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Communication has not been studied in S. annulatus. However, Spermophilus species in general communicate with sounds, body language, by way of smells, and by touch, as do most mammals. Ground squirrels are known for the range of vocalizations they use, from whistles and chatters to trills and buzzes. S. annulatus is known to emit shrill whistling noises when alarmed. Specific warning vocalizations that distinguish between terrestrial and avian predators are known in other Spermophilus species. Some species have been recorded "kissing" when they meet and using scent marking. Ground squirrels perceive their environment using this same suite of senses.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical
This species has a global conservation heritage status of G4 that indicates that S. annulatus is uncommon but not rare. Although population numbers are decreasing, they are not considered in danger of extinction.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Much of the natural habitat of these ground squirrels is being cleared for agricultural purposes. They are considered agricultural pests in some areas because they eat fruit from orchards, corn, and other crops.
Negative Impacts: crop pest
It is not known what, if any, benefits this species provides to humans. They may act to disperse the seeds of some wild, native plants.
Although ecosystem roles of S. annulatus have not been described in detail, they impact plant regeneration through their seed predation and may help to disperse the seeds of some plants. They may also act as an important prey base for birds of prey and other predators.
Spermophilus annulatus eats fruits and nuts and may also consume insects. Oil palm, mesquite, and cactus seeds are eaten, as well as the fleshy fronds of Opuntia cactus, figs, and other wild fruits and seeds. In agricultural areas they eat corn and the seeds of other agricultural plants. They can climb to the ends of branches in search of fruits and seed pods and will dig for seeds as well.
Animal Foods: insects
Plant Foods: seeds, grains, and nuts; fruit
Primary Diet: herbivore (Frugivore , Granivore )
Spermophilus annulatus is endemic to west-central Mexico.
Biogeographic Regions: nearctic ; neotropical
Ring-tailed ground squirrels inhabit the tropical lowlands of western Mexico. They are found in dense tropical forests and palm groves, especially in areas with thick, vine growth on larger trees. Spermophilus annulatus create burrows and cavities under cover of thick vegetation, on hillsides and near cultivated areas. These squirrels have been known to live in the walls of barns.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest
Other Habitat Features: agricultural
The lifespan of S. annulatus is not known. Other Spermophilus species live for a maximum of 11 years (S. beldingi), but typically for about 3 to 4 years in males and 4 to 6 years in females. The higher male mortality is a result of the risks associated with male-biased dispersal.
The coloration of ring-tailed ground squirrels varies seasonally; these squirrels are more brightly colored during the breeding season. The head is predominantly black, while the body is a mix of black, buff, and pinkish coloration. Total length varies from 383 to 470 mm. The tail is narrow and has approximately fifteen annulations, or stripes. It is not as bushy as the tails of other squirrel species and is as long as the head and body of the animal. The skulls of females are generally larger than those of males.
Range length: 383 to 470 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: female larger
Predation on S. annulatus has not been described but it is likely that they are taken by a variety of small to medium-sized predators, especially birds of prey. They are agile, vigilant, and seek refuge in burrows and cavities to avoid predation.
The mating system of S. annulatus has not been described. In other Spermophilus species, males compete for access to females as they emerge from hibernation in the spring.
The breeding season of S. annulatus is in the dry season (December to June). Little has been published on the reproduction of this species, however other species in the genus Spermophilus breed once yearly, have a gestation period of approximately 30 days, and have 3 to 6 young in a litter.
Breeding interval: Breeding occurs once yearly.
Breeding season: Breeding occurs from December through June.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Parental care has not been studied in S. annulatus. As in all mammals, females nurse and care for their young until they reach independence. In other Spermophilus species, the young are born helpless, are cared for in a nest chamber, and are weaned in the first 1 to 2 months of life. They begin making excursions from the burrow around the time of weaning. Typically male young disperse at independence but female young remain in their natal area.
Parental Investment: altricial ; female parental care
Notocitellus annulatus ye una especie de royedor de la familia Sciuridae.
Ye endemismu de la rexón de la mariña del Pacíficu del centru de Méxicu.
Der Ringelschwanzziesel (Notocitellus annulatus, Syn.: Spermophilus annulatus) ist eine Hörnchenart aus der Gattung Notocitellus. Er kommt ausschließlich im Bereich der Pazifikküste im westlichen Mexiko vor.
Der Ringelschwanzziesel erreicht eine Kopf-Rumpf-Länge von etwa 20,9 bis 22,1 Zentimetern und eine Schwanzlänge von 20,7 bis 21,5 Zentimetern, das Gewicht beträgt etwa 200 bis 390 Gramm.[1] Der Schwanz ist damit für ein Erdhörnchen vergleichsweise lang mit einer Länge, die mehr als 90 % der Kopf-Rumpf-Länge entspricht.[2] Beide Arten der Gattung haben einen schwarzgrau gesprenkelten Rücken, der sich aus der schwarz-blassschwarzen Bänderung der Rückenhaare ergibt. Im Gesicht, Nacken und am Schwanz besitzen die Tiere eine rötliche Färbung. Das Fell ist rau im Vergleich zu dem eher weichen Fell anderer Erdhörnchengattungen. Der Körper ist lang und schlank, der Schwanz ist schmal und nur leicht buschig und entspricht eher dem der Baumhörnchen als dem anderer Erdhörnchen.[2]
Von dem sehr ähnlichen, jedoch etwas kleineren Tropischen Ziesel (Notocitellus adocetus) unterscheidet sich der Ringelschwanzziesel vor allem durch die etwas kräftigere, dunklere und mehr rötliche Fellfärbung, die größeren Ohren und die längere und schmalere Schnauze. Er besitzt zudem deutliche helle Schwanzringe.[1]
Der Ringelschwanzziesel kommt nur im Bereich der Pazifikküste im westlichen Mexiko vor, wo er entsprechend endemisch ist. Das Verbreitungsgebiet beinhaltet Teile der mexikanischen Bundesstaaten Nayarit, Jalisco, Colima, Michoacán und das nördliche Guerrero.[1] Die Höhenverbreitung reicht bis etwa 1200 Meter.[3]
Der Ringelschwanzziesel lebt vor allem in trockenen Laubwäldern der Pazifikküste bis in Höhen von etwa 1200 Metern. Die natürliche Vegetation seines Lebensraumes besteht häufig aus Feigen, Ölpalmen, Acacia und Prosopis-Sträuchern.[1] Der Ziesel lebt als Erdhörnchen am Boden und gräbt vor allem Baue in den sandigen bis steinigen Boden, kann jedoch auch Nester in Baumhöhlen anlegen. Er ist tagaktiv, sozial und über beinahe das gesamte Jahr aktiv; im Sommer mit den Höchsttemperaturen kommt es jedoch gelegentlich zu Ruhephasen. Die Tiere sind bei Verfügbarkeit von Samen primär granivor, ansonsten jedoch omnivor. Sie fressen vor allem verschiedene verfügbare Samen, Nüsse und Früchte sowie landwirtschaftlich angebaute Feldfrüchte. Die Tiere sind gute Kletterer und steigen in die Bäume, wo sie sich in der Regel in einigen Metern Höhe aufhalten. Die Tiere kommunizieren über hohe Rufe, wenn Menschen oder potenzielle Beutegreifer in der Nähe sind, und verstecken sich dann. Die Fortpflanzung findet in der Trockenzeit von Dezember bis Juni statt, über das Fortpflanzungsverhalten liegen jedoch kaum Angaben vor. Beutegreifer sind nicht bekannt, als Ektoparasiten wurden bisher nur Dasselfliegen der Gattung Cuterebra identifiziert.[1]
Der Ringelschwanzziesel wird als eigenständige Art innerhalb der Gattung Notocitellus eingeordnet, die aus zwei Arten besteht und neben ihm noch den Tropischen Ziesel (Notocitellus adocetus) beinhaltet.[1] Die wissenschaftliche Erstbeschreibung stammt von John James Audubon und John Bachman aus dem Jahr 1842, die die Art anhand von Individuen aus Manzanillo im Bundesstaat Colima beschrieben.[4] Die beiden Arten wurden lange als Teil der Ziesel (Spermophilus) eingeordnet, nach einer umfassenden molekularbiologischen Untersuchung[5] wird Notocitellus jedoch als eigenständige Gattung gemeinsam mit mehreren weiteren Gattungen betrachtet.[2][1]
Innerhalb der Art werden gemeinsam mit der Nominatform zwei Unterarten unterschieden:[1]
Der Ringelschwanzziesel wird von der International Union for Conservation of Nature and Natural Resources (IUCN) als „nicht gefährdet“ (least concern) eingeordnet.[3] Begründet wird dies mit dem verhältnismäßig großen Verbreitungsgebiet, den angenommen großen Beständen und dem nur geringen Rückgang. Potenzielle bestandsgefährdende Risiken sind nicht bekannt.[3]
Der Ringelschwanzziesel (Notocitellus annulatus, Syn.: Spermophilus annulatus) ist eine Hörnchenart aus der Gattung Notocitellus. Er kommt ausschließlich im Bereich der Pazifikküste im westlichen Mexiko vor.
The ring-tailed ground squirrel (Notocitellus annulatus) is a species of rodent in the family Sciuridae.[2] It is endemic to the Pacific coast region of central Mexico.[3] It is a common species and feeds mainly on fruits and nuts. The IUCN has assessed it as being of "least concern".
The ring-tailed ground squirrel is between 383 and 470 mm (15 and 19 in) long, half of this being the tail. Compared to the California ground squirrel (Otospermophilus beecheyi) it is slightly smaller, has more slender legs and broader, less-pointed ears. The incisors are orange and the large cheek pouches open inside the mouth. The crown of the head and upper parts of the body have mixed blackish-brown and buff hairs. The chin, throat and underparts are buff. The tail is slender and not bushy, the colour being mixed buff and black above and brownish beneath, with about fifteen dark rings.[4]
The ring-tailed ground squirrel is endemic to western Mexico, with a range extending from the State of Nayarit to the State of Guerrero. It is a lowland species, ranging up to elevations of about 1,200 metres (3,900 ft). It occupies a range of habitat types. It may live in deciduous forests of vine-clad trees or on more open slopes among rocks. The species also inhabits the borders of cultivated fields, and oil palm (Elaeis guineensis) plantations where the ground is littered with fallen palm fronds and mesquite scrub. Its burrows are often in walls or dykes, or hidden under spreading cacti or scrub. It sometimes inhabits holes in trees.[4]
The ring-tailed ground squirrel eats corn and other seeds, but mainly feeds on fruit and nuts. Food includes oil palm seeds, wild figs, mesquite seeds and the fleshy fruits of prickly pears (Opuntia). The squirrel may also consume insects. It mostly moves about on the ground, scurrying from one piece of cover to another, sometimes pausing to dig up some morsel or sit on its haunches to eat, holding the food in its forepaws. It sometimes climbs a few metres up a small tree and gathers food from low branches. When startled, it may rush a short way up a tree, peer at the intruder, retire round the back of the trunk and descend to the ground, running away under cover to the nearest burrow. If startled in the open it may freeze, or may run directly to a burrow, often stopping at the entrance to utter a short whistle or emit chirping notes. When moving about, it sometimes stops and stands upright on its hind feet, propping itself up with its tail. When it runs, it carries its tail in a curve, and is altogether more dainty and agile than most ground squirrels.[4]
Breeding takes place in the dry season between December and June; one female specimen found to be was carrying a litter of four embryos.[4]
The ring-tailed ground squirrel is common in suitable locations within its range. The International Union for Conservation of Nature has identified no particular threats and has assessed its conservation status as being of "least concern".[1]
The ring-tailed ground squirrel (Notocitellus annulatus) is a species of rodent in the family Sciuridae. It is endemic to the Pacific coast region of central Mexico. It is a common species and feeds mainly on fruits and nuts. The IUCN has assessed it as being of "least concern".
Notocitellus annulatus es una especie de roedor de la familia Sciuridae.[2]
Es endémica de la región de la costa del Pacífico del centro de México.
Spermophilus annulatus Spermophilus generoko animalia da. Karraskarien barruko Xerinae azpifamilia eta Sciuridae familian sailkatuta dago.
Spermophilus annulatus Spermophilus generoko animalia da. Karraskarien barruko Xerinae azpifamilia eta Sciuridae familian sailkatuta dago.
반지꼬리땅다람쥐(Notocitellus annulatus)는 다람쥐과에 속하는 설치류의 일종이다.[2] 멕시코 중부 태평양 해안의 토착종이다.[3] 흔하게 발견되는 종으로 과일과 견과류를 주로 먹는다. 국제 자연 보전 연맹(IUCN)은 보전 등급을 "관심대상종"으로 분류하고 있다.
반지꼬리땅다람쥐의 몸길이는 약 383~470mm이고, 꼬리 길이는 몸길이의 약 절반이다. 캘리포니아땅다람쥐(Otospermophilus beecheyi)와 비교하여 약간 작고 더 가늘고 긴 다리와 더 넓고 덜 뾰족한 귀를 갖고 있다. 앞니는 오렌지색이고 큰 뺨주머니는 입 안쪽에 열려 있다. 윗머리 부분과 상체는 거무스레한 갈색과 담황색 털이 섞여 있다. 턱과 목, 하체는 담황색이다. 꼬리는 가늘고 길며 털이 텁수룩하지 않고, 담황색과 꼬리 윗면의 검은색, 아랫면의 갈색이 섞인 색을 띠며, 약 15개의 짙은 반지 꼬리를 갖고 있다.[4]
반지꼬리땅다람쥐는 멕시코 서부의 토착종으로 분포 지역은 나야리트주부터 게레로주까지이다. 저지대 종으로 해발 약 1200m 높이까지 서식한다. 다양한 서식지 유형을 갖고 있다. 덩굴 나무로 덮인 탈락성 숲과 암석 사이의 좀더 앞이 트인 경사면에서 서식하는 것으로 추정된다. 땅이 쓰러진 야자나무 잎들과 메스키트 관목으로 덮여 있는 경작지 경계와 아프리카기름야자나무(Elaeis guineensis) 농장에서도 서식한다. 굴은 벽이나 제방 속 또는 퍼져 있는 선인장 또는 관목 아래에 숨겨져 있다. 나무 구멍 속에서도 서식한다.[4]
반지꼬리땅다람쥐는 곡식과 기타 씨앗 등을 먹지만 주로 과일과 견과류를 먹는다. 기름야자나무 씨앗과 야생 무화과 잎, 메스키트 씨앗, 부채선인장의 과육도 먹이에 포함된다. 곤충을 먹을 수도 있다. 주로 땅 위의 이쪽에서 저쪽으로 잽싸게 움직이고, 약간의 먹이를 파내기 위해 멈추거나 먹이를 앞발로 잡고 먹기 위해 궁둥이로 앉는다. 때로는 작은 나무 위로 수 미터를 오르거나 낮은 가지로부터 먹이를 구한다. 깜짝 놀랄 때는 칩입자를 피해 나무 위 짧은 길로 뛰어 오르거나 나무 줄기 뒤로 물러나 숨고, 땅으로 내려가 가장 가까운 굴 덮개 아래로 도망친다.
굴 입구에서 깜짝 놀라게 되면 그 자리에서 얼어붙거나 굴 바로 아래로 도망치거나 입구에 멈춘 상태로 짧게 삑삑 소리를 내거나 지저귀는 소리를 낼 수도 있다. 움직일 때는 멈추어서 뒷다리로 똑바로 서고 꼬리를 곧추세운다. 달릴 때는 대부분의 땅다람쥐류 보다 우아하고 잽싸게 꼬리를 둥글게 만다.[4] 12월~6월 사이의 건기에 번식을 한다. 4마리의 새끼를 밴 암컷 표본이 발견된 적이 있다.[4]
반지꼬리땅다람쥐는 분포 지역 안의 적당한 곳에서 흔하게 발견된다. 특별한 멸종 위협이 없기 때문에 국제 자연 보전 연맹(IUCN)이 보전 등급을 "관심대상종"으로 분류하고 있다.[1]
다음은 2009년 헬겐(Helgen) 등의 연구에 기초한 계통 분류이다.[5]
마멋족 열대땅다람쥐속
