98-567: Ptychadena is a genus of frogs in the grassland frog family, Ptychadenidae . They are distributed in Sub-Saharan Africa , as well as nilotic Egypt . The common names of this genus are ridged frogs and grass frogs . This type of family have many different characteristics such as the species, Ptychadena neumanni who have long hindlimbs and a large ear drum compared to the Ptychadena erlangeri , for example. They also have
196-471: A courtship signal. The second problem has been more controversial. The early ethologists assumed that communication occurred for the good of the species as a whole, but this would require a process of group selection which is believed to be mathematically impossible in the evolution of sexually reproducing animals. Altruism towards an unrelated group is not widely accepted in the scientific community, but rather can be seen as reciprocal altruism, expecting
294-484: A positive feedback process that leads to the rapid exaggeration of a characteristic that confers an advantage in a competitive mate-selection situation. One theory to explain the evolution of traits like a peacock's tail is 'runaway selection'. This requires two traits—a trait that exists, like the bright tail, and a preexisting bias in the female to select for that trait. Females prefer the more elaborate tails, and thus those males are able to mate successfully. Exploiting
392-456: A benefit to both the signaler and receiver; they prevent the sender from wasting time and energy fleeing, and they prevent the receiver from investing in a costly pursuit that is unlikely to result in capture. Such signals can advertise prey's ability to escape, and reflect phenotypic condition (quality advertisement), or can advertise that the prey has detected the predator (perception advertisement). Pursuit-deterrent signals have been reported for
490-402: A brightly coloured belly. When confronted with a potential threat, they show their belly, indicating that they are poisonous in some way. Another example of prey to predator communication is the pursuit-deterrent signal. Pursuit-deterrent signals occur when prey indicates to a predator that pursuit would be unprofitable because the signaler is prepared to escape. Pursuit-deterrent signals provide
588-644: A different meaning for dogs as it refers to a direction or location. It has also been shown that dogs exhibit a left gaze bias when looking at human faces, indicating that they are capable of reading human emotions. Dogs do not make use of direction of gaze or exhibit left gaze bias with other dogs. A new approach in the 21st century in the field of animal communication uses applied behavioural analysis , specifically functional communication training. This form of training previously has been used in schools and clinics with humans with special needs, such as children with autism, to help them develop language. Sean Senechal at
686-449: A distinct alarm call for each of its four different predators, and the reactions of other monkeys vary appropriately according to the call. For example, if an alarm call signals a python, the monkeys climb into the trees, whereas the "eagle" alarm causes monkeys to seek a hiding place on the ground. Prairie dogs also use complex calls that signal predator differences. According to Con Slobodchikoff and others, prairie dog calls communicate
784-469: A few feed on plant matter. Frog skin has a rich microbiome which is important to their health. Frogs are extremely efficient at converting what they eat into body mass. They are an important food source for predators and part of the food web dynamics of many of the world's ecosystems . The skin is semi-permeable , making them susceptible to dehydration, so they either live in moist places or have special adaptations to deal with dry habitats. Frogs produce
882-432: A form of commutation through the environment. Active signals or other types of signals influence receivers behavior and signals move quicker in distance to reach receivers. Many animals communicate through vocalization. Vocal communication serves many purposes, including mating rituals, warning calls, conveying location of food sources, and social learning. In a number of species, males perform calls during mating rituals as
980-482: A form of competition against other males and to signal to females. Examples include frogs , hammer-headed bats , red deer , humpback whales , elephant seals , and songbirds . Other instances of vocal communication include the alarm calls of the Campbell monkey , the territorial calls of gibbons , and the use of frequency in greater spear-nosed bats to distinguish between groups. The vervet monkey gives
1078-541: A mild affiliative response of slowly closing their eyes; humans often mimic this signal towards a pet cat to establish a tolerant relationship. Stroking, petting and rubbing pet animals are all actions that probably work through their natural patterns of interspecific communication. Dogs have shown an ability to understand human communication. In object choice tasks, dogs utilize human communicative gestures such as pointing and direction of gaze in order to locate hidden food and toys. However, in contrast to humans pointing has
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#17327900743741176-399: A more advanced understanding. A much discussed example is the use of alarm calls by vervet monkeys . Robert Seyfarth and Dorothy Cheney showed that these animals emit different alarm calls in the presence of different predators ( leopards , eagles , and snakes ), and the monkeys that hear the calls respond appropriately—but that this ability develops over time, and also takes into account
1274-482: A number of different contexts, one of which is when it encounters a snake. The foot-drumming may alert nearby offspring but most likely conveys vibrations through the ground that the rat is too alert for a successful attack, thus preventing the snake's predatory pursuit. Typically, predators attempt to reduce communication to prey as this will generally reduce the effectiveness of their hunting. However, some forms of predator to prey communication occur in ways that change
1372-682: A point of common ancestry. It is based on Frost et al. (2006), Heinicke et al. (2009) and Pyron and Wiens (2011). Leiopelmatidae Ascaphidae Bombinatoridae Alytidae Discoglossidae Pipidae Rhinophrynidae Scaphiopodidae Pelodytidae Pelobatidae Megophryidae Heleophrynidae Sooglossidae Nasikabatrachidae Calyptocephalellidae Myobatrachidae Limnodynastidae Ceuthomantidae Brachycephalidae Eleutherodactylidae Craugastoridae Hemiphractidae Hylidae Bufonidae Aromobatidae Dendrobatidae Leptodactylidae Allophrynidae Animal communication Animal communication
1470-465: A predator's cue: when an individual is damaged by a predator, it releases a chemical cue to its conspecifics. As has also been observed in other species, acidification and changes in pH physically disrupt these chemical cues, which has various implications for animal behavior . Scent marking and scent rubbing are common forms of olfactory communication in mammals. An example of scent rubbing by an animal can be seen from bears, bears do this as
1568-474: A prefrontal bone, presence of a hyoid plate , a lower jaw without teeth (with the exception of Gastrotheca guentheri ) consisting of three pairs of bones (angulosplenial, dentary, and mentomeckelian, with the last pair being absent in Pipoidea ), an unsupported tongue, lymph spaces underneath the skin, and a muscle, the protractor lentis, attached to the lens of the eye . The anuran larva or tadpole has
1666-452: A range of about 10 to 15 cm. This infrared perception may be used in detecting regions of maximal blood flow on targeted prey. Autocommunication is a type of communication in which the sender and receiver are the same individual. The sender emits a signal that is altered by the environment and eventually is received by the same individual. The altered signal provides information that can indicate food, predators or conspecifics. Because
1764-510: A sample. The ability to detect chemicals in the environment serves many functions, a crucial one being the detection of food, a function that first arose in single-celled organisms ( bacteria ) living in the oceans during the early days of life on Earth. As this function evolved, organisms began to differentiate between chemical compounds emanating from resources, conspecifics (same species; i.e., mates and kin), and heterospecifics (different species; i.e., competitors and predators). For instance,
1862-496: A signal to be maintained in the population, both the sender and receiver should usually receive some benefit from the interaction. Signal production by senders and the perception and subsequent response of receivers are thought to coevolve . Signals often involve multiple mechanisms, e.g., both visual and auditory, and for a signal to be understood, the coordinated behavior of both sender and receiver requires careful study. The sounds animals make are important because they communicate
1960-500: A similar way to warning colouration. For example, canines such as wolves and coyotes may adopt an aggressive posture, such as growling with their teeth bared, to indicate they will fight if necessary, and rattlesnakes use their well-known rattle to warn potential predators of their venomous bite. Sometimes, a behavioural change and warning colouration will be combined, as in certain species of amphibians which have most of their body coloured to blend with their surroundings, except for
2058-466: A single central respiratory spiracle and mouthparts consisting of keratinous beaks and denticles . Frogs and toads are broadly classified into three suborders: Archaeobatrachia , which includes four families of primitive frogs; Mesobatrachia , which includes five families of more evolutionary intermediate frogs; and Neobatrachia , by far the largest group, which contains the remaining families of modern frogs, including most common species throughout
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#17327900743742156-537: A slightly warty skin and prefers a watery habitat whereas the Panamanian golden frog ( Atelopus zeteki ) is in the toad family Bufonidae and has a smooth skin. The origin of the order name Anura —and its original spelling Anoures —is the Ancient Greek alpha privative prefix ἀν- ( an- from ἀ- before a vowel) 'without', and οὐρά ( ourá ) 'animal tail'. meaning "tailless". It refers to
2254-417: A small minnow species may do well to avoid habitat with a detectable concentration of chemical cues associated with a predator species such as a northern pike. Minnows with the ability to perceive the presence of predators before they are close enough to be seen and then respond with adaptive behavior (such as hiding) are more likely to survive and reproduce. Atlantic salmon go a step further than detecting
2352-430: A unique bone structure which is a fusion between the presacral vertebrae and sacrum . The following species are recognised in the genus Ptychadena : This Ranoidea -related article is a stub . You can help Misplaced Pages by expanding it . Frog See text A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (coming from
2450-546: A way to mark territory or let others know they are there and to stay away. Wolves scent-mark frequently during the breeding season . Electrocommunication is a rare form of communication in animals. It is seen primarily in aquatic animals, though some land mammals, notably the platypus and echidnas , sense electric fields that might be used for communication. Weakly electric fishes provide an example of electrocommunication, together with electrolocation . These fish use an electric organ to generate an electric field, which
2548-502: A wide range of vocalisations , particularly in their breeding season , and exhibit many different kinds of complex behaviors to attract mates, to fend off predators and to generally survive. Frogs are valued as food by humans and also have many cultural roles in literature, symbolism and religion. They are also seen as environmental bellwethers , with declines in frog populations often viewed as early warning signs of environmental damage. Frog populations have declined significantly since
2646-528: A wide variety of taxa, including fish (Godin and Davis, 1995), lizards (Cooper etc. al., 2004), ungulates (Caro, 1995), rabbits (Holley 1993), primates (Zuberbuhler et al. 1997), rodents (Shelley and Blumstein 2005, Clark, 2005), and birds (Alvarez, 1993, Murphy, 2006, 2007). A familiar example of quality advertisement pursuit-deterrent signal is stotting (sometimes called pronking ), a pronounced combination of stiff-legged running while simultaneously jumping shown by some antelopes such as Thomson's gazelle in
2744-408: Is a better mate. The second is the handicap hypothesis. This explains that the peacock's tail is a handicap, requiring energy to keep and makes it more visible to predators. Thus, the signal is costly to maintain, and remains an honest indicator of the signaler's condition. Another assumption is that the signal is more costly for low quality males to produce than for higher quality males to produce. This
2842-448: Is a key factor in many social interactions. Examples include: Seismic communication is the exchange of information using self-generated vibrational signals transmitted via a substrate such as the soil, water, spider webs, plant stems, or a blade of grass. This form of communication has several advantages, for example it can be sent regardless of light and noise levels, and it usually has a short range and short persistence, which may reduce
2940-433: Is a rapidly growing area of study in disciplines including animal behavior , sociology, neurology, and animal cognition . Many aspects of animal behavior, such as symbolic name use, emotional expression, learning, and sexual behavior , are being understood in new ways. When the information from the sender changes the behavior of a receiver, the information is referred to as a "signal". Signalling theory predicts that for
3038-410: Is active electrolocation , where the organism emits an electrical pulse through its electric organ and senses the projected geometrical property of the object. This is found in the electric fish Gymnotiformes (knifefishes) and Mormyridae (elephantfish). The second type of autocommunication is echolocation , found in bats and toothed whales . Echolocation involves emitting sounds and interpreting
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3136-441: Is an extension of the male cloaca). Frogs have glandular skin, with secretions ranging from distasteful to toxic. Their skin varies in colour from well- camouflaged dappled brown, grey and green to vivid patterns of bright red or yellow and black to show toxicity and ward off predators . Adult frogs live in fresh water and on dry land; some species are adapted for living underground or in trees. Frogs typically lay their eggs in
3234-616: Is an intriguing one that demands further investigation. The same researchers later found that common bottlenose dolphin ( Tursiops truncatus ) mothers inflect their signature whistle when their dependent calf is present. Signature whistles, which are in a higher frequency range than humans can hear, have an important role in facilitating mother–calf contact. In the Sarasota Dolphin Research Program's library of recordings were 19 female common bottlenose dolphins producing signature whistles both with and without
3332-402: Is carrying a gun . This method of communication is usually done by having a sentry stand on two feet and surveying for potential threats while the rest of the pack finds food. Once a threat has been identified the sentry sounds a whistle alarm , (sometimes describing the threat) at which point the pack retreats to their burrows. The intensity of the threat is usually determined by how long
3430-499: Is communicating with its predator. This is consistent with the definition of "communication" given above. This type of communication is known as interceptive eavesdropping if a predator intercepts a message intended for conspecifics. There are however, some actions of prey species are clearly directed to actual or potential predators. A good example is warning coloration : species such as wasps that are capable of harming potential predators are often brightly coloured, and this modifies
3528-492: Is detected by electroreceptors . Differences in the waveform and frequency of changes in the field convey information on species, sex, and identity. These electric signals can be generated in response to hormones, circadian rhythms, and interactions with other fish. They can also serve to mediate social hierarchy amongst species that have a social order. Some predators, such as sharks and rays, are able to eavesdrop on these electrogenic fish through passive electroreception. Touch
3626-446: Is not, as in mimicry ). The possibility of evolutionarily stable dishonest communication has been the subject of much controversy, with Amotz Zahavi in particular arguing that it cannot exist in the long term. Sociobiologists have also been concerned with the evolution of apparently excessive signaling structures such as the peacock's tail; it is widely thought that these can only emerge as a result of sexual selection , which can create
3724-458: Is now believed that they may also be used to control body temperature. The facial pits enabling thermoregulation underwent parallel evolution in pitvipers and some boas and pythons , having evolved once in pitvipers and multiple times in boas and pythons. The electrophysiology of the structure is similar between lineages, but it differs in gross structure anatomy . Most superficially, pitvipers possess one large pit organ on either side of
3822-436: Is observed in the genus of jumping spiders ( Myrmarachne ). These spiders are commonly referred to as " antmimicking spiders" because of the way they wave their front legs in the air to simulate antennae . Various ways in which humans interpret the behavior of animals, or give commands to them, are consistent with the definition of interspecies communication . Skillful interpretation of animal communications may be critical to
3920-480: Is simply because the higher quality males have more energy reserves available to allocate to costly signaling. Ethologists and sociobiologists have characteristically analysed animal communication in terms of more or less automatic responses to stimuli, without raising the question of whether the animals concerned understand the meaning of the signals they emit and receive. That is a key question in animal cognition . There are some signalling systems that seem to demand
4018-553: Is tempting, especially with domesticated animals and apes, to anthropomorphize , that is, to interpret animal actions in human terms, but this can be quite misleading; for example, an ape's "smile" is often a sign of aggression. Also, the same gesture may have different meanings depending on context within which it occurs. For example, a domestic dog 's tail wag and posture may be used in different ways to convey many meanings as illustrated in Charles Darwin 's The Expression of
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4116-524: Is the name of the total group that includes modern frogs in the order Anura as well as their close fossil relatives, the "proto-frogs" or "stem-frogs". The common features possessed by these proto-frogs include 14 presacral vertebrae (modern frogs have eight or 9), a long and forward-sloping ilium in the pelvis , the presence of a frontoparietal bone , and a lower jaw without teeth. The earliest known amphibians that were more closely related to frogs than to salamanders are Triadobatrachus massinoti , from
4214-451: Is the transfer of information from one or a group of animals (sender or senders) to one or more other animals (receiver or receivers) that affects the current or future behavior of the receivers. Information may be sent intentionally, as in a courtship display , or unintentionally, as in the transfer of scent from the predator to prey with kairomones . Information may be transferred to an "audience" of several receivers. Animal communication
4312-593: Is the vibration of swim bladders in bony fish . The structure of swim bladders and the attached sonic muscles varies greatly across bony fish families, resulting in a wide variety of sounds. Striking body parts together can also produce auditory signals. A well-known example of this is the tail tip vibration of rattlesnakes as a warning signal. Other examples include bill clacking in birds, wing clapping in manakin courtship displays, and chest beating in gorillas . Burrowing animal species are known to whistle to communicate threats, and sometimes mood . Species such as
4410-653: Is uncertain, but agrees with arguments that it could plausibly derive from a Proto-Indo-European base along the lines of * preu , meaning 'jump'. How Old English frosc gave rise to frogga is, however, uncertain, as the development does not involve a regular sound-change . Instead, it seems that there was a trend in Old English to coin nicknames for animals ending in - g , with examples—themselves all of uncertain etymology—including dog , hog , pig, stag , and (ear)wig . Frog appears to have been adapted from frosc as part of this trend. Meanwhile,
4508-539: The Ancient Greek ἀνούρα , literally 'without tail'). The oldest fossil "proto-frog" Triadobatrachus is known from the Early Triassic of Madagascar (250 million years ago ), but molecular clock dating suggests their split from other amphibians may extend further back to the Permian , 265 million years ago. Frogs are widely distributed, ranging from the tropics to subarctic regions, but
4606-550: The Antarctic Peninsula , indicating that this region was once home to frogs related to those now living in South American Nothofagus forest . A cladogram showing the relationships of the different families of frogs in the clade Anura can be seen in the table below. This diagram, in the form of a tree , shows how each frog family is related to other families, with each node representing
4704-740: The Cretaceous–Paleogene extinction event associated with the Chicxulub impactor . All origins of arboreality (e.g. in Hyloidea and Natatanura) follow from that time and the resurgence of forest that occurred afterwards. Frog fossils have been found on all of the Earth's continents. In 2020, it was announced that 40 million year old helmeted frog fossils had been discovered by a team of vertebrate palaeontologists in Seymour Island on
4802-561: The Permian , rather less than 300 million years ago, a date in better agreement with the palaeontological data. A further study in 2011 using both extinct and living taxa sampled for morphological, as well as molecular data, came to the conclusion that Lissamphibia is monophyletic and that it should be nested within Lepospondyli rather than within Temnospondyli . The study postulated that Lissamphibia originated no earlier than
4900-524: The divergence of the three groups took place in the Paleozoic or early Mesozoic before the break-up of the supercontinent Pangaea and soon after their divergence from the lobe-finned fishes . This would help account for the relative scarcity of amphibian fossils from the period before the groups split. Another molecular phylogenetic analysis conducted about the same time concluded that lissamphibians first appeared about 330 million years ago and that
4998-623: The edible frog ( Pelophylax esculentus ) is a hybrid between the pool frog ( P. lessonae ) and the marsh frog ( P. ridibundus ). The fire-bellied toads Bombina bombina and B. variegata are similar in forming hybrids. These are less fertile than their parents, giving rise to a hybrid zone where the hybrids are prevalent. The origins and evolutionary relationships between the three main groups of amphibians are hotly debated. A molecular phylogeny based on rDNA analysis dating from 2005 suggests that salamanders and caecilians are more closely related to each other than they are to frogs and
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#17327900743745096-463: The eyebrow flash on greeting are universal human communicative signals that can be related to corresponding signals in other primates . Given how recently spoken language has emerged, it is very likely that human body language does include some more or less involuntary responses that have a similar origin to the communication we have. Humans also often seek to mimic animals' communicative signals in order to interact with them. For example, cats have
5194-405: The marmot species, including the groundhog (woodchuck), and the alpine marmot show this trait. Whistling is used by animals such as prairie dogs to communicate threats , with prairie dogs having one of the most complex communication systems in the animal kingdom . Prairie dogs are able to communicate an animal's speed, shape, size, species, and for humans specific attire and if the human
5292-425: The middle Jurassic is slightly younger, about 155–170 million years old. The main evolutionary changes in this species involved the shortening of the body and the loss of the tail. Tadpoles of N. degiustoi constitute the oldest tadpoles found as of 2024, dating back to 168-161 million years ago. These tadpoles also showed adaptations for filter-feeding , implying residence in temporary pools by filter-feeding larvae
5390-429: The richest in species . The Anura include all modern frogs and any fossil species that fit within the anuran definition. The characteristics of anuran adults include: 9 or fewer presacral vertebrae, the presence of a urostyle formed of fused vertebrae, no tail, a long and forward-sloping ilium, shorter fore limbs than hind limbs, radius and ulna fused, tibia and fibula fused, elongated ankle bones , absence of
5488-551: The temnospondyl-origin hypothesis is more credible than other theories. The neobatrachians seemed to have originated in Africa/India, the salamanders in East Asia and the caecilians in tropical Pangaea. Other researchers, while agreeing with the main thrust of this study, questioned the choice of calibration points used to synchronise the data. They proposed that the date of lissamphibian diversification should be placed in
5586-412: The 1950s. More than one third of species are considered to be threatened with extinction and over 120 are believed to have become extinct since the 1980s. The number of malformations among frogs is on the rise and an emerging fungal disease, chytridiomycosis , has spread around the world. Conservation biologists are working to understand the causes of these problems and to resolve them. The use of
5684-643: The AnimalSign Center has been using an approach similar to functional communication training with domesticated animals, such as dogs since 2004 and horses since 2000, with encouraging results and benefits to the animals and people. Functional communication training for animals, Senechal calls "Animal Sign Language". This includes teaching communication through gestures (like simplified American sign language ), Picture Exchange Communication System , tapping, and vocalisation. The process for animals includes simplified and modified techniques. For linguistics ,
5782-524: The Emotions in Man and Animals published in 1872. Some of Darwin's illustrations are reproduced here. Much animal communication is intraspecific, that is, it occurs between members of the same species. As for interspecific communication, that between predator and prey is of particular interest. If a prey animal moves, makes a noise or vibrations, or emits a smell in such a way that a predator can detect it, it
5880-423: The ability to sense infrared (IR) thermal radiation, which allows these reptiles to derive thermal images from the radiant heat emitted by predators or prey at wavelengths between 5 and 30 μm . The accuracy of this sense is such that a blind rattlesnake can target its strike to the vulnerable body parts of a prey animal. It was previously thought that the pit organs evolved primarily as prey detectors, but it
5978-631: The animals' state. Some animals species have been taught simple versions of human languages. Animals can use, for example, electrolocation and echolocation to communicate about prey and location. There are many different types of signals that animals use to differentiate their position of direction, location, and distance. Practitioners study the issues of animal position by geometric viewings. Environmental and social influences are indicators of geometric viewings. Animals rely on signals called electrolocating and echolocating; they use sensory senses in order to navigate and find prey. Signals are used as
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#17327900743746076-534: The anuran lineage proper all lived in the early Jurassic period. One such early frog species, Prosalirus bitis , was discovered in 1995 in the Kayenta Formation of Arizona and dates back to the Early Jurassic epoch (199.6 to 175 million years ago), making Prosalirus somewhat more recent than Triadobatrachus . Like the latter, Prosalirus did not have greatly enlarged legs, but had
6174-402: The behavior of the predator, who either instinctively or as the result of experience will avoid attacking such an animal. Some forms of mimicry fall in the same category: for example hoverflies are coloured in the same way as wasps, and although they are unable to sting, the strong avoidance of wasps by predators gives the hoverfly some protection. There are also behavioural changes that act in
6272-458: The behavior of the prey and make their capture easier, i.e. deception by the predator. A well-known example is the angler fish , an ambush predator which waits for its prey to come to it. It has a fleshy bioluminescent growth protruding from its forehead which it dangles in front of its jaws. Smaller fish attempt to take the lure, placing themselves in a better position for the angler fish to catch them. Another example of deceptive communication
6370-475: The caller's voice or location. The paper concludes that: The fact that signature whistle shape carries identity information independent from voice features presents the possibility to use these whistles as referential signals, either addressing individuals or referring to them, similar to the use of names in humans. Given the cognitive abilities of bottlenose dolphins, their vocal learning and copying skills, and their fission–fusion social structure, this possibility
6468-654: The child to pay attention, long-term bonding, and promoting the development of lifelong vocal learning , with parallels in these bottlenose dolphins in an example of convergent evolution . Another controversial issue is the extent to which human behaviours resemble animal communication, or whether all such communication has disappeared as a result of our linguistic capacity. Some of our bodily features—eyebrows, beards and moustaches, deep adult male voices, perhaps female breasts—strongly resemble adaptations to producing signals. Ethologists such as Irenäus Eibl-Eibesfeldt have argued that facial gestures such as smiling, grimacing, and
6566-540: The common names frog and toad has no taxonomic justification. From a classification perspective, all members of the order Anura are frogs, but only members of the family Bufonidae are considered "true toads". The use of the term frog in common names usually refers to species that are aquatic or semi-aquatic and have smooth, moist skins; the term toad generally refers to species that are terrestrial with dry, warty skins. There are numerous exceptions to this rule. The European fire-bellied toad ( Bombina bombina ) has
6664-589: The danger of detection by predators. The use of seismic communication is found in many taxa, including frogs, kangaroo rats, mole rats, bees, nematode worms, and others. Tetrapods usually make seismic waves by drumming on the ground with a body part, a signal that is sensed by the sacculus of the receiver. The sacculus is an organ in the inner ear containing a membranous sac that is used for balance, but can also detect seismic waves in animals that use this form of communication. Vibrations may be combined with other sorts of communication. A number of different snakes have
6762-481: The early Triassic period of Madagascar (about 250 million years ago), and Czatkobatrachus polonicus , from the Early Triassic of Poland (about the same age as Triadobatrachus ). The skull of Triadobatrachus is frog-like, being broad with large eye sockets, but the fossil has features diverging from modern frogs. These include a longer body with more vertebrae . The tail has separate vertebrae unlike
6860-460: The experience of the individual emitting the call. Metacommunication, discussed above, also seems to require a more sophisticated cognitive process. It has been reported that bottlenose dolphins can recognize identity information from signature whistles even when otherwise stripped of the characteristics of the whistle; making bottlenose dolphins the only animals other than humans that have been shown to transmit identity information independent of
6958-533: The fused urostyle or coccyx in modern frogs. The tibia and fibula bones are also separate, making it probable that Triadobatrachus was not an efficient leaper. A 2019 study has noted the presence of Salientia from the Chinle Formation , and suggested that anurans might have first appeared during the Late Triassic . On the basis of fossil evidence, the earliest known "true frogs" that fall into
7056-497: The greatest concentration of species diversity is in tropical rainforest . Frogs account for around 88% of extant amphibian species. They are also one of the five most diverse vertebrate orders. Warty frog species tend to be called toads , but the distinction between frogs and toads is informal, not from taxonomy or evolutionary history. An adult frog has a stout body, protruding eyes , anteriorly-attached tongue , limbs folded underneath, and no tail (the tail of tailed frogs
7154-407: The head, between the eye and the nostril ( loreal pit ), while boas and pythons have three or more comparatively smaller pits lining the upper and sometimes the lower lip, in or between the scales. Those of the pitvipers are the more advanced, having a suspended sensory membrane as opposed to a simple pit structure. Within the family Viperidae , the pit organ is seen only in the subfamily Crotalinae :
7252-523: The importance of communication in animals is the prioritisation of physiological features to this function. For example, birdsong appears to have brain structures entirely devoted to its production. All these adaptations require evolutionary explanation. There are two aspects to the required explanation: Significant contributions to the first of these problems were made by Konrad Lorenz and other early ethologists . By comparing related species within groups, they showed that movements and body parts that in
7350-437: The interest of animal communication systems lies in their similarities to and differences from human language: There becomes possibility for error within communication between animals when certain circumstances apply. These circumstances could include distance between the two communicating subjects, as well as the complexity of the signal that is being communicated to the "listener" of the situation. It may not always be clear to
7448-481: The late Carboniferous , some 290 to 305 million years ago. The split between Anura and Caudata was estimated as taking place 292 million years ago, rather later than most molecular studies suggest, with the caecilians splitting off 239 million years ago. In 2008, Gerobatrachus hottoni , a temnospondyl with many frog- and salamander-like characteristics, was discovered in Texas . It dated back 290 million years and
7546-438: The most striking structures in the animal kingdom, such as the peacock 's tail, the antlers of a stag and the frill of the frill-necked lizard , but also include even the modest red spot on a European herring gull 's bill. Highly elaborate behaviours have evolved for communication such as the dancing of cranes , the pattern changes of cuttlefish , and the gathering and arranging of materials by bowerbirds . Other evidence for
7644-489: The nineteenth century, and is paralleled widely in other Germanic languages , with examples in the modern languages including German Frosch , Norwegian frosk , Icelandic froskur , and Dutch (kik)vors . These words allow reconstruction of a Common Germanic ancestor * froskaz . The third edition of the Oxford English Dictionary finds that the etymology of * froskaz
7742-401: The pitvipers. Despite the detection of IR radiation, the pits' IR mechanism is dissimilar to photoreceptors; while photoreceptors detect light via photochemical reactions, the protein in the facial pits of snakes is a temperature sensitive ion channel. It senses infrared signals through a mechanism involving warming of the pit organ, rather than chemical reaction to light. This is consistent with
7840-558: The presence of a predator. At least 11 hypotheses for stotting have been proposed. A leading theory today is that it alerts predators that the element of surprise has been lost. Predators like cheetahs rely on surprise attacks, proven by the fact that chases are rarely successful when antelope stot. Predators do not waste energy on a chase that will likely be unsuccessful (optimal foraging behavior). Quality advertisement can be communicated by modes other than visual. The banner-tailed kangaroo rat produces several complex foot-drumming patterns in
7938-430: The presence of their calf. In all 19 cases, the mother dolphin inflected the signature whistle when their calf was present, by reaching a higher frequency, or using a wider frequency range. Similarly, humans use higher fundamental frequencies and a wider pitch range to inflect child–directed speech (CDS). This has rarely been discovered in other species. The researchers stated that CDS benefits for humans are cueing
8036-419: The primitive forms had no communicative function could be "captured" in a context where communication would be functional for one or both partners, and could evolve into a more elaborate, specialised form. For example, Desmond Morris showed in a study of grass finches that a beak-wiping response occurred in a range of species, serving a preening function, but that in some species this had been elaborated into
8134-420: The psychology of the female, a positive feedback loop is enacted and the tail becomes bigger and brighter. Eventually, the evolution will level off because the survival costs to the male do not allow for the trait to be elaborated any further. Two theories exist to explain runaway selection. The first is the good genes hypothesis. This theory states that an elaborate display is an honest signal of fitness and truly
8232-433: The same behaviour from others, a benefit of living in a group. Sociobiologists argued that behaviours that benefited a whole group of animals might emerge as a result of selection pressures acting solely on the individual. A gene-centered view of evolution proposes that behaviours that enabled a gene to become wider established within a population would become positively selected for, even if their effect on individuals or
8330-466: The sender and receiver are the same animal, selection pressure maximizes signal efficacy, i.e. the degree to which an emitted signal is correctly identified by a receiver despite propagation distortion and noise. There are some species, such as the pacific herring, which have evolved to intercept these messages from their predators. They are able to use it as an early warning sign and respond defensively. There are two types of autocommunication. The first
8428-411: The sentry whistles. The sentry continues to whistle the alarm until the entirety of the pack has gone to safety, at which point the sentry returns to the burrow. Despite being the oldest method of communication, chemical communication is one of the least understood forms due in part to the sheer abundance of chemicals in our environment and the difficulty of detecting and measuring all the chemicals in
8526-438: The species as a whole was detrimental; In the case of communication, an important discussion by John Krebs and Richard Dawkins established hypotheses for the evolution of such apparently altruistic or mutualistic communications as alarm calls and courtship signals to emerge under individual selection. This led to the realization that communication might not always be "honest" (indeed, there are some obvious examples where it
8624-544: The tailless character of these amphibians. The origins of the word frog are uncertain and debated. The word is first attested in Old English as frogga , but the usual Old English word for the frog was frosc (with variants such as frox and forsc ), and it is agreed that the word frog is somehow related to this. Old English frosc remained in dialectal use in English as frosh and frosk into
8722-526: The thin pit membrane, which allows incoming IR radiation to quickly and precisely warm a given ion channel and trigger a nerve impulse, as well as vascularize the pit membrane to rapidly cool the ion channel back to its original "resting" or "inactive" temperature. Common vampire bats ( Desmodus rotundus ) have specialized IR sensors in their nose-leaf. Vampire bats are the only mammals that feed exclusively on blood. The IR sense enables Desmodus to localize homeothermic animals such as cattle and horses within
8820-694: The type, size, and speed of an approaching predator. Whale vocalizations have been found to have different dialects based on social learning. Mammalian acoustic culture was first discovered in southern resident orcas in 1978. Not all animals use vocalization as a means of auditory communication. Many arthropods rub specialized body parts together to produce sound. This is known as stridulation . Crickets and grasshoppers are well known for this, but many others use stridulation as well, including crustaceans , spiders , scorpions , wasps , ants , beetles , butterflies , moths , millipedes , and centipedes . Another means of auditory communication
8918-428: The typical three-pronged pelvic structure of modern frogs. Unlike Triadobatrachus , Prosalirus had already lost nearly all of its tail and was well adapted for jumping. Another Early Jurassic frog is Vieraella herbsti , which is known only from dorsal and ventral impressions of a single animal and was estimated to be 33 mm ( 1 + 1 ⁄ 4 in) from snout to vent. Notobatrachus degiustoi from
9016-583: The vibrations that return from objects. In bats, echolocation also serves the purpose of mapping their environment. They are capable of recognizing a space they have been in before without any visible light because they can memorize patterns in the feedback they get from echolocation. There are many functions of animal communication. However, some have been studied in more detail than others. This includes: As described above, many animal gestures, postures, and sounds, convey meaning to nearby animals. These signals are often easier to describe than to interpret. It
9114-467: The water. The eggs hatch into aquatic larvae called tadpoles that have tails and internal gills . They have highly specialised rasping mouth parts suitable for herbivorous , omnivorous or planktivorous diets. The life cycle is completed when they metamorphose into adults. A few species deposit eggs on land or bypass the tadpole stage. Adult frogs generally have a carnivorous diet consisting of small invertebrates , but omnivorous species exist and
9212-436: The welfare of animals that are being cared for or trained by humans. Non-human animal species may interpret the signals of humans differently than humans themselves. For instance, a pointing command refers to a location rather than an object in dogs. The importance of communication is evident from the highly elaborate morphology, behaviour and physiology that some animals have evolved to facilitate this. These include some of
9310-548: The word toad , first attested as Old English tādige , is unique to English and is likewise of uncertain etymology. It is the basis for the word tadpole , first attested as Middle English taddepol , apparently meaning 'toad-head'. About 88% of amphibian species are classified in the order Anura. These include over 7,700 species in 59 families , of which the Hylidae (1062 spp.), Strabomantidae (807 spp.), Microhylidae (758 spp.), and Bufonidae (657 spp.) are
9408-438: The world. The suborder Neobatrachia is further divided into the two superfamilies Hyloidea and Ranoidea . This classification is based on such morphological features as the number of vertebrae, the structure of the pectoral girdle , and the morphology of tadpoles. While this classification is largely accepted, relationships among families of frogs are still debated. Some species of anurans hybridise readily. For instance,
9506-545: Was already commonplace. The evolution of modern Anura likely was complete by the Jurassic period. Since then, evolutionary changes in chromosome numbers have taken place about 20 times faster in mammals than in frogs, which means speciation is occurring more rapidly in mammals. According to genetic studies, the families Hyloidea , Microhylidae , and the clade Natatanura (comprising about 88% of living frogs) diversified simultaneously some 66 million years ago, soon after
9604-473: Was hailed as a missing link , a stem batrachian close to the common ancestor of frogs and salamanders, consistent with the widely accepted hypothesis that frogs and salamanders are more closely related to each other (forming a clade called Batrachia) than they are to caecilians. However, others have suggested that Gerobatrachus hottoni was only a dissorophoid temnospondyl unrelated to extant amphibians. Salientia (Latin salire ( salio ), "to jump")
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