Owls are the most common predators of least shrews. Other common predators include rough-legged hawks, foxes, and snakes. Domesticated house cats and spotted skunks are also known predators. When food is scarce, least shrews may also resort to cannibalism. Their ability to stay camouflaged is the only defense of least shrews against predators.
Known Predators:
Anti-predator Adaptations: cryptic
Least shrews have dense, short hair, which is dark brown to reddish brown on the dorsal side during the winter. During the summer, fur becomes grayish brown in color. They have a bicolored tail, with a darker brown on top and a lighter underside. Least shrews measure 70 to 92 mm in length and usually weigh between 3 and 6 g. Members of this species have two distinct ear holes hidden in their fur. Males and females both have scent glands on their flanks, and females have an extra set in front of their ears. Females have six mammae along the lower body. Least shrews can be distinguished from other closely related species by both their tail length and dentition. The tail of least shrews is relatively short and measures 12 to 26 mm. Unlike related species which have three, least shrews have four unicuspid teeth, though the fourth is very small and hidden.
Range mass: 3 to 6 g.
Range length: 70 to 92 mm.
Sexual Dimorphism: sexes alike
Other Physical Features: endothermic ; bilateral symmetry
Average basal metabolic rate: 0.164 W.
Least shrews tend to live a little over 1 year in the wild. Captive least shrews live can live about 21 months.
Range lifespan
Status: captivity: 21 (high) months.
Average lifespan
Status: wild: 1 years.
Average lifespan
Status: captivity: 2.6 years.
Least shrews are most commonly found in open fields with tall grasses or areas with fallen trees and brush that provide protection. Least shrews can also be found in softer soil near saltwater marshes along the Atlantic Coast. Some occur in the forests of Florida, relying on the underbrush for cover. Least shrews have been found at elevations as high as 2,100 m.
Range elevation: 0 to 2,100 m.
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: savanna or grassland ; forest ; scrub forest
Wetlands: marsh
Other Habitat Features: agricultural
Least shrews, Cryptotis parva, occur in greatest densities in the eastern United States. Their geographical range extends from Florida to New York and reaches as far west as Texas and South Dakota. Least shrews also occur in Central America from northern Mexico to Costa Rica and into Panama.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
Least shrews have immense dietary needs. They generally eat 60 to 100% of their own body weight every day. Least shrews are largely insectivorous, and their diet primarily consists of insect larva and centipedes. They also have been known to eat snails, spiders, and crickets. Least shrews immobilize their prey by attacking the joints of the organism so they cannot flee. The species has also been known to eat small quantities of fungi and other green plants.
Animal Foods: insects; terrestrial non-insect arthropods; mollusks; terrestrial worms
Plant Foods: leaves
Other Foods: fungus
Foraging Behavior: stores or caches food
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods)
Because of their burrowing habits, least shrews aerate soil and aid the transport of nutrients within soil. Least shrews can eat up to 100% of their body weight in a day and may contribute to regulation of insect populations. They are also eaten by a variety of predators, such as snakes and owls. Least shrews are known to host various fleas and mites such as Orycteroxenus soricis and Androlaelaps fahrenholzi.
Ecosystem Impact: soil aeration
Commensal/Parasitic Species:
Least shrews are highly insectivorous and may inadvertently help protect crops from harmful insects. Shrews also aerate soil, which is a benefit to agricultural practices.
Positive Impacts: controls pest population
There are no known negative impacts of least shrews on humans.
A national survey in 2007 listed Cryptotis parva as a secure species in the United states. However, the state of Michigan lists least shrews as threatened. Currently, no conservation efforts are in place; little is known as to why populations are declining in Michigan.
US Federal List: no special status
CITES: no special status
State of Michigan List: threatened
IUCN Red List of Threatened Species: least concern
Least shrews are very vocal. They make a variety of high frequency sounds including chirps and clicks, some of which are inaudible to humans. Least shrews also use ultrasonic sounds for tunnel exploration. This form of echolocation may be useful while moving underground, but there is no proof that this species uses sound to hunt. Males and females also communicate through scent. Males announce their presence to females through their scent. Females, however use their scent differently; when females stop producing pheromones, they are ready to mate. When females produce a scent, they are not ready to mate or are pregnant.
Communication Channels: acoustic ; chemical
Other Communication Modes: pheromones
Perception Channels: visual ; tactile ; acoustic ; echolocation ; chemical
Mating of least shrews generally occurs within the nest. Females alert all males sharing the nest and males in adjoining areas that they are ready to mate by stopping the release of pheromones from their scent glands. When this scent is absent, males show interest by sniffing both the anal glands and glands located in front of the ears of a female. The male then attempts to mount the female. If she is unreceptive, the female may become aggressive, making loud noises and arching her back. The male then ceases its approach and lays on its back, exposing both its neck and belly until he is ready to make another attempt. Females show signs of receptiveness by lifting their tail and presenting themselves. When more than one male is present, aggression levels determine a male hierarchy, and the most aggressive males mate first. Once mating is complete, males take a dominant station over the female. The mating process on average lasts 3 days.
Mating System: polyandrous ; cooperative breeder
Least shrews may reproduce several times during the mating season, which lasts from February to November. Gestation lasts 21 to 23 days. Females give birth to an average of 5 young per litter, though litters can range from 2 to 7 individuals. Newborn least shrews weigh approximately 0.34 g. Young are weaned at about 23 days of age. Males reach sexual maturity around 43 days of age and females around 40 days.
Breeding interval: Least shrews may breed several times per year.
Breeding season: Breeding of least shrews occurs between February and November.
Range number of offspring: 2 to 7.
Average number of offspring: 5.
Range gestation period: 21 to 23 days.
Average gestation period: 21 days.
Range weaning age: 21 to 23 days.
Average weaning age: 21 days.
Range time to independence: 20 to 30 days.
Average age at sexual or reproductive maturity (female): 40 days.
Average age at sexual or reproductive maturity (male): 43 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous ; post-partum estrous
Average birth mass: 0.34 g.
Average number of offspring: 4.5.
Average age at sexual or reproductive maturity (male)
Sex: male: 43 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 40 days.
Female least shrews provide almost a full month of care to their young, which are nursed for 20 to 23 days. Most adult members within the nest take an active role in preventing juveniles from getting lost by carrying them in their mouths. Mothers show panic when separated from their young and, when reunited, gather all young together.
Parental Investment: altricial ; male parental care ; female parental care ; pre-fertilization (Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Male, Female); pre-independence (Provisioning: Female, Protecting: Male, Female)
La musaranya d'orelles petites nord-americana (Cryptotis parva) és una espècie de mamífer de la família de les musaranyes que es troba als Estats Units, Mèxic, Guatemala, Belize, El Salvador, Hondures i Nicaragua.
La musaranya d'orelles petites nord-americana (Cryptotis parva) és una espècie de mamífer de la família de les musaranyes que es troba als Estats Units, Mèxic, Guatemala, Belize, El Salvador, Hondures i Nicaragua.
Cryptotis parva ist ein in Nord- und Mittelamerika lebender Insektenfresser (Eulipotyphla) aus der Familie der Spitzmäuse (Soricidae).
Cryptotis parva ist eine besonders kleine Spitzmaus mit langer, spitzer Schnauze und kleinen Ohren. Das Fell ist kurz, im Winter dunkelbraun bis rotbraun, im Sommer graubraun gefärbt. Der Schwanz ist zweifarbig, oberseits dunkelbraun, unterseits hellbraun. Die Gesamtlänge der Tiere beträgt 70 bis 92 Millimeter, wobei der Schwanz 12 bis 26 Millimeter lang ist. Sie wiegen zwischen drei und sechs Gramm.[1] Sowohl Männchen als auch Weibchen haben je eine Duftdrüse an den Flanken. Die Weibchen verfügen über einen zusätzlichen Satz an Duftdrüsen in der Nähe der Ohren und besitzen sechs Zitzen. Die Zahnformel lautet I3/2-C1/0-P2/1-M3/3 = 30.[2]
Im Gegensatz zu verwandten Kleinohrspitzmaus-Arten hat Cryptotis parva nicht drei, sondern vier einhöckrige (unikuspid) Zähne, wobei der vierte sehr klein und versteckt ist.[2]
Cryptotis parva kommt in den östlichen und mittleren Vereinigten Staaten verbreitet vor. Ihre Reichweite erstreckt sich von New York bis nach Florida und setzt sich Richtung Westen bis nach Texas und South Dakota fort. In Mittelamerika kommt sie von Nordmexiko über Costa Rica bis nach Panama vor. Sie bewohnt in erster Linie Graslandschaften, nur gelegentlich Wälder und kommt auch in der Nähe von Salzwassersümpfen entlang der Atlantikküste vor. Die Höhenverbreitung reicht bis auf 2100 Meter.[1]
Cryptotis parva ist ganztägig aktiv, die Hauptaktivität findet jedoch nachts statt. Die Tiere bewohnen einen aus mehreren Kammern bestehenden unterirdischen Bau, der ca. 20 Zentimeter unter der Erdoberfläche liegt und meist unter flachen Steinen oder umgestürzten Baumstämmen angelegt wird. Sie leben überwiegend gesellig, was für Spitzmausarten im Grunde ungewöhnlich ist. In einem Bau im Nacogdoches County wurden beispielsweise 31 Individuen gefunden.[2]
Die Brutzeit erstreckt sich von Anfang März bis Ende November. Die Weibchen generieren zwei oder mehr Würfe pro Jahr. Die überwiegend drei bis sechs Jungtiere werden nach einer Tragzeit von 21 bis 23 Tagen haarlos und blind geboren und wiegen jeweils ca. 0,3 Gramm. Sie wachsen schnell und sind bereits nach etwa einem Monat ausgewachsen.[2]
Die Nahrung von Cryptotis parva setzt sich nahezu ausschließlich aus tierischer Substanz zusammen und besteht vorrangig aus Insekten (Insecta) sowie anderen Wirbellosen (Evertebrata), beispielsweise Schnecken (Gastropoda). Gelegentlich werden auch kleine Wirbeltiere (Vertebraten) gefressen. Bei großer Nahrungsknappheit wurde sogar Kannibalismus beobachtet.[1] Die Tiere benötigen jeden Tag 60 bis 100 % ihres eigenen Körpergewichts an Nahrung. Nur selten werden kleine Mengen an Pilzen (Fungi) oder grünen Pflanzen gefressen.
Cryptotis parva hat viele Fressfeinde. Dazu zählen in erster Linie die Schleiereule (Tyto alba) und der Raufußbussard (Buteo lagopus). Untersuchungen im Jefferson County in Texas ergaben, dass 73 % der Gewölle von Schleiereulen aus den Resten dieser Spitzmausart bestanden.[2] Auch Säugetiere jagen die Kleinohrspitzmäuse, beispielsweise Füchse (Vulpini), Skunks (Mephitidae) und Hauskatzen (Felis catus).
In ihren Vorkommensgebieten ist Cryptotis parva zumeist zahlreich anzutreffen und wird demzufolge von der Weltnaturschutzorganisation IUCN als „Least Concern = nicht gefährdet“ klassifiziert.[3]
Cryptotis parva ist ein in Nord- und Mittelamerika lebender Insektenfresser (Eulipotyphla) aus der Familie der Spitzmäuse (Soricidae).
The North American least shrew (Cryptotis parvus) is one of the smallest mammals, growing to be only up to 3 inches long. It has a long pointed snout and a tail never more than twice the length of its hind foot. The dense fur coat is either grayish-brown or reddish-brown with a white belly. Its fur becomes lighter in the summer and darker in the winter. Although similar in appearance to several species of rodents, all shrews are members of the order Eulipotyphla and should not be mistaken for a member of the order Rodentia. The North American least shrew's eyes are small and its ears are completely concealed within its short fur, giving it very poor eyesight and hearing.
It is found from the grasslands of southern Canada through the eastern and central United States and Mexico.[3] In Canada, only a small population of this animal has been found at Long Point in Ontario.[4]
The North American least shrew mostly dwells in mesic grasslands, marshes, and meadows.[5] Most shrews prefer these wet habitats, but the least shrew will also inhabit dry upland regions.[4] This species can be found in meadows, fields, and weedy areas, where the vegetation attracts its insect diet.[4][6]
This tiny shrew is active at all hours of the day, but mostly at night. Hunting by smell and touch, the North American least shrew digs through loose soil and leaf litter for its prey along the surface of the ground. The behavior of captive individuals suggests it can also tunnel through moist soil in search of food much like moles do. However, it mostly occupies burrows built by other mammals.[4]
Its diet consists of mostly small invertebrates, such as caterpillars, beetle larvae, earthworms, centipedes, slugs, and sow bugs.[4] It will also eat from the corpses of dead animals, and small amounts of seeds or fruits. This shrew will eat its prey whole, but when eating crickets and grasshoppers, the North American least shrew will bite off the head of its prey and eat only the internal organs.[4] When fighting a larger creature, it will aim for the legs and try to cripple its adversary, and will bite lizards, which are often too large for it to kill, on the tail, which then falls off and provides it with a meal while the lizard escapes. The North American least shrew will also sometimes live inside beehives and eat all the larvae. It will often share its food with other shrews. It eats more than its body weight each day and is known to store food.[4][7]
The North American least shrew makes its home in burrows or shallow runways under flat stones or fallen logs. Its burrows are about 2.5 cm in diameter, from 25 cm to 1.5 m long, and seldom more than 20 cm below the ground. Most shrews are aggressive towards each other, but this species is a social creature and often cooperates in digging its burrows and often sleeps with other shrews. From 2 to 31 of these shrews will live together at a time, although it is more common to find them together in the winter months to keep warm.[4] It will line its burrows with leaves and grass in nests for the purpose of rearing offspring. The breeding season extends from early March to late November. Females produce two or more litters each season. Each litter will consist of about three to six young, each one weighing about 0.3 g, which grow quickly and will be adult size in about one month. Litters are born 21–23 days after copulation.[4] When first born, young are deaf, blind, and hairless.[4] At 14 days old, they will open their eyes and have fur. By day 21, they will weigh 4-5 g and weaning will begin.[4] The North American least shrew rarely lives more than a year. Its natural predators are owls, hawks, the red fox, the raccoon, skunks, and snakes.[4] The North American least shrew will try to defend itself with its venomous saliva.
Evolutionary analysis seems to show the shrews evolved from the ancestor Crocidosorex in Europe and crossed over into the Nearctic, consisting of North and Central America, via the Bering Strait (above sea level at the time). The earliest fossils of shrews, Crocidosorex piveteaui, are from the family Soricidae and date back to the Oligocene epoch, but shrews are thought to have originated in the late Eocene (30-40 million years ago). It is debated whether four or five ancient subfamilies occurred, but only two are left today: Soricinae and Crocidurinae. Once the descendants of the Crocidosorex crossed into North America, this subfamily of Soricidae gave rise to the genus Antesorex during the Miocene. In the late Miocene, they split into Adeloblarina and Alluvisorex. From Adeloblarina, two genera, Blarina and Cryptotis, diverged during the Pliocene. The North American least shrew species, Cryptotis parva, then arose from the genus Cryptotis.[6]
The primitive features of Cryptotis parva suggest its ancient origins. The zygomatic arches are missing in the skull, which are present in most mammals even of that size, such as rodents. The mandible also has a more primitive structure with a double articulating surface. The cerebral hemisphere is relatively small, which is necessary in manipulative abilities. However, the olfactory lobes are well developed, revealing the significance of the ability to smell in the shrew's survival. The reproductive and urinary systems are joined in one external opening, called the cloaca, which is a primitive character not found in higher mammals. Another trait uncommon in mammals is the testes are found inside the abdominal cavity.[6]
Least shrews are being used in research as emesis models, to see how delta-9 tetrahydrocannabinol prevents emesis in the cannabinoid receptors. This research is especially useful for cancer patients because chemotherapy drugs, such as cisplatin, cause nausea and vomiting.[8]
The North American least shrew is listed as endangered in Connecticut and in Pennsylvania. The greatest threat to it is the development of coastal habitat, particularly dunes and marshes.[9]
The North American least shrew (Cryptotis parvus) is one of the smallest mammals, growing to be only up to 3 inches long. It has a long pointed snout and a tail never more than twice the length of its hind foot. The dense fur coat is either grayish-brown or reddish-brown with a white belly. Its fur becomes lighter in the summer and darker in the winter. Although similar in appearance to several species of rodents, all shrews are members of the order Eulipotyphla and should not be mistaken for a member of the order Rodentia. The North American least shrew's eyes are small and its ears are completely concealed within its short fur, giving it very poor eyesight and hearing.
La musaraña orejillas mínima[2] (Cryptotis parva) es una especie de musaraña de la familia Soricidae.[3] Es nativa de Canadá, Estados Unidos y México.[1]
Se reconocen las siguientes subespecies:[2]
La musaraña orejillas mínima (Cryptotis parva) es una especie de musaraña de la familia Soricidae. Es nativa de Canadá, Estados Unidos y México.
Cryptotis parva Cryptotis generoko animalia da. Lehen Insectivora edo Soricomorpha deitzen zen taldearen barruan daude. Gaur egun Lipotyphla deitzen den taldearen barruko Soricinae azpifamilia eta Soricidae familian sailkatuta dago.
Cryptotis parva Cryptotis generoko animalia da. Lehen Insectivora edo Soricomorpha deitzen zen taldearen barruan daude. Gaur egun Lipotyphla deitzen den taldearen barruko Soricinae azpifamilia eta Soricidae familian sailkatuta dago.
Cryptotis parva
La Petite musaraigne (Cryptotis parva) est une espèce de mammifères de la famille des Soricidae. C'est l'une des plus petites espèces de mammifères avec une taille maximale de seulement 75 mm.
Selon Catalogue of Life (29 juin 2019)[3] :
Cryptotis parva
La Petite musaraigne (Cryptotis parva) est une espèce de mammifères de la famille des Soricidae. C'est l'une des plus petites espèces de mammifères avec une taille maximale de seulement 75 mm.
De kortoorspitsmuis (Cryptotis parva) is een zoogdier uit de familie van de spitsmuizen (Soricidae). De wetenschappelijke naam van de soort werd voor het eerst geldig gepubliceerd door Say in 1823.
Bronnen, noten en/of referenties
Cryptotis parva[2][3][4][5][6][7] är en däggdjursart som först beskrevs av Thomas Say 1823. Cryptotis parva ingår i släktet pygménäbbmöss och familjen näbbmöss.[8][9] IUCN kategoriserar arten globalt som livskraftig.[1]
Arten blir med svans 70 till 92 mm lång (enligt en annan källa 67 till 103 mm) och den väger 3 till 6 g. Själva svansen är 12 till 26 mm lång. Pälsen på ovansidan är under sommaren gråbrun och under vintern mörkbrun till rödbrun.[10] På undersidan förekommer ljusare päls.[11] Hanar och honor har doftkörtlar vid kroppens sidor.[10] Liksom hos andra näbbmöss förekommer en spetsig långdragen nos och små ögon.[12]
Cryptotis parva skiljer sig från andra arter i samma släkte genom en avvikande tanduppsättning. Den har i varje övre käkhalva en framtand med två spetsiga knölar och sedan fyra tänder med en spets. Andra näbbmöss från samma släkte har efter den första framtanden bara tre spetsiga tänder. Dessutom tillkommer kindtänderna. Tandformeln är därför I 1/1 U 4/1 P 1/1 M 3/3, alltså 30 tänder. De fyra spetsiga tänderna betraktas här inte som hörntänder (Dens caninus). De fick istället ett U (unicuspids) som symbol.[12]
Denna näbbmus förekommer i sydöstra Kanada, östra USA och Mexiko. Den lever i låglandet och i bergstrakter upp till 2750 meter över havet. Habitatet utgörs främst av öppna landskap som gräsmarker, regioner med några buskar eller träd samt områden nära sjöar som liknar marskland. Vanligen finns ett tätare växtskikt med örter eller ett lövskikt på marken. Ibland hittas arten i tätare buskskogar, blandskogar, molnskogar eller i mera torra slättland nära havet.[1]
Tidigare räknades liknande näbbmöss som förekommer söder om Mexiko och fram till Panama till Cryptotis parva.[12] De godkänns numera som arter, bland annat Cryptotis orophila.
Cryptotis parva har huvudsakligen insekter, daggmaskar och andra ryggradslösa djur som föda. Ibland äter den olika växtdelar. Arten är allmänt gömd och svårfångad för människor. Att den förekommer i ett visst område är oftast känt från kvarlevor i ugglornas spybollar.[1]
Arten har liksom andra näbbmöss en hög ämnesomsättning. Individer som fångades i Florida och som troligen var Cryptotis parva åt under 24 timmar föda som motsvarade näbbmössens egen vikt. Zoologerna hittade i några fall flera exemplar i samma gömställe vad som indikerar att arten är mer social än andra näbbmöss. Cryptotis parva bygger bon av blad och gräs som göms i växtligheten på marken. De största bon som upptäcktes var 15 cm lång och 10 cm bred eller de hade en cirkelrund grundform med en diameter av 18 cm och en höjd av 5 cm.[12]
Fortplantningstiden sträcker sig antagligen över hela året eller i norra delen av utbredningsområdet från mars till november. Dräktigheten varar 21 till 23 dagar. Nyfödda ungar är cirka 22 mm långa och bara 0,3 g tunga. Ungarna diar sin mor ungefär tre veckor.[12]
Arten delas in i följande underarter:[8]
Wikimedia Commons har media som rör Cryptotis parva.
Wikispecies har information om Cryptotis parva.
Cryptotis parva är en däggdjursart som först beskrevs av Thomas Say 1823. Cryptotis parva ingår i släktet pygménäbbmöss och familjen näbbmöss. IUCN kategoriserar arten globalt som livskraftig.
Cryptotis parva — вид роду мідиць (Sorex) родини мідицевих (Soricidae).
Країни поширення: Канада (у південно-східному Онтаріо), Мексика, Сполучені Штати Америки. Вертикальний діапазон поширення від 0-2750 м над рівнем моря. Зазвичай проживає на відкритій місцевості з щільною трав'янистою рослинністю.
В основному харчується комахами та іншими безхребетними (наприклад, дощові хробаки, павуки), також деякими речовинами рослинного походження.
Cryptotis parva là một loài động vật có vú trong họ Chuột chù, bộ Soricomorpha. Loài này được Say mô tả năm 1823.[2]
Phương tiện liên quan tới Cryptotis parva tại Wikimedia Commons
Bài viết liên quan đến họ Chuột chù này vẫn còn sơ khai. Bạn có thể giúp Wikipedia bằng cách mở rộng nội dung để bài được hoàn chỉnh hơn. Cryptotis parva là một loài động vật có vú trong họ Chuột chù, bộ Soricomorpha. Loài này được Say mô tả năm 1823.
Cryptotis parva (Say, 1823)
Ареал
Малый скрытоух (лат. Cryptotis parva) — вид млекопитающих семейства землеройковые (Soricidae), обитающий в Северной Америке.
Вид распространён в Канаде (в юго-восточном Онтарио), Мексике, США. Диапазон распространения от 0 до 2750 м над уровнем моря. Обычно обитает на открытой местности с густой травянистой растительностью.
В основном питается насекомыми и другими беспозвоночными (например, дождевыми червями, пауками), а также растительным материалом.
북아메리카꼬마땃쥐(Cryptotis parva)는 땃쥐과에 속하는 포유류의 일종이다.[2] 가장 작은 포유류 중의 하나로, 다 자랐을 때 몸길이가 7~8cm에 불과하다.
5종의 아종이 알려져 있다.[2]
