Interspecies communication is communication between different species of animals, plants, fungi or bacteria.
Cooperative interspecies communication implies the sharing and understanding of information from two or more species that work towards the benefit of both species (mutualism).
Since the 1970s, primatologist Sue Savage-Rumbaugh has been working with primates at Georgia State University's Language Research Center (LRC), and more recently, the Iowa Primate Learning Sanctuary. In 1985, using lexigram symbols, a keyboard and monitor, and other computer technology, Savage-Rumbaugh began her groundbreaking work with Kanzi, a male bonobo (P. paniscus). Her research has made significant contributions to a growing body of work in sociobiology studying language learning in non-human primates and exploring the role of language and communication as an evolutionary mechanism.
Koko, a lowland gorilla, began learning a modified American Sign Language as an infant, when Francine "Penny" Patterson, PhD, started working with her in 1975. Thirty-some years later, Penny and Koko continue to work together at the Gorilla Foundation in one of the longest interspecies communication studies ever conducted, the only one with gorillas. Koko now has a vocabulary of over 1000 signs, and understands even more spoken English.
On 26 April 1998, Koko the gorilla gave an AOL live chat. Sign language was used to relay to Koko questions from the online audience of 7,811 AOL members, the fifth most popular chat in AOL's history. The following is an excerpts from the live chat.
- HaloMyBaby: ...MInyKitty asks Koko are you going to have a baby in the future?
- LiveKOKO: Pink
- DrPPatrsn: We've had earlier discussion about colors today
- LiveKOKO: Listen, Koko loves eat
- HaloMyBaby: Me too!
- DrPPatrsn: What about a baby? She's thinking...
- LiveKOKO: Unattention
- DrPPatrsn: She covered her face with her hands....which means it's not happening, basically, or it hasn't happened yet.
- LiveKOKO: I don't see it.
- HaloMyBaby: That's sad!
- DrPPatrsn: In other words, she hasn't had one yet, and she doesn't see it happening. She needs several females and one male to have a family. In our setting it really isn't possible for her to have a baby.
- Question: Do you like to chat with other people?
- LiveKOKO: fine nipple
- DrPPatrsn: Nipple rhymes with people, she doesn't sign people per se, she was trying to do a "sounds like..."
Research observing cooperative communication has largely focused on primates, as well as predatory animals. Red-fronted lemurs and sifakas have reciprocal recognition of one another's alarm calls. The same has been found in West African Diana monkey and Campbell's monkeys. When one species elicits an alarm signal specific to a certain predator, the other species react in the same pattern as the species that called. For example, leopards hunt both species by capitalizing the elements of stealth and surprise. If the monkeys detect the leopard before it attacks (usually resulting in mobbing), the leopard will typically not attack. Therefore, when a leopard alarm call is given both species respond by positioning near the leopard signaling that it has been found out. It also seems that the monkeys are able to distinguish a leopard alarm call from, for example, a raptor alarm call. When a raptor alarm call is given, the monkeys respond by moving towards the forest floor and away from aerial attack. Therefore, it is not simply that the monkeys act upon hearing the alarm calls but rather they are able to actually extract particular information from a call. Responses to heterospecific alarm calls are not confined to simian species but have also been found in the Sciuridae species: yellow-bellied marmot and the golden-mantled ground squirrel. Researchers have also determined that species of bird are able to understand, or at least respond, to alarms calls by species of mammals and vice versa; red squirrels' acoustic response to raptors is near-identical to that of birds, making the latter also aware to a potential predatory threat, while eastern chipmunks are keen to mobbing calls by eastern tufted titmice.
Whether heterospecific understanding is a learned behavior or not is also of interest. Ramakrishnan and Coss (2000) found that age and interspecies experience were important factors in the ability for bonnet macaques to recognize heterospecific calls. Macaques who were younger and exposed longer to other species' alarm calls were more likely to correctly respond to heterospecific alarm calls. A key component of this early learning was the reinforcement of a predatory threat. That is, when an alarm call was given a corresponding threat had to be presented in order to make the association. Therefore, interspecies communication may not be an innate ability but rather a sort of imprinting that may have to be coupled with an intense emotion (fear) early in life.
It is not unusual for interspecies communication to be observed in an older animal taking care of a younger animal of a different species. For example, Owen and Mzee, the odd couple of an orphaned baby hippopotamus and a 130-year-old Aldabran tortoise, display a relationship rarely seen in the animal world. Dr. Kahumbu of the sanctuary that holds the two believes that the two actually vocalize to one another in neither a stereotypical tortoise nor a hippopotamus fashion. Interestingly, Owen also does not respond to hippopotamus calls. It is likely that when Owen was first introduced to Mzee he was still young enough where imprinting could occur.
Parasitic communication and eavesdropping
Unlike cooperative communication, parasitic communication involves an unequal sharing of information (parasitism). In terms of alarm calls, this means that the warnings are not bi-directional. However, it would be faulty to say that the eavesdroppers are not giving any information in return. It may be that the other species has simply not been able to decipher the eavesdroppers' calls. Much of the research done on this type of communication has been found in bird species, including the nuthatch and the great tit. In 2007, Templeton and Greene found that nuthatches are able to discriminate between subtle differences in chickadee alarm calls, which broadcast the location and size of a predator. Since chickadees and nuthatches typically occupy the same habitat, mobbing predators together acts as a deterrent that benefits both species. The team also found that nuthatches screen chickadee alarm calls in order to determine whether it is cost-efficient to mob a particular predator. This is because not all predators pose the same risk to nuthatches as to chickadees. Templeton and Greene speculate that screening may be most important in the winter when energy demands are the highest.
Work by Gorissen, Gorissen, and Eens (2006) has focused on blue tit song matching (or, "song imitation") by great tits. Blue and great tits compete for resources such as food and nesting cavities and their coexistence has important fitness consequences for both species. These fitness costs might promote interspecific aggression because resources need to be defended against heterospecifics as well. So, the use of efficient vocal strategies such as matching might prove to be effective in interspecific communication. Hence, heterospecific matching could be a way of phrasing a threat in the language of the heterospecfic intruder. It could equally be well argued that these imitations of blue tit sounds have no function at all and are merely the result of learning mistakes in the sensitive period of great tits because blue and great tits form mixed foraging flocks together. While the authors agree with the first hypothesis, it is plausible that the latter also being true given the data on age and experience in primates.
In addition to birds, eavesdropping has been found in tungara frogs and their sympatric heterospecifics. The scientists posit that mixed-species choruses may reduce their risk of predation without increasing mate competition.
Much of the communication between predators and prey can be defined as signaling. In some animals, the best way to avoid being preyed upon is an advertisement of danger or unpalatability, or aposematism. Given the effectiveness of this, it is no surprise that many animals employ styles of mimicry to ward off predators. Some predators also use aggressive mimicry as a hunting technique. For example, Photuris fireflies mimic female Photinus fireflies by scent and glow patterns in order to lure interested male Photinus fireflies, which they then kill and eat. Lophiiformes, or anglerfish, are also famous for their use of escas as bait for small unsuspecting fish.
Recently, two interesting examples of predator–prey signaling were found in caterpillars and ground squirrels. When physically disturbed, Lepidoptera larvae produce a clicking noise with their mandibles followed by an unpalatable oral secretion. Scientists believe this to be “acoustic aposematism” which has only been previously found in a controlled study with bats and tiger moths. While the defense mechanisms of ground squirrels to predatory rattlesnakes have been well studied (i.e. tail flagging), only recently have scientists discovered that these squirrels also employ a type of infrared heat signaling. By using robotic models of squirrels, the researchers found that when infrared radiation was added to tail flagging, rattlesnakes shifted from predatory to defensive behavior and were less likely to attack than when no radiation component was added.
Social scientists and others have historically criticized research in interspecies communication, characterizing it as anthropomorphizing. This perspective has become increasingly less common in recent years. Additionally, assertions arising from a lack of linguistic consensus as to what is and what is not communication, have been made to suggest the methodology in the field of interspecies communication is flawed.
Animal telepathy, a variant of interspecies communication in which human psychics claim to communicate with animals by reading their minds lacks scientific evidence supporting these claims.
- Animal communication
- Clever Hans
- Great ape language
- Human–animal communication
- Jim Nollman
- John C. Lilly
- The New Scientist: Lab chimp speaks his own language 10:15 2 January 2003 by Anil Ananthaswamy
- Doctor Dolittle's Delusion, Subtitle: Animals and the Uniqueness of Human Language Published: 2004 Yale University Press by Anderson
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- Zuberbuhler, K. (2000) Interspecies semantic communication in two forest primates. Proc R Soc Lond Ser B Biol Sci 267:713–718.
- Shriner W.M.K.E.E. (1998) Yellow-bellied marmot and golden-mantled ground squirrel responses to heterospecific alarm calls. Animal Behaviour 55:529–536.
- Solomon, Christopher (18 May 2015). "When Birds Squawk, Other Species Seem to Listen". The New York Times. ISSN 0362-4331. Retrieved 2015-05-21.
- Ramakrishnan, U. and Coss, R. G. (2000) Recognition of Heterospecific Alarm Vocalization by Bonnet Macaques (Macaca radiata). Journal of Comparative Psychology 114:3–12.
- Owen & Mzee
- Templeton, C.N. and Greene, E. (2007) Nuthatches eavesdrop on variations in heterospecific chickadee mobbing alarm calls. PNAS 104:5479–5482.
- Gorissen,L.; Gorissen,M.; Eens,M. (2006) Heterospecific song matching in two closely related songbirds (Parus major and P. caeruleus): Great tits match blue tits but not vice versa. Behavioral Ecology and Sociobiology 60:260–269.
- Phelps, S.M.; Rand, A.S.; Ryan, M.J. (2007) The mixed-species chorus as public information: túngara frogs eavesdrop on a heterospecific. Behav. Ecol. 18:108–114.
- Brown, S.G.; Boettner, G.H.; Yack, J.E. (2007) Clicking caterpillars: acoustic aposematism in Antheraea polyphemus and other Bombycoidea. J Exp Biol 210:993–1005.
- Hristov, N. I. and Conner, W. E. (2005) Sound strategy: acoustic aposematism in the bat–tiger moth arms race. Naturwissenschaften 92: 164–169.
- Rundus, A.S.; Owings, D.H.; Joshi, S.S.; Chinn, E; Giannini, N. Ground squirrels use an infrared signal to deter rattlesnake predation. Proceedings of the National Academy of Sciences 104:14372-14376.