How do tree frogs climb


Tree Frogs | National Wildlife Federation

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Tree Frogs

Family: Hylidae

Status: Not Listed

Classification: Amphibian

Description

Tree frogs are a diverse family of amphibians that includes over 800 species. Not all tree frogs live in trees. Rather, the feature that unites them has to do with their feet—the last bone in their toes (called the terminal phalanx) is shaped like a claw. Tree frogs also have toe pads to help them climb and many have extra skeletal structures in their toes. Tree frogs can be a variety of colors, but most of the species found in the United States are green, gray, or brown. Some of them, like the squirrel tree frog (Hyla squirella), are chameleon-like in their ability to change color.

Although tree frogs can grow to be a range of sizes, most arboreal species are very small because they rely on leaves and slender branches to hold their weight. At 4 to 5.5 inches (10 to 14 centimeters) long, the white-lipped tree frog (Litoria infrafrenata) from Australia and Oceania is the largest tree frog in the world. The largest tree frog in the United States is the non-native Cuban tree frog, which reaches 1.5 to 5 inches (3.8 to 12.7 centimeters) in length. The world’s smallest tree frogs are less than an inch (2.5 centimeters) long!

Range

Tree frogs are found on every continent except Antarctica, but they’re most diverse in the tropics of the western hemisphere. About 30 species live in the United States, and over 600 can be found in South and Central America. Not surprisingly, lots of tree frogs are arboreal, meaning they live in trees. Special adaptations like toe pads and long legs aid them in climbing and jumping. Non-arboreal tree frogs find habitats in lakes and ponds or among moist ground cover.

Tree frogs are consumed by many different carnivorous animals. Mammals, reptiles, birds, and fish all eat tree frogs. Many of the frogs rely on camouflage to protect themselves from predators, and the more arboreal species escape ground-dwelling predators by hiding in trees.

Diet

Adult tree frogs are insectivores that eat flies, ants, crickets, beetles, moths, and other small invertebrates. However, as tadpoles, most of them are herbivores.

Life History

Almost all male frogs attract mates with advertisement calls. Each frog species has its own call so female frogs can listen for potential suitors of their own species. The frog call that most people are familiar with—“Ribbet!”—belongs to the Baja California tree frog (Pseudacris hypochondriaca). The ribbeting call has been incorporated into outdoor scenes of many Hollywood movies, even outside of the frog’s range.

Some frogs hatch as miniature adults. More commonly, however, tadpoles emerge from frog eggs. As tadpoles mature, they lose their tail and grow legs until they eventually reach their adult form. The lifespan of tree frogs varies among species. Some of them are long-lived, such as the Australian green tree frog (Litoria caerulea), which is often kept in captivity for upward of 15 years. Species with lifespans of less than three years are considered short-lived. North America’s gray tree frogs (Hyla versicolor and Hyla chrysoscelis) are somewhere in the middle with a lifespan of five to nine years.

Conservation

Amphibians are declining worldwide and are collectively one of the most at-risk groups for extinction. They breathe through their skin, which makes them especially sensitive to environmental change. Threats to tree frogs include habitat destruction, pollution, climate change, and diseases like chytridiomycosis.

Fun Fact

Not all members of the tree frog family Hylidae live in trees, and not all frogs that live in trees are in the hylid family.

Sources

Amphibian Ark

AmphibiaWeb

Animal Diversity Web, University of Michigan Museum of Zoology

EDGE of Existence, Zoological Society of London

Florida Wildlife Extension

World Association of Zoos and Aquariums

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Gray tree frog | Smithsonian's National Zoo

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Class: Amphibia
Order: Anura
Family: Hylidae
Genus and Species: Hyla versicolor

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Gray tree frog

Gray tree frogs are large, arboreal species common throughout much of the eastern U.S. and southeastern Canada. They have highly adapted toe tips for climbing and change color based on their temperature and activity.

  • Fact sheet
  • Conservation

Physical Description

The gray tree frog's color changes in response to its environment and activities, and can range from green to gray or brown. The upper surface of the body has a blotchy pattern that resembles lichen. Although the pattern varies, it usually features two dark central patches, which can be green, buff or gray. These frogs have a white spot beneath each eye and a dark stripe from the rear of the eyes to the front of the legs. The snout is short, and the skin is warty and coarse.

The upper surfaces of the legs feature a dark, banded pattern, which contrasts starkly with the bright yellow or orange undersides of the legs. Scientists believe the bright coloration serves as a warning for predators not to attack. The gray tree frog has webbed hands and feet. The enlarged tip of each digit produces an adhesive fluid that allows this species to better grip trees and improves its climbing abilities. The frog's belly is white, although the male reveals a black throat when it is calling.

Like the adult, the gray tree frog tadpole has inconsistent coloring, including different shades of brown or olive green. As tadpoles, they are scarlet or orange-vermilion with black blotches around the edge of the crests. The body and tail are patterned with many specks of black and gold. As the individual ages, it develops its adult coloration.

Size

Adult male gray tree frogs are around 1.25-2 inches (32-52 millimeters) in length. Females are typically slightly larger than males, ranging from 1.5-2.25 inches (38-60 millimeters) in length.

Native Habitat

The gray tree frog's range covers much of the eastern United States, from northern Florida to central Texas and north to parts of southeastern Canada. It is a largely arboreal species that occupies a variety of wooded habitats and is frequently found in forests, swamps, on agricultural lands and in backyards.

Access to trees and a water source is common to all habitats it occupies. When a gray tree frog is young and newly metamorphosed, it usually remains near the forest floor. As it ages, it may transition to living in the forest canopy.

Communication

Males emit a loud, musical call, usually after dusk, for as long as four hours. The male uses the call to establish a breeding territory and to find a mate.

Food/Eating Habits

Adult gray tree frogs mainly prey upon different types of insects and their own larvae. Mites, spiders, plant lice, snails and slugs are common prey. They may also occasionally eat smaller frogs, including other tree frogs.

They are nocturnal and hunt in the understory of wooded areas in trees and shrubs. As tadpoles, they eat algae and organic detritus found in the water.

Reproduction and Development

A male begins the mating call in early spring, shortly after emerging from hibernation. In the mid-range areas males begin calling in late April to early May. Males call to females from trees and bushes that are usually close to, or overhanging, streams or standing water.

The exact timing of breeding for gray tree frogs varies based on temperature and their location throughout the range. Most reproduction takes place early on, although the calling season lasts from late April to early August. Individuals may mate up to three times in a season.

Males are very territorial and will fight other males to defend their area. Fights may last 30 to 90 seconds and consist of wrestling, shoving, kicking and head butting until the subordinate male retreats. Females instigate mating by approaching a calling male and touching him before rotating 90 degrees.

The individuals engage in amplexus, a mating position in which the male grasps the female with his front legs, as the female deposits 1,000 to 2,000 eggs which are externally fertilized by the male. Since mating occurs while the frogs are floating in water, eggs are deposited into the water in small clusters, which attach themselves to structures via a transparent, mucous outer layer.

Tadpoles usually hatch after three to seven days, depending on the water temperature. About 10 minutes to an hour before hatching, the embryo has to release a fluid to help break down the wall of the egg. Tadpole development depends on water temperature with metamorphosis typically occurring in 45 to 65 days. They become sexually mature after two years.

Sleep Habits

Gray tree frogs are a nocturnal species. They hide in tree holes, under bark, in rotten logs, under leaves and under tree roots when inactive. At night, they search for insects in trees, where they can climb vertically or move horizontally with specially adapted toe pads.

Lifespan

Gray tree frogs typically live for seven to nine years.

The gray tree frog has a wide distribution and presumed large population. Threats to regional populations include habitat loss, the pollution of water ways, invasive species and the threat of diseases, such as the chytrid fungus. Exposure to pesticide and insecticide has also been found to negatively affect this species.

Help this Species

  • Conservation starts with you! Join a citizen science project, such as FrogWatch or Neighborhood Nestwatch, where you can help collect valuable data for scientists. Encourage your friends and family to get involved too.
  • Are you a student? Did you love what you learned about this animal? Make it the topic of your next school project, or start a conservation club at your school. You'll learn even more and share the importance of saving species with classmates and teachers, too.
  • Protect local waterways by using fewer pesticides when caring for your garden or lawn. Using fertilizers sparingly, keeping storm drains free of litter and picking up after your pet can also improve watershed health.

Flight adaptations found in tree frog genome - PCR News

A team led by researchers from the Chinese Academy of Sciences described the adaptations of flying frogs (genus Rhacophorus ) to an arboreal lifestyle. Among them are the accelerated evolution of genes that regulate limb development, a replacement in the keratin cytoskeleton gene, as well as the involvement of the Wnt signaling pathway and vascular development genes.

Tree frogs are capable of climbing and gliding from branch to branch. The development of suckers, as well as tubercles on the metacarpal bones and Y-shaped elements inside the terminal phalanges of the fingers, supporting sticky pads, allow them to stay on the branches due to capillary forces and friction. And the flight between the branches is probably associated with the presence of interdigital membranes. A similar structure of the limbs allowed tree frogs to develop an ecological niche that is inaccessible to most amphibians. For example, frog Rhacophorus kio lives in the crowns of trees up to 57 m high. At this height, it is not threatened by terrestrial predators and new food resources are available. This species is characterized by rough interdigital membranes.

At the same time, the molecular mechanisms underlying these adaptations remained undiscovered. For their study, the researchers chose frogs of two species: Rhacophorus kio , capable of flight, and flightless Rhacophorus dugritei with poorly developed membranes, which lives on the ground, among shrubs and swamps.

As expected, frogs R . dugritei when falling from a height of 1–2 m, they did not extend their legs and almost did not plan, in contrast to R . kio . Scientists noted that the ability to fly depends not only on the presence of membranes, but also on the size and body weight of amphibians.

The researchers sequenced and assembled the de novo genomes of these two species. Further analysis and comparison with frog genetic data Xenopus , N anorana parkeri , Rhinella marina , as well as reptiles, birds and mammals, made it possible to isolate genes that evolved faster in Rhacophorus or were subjected to positive selection. These included genes necessary for the formation of limbs, such as F gfr 2, C2 d 2a, Zak, Dlx5, Sf3b4 and Bbs .

Gene P pl contains a replacement that is conservative within the genus Rhacophorus . This gene encodes the protein periplakin, which regulates the organization of the cytoskeleton in skin cells, including those on the fingertips, through interaction with keratin proteins. Alpha keratins in the finger pads of flying frogs are highly diverse: 48 genes encoding type I keratins and 23 genes for type II keratins have been identified. These genetic traits are adaptations for climbing and grasping—providing a strong foot grip on the substrate.

The structure of the membrane is obviously determined in the early stages of development. The scientists followed the formation of the hind limb in tadpoles R. kio and R. dugritei and determined the key period of formation of interdigital membranes. Analysis of the time-ordered gene coexpression network, TO-GCN) revealed differences in the expression of genes belonging to the Wnt signaling pathway and regulating limb formation at the five-digit differentiation stage. According to the authors, these genes can regulate the size of the membrane in amphibians, which is consistent with data on salamander morphology.

In subsequent stages, scientists noticed the activation of a network of genes, including Hes5 and Ednrb and associated with the organization of blood vessels in the limb. It is likely that activation promotes membrane growth by increasing the number of vessels carrying nutrients and signaling molecules.

Thus, the genes that control the formation of the limb skeleton and finger skin cells have played an important role in the evolution of climbing and gliding in tree frogs. The researchers have identified a key network of genes whose co-expression is involved in the formation of webbed hind limbs and uncovered the molecular basis for these unusual features. The authors, however, noted that they did not conduct a transcriptomic study of the forepaw, although the webs on these should be even more important for altitude gain than the webs on the hind legs, which help the frog swim. it would be interesting to compare expression patterns in the forelimb and hindlimb.

Tree frogs

So far, amphibians living in water and on land have been described, but many of them decided to climb higher! Representatives of the family of tree frogs, or trees, (Hylidae) are especially popular with terrariumists. They spend most of their lives on trees and shrubs, and only occasionally go down. Some tropical species do even without these "visits".

They "take baths" and lay their eggs in small reservoirs, formed in the axils or rosettes of leaves, hollows of trees. Long fingers with suction cups at the end allow them to climb not only on trunks and branches, but also on smooth leaves, and in captivity on glass, easily holding onto vertical surfaces. In addition, tree frogs are able to make huge jumps, instantly “sticking”, for example, to the opposite wall of the room.

Many species are brightly colored, which is reflected in their names: "orange-sided", "golden", "multi-colored", etc., although most of them are green or brownish in spots and stripes protective coloration. Three domestic species are widespread in Russia: ordinary (Hula arborea), Asia Minor (H. savignyi) and Far Eastern (H.japonica) tree frogs. These are medium-sized (3-4 cm) frogs, leading an arboreal lifestyle. All of them are somehow protected species.

As an example, consider the common tree frog, which lives in the south of the European part of Russia, in the Krasnodar Territory and the Caucasus. But in some years with especially hot summers, tree frogs were found in the south of the Moscow region. The green color makes them completely invisible against the background of green leaves. Their existence is given out only by the sharp cries of males. Their singing can be heard at night and during the day, especially before the rain. Adult tree frogs usually live on trees far from the water, and young ones often stay on aquatic vegetation, sitting directly above the water (on reeds, cattails, reeds, sedges).

These frogs are active both day and night, but at night they feel bolder: they descend from trees and catch insects in the grass. They overwinter, burrowing into bedding or hiding in burrows, hollows, under stones. Before wintering, the color of tree frogs changes to a darker one. They prey on various insects, but prefer winged ones - flies or butterflies. Large prey, like other frogs, are stuffed into the mouth with the help of the front paws. For breeding, reservoirs are chosen, whose banks are bordered by reeds, bushes and trees. Females lay their eggs in spring, in large lumps, in several stages. One female can lay up to a thousand eggs. Very small tadpoles, no more than 0.5 cm, hatch after 10 days. Their development lasts for 3 months; the size of the tadpole before metamorphosis is up to 5 cm. The frogs become sexually mature at the 3-4th year of life.

More attractive for home keeping are tropical tree frogs, whose captive breeding is well established, and therefore some species are sold in pet stores. Most often these are Australian species: blue, or coral-toed, (Litoria caerulea) and long-legged (L. infrafrenata) litoria. These are large (up to 14 cm) amphibians of green color, sometimes with a bluish tint. Calm, even phlegmatic, they live great at home and are capable of simple training, so they often become pets. They require a spacious high terrarium. As a pound, a mixture of leafy soil, peat and expanded clay is used, in which plants with dense leathery leaves can be planted. At the bottom you need to put a wide and deep pond for swimming. When decorating the terrarium, you can use snags and tree branches that will protect the stems of plants from breakage. The temperature of the content is slightly above room temperature: 20-32 ° C. Humidity - about 80%. Food: crickets, cockroaches and other insects of suitable size. Frogs are very willing to eat flies and mosquitoes. They quickly get used to taking food from their fingers or from tweezers. Tree frogs can be trained to croak when the lights are turned on. In order for the frogs to start making sounds, they use a box of matches - just shake it next to the terrarium, as the males begin to "respond". If you do this every day when you turn on the light (lamps for illuminating the terrarium), then the tree frog develops a conditioned reflex - to croak when the owner approaches the terrarium and turns on the lamp. During the mating season, male tree frogs scream loudly on their own initiative, warning a possible rival that the territory is already occupied, and attracting females with their calls.

Outwardly, representatives of the family of copepod frogs, or copepods, (Rhacophoridae), common in Southeast Asia and tropical Africa, are similar in appearance to tree frogs. Some Asian species are famous for their ability to gliding flight using greatly enlarged webs between the toes of the hind legs. Most often, house copepods (Polypedates leucomystax), breeding in captivity, get to amateurs. These are medium-sized amphibians: the body length of males is 4-5 cm, females are twice as large. The color is brown with darker spots and stripes. To the conditions of detention are undemanding. The main thing that attracts the attention of lovers to them is the method of reproduction. The eggs are laid in a foam nest built by the parents. It is located above the water, between the leaves of low-hanging plants. In a terrarium, copepods build a nest on the side walls or just on the ground. After 2-5 weeks, the foam liquefies and the hatched tadpoles roll into the water. They feed small copepods in the same way as tree frogs. And reproduction in captivity is stimulated with the help of hormonal injections, which is not available to beginners.

Of course, representatives of the family of poison dart frogs (Dendrobatidae) are considered the “most-most” among tailless frogs. Incredibly bright coloration, interesting behavior, beautiful "singing" and, last but not least, the deadly poison produced by the skin of some species, attract the attention of not only biologists and ecologists, but also a large army of terrarium amateurs. Fortunately, when kept and bred in captivity, the toxicity of the poison practically disappears. It is possible that it depends on habitat conditions and the type of food, but nothing is known for sure. Which allows us to recommend dendrobates as pets.

A group of poison dart frogs (1 male and 3-4 females) needs a spacious terrarium, at least 40 x 25 x 25 cm in size. The soil is a mixture of peat, fern roots and sphagnum. A snag with plants from the bromeliad family placed on it is obligatory. Ventilation required. Temperature during the day 23-27 °C, at night 19-22 °C. Humidity - about 70%. Lighting is a must; at the same time, it is desirable to provide for a daily 30-60-minute quartz treatment with a LAU-30 lamp. Food: small insects, spiders and other invertebrates; should be in stock, since poison dart frogs are very energetic frogs and in the event of a week-long hunger strike they can simply die, which is how they differ from their other cold-blooded relatives, who eat just once a week.

The reproduction of poison dart frogs is incredibly interesting, although very difficult for a novice terrariumist. A male sitting on a horizontal leaf of a plant, with melodious trills, calls females ready for breeding to him. Caviar in the amount of 5-10 pieces is laid directly on this sheet. The male fertilizes her, and then stays nearby for a while, moistening the eggs with his mucus as needed. Tadpoles hatch on the 10-15th day, and the father carries them on his own back in a lump of foamy mucus to the nearest reservoir: such a reservoir is often water accumulated in the axils of bromeliad leaves. The female periodically visits her children, laying unfertilized eggs into the water, which serves as food for them. The male defends his territory and his "harem" (usually he has several females), courageously attacking the male poison dart frogs of his species.

The following types of dendrobates are imported into our country: coloring (D. auratus) poison dart frog - black-blue or black-yellow, about 4 cm in size; small (D. pumilo) poison dart frog - usually bright red with black or blue legs, 1. 5-2 cm in size; blue (D. azureus) poison dart frog - blue-blue with black spots, 4 cm in size; sacred (D. leucomelas) poison dart frog - black with bright yellow spots and stripes, 3.5 cm.

In terms of complexity of keeping, other amphibians of the same bright color can be compared with dendrobates. For example, harlequins (Atelopus) - small toads from the tropical regions of America and Madagascar mantella frogs (Mantella). Unfortunately, all these most interesting tailless amphibians do not live long - 5-6 years. (However, this is longer than the lifespan of a laboratory white rat - about a year and a half!). In addition, all exotics are poorly tamed, completely ignoring the existence of their own owner. Therefore, I do not suggest that beginners start them without fail - this is the lot of "advanced" terrariumists who have accumulated extensive experience in keeping amphibians in captivity. I just want you to love all amphibians, these wonderful animals - slippery, cold, but incredibly interesting and cute.


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