Alarm signal

If alarm-calling is truly an example of altruism, then human understanding of natural selection becomes more complicated than simply "survival of the fittest gene".

[citation needed] Another theory suggests that alarm signals function to attract further predators, which fight over the prey organism, giving it a better chance of escape.

Like small children who cannot communicate words effectively make random noises when being played with or are stimulated by something in their immediate environment.

The point of the experiment was to gather the acoustic sounds of these monkeys when stimulated by the presence of snakes (mainly Python), raptors, terrestrial animals (mostly Leopards), and aggression.

[10] In an experiment conducted by Dr. Julia Fischer, a drone was flown over Vervet monkeys and recorded the sounds produced.

When a sound recording of the drone was played back a few days later to a monkey that was alone and away from the main group it looked up and scanned the sky.

The common middle ground argument is that they give alarm calls because they want others to elicit a certain response, not necessarily because they want the group to think that there is a specific threat near.

[11] Similarly, the cotton-top tamarin is able to use a limited vocal range of alarm calls to distinguish between aerial and land predators.

[17] Their calls differ based on signaller sex, threat type, habitat, and caller ontogenetic or lifetime predator experience.

[20] The tendency to switch responses is especially prominent among Diana monkey populations that live within the main range of the chimpanzee community.

[20] This shift in antipredator response suggests that the monkeys interpret chimpanzee-produced, leopard-induced alarm calls as evidence for the presence of a leopard.

[20] There are three possible cognitive mechanisms explaining how Diana monkeys recognize chimpanzee-produced, leopard-induced alarm calls as evidence for a nearby leopard: associative learning, causal reasoning, or a specialized learning programme driven by adaptive antipredator behaviour necessary for survival.

[20] In Taï National Park and Tiwai Island, Sierra Leone, specific acoustic markers in the alarm calls of Diana monkeys convey both threat type and caller familiarity information to a receiver.

In Taï National Park, males respond to eagle alarm signals based on predator type and caller familiarity.

[17] Diana monkeys also display a predisposition for flexibility in acoustic variation of alarm call assembly related to caller ontogenetic or lifetime predator experience.

[21] In Taï National Park, males produce three threat-specific calls in response to three threats: eagles, leopards, and general disturbances.

[21] On Tiwai Island, males produce two threat-specific calls in response to two groups of threats: eagles, and leopards or general disturbances.

[21] These differences in alarm call arrangement between habitats are due to ontogenetic experience; specifically, a lack of experience with leopards on Tiwai Island causes them to be classified in the same predator category as general disturbances, and accordingly, leopards receive the same type of alarm call arrangement.

[26] Not all scholars of animal communication accept the interpretation of alarm signals in monkeys as having semantic properties or transmitting "information".

Prominent spokespersons for this opposing view are Michael Owren and Drew Rendall,[27][28] whose work on this topic has been widely cited and debated.

[29][30] The alternative to the semantic interpretation of monkey alarm signals as suggested in the cited works is that animal communication is primarily a matter of influence rather than information, and that vocal alarm signals are essentially emotional expressions influencing the animals that hear them.

[33] When judging if conspecifics are unaware of potential dangers, chimpanzees do not solely look for behavioural cues, but also assess receiver mental states and use this information to target signalling and monitoring.

experiment, caller chimpanzees were shown a fake snake as a predator and were played pre-recorded calls from receivers.

Researchers propose that communication evolved as natural selection diversified 'hoo' vocalizations into context-dependent 'hoos' for travel, rest, and threats.

[36] Context-dependent communication is beneficial and likely maintained by selection as it facilities cooperative activities and social cohesion between signallers and receivers that can increase the likelihood of survival.

[32][34] Filling a gap in information and incorporating social cues and intentionality into communication are all components of human language.

[38] Males give these false alarm calls when females leave the nest area during the mating season, and are thus able to disrupt extra-pair copulations.

By sounding a bogus alarm call normally used to warn of aerial predators, they can frighten other birds away, allowing them to eat undisturbed.

Minnows and catfish release alarm pheromones (Schreckstoff) when injured, which cause nearby fish to hide in dense schools near the bottom.

Lima beans release volatile chemical signals that are received by nearby plants of the same species when infested with spider mites.