Common garter snakes typically eat earthworms, amphibians, leeches, slugs, snails, insects, crayfish, small fish and other snakes. They seem immune to the toxic skin secretions of toads and can eat them without harm. Occasionally small mammals, lizards, or baby birds are eaten as well. Common garter snakes find their prey using their excellent sense of smell and their vision. They use several different hunting methods, such as peering, craning, and ambushing to capture their prey. The different techniques describe the way the snakes move while they hunt. They immobilize their prey using their sharp teeth and quick reflexes. The saliva of common garter snakes may be slightly toxic to some of their small prey, making it easier to handle them while they are being eaten. Like other snakes, they swallow their food whole.
Animal Foods: birds; mammals; amphibians; reptiles; fish; insects; terrestrial non-insect arthropods; mollusks; terrestrial worms; aquatic crustaceans
Primary Diet: carnivore (Eats terrestrial vertebrates)
Common garter snakes are eaten by a wide variety of predators, which varies throughout their range. Large fish, bullfrogs, snapping turtles, milk snakes, American crows, hawks, great blue herons, raccoons, foxes, squirrels, and shrews are some of the animals that prey on common garter snakes. They rely on stealth and camouflage for protection, and will flee into water to escape predators on land. Their stripes make them difficult to see properly and capture in grassy areas. If unable to flee they coil to make themselves appear larger, and may strike and bite. If grabbed, these snakes writhe and release a foul-smelling secretion; they will also urinate on their attacker.
Known Predators:
Anti-predator Adaptations: cryptic
Common garter snakes are highly variable in color pattern. They typically have three light stripes that run along the length of their body on a black, brown, gray, or olive background. The stripes can be white, yellow, blue, greenish, or brown. One stripe runs down the center of the snake's back, the other two stripes run alongside this central stripe. Sometimes the stripes are absent or poorly defined. Some garter snakes have alternating rows of dark spots that run along the stripes, making the stripes look more like checkerboard patterns of light, rather than lines. Common garter snakes have a head that is wider than the neck and is uniformly dark. Their tongues are red, tipped in black, and their scales are keeled (with a raised ridge along the length of the scale). The chin, throat and belly resemble the stripes in coloration, ranging from white to yellow, greenish, blue, or brown.
Common garter snakes grow to be 46 to 137 cm in total length. Males are generally smaller than females and have longer tails. Young common garter snakes are born at 12.5 to 23 cm long and are similar in appearance to the adults. There are many dozens of recognized regional populations of common garter snakes that have distinct color patterns. In some areas there are populations that have a high percentage of entirely black garter snakes. Common garter snakes are similar in appearance to their close relatives, ribbon snakes (Thamnophis sauritus) and Butler's garter snakes (Thamnophis butleri).
Range length: 46 to 137 cm.
Average length: 88.00 cm.
Other Physical Features: heterothermic ; polymorphic
Sexual Dimorphism: female larger; sexes shaped differently
Average mass: 150 g.
The average lifespan of wild common garter snakes is approximately two years. Most common garter snakes probably die in their first year of life. Common garter snakes reach sexual maturity, and maximum size, at 3 to 4 years of age. The lifespan of common garter snakes kept in captivity is longer, between 6 and 10 years. One captive common garter snake lived to be 20 years old, but few wild snakes live this long.
Average lifespan
Status: wild: 2 years.
Range lifespan
Status: captivity: 20 (high) years.
Average lifespan
Status: captivity: 6-10 years.
Typical lifespan
Status: captivity: 6 to 20 years.
Common garter snakes are very widespread, highly adaptable and can survive extreme environmental conditions. Common garter snakes are found in a wide variety of habitats, including meadows, marshes, woodlands, and hillsides. They tend to prefer moist, grassy environments. They are often found near water, such as near the edges of ponds, lakes, ditches, and streams, and are common in suburban and urban areas with plenty of cover (debris, boards, vegetation, logs, or rocks).
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: savanna or grassland ; forest
Wetlands: marsh ; swamp
Other Habitat Features: suburban ; agricultural ; riparian
Common garter snakes are native to the Nearctic region only. They occur throughout much of North America, although they are largely absent from the arid southwestern United States. Common garter snakes are found throughout eastern North America from Florida to coastal Quebec, west to British Columbia, south into southern California east of the Sierras, and throughout the less arid areas of the southwest. Isolated populations occur on mountain ranges in New Mexico and northern Mexico (New Mexico garter snakes, Thamnophis sirtalis dorsalis). They are found as far south as the Gulf of Mexico in the eastern United States.
Biogeographic Regions: nearctic (Native )
Garter snakes are low-level predators, feeding on many small animals and in turn being eaten by other predators higher in the food web. These snakes are one of the few kinds of animals that can eat toads, newts, and other amphibians with strong chemical defenses.
Common garter snakes are infected by a parasitic nematode that lives in the tissues of their tail. Snakes with this condition often have shortened or stubby tails. The nematodes live part of their lifecycle in small aquatic crustaceans and in amphibian larvae. The snakes are infected when they eat the amphibian larvae.
Common garter snakes act to control populations of insect and mollusk pests. They are a common and welcome sight to many gardeners. They also tame easily and are sometimes kept as pets.
Positive Impacts: pet trade ; controls pest population
On very rare occasions people have been known to have allergic reactions to common garter snake saliva after handling one and being bitten. These are extremely rare, though, and their reputation as harmless snakes is well deserved.
Negative Impacts: injures humans (bites or stings)
The young grow quickly and become mature in their second or third year, when they reach about 55 cm in length. Growth continues throughout the lifespan of these snakes.
Development - Life Cycle: indeterminate growth
Common garter snakes are some of the most common and abundant snakes throughout the eastern United States, at least partly because they do well in urban and suburban areas. Despite the fact that they are harmless snakes, they are often persecuted by humans. Pesticide use in some areas has significantly reduced common garter snake populations. Habitat destruction and over-collection for the commercial pet trade have also led to a decline in the number of garter snakes in the wild. Water pollution is a problem for this species, because so much of its food is aquatic. Northern populations are more vulnerable than southern ones, because they hibernate in larger groups (which are easily harvested) and produce smaller numbers of young each year. It is important to continue to monitor populations of 'common' species as declines in their populations can tell us a great deal about environmental health.
One subspecies, the San Francisco garter snake, Thamnophis sirtalis tetrataenia, is considered endangered, and placed on the US and California Endangered Species list in 1967. Other subspecies may be protected by state laws.
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Common garter snakes communicate with each other primarily through touch and smell, especially for breeding. Outside of the breeding season they do not interact much with other snakes. They use their forked tongues to collect chemicals from the air and insert these forks into a special organ in the roof of their mouth, which interprets these chemical signals, called pheromones. Pheromones can be used as a tracking device for garter snakes. Using their acute sense of smell, common garter snakes can locate other snakes or trails left behind by other snakes through the pheromones given off by their skin. After they are born, baby snakes follow the same pheromone trails to feed and locate other common garter snakes. Snakes are also sensitive to vibrations and have reasonably good vision.
During the breeding season, common garter snakes use complex systems of chemical communication. Male common garter snakes use skin lipids as pheromonal cues for sex recognition because female and male skin pheromones are extremely different. However, some males are occasionally born with both female and male skin pheromones. During mating season these males with female pheromones are courted by other males. The confusion often allows the males with female pheromones to mate first because the other males are courting the wrong sex. Shine et al. (2000) hypothesized that the behavior could provided a mating advantage to the genetically altered males.
Communication Channels: tactile ; chemical
Other Communication Modes: pheromones
Perception Channels: visual ; infrared/heat ; tactile ; vibrations ; chemical
Some of the subspecies of common garter snakes (Thamnophis sirtalis) are: Thamnophis sirtalis semifasciatus (Chicago Garter Snake), Thamnophis sirtalis parietalis (Red-sided Garter Snake), Thamnophis sirtalis dorsalis (New Mexico Garter Snake), Thamnophis sirtalis annectens (Texas Garter Snake), Thamnophis sirtalis similes (Blue-stripe Garter Snake), Thamnophis sirtalis pallidulus (Maritime Garter Snake), Thamnophis sirtalis fitchi (Valley Garter Snake), Thamnophis sirtalis infernalis (California red-sided Garter Snake), and Thamnophis sirtalis tetrataenia (San Francisco Garter Snake). All of these subspecies are similar, but vary in details of coloration and geographic distribution.
These snakes begin mating in the spring as soon as they emerge from hibernation. The males leave the den first and wait for the females to exit. Once the females leave the den the males surround them. The males give off pheromones that attract the females. After the female has chosen her mate and mated, she returns to her summer habitat to feed and to find a proper birth place. However, the males stay to re-mate with other available females. The females have the ability to store the male's sperm until it is needed and thus a female may not mate if she does not find a proper partner.
Mating System: polygynandrous (promiscuous)
Common garter snakes are ovoviviparous (bearing live young). The young are incubated in the lower abdomen, about half way down from the snake's body. Gestation is usually two to three months. Most females in the northern parts of their range give birth to from 4 to 80 young between late July and October. Most litters range from 10 to 40 young and litter size depends on the size of the female, with larger females giving birth to larger litters. Upon birth, baby garter snakes are independent and must find food on their own.
Common garter snakes become sexually mature at 1.5 years (males) or two years (females).
Breeding interval: Common garter snakes breed once each year.
Breeding season: Common garter snakes breed in the spring and give birth to their young in late summer.
Range number of offspring: 4 to 80.
Average number of offspring: 10 to 40.
Range gestation period: 2 to 3 months.
Average age at sexual or reproductive maturity (female): 2 years.
Average age at sexual or reproductive maturity (male): 1.5 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; sexual ; fertilization ; ovoviviparous ; sperm-storing
Average age at sexual or reproductive maturity (male)
Sex: male: 730 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 730 days.
Female common garter snakes nurture their young in their bodies until they are born. The mother gives birth to live young, she doesn't lay eggs. Newly born snakes tend to stay around their mother for several hours or days but she provides no parental care or protection after they are born.
Parental Investment: pre-hatching/birth (Provisioning: Female, Protecting: Female)
Užovka proužkovaná (Thamnophis sirtalis) je nejedovatý severoamerický had. Je nenáročná, přizpůsobivá a nekousavá, chová se proto často v teráriích.
Užovka proužkovaná je had s hlavou málo odlišenou od těla a poměrně dlouhým ocasem. Šupiny jsou kýlnaté, horní strana hlavy vždy černá nebo tmavá. Užovka vytváří řadu poddruhů, které se liší zbarvením i velikostí. Základní zbarvení proto záleží na konkrétním poddruhu, většinou je však doplněno jedním pruhem na zádech a dvěma postranními pruhy, které však mohou chybět nebo se rozpadají v izolované skvrny. Mezi nejkrásněji zbarvené poddruhy patří chráněná užovka proužkovaná sanfranciská, která žije jen v okolí San Francisca.
V závislosti na poddruhu dorůstá délky 45 až 140 cm, samci jsou obvykle kratší než samice a mají delší ocasy.
Užovka proužkovaná je hojná na většině území Severní Ameriky, vyskytuje se na území od jižní Kanady, přes USA až po Severní Mexiko, i když se spíše vyhýbá pouštním oblastem jihozápadu Spojených států.
Jsou to velmi přizpůsobiví hadi, nicméně patří mezi vodní užovky - proto preferují vlhká travnatá místa v okolí vod, jako jsou potoky, jezera, rybníky nebo i vlhké příkopy, vyskytují se také v mokřadech, na loukách a v lesích. Často jsou k nalezení v blízkosti lidí a všude to tam, kde nacházejí úkryt.
Užovka proužkovaná je aktivní hlavně ve dne, kdy loví drobné rybky, žáby i jejich pulce, mloky, žížaly, různé členovce, korýše i plže. Sežere i jiné druhy hadů, ještěry, malé savce i mláďata ptáků. Jsou imunní vůči jedu ropuch a mloků, kteří se tak stávají jejich kořistí.
Většinou žijí samotářsky, na zimovištích se však někdy vyskytují ve velkých množstvích. Zimují od konce října do března nebo do dubna, obvykle ve skulinách nebo v norách hlodavců. V jediném úkrytu zimuje více hadů, kteří si tak zajistí minimální teplotu nutnou k přežití zimy.
Jsou vejcoživorodí, mláďata se rodí po 2-3 měsících, v červnu až září. Po narození měří 15-20 cm a jsou plně samostatná, většinou jich je 10 až 40, starší a tudíž větší samice mívají větší počet mladých.
Pohlavně dospívají asi ve dvou letech, v přírodě mají však mnoho nepřátel a proto většina užovek proužkovaných nepřežije první rok života. Při vylekání mohou kousat a také z kloaky vypouští silně páchnoucí sekret, podobně jako užovka obojková, přesto jsou loveni většími rybami, skokany volskými, kajmankami, korálovkami, vránami, káňati, volavkami, mývaly, liškami, rejsky i dalšími živočichy.
V zajetí se dožívají 6 - 10 let.
Na chov je vhodné menší terárium s velkou vodní nádrží, nebo akvaterárium. Teplota by měla být okolo 22 až 28 °C, v noci nižší. V teráriu by měly být větve, kameny a důležité jsou i úkryty. Zazimování není k rozmnožování nutné, ale hadům by se mělo poskytnout 2-3 měsíční období klidu se sníženou teplotou.
Dospělé užovky požírají malé rybky, žáby, občas i myšata, žížaly, slimáky a hovězí maso. nebo rybí maso, mláďata se krmí akvarijními rybkami, nitěnkami a žížalami.
Užovka proužkovaná vytváří celou řadu poddruhů, které se liší velikostí, zbarvením a místem výskytu.
Obrázky, zvuky či videa k tématu užovka proužkovaná ve Wikimedia Commons
Užovka proužkovaná (Thamnophis sirtalis) je nejedovatý severoamerický had. Je nenáročná, přizpůsobivá a nekousavá, chová se proto často v teráriích.
Die Gewöhnliche Strumpfbandnatter (Thamnophis sirtalis) ist die bekannteste Schlangenart innerhalb der Gattung Strumpfbandnattern (Thamnophis).
Die 12 Unterarten der Gewöhnlichen Strumpfbandnatter unterscheiden sich unter anderem durch vielfältige Farbvariationen. Allen gemeinsam sind die meistens hell abgesetzten Rücken- und Seitenstreifen, denen die Gattung den Namen Strumpfbandnatter verdankt. Die Weibchen werden meist einen Meter lang, manchmal bis zu 1,20 m. Männchen erreichen selten eine Länge von mehr als 60 cm.
Sie haben ein breites Nahrungsspektrum und fressen Fische, Nacktschnecken, Würmer, Amphibien, Mäuse, Ratten und sogar kleine Vögel. Eine Besonderheit dieser Schlangenart ist, dass sie eine der wenigen, wenn nicht gar der einzige natürliche Feind des Rauhäutigen Gelbbauchmolchs (Taricha granulosa) ist. Im Laufe der Evolution entwickelte sie eine Immunität gegen den hochgiftigen Abwehrstoff dieses Salamanders, das Tetrodotoxin (TTX, auch bekannt unter dem Namen Tarichatoxin). Nachdem sie den Salamander gefressen hat, geht sie in ein Ruhestadium über und verlangsamt den Stoffwechsel, so dass sie die Wirkung dieses Gifts kompensieren kann. Sie ist wohl der einzige Organismus, der nach der Aufnahme dieses Giftes überleben kann. Es handelt sich um eine Koevolution zwischen dem Molch und der Schlangenart. In Regionen wo diese Schlange anzutreffen ist, ist die Produktion von Tetrodotoxin des Molches erhöht und im Gegenzug hat sich die Resistenz der Schlange gesteigert. Man spricht von “geographic mosaic theory of evolution”.[1]
Anders als die meisten Schlangen sind Strumpfbandnattern lebendgebärend (ovovivipar). Ihre Jungtiere sind bei der Eiablage bereits voll ausgebildet und nur noch von einer dünnen, durchsichtigen Eihülle umgeben. Diese Hülle muss während oder direkt nach der Geburt von den Jungtieren durchstoßen werden, da sie sonst ersticken. Ein Strumpfbandnattern-Wurf umfasst in der Regel fünf bis zwanzig Jungtiere. In Einzelfällen wurden allerdings auch schon Wurfgrößen von mehr als 80 Jungtieren beobachtet.
In Nordamerika stellt die Gewöhnliche Strumpfbandnatter die am weitesten verbreitete Reptilienart dar. In Alaska ist sie die einzige Schlangenart überhaupt. Ihr Lebensraum erstreckt sich gen Süden bis nach Mexiko in Mittelamerika.
Der Unterart-Status von T. s. similis und T. s. semifasciatus ist umstritten.
Die Gewöhnliche Strumpfbandnatter (Thamnophis sirtalis) ist die bekannteste Schlangenart innerhalb der Gattung Strumpfbandnattern (Thamnophis).
The Common garter snake (Thamnophis sirtalis) is an indigenous North American snake foond widely athort the continent. Maist garter snakes hae a pattern o yellae stripes on a broun or green backgrund an thair average length is aboot 55 cm (22 in), wi a maximum length o aboot 137 cm (54 in).[1][2] The average body mass is 150 g (5.3 oz).[3]
The Common garter snake (Thamnophis sirtalis) is an indigenous North American snake foond widely athort the continent. Maist garter snakes hae a pattern o yellae stripes on a broun or green backgrund an thair average length is aboot 55 cm (22 in), wi a maximum length o aboot 137 cm (54 in). The average body mass is 150 g (5.3 oz).
The common garter snake (Thamnophis sirtalis) is a species of snake in the subfamily Natricinae of the family Colubridae. The species is indigenous to North America and found widely across the continent. There are several recognized subspecies. Most common garter snakes have a pattern of yellow stripes on a black, brown or green background, and their average total length (including tail) is about 55 cm (22 in), with a maximum total length of about 137 cm (54 in).[2][3] The average body mass is 150 g (5.3 oz).[4] The common garter snake is the state reptile of Massachusetts.[5]
Common garter snakes are thin snakes. Few grow over about 4 ft (1.2 m) long, and most stay smaller. Most have longitudinal stripes in many different colors. Common garter snakes come in a wide range of colors, including green, blue, yellow, gold, red, orange, brown, and black.
The common garter snake is a diurnal snake. In summer, it is most active in the morning and late afternoon; in cooler seasons or climates, it restricts its activity to the warm afternoons.
In warmer southern areas, the snake is active year-round; otherwise, it sleeps in common dens, sometimes in great numbers. On warm winter afternoons, some snakes have been observed emerging from their hibernacula to bask in the sun.
The saliva of a common garter snake may be toxic to amphibians and other small animals. Garter snakes have a mild venom in their saliva.[6] For humans, a bite is not dangerous, though it may cause slight itching, burning, and/or swelling. Common garter snakes may also secrete a foul-smelling fluid from postanal glands when handled or harmed.
Common garter snakes are resistant to naturally found poisons such as that of the American toad and rough-skinned newt, the latter of which can kill a human if ingested. They have the ability to absorb the toxin from the newts into their bodies, making them poisonous, which can deter potential predators.[7]
The common garter snake uses toxicity for both offense and defense. On the offensive side, the snake's venom can be toxic to some of its smaller prey, such as mice and other rodents.[7] On the defensive side, the snake uses its resistance to toxicity to provide an important antipredator capability.[8] A study on the evolutionary development of resistance of tetrodotoxin compared two populations of Thamnophis and then tested inside a population of T. sirtalis. Those that were exposed to and lived in the same environment as the newts (Taricha granulosa) or rough-skinned newt, that produce tetrodotoxin when eaten were more immune to the toxin (see figure).[8]It seems that the two species were in an evolutionary arms race.
While resistance to tetrodotoxin is beneficial in acquiring newt prey, costs are associated with it as well. Consuming the toxin can lead to reduced speed and sometimes no movement for extended periods of time, along with impaired thermoregulation.[9] The antipredator display that this species uses demonstrates the idea of an "arms race" between different species and their antipredator displays.[8] Along the entire geographical interaction of T. granulosa and T. sirtalis, patches occur that correspond to strong coevolution, as well as weak or absent coevolution. Populations of T. sirtalis that do not live in areas that contain T. granulosa contain the lowest levels of tetrodotoxin resistance, while those that do live in the same area have the highest levels of tetrodotoxin resistance. In populations where tetrodotoxin is absent in T. granulosa, resistance in T. sirtalis is selected against because the mutation causes lower average population fitness. This helps maintain polymorphism within garter snake populations.[10]
Current scientific classification recognizes 13 subspecies (ordered by date):[11]
A trinomial authority in parentheses indicates that the subspecies was originally described in a genus other than Thamnophis.
The subspecific name fitchi is in honor of the American herpetologist Henry Sheldon Fitch.[12]
The subspecific name lowei is in honor of the American herpetologist Charles Herbert Lowe.[13]
The subspecific name pickeringii is in honor of the American naturalist Charles E. Pickering.[14]
Generally, populations include far more males than females, so during mating season, they form "mating balls", in which one or two females are completely swamped by ten or more males. Sometimes a male snake mates with a female before hibernation, and the female stores the sperm internally until spring, when she allows her eggs to be fertilized. If she mates again in the spring, the fall sperm degenerate and the spring sperm fertilize her eggs. The females may give birth ovoviviparously to 12 to 40 young from July through October.
In the early part of sex, when snakes are coming out of hibernation, the males generally emerge first to be ready when the females wake up. Some males assume the role of a female and lead other males away from the burrow, luring them with a fake female pheromone.[15] After such a male has led rivals away, he "turns" back into a male and races back to the den, just as the females emerge. He is then the first to mate with all the females he can catch. This method also serves to help warm males by tricking other males into surrounding and heating up the male, and is particularly useful to subspecies in colder climates (such as those inhabited by T. s. parietalis); this type of mimicry is primarily found in that subspecies.[16] These deceptive males have been found to mate with females significantly more often than males that do not exhibit this mimicry.[17]
The habitat of the common garter snake ranges from forests, fields, and prairies to streams, wetlands, meadows, marshes, and ponds, and it is often found near water. Depending on the subspecies, the common garter snake can be found as far south the southernmost tip of Florida in the United States and as far north as the southernmost tip of the Northwest Territories in Canada. It is found at altitudes from sea level to mountains.
The diet of T. sirtalis consists mainly of amphibians and earthworms, but also leeches, slugs, snails, insects, crayfish,[18] fish, lizards, other snakes,[18] small birds, and rodents. Common garter snakes are effective at catching fast-moving creatures such as fish and tadpoles.
Animals that prey on the common garter snake include large fish (such as bass and catfish), American bullfrogs, common snapping turtles, larger snakes, hawks, raccoons, foxes, wild turkeys, and domestic cats and dogs.
Water contamination, urban expansion, and residential and industrial development are all threats to the common garter snake. The San Francisco garter snake (T. s. tetrataenia), which is extremely scarce and occurs only in the vicinity of ponds and reservoirs in San Mateo County, California, has been listed as an endangered species by the U.S. Fish and Wildlife Service since 1967.
Garter snakes exhibit many different behaviors to ward off predators. Garter snakes exhibit a greater variety of body postures than other snakes. Under selection by predation, these snakes have developed postural responses that are highly variable and heritable. These are highly variable even within a single population.[19] Different postures indicate whether the snake is preparing to flee, fight, or protect itself. Different biological factors such as body temperature and sex also influence whether the snake exhibits certain antipredatory behaviors.[20]
The warmer the temperature of a garter snake, the more likely the snake is to flee a predator; a snake with a cooler body temperature is more likely to remain stationary or attack. Male garter snakes are also more likely to flee.[20][21] Garter snakes that exhibit more aggressive antipredatory displays tend to also be fast and have high stamina. However, the reason for this correlation is unknown.[22]
The first response of the snake to a predator is often a bluff. When the snake was teased with a finger under laboratory conditions, the snake reacted aggressively, but once touched, it became passive.[21] This may be because the snake is disinclined to attack an organism it sees as larger than itself. Garter snakes do not exhibit mimicry or aposematic coloration; relying on cryptic coloration for protection, they will freeze until they know they are spotted, then attempt a stealthy departure.[23]
The decision of a juvenile garter snake to attack a predator can be affected by whether the snake has just eaten or not. Snakes that have just eaten are more likely to strike a predator or stimulus than snakes that do not have a full stomach. Snakes that have just eaten a large animal are less mobile.[24]
Another factor that controls the antipredatory response of the garter snake is where on its body the snake is attacked. Many birds and mammals prefer to attack the head of the snake. Garter snakes are more likely to hide their heads and move their tails back and forth when being attacked close to the head. Snakes that are attacked in the middles of their bodies are more likely to flee or exhibit open-mouthed warning reactions.[25]
Age may be another factor that contributes to antipredatory responses. As garter snakes mature, the length of time for which they can engage in physical activity at 25 °C increases. Juvenile snakes can only be physically active for 3–5 minutes. Adult snakes can be physically active for up to 25 minutes. This is mostly due to aerobic energy production; pulmonary aeration increases up to three times in adult garter snakes when compared to juveniles. The quick fatigue of the juveniles limits the habitats they can live in, as well as their food sources.[26] It also affects the antipredator response of both juvenile and adult garter snakes; without sufficient energy production, the snake cannot effect an antipredatory response.
T. s. sirtalis (Ontario specimen)
T. s. sirtalis (Quebec, Canada)
T. s. sirtalis (Florida specimen)
T. s. pallidulus
{{cite journal}}: CS1 maint: uses authors parameter (link) The common garter snake (Thamnophis sirtalis) is a species of snake in the subfamily Natricinae of the family Colubridae. The species is indigenous to North America and found widely across the continent. There are several recognized subspecies. Most common garter snakes have a pattern of yellow stripes on a black, brown or green background, and their average total length (including tail) is about 55 cm (22 in), with a maximum total length of about 137 cm (54 in). The average body mass is 150 g (5.3 oz). The common garter snake is the state reptile of Massachusetts.
La serpiente de jarretera o culebra rayada (Thamnophis sirtalis) es una especie de reptil ovovivíparo inofensivo de la familia Colubridae. Habita en Estados Unidos y Canadá.[2]
Datos: Q911786
Multimedia:
Especies: Thamnophis sirtalis
La serpiente de jarretera o culebra rayada (Thamnophis sirtalis) es una especie de reptil ovovivíparo inofensivo de la familia Colubridae. Habita en Estados Unidos y Canadá.
Thamnophis sirtalis Thamnophis generoko animalia da. Narrastien barruko Natricidae familian sailkatuta dago.
Thamnophis sirtalis Thamnophis generoko animalia da. Narrastien barruko Natricidae familian sailkatuta dago.
Thamnophis sirtalis
La Couleuvre rayée ou Serpent-jarretière, Thamnophis sirtalis, est une espèce de serpents de la famille des Natricidae[1].
Cette espèce se rencontre fréquemment en Amérique du Nord[1]. On peut la rencontrer partout sauf dans les climats extrêmes, c'est-à-dire dans des régions très sèches ou très froides. Si elle se trouve dans une région plutôt froide, il lui arrive qu'elle hiberne. Elle va donc chercher un terrier, une cave[2] ...
Elle est d'un brun sombre avec trois raies jaunes ou rouges; l'une sur le dos et les deux autres sur les côtés, hormis une exception où les rayures deviennent des taches. Sa longueur moyenne est comprise entre 50 et 125 cm. Son poids varie entre 140 et 180 g[2].
Plus grosse que le mâle, la femelle est facilement repérable aux yeux des humains ; les serpents, eux, ne l'identifient qu'à son odeur.
Sa nourriture se compose de petits poissons d'eau douce (vivants) ou bouts de saumons frais, de vers de terre, et parfois de souriceaux.
La couleuvre rayée possède des écailles carénées et une plaque anale non-divisée. Cette espèce est ovovivipare et donne naissance à un nombre de petits compris entre 10 et 70 par portée[2].
Ce serpent est l'unique prédateur des tritons rugueux, qu'il est le seul à pouvoir consommer sans subir les effets des terribles toxines de la peau du triton, largement mortelles pour toute autre espèce (y compris pour l'Homme). Ce fait résulte d'un équilibre écologique qui s'est mis en place entre les deux espèces : les tritons les plus venimeux survivent davantage à la prédation des couleuvres, et les couleuvres les plus résistantes aux toxines sont favorisées dans leur accès à la nourriture. La couleuvre rayée se nourrit également de vers, de poissons et d'autres amphibiens[2].
Selon Reptarium Reptile Database (6 septembre 2013)[3] :
Thamnophis sirtalis
La Couleuvre rayée ou Serpent-jarretière, Thamnophis sirtalis, est une espèce de serpents de la famille des Natricidae.
Thamnophis sirtalis é unha especie de serpe natricina natural de Norteamérica, que se encontra amplamente espallada polo continente. A maioría dos exemplares teñen un patrón de bandas amarelas sobre fondo castaño ou verde (pero a cor e o patrón é moi variable). A súa lonxitude media total (incluíndo a cola) é duns 55 cm, cunha lonxitude máxima total rexistrada duns 137 cm.[2][3] A súa masa corporal media é duns 150 g.[4]
A actual clasificación científica recoñece 13 subespecies (aquí ordenadas por data):[5]
Nota bene: unha autoridade trinomial entre parénteses indica que a subespecie foi descrita orixinalmente nun xénero distinto de Thamnophis.
Son serpes delgadas que non crecen normalmente moito máis de 1,2 m, e a maioría son máis pequenas. A maioría teñen bandas lonxitudinais de distintas cores. Poden ter unha ampla gama de cores: verde, azul, dourada, amarela, vermella, laranxa, castaña e negra.
É diúrna. No verán é máis activa pola mañá e ao serán; nas estacións e climas fríos restrinxe a súa actividade aos mediodías cálidos. Nas áreas cálidas do sur, é activa todo o ano; cando non, dorme en goridas comúns, ás veces en gran número. En mediodías cálidos de inverno observouse que sae dos seus hibernáculos para tomar o sol.
A saliva desta serpe pode ser tóxica para anfibios e outros pequenos animais, xa que teñen un veleno de efectos suaves na saliva.[6] Para os humanos a súa mordedura non é perigosa, aínda que pode causar un lixeiro proído, queimura ou inchazón. A maioría dos exemplares tamén segregan un fluído de cheiro fedorento das súas gándulas postanais cando os collen ou danan.
Son resistentes a velenos que se encontran na natureza como os de sapos e o do urodelo Taricha granulosa. Esta serpe ten a capacidade de absorber no seu corpo a toxina dos Taricha granulosa (produtores de tetrodotoxina) que come, o que fai que o seu corpo sexa velenoso e iso detén a posibles depredadores.[7][8] Fíxose un estudo sobre a resistencia á tetrodotoxina en dúas poboacións de Thamnophis e despois nas poboacións de T. sirtalis. As poboacións que estaban expostas e vivían no mesmo ambiente que os anfibios Taricha granulosa, que producen tetrodotoxina, eran inmunes á toxina cando os comían (ver figura).[8]
Aínda que a resistencia á tetrodotoxina da serpe é beneficiosa ao permitirlle comer novas presas, tamén ten algúns custos asociados. Consumir a toxina pode reducir a súa velocidade de movementos e ás veces causa parálise durante longos períodos de tempo, e unha alteración da termorregulación.[9] Pode dicirse que se produce unha carreira de armamentos evolutiva entre o anfibio e a serpe en canto os niveis de toxina producidos e os niveis de resistencia. En toda a área de interacción xeografica entre Taricha granulosa e T. sirtalis, hai zonas nas que se observa unha forte coevolución e outras nas que a coevolución está ausente. Poboacións de T. sirtalis que non viven en áreas con T. granulosa teñen menor resistencia á tetrodotoxina, mentres que as que viven na mesma área presentan alta resistencia. En poboacións nas que está ausente a tetrodotoxina en T. granulosa, a resistencia en T. sirtalis sofre unha selección en contra porque a mutación para a resistencia causa unha fitness media da poboación menor. Isto axuda a manter o polimorfismo nas pobaocións da serpe.[10]
A inicios da primavera, cando estas serpes saen da súa hibernación, os machos son os que primeiro saen para estaren listos cando esperten as femias. Algúns machos asumen o papel de femia e atraen a outros machos fora das súas goridas, enganándoos cunha feromona similar á das femias.[11] Unha vez que con esa estratexia o macho afastou aos seus rivais, "volve" ás súas características de macho e regresa á gorida, xusto cando as femias saen, para ser así o primeiro que se aparea coas femias. Este método tamén serve para axudar a quentar aos machos ao verse rodeado por outros machos que lle dan calor, e é especialmente útil nas subespecies que viven en climas máis fríos (como T. s. parietalis).[12] Tamén se evitan competir con machos máis fortes. Xeralmente hai moitos máis machos que femias e esta é a razón pola cal na tempada reprodutora forman "bólas de apareamento", nas que unha ou máis femias están completamente rodeadas por dez ou máis machos, formando unha bóla. Ás veces un macho aparéase cunha femia antes da hibernación e a femia almacena internamente o esperma ata a primavera, momento en que permite que se fecunden os ovos con ese esperma. Se se aparea de novo en primavera, o esperma antigo pode dexenerar e os ovos serán fecundados co esperma novo. As femias dan a luz de 12 a 40 crías (son animais ovoviviparos) entre xullo e outubro.
O seu hábitat son os bosques, campos e praderías, ríos, zonas húmidas, pantanos, e pozas, e xeralmente se encontra preto da auga. Encóntrase en altitudes desde o nivel do mar ata zonas montañosas. A súa dieta consiste principalmente en anfibios e miñocas, pero tamén come peixes, peqeunas aves e roedores. Son boas cazadoras e capturan animais que se moven velozmente como peixes e cágados. Os animais que a comen a ela son peixes grandes (como os Micropterus e siluros), a ra touro americana (Lithobates catesbeianus), a tartaruga mordedora Chelydra serpentina, outras serpes máis grandes, falcóns, mapaches, raposos, pavos salvaxes (Meleagris gallopavo) e gatos e cans domésticos.
A contaminación da auga, a expansión urbana, e o desenvolvemento residencial e industrial son ameazas para este especie. A subespecie de San Francisco (T. s. tetrataenia), que é extremadamente escasa e vive só arredor de pozas e depósitos de auga en San Mateo County, California, está na lista de especies ameazadas do Servizo de Pesca e Vida salvaxe de Estados Unidos desde 1967.
T. sirtalis mostra moitos comportamentos para evitar ou repeler os depredadores. Mostran unha gran variación na súa morfoloxía en comparación con outras serpes. A predación creou unha intensa presión de selección sobre estas serpes que fixo que desenvolvesen xeometrías corporais (posturas) moi variables (mesmo dentro dunha mesma poboación) e herdables.[13] As diferentes xeometrías que adopta indican se a serpe se está a preparar para escapar, loitar, ou protexerse. Como os trazos son herdables, debe haber neles algún beneficio evolutivo, como repeler os depredadores. Diferentes factores biolóxicos como a temperatura corporal e o sexo inflúen en que a serpe mostre certos comportamentos antidepredadores.[14]
Canto maior é a temperatura da serpe, máis probable é que a serpe trate de fuxir do depredador. As serpes co corpo máis frío permanecen estacionarias ou atacan. Os machos é máis probable que decidan escapar.[14][15] As que mostran un comportamento máis agresivo antidepredadores adoitan ser tamén rápidas e resistentes, pero a causa desta correlación é descoñecida.[16] A primeira resposta da serpe é un farol. Cando a serpe é molestada cos dedos, reacciona agresivamente, pero, despois de tocala, permanece pasiva e non reacciona con máis violencia.[15]
O aposematismo, ou coloración de advertencia, é outro factor que inflúe no comportamento antidepreddor.[17] Aínda que T. sirtalis non mostra mimetismo ou coloración aposemática, as que teñen un patrón de bandas é máis probable que marchen reptando sucesiva e lentamente, mentres que as que teñen pintas e non bandas é máis probable que escapen enganando os depredadores.[18]
A decisión de que unha T. sisrtalis xuvenil ataque a un depredador pode depender de se a serpe comeu recentemente algo ou non. Se acaba de comer é máis probable que ataque, e co estómago baleiro é máis probable que escapen. Cando acaban de comer son menos móbiles e máis resistentes.[19]
Outro factor que controla a resposta antidepredadores é a parte do seu corpo na que a serpe se ve atacada. Moitas aves e mamíferos prefiren atacar a cabeza da serpe. A serpe agocha a cabeza e move a cola cando é atacada preto da cabeza, pero se son atacadas no medio do corpo é probable que fuxan ou abran a boca en sinal de advertencia.[20]
A madurez da serpe é outro factor que contribúe ás respostas antidepredadores. Nas serpes maduras increméntase o tempo que poden despregar actividade física a 25 °C. As serpes xuvenís, inmaduras, só son fisicamente activas durante de 3 a 5 minutos, pero nas adultas ese tempo é de 25 minutos. Isto débese principalmente á produción aeróbica de enerxía; o incremento da aireación pulmonar é tres veces maior nos adultos. A rápida fatiga que experimentan os xuvenís limita os hábitats nos que poden vivir e as súas fontes de alimento.[21] Sen suficiente produción de enerxía as serpes xuvenís ou adultas non poden mostrar respostas antidepredadores.
Thamnophis sirtalis é unha especie de serpe natricina natural de Norteamérica, que se encontra amplamente espallada polo continente. A maioría dos exemplares teñen un patrón de bandas amarelas sobre fondo castaño ou verde (pero a cor e o patrón é moi variable). A súa lonxitude media total (incluíndo a cola) é duns 55 cm, cunha lonxitude máxima total rexistrada duns 137 cm. A súa masa corporal media é duns 150 g.
Paprastoji raištinė gyvatė (lot. Thamnophis sirtalis, angl. Common Garter Snake, vok. Gewöhnliche Strumpfbandnatter) – žaltinių (Colubridae) šeimos roplys.
Kūnas 55-75 cm ilgio, patinas trumpesnis už patelę. Lytiškai subręsta po 2-3 metų. Poruojasi pavasarį. Jauniklių kiekis 12-60. Inkubacinis laikotarpis 3 mėnesiai.
Šios gyvatės mėgsta draugiją; poravimosi ir žiemos miego metu jos laikosi didelėmis grupėmis.
Minta varlėmis, rupūžėmis, žuvimis, salamandromis, smulkiais žinduoliais, paukščiais, dvėsena. Gyvenimo trukmė – iki 12 metų.
Sutinkamos nuo Kanados per visą JAV teritoriją iki Meksikos, nuo Ramiojo vandenyno iki Atlanto vandenyno.
Paprastoji raištinė gyvatė (lot. Thamnophis sirtalis, angl. Common Garter Snake, vok. Gewöhnliche Strumpfbandnatter) – žaltinių (Colubridae) šeimos roplys.
Kūnas 55-75 cm ilgio, patinas trumpesnis už patelę. Lytiškai subręsta po 2-3 metų. Poruojasi pavasarį. Jauniklių kiekis 12-60. Inkubacinis laikotarpis 3 mėnesiai.
Šios gyvatės mėgsta draugiją; poravimosi ir žiemos miego metu jos laikosi didelėmis grupėmis.
Minta varlėmis, rupūžėmis, žuvimis, salamandromis, smulkiais žinduoliais, paukščiais, dvėsena. Gyvenimo trukmė – iki 12 metų.
Strømpebåndssnok (Thamnophis sirtalis) er en slange som er vanlig i store deler av Nord-Amerika.[1]
Strømpebåndssnok (Thamnophis sirtalis) er en slange som er vanlig i store deler av Nord-Amerika.
Multimedia w Wikimedia Commons Ogrodowiec zwyczajny[4], wąż pończosznik, pończosznik prążkowany (Thamnophis sirtalis) – gatunek węża z podrodziny zaskrońców w rodzinie połozowatych, występujący na terytorium od Kanady przez USA po Meksyk – od Pacyfiku po Atlantyk[2].
Osiąga długość ciała 55-75 cm (samiec jest krótszy od samicy).
Żyje w grupach liczących tysiące osobników. Na miejsce snu zimowego wybierają głębokie szczeliny. Żywi się płazami, rybami, małymi ssakami, ptakami i padliną. Żyje do 12 lat.
Okres godowy przypada na wiosnę. Jedna samica zostaje otoczona przez setki samców. Sperma samca znajduje się w żelatynowej osłonce, co zapewnia plemnikom niezbędny czas do zapłodnienia jaj, zanim dotrze nasienie kolejnego partnera samicy[4]. Pończoszniki są jajożyworodne. Samica rodzi 12-85 młodych. Badania DNA wykazały, że w jednym miocie samicy znajduje się potomstwo różnych ojców[4]. Po 3 miesiącach wylęgają się młode węże. Dojrzałość płciową osiągają w 2-3 roku życia.
Ogrodowiec zwyczajny, wąż pończosznik, pończosznik prążkowany (Thamnophis sirtalis) – gatunek węża z podrodziny zaskrońców w rodzinie połozowatych, występujący na terytorium od Kanady przez USA po Meksyk – od Pacyfiku po Atlantyk.
Thamnophis sirtalis é uma cobra não-peçonhenta endémica da América do Norte. A maioria destas cobras possui um padrão de riscas amarelas num fundo castanho e o seu comprimento médio é cerca de 1-1,5 metros. Como todas as outras cobras, esta espécie usa a sua língua para cheirar. Essa espécie de cobras se destaca principalmente pelas suas cores.[1]
Thamnophis sirtalis é uma cobra não-peçonhenta endémica da América do Norte. A maioria destas cobras possui um padrão de riscas amarelas num fundo castanho e o seu comprimento médio é cerca de 1-1,5 metros. Como todas as outras cobras, esta espécie usa a sua língua para cheirar. Essa espécie de cobras se destaca principalmente pelas suas cores.
Common Garter Snake (Thamnophis sirtalis) Kuzey Amerika'nın yerli yılanlarındandır. Yılanın ortama uzunluğu 50 cm (20 in) sahiptir, maksimum 125 cm (49 in) uzunluğuna sahiptir.[1]
Bilimsel sınıflandırmaya göre 13 alttürleri bulunmaktadır (tarihleriyle birlikte).
T. s. sirtalis (Ontario specimen)
T. s. pallidulus
Common Garter Snake (Thamnophis sirtalis) Kuzey Amerika'nın yerli yılanlarındandır. Yılanın ortama uzunluğu 50 cm (20 in) sahiptir, maksimum 125 cm (49 in) uzunluğuna sahiptir.
Rắn nịt tất thường (Thamnophis sirtalis) là một loài rắn bản địa Bắc Mỹ. Phần lớn rắn này có dải vàng trên nèn nâu hoặc xanh lá cây và dài trung bình khoảng 55 cm (22 in), tối đa khoảng 137 cm (54 in).[1][2] Trọng lượng trung bình 150 g (5,3 oz).[3] Rắn Thamnophis sirtalis tiến hóa sự chống chịu chất độc tetrodotoxin ở các con mồi lưỡng cư của nó.
Phân loại khoa học hiện nay công nhận mười ba phân loài:[4]
Rắn nịt tất thường (Thamnophis sirtalis) là một loài rắn bản địa Bắc Mỹ. Phần lớn rắn này có dải vàng trên nèn nâu hoặc xanh lá cây và dài trung bình khoảng 55 cm (22 in), tối đa khoảng 137 cm (54 in). Trọng lượng trung bình 150 g (5,3 oz). Rắn Thamnophis sirtalis tiến hóa sự chống chịu chất độc tetrodotoxin ở các con mồi lưỡng cư của nó.
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