements, Home range and Social organization.</b> Greater White-toothed Shrews are semi-social and live in close proximity to one another, which is relatively unusual among shrews but might be common within Crocidurinae. Females and males stay together in a nest through the breeding season and to rear young. Females generally disperse relatively quickly, and males stay closer to their natal home ranges. Home ranges are reported to be small and overlap extensively in winter, especially between males and females. In summer, males and females come together and have continually overlapping home ranges but will become more territorial to the same sex. They can be relatively vocal and make various high frequency twitters and chirps during social interactions. Home ranges have been reported to be 75-395 m®. It is thought that they navigate with a primitive form of echolocation, producing a twittering call (i.e. a high-pitched laryngeal call) and using echoes to interpret their environment. These techniques, along with use oftheir vibrissae, are used to find their way around. <b>Status and Conservation.</b> Classified as Least Concern on The IUCN Red List. The Greater White-toothed Shrew is very common throughoutits wide distribution. It is often found in or near human dwellings and can adapt to loss of habitat, especially in areas around cultivated fields and gardens. Nevertheless,it is negatively affected by toxins, such as metal pollutants from runoff at pyrite mines in Europe. Metal toxins bioaccumulate primarily in livers and kidneys but also other bodily tissues in smaller amounts. <b>Bibliography.</b> Aulagnier &amp; Vogel (2013), Aulagnier et al. (2016), Balloux et al. (1998), Bouteiller &amp; Perrin (2000), Bouteiller-Reuter &amp; Perrin (2005), Brahmi et al. (2012), Brandli et al. (2005), Burton (1991), Cantoni &amp; Vogel (1989), Cosson et al. (2005), Duarte et al. (2003), Favre et al. (1997), Genoud (1985), Handley et al. (2006), Hutterer, Maddalena &amp; Molina (1992), Hutterer, Vogel et al. (1979), Jaquiéry et al. (2008), Kraft (2000), Nagel (1977), Sanchez-Chardi, Lépez-Fuster &amp; Nadal (2007), Sanchez-Chardi, Marques et al. (2008), Sanchez-Chardi, Ribeiro &amp; Nadal (2009), Sara &amp; Vogel (1996), Tosh et al. (2008), Vogel et al. (2003).
description: Published as part of <i>Russell A. Mittermeier &amp; Don E. Wilson, 2018, Soricidae, pp. 332-551 in Handbook of the Mammals of the World – Volume 8 Insectivores, Sloths and Colugos, Barcelona :Lynx Edicions</i> on pages 500-501, DOI: 10.5281/zenodo.6870843