Content deleted Content added
→Predator-directed Signalling: capitalization and spelling |
m snd |
||
| (9 intermediate revisions by 6 users not shown) | |||
Line 1:
{{short description|Signal made by social animals to warn others of danger}}▼
{{for|devices giving alarm signals|Alarm device}}
{{redirect2|Alarm call|Alarmer|the Björk song|Alarm Call|the shoulder dystocia mnemonic|ALARMER}}
▲{{short description|Signal made by social animals to warn others of danger}}
[[Image:Spermophilus beldingi.jpg|right|thumb|Alarm calls have been studied in many species, such as [[Belding's ground squirrel]]s.]]
[[File:European Robin (Erithacus rubecula) (W1CDR0001525 BD17).ogg|right|200px|thumb|Characteristic 'ticking' alarm call of a [[European robin]], ''Erithacus rubecula'']]
Line 8:
Different calls may be used for predators on the ground or from the air. Often, the animals can tell which member of the group is making the call, so that they can disregard those of little reliability.<ref>[http://rsbl.royalsocietypublishing.org/content/9/5/20130535 Biology Letters. Titi monkey call sequences vary with predator location and type]</ref>
Evidently, alarm signals promote survival by allowing the receivers of the alarm to escape from the source of peril; this can evolve by [[kin selection]], assuming the receivers are related to the signaller. However, alarm calls can increase individual fitness, for example by informing the predator it has been detected.<ref>{{cite journal | doi=10.1046/j.1439-0310.1999.00396.x | volume=105 | issue=6 | title=The Predator Deterrence Function of Primate Alarm Calls | journal=Ethology | pages=477–490| year=1999 | last1=Zuberbühler | first1=Klaus | last2=Jenny | first2=David | last3=Bshary | first3=Redouan | bibcode=1999Ethol.105..477Z | url=http://doc.rero.ch/record/209806/files/Zuberbuhler_K-Predator_detterence-20140416.pdf }}</ref>
Alarm calls are often high-frequency sounds because these sounds are harder to localize.<ref>{{cite web |url=http://mue.music.miami.edu/thesis/robert_hartman/robert_hartman_thesis.pdf |title=Archived copy |access-date=2011-03-20 |url-status=dead |archive-url=https://web.archive.org/web/20110822171129/http://mue.music.miami.edu/thesis/robert_hartman/robert_hartman_thesis.pdf |archive-date=2011-08-22 }}</ref><ref>{{Cite web| url=http://primatology.net/2011/03/09/the-semantics-of-vervet-monkey-alarm-calls-part-i/| title=The Semantics of Vervet Monkey Alarm Calls: Part I| date=2011-03-09| access-date=2011-03-20| archive-date=2018-01-07| archive-url=https://web.archive.org/web/20180107053818/https://primatology.net/2011/03/09/the-semantics-of-vervet-monkey-alarm-calls-part-i/| url-status=dead}}</ref>
==Selective advantage==
{{
{{main|Signalling theory}}
[[File:Otospermophilus variegatus.webm|thumb|right|Alarm call by a [[rock squirrel]]]]
Line 20:
=== Altruism ===
{{More citations needed section|date=June 2024}}
Some scientists have used the evidence of alarm-calling behaviour to challenge the theory that "evolution works only/primarily at the level of the [[gene]] and of the gene's 'interest' in passing itself along to future generations." 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".
Line 28 ⟶ 29:
=== Further research ===
{{Unreferenced section|date=June 2024}}
Considerable research effort continues to be directed toward the purpose and ramifications of alarm-calling behaviour, because, to the extent that this research has the ability to comment on the occurrence or non-occurrence of altruistic behaviour, these findings can be applied to the understanding of altruism in human behaviour.
Line 34 ⟶ 36:
=== Vervet monkeys ===
[[Vervet monkey
However, there is much debate on whether the vervet monkeys alarm calls are actual “words” in the sense of purposely manipulating sounds to communicate specific meaning or are unintentional sounds ''that are made when interacting with an outside stimulus. Like small children who cannot communicate words effectively make random noises when being played with or are stimulated by something in their immediate environment. As children grow and begin learning how to communicate the noises, they make are very broad in relation to their environment. They begin to recognize the things in their environment but there more things than known words or noises so a certain sound may reference multiple things. As children get older, they can become more specific about the noises and words made in relation to the things in their environment''. It is thought that as Vervet monkeys get older they are able to learn and break the broad categories into more specific sub categories to a specific context.<ref name=":5">{{Cite book|last=Dorothy|first=Cheney|title=How Monkeys See the World: Inside the Mind of Another Species|publisher=U of Chicago P|year=2018|language=english}}</ref>▼
▲However, there is much debate on whether the vervet monkeys alarm calls are actual
In an experiment conducted by Dr. Tabitha Price, they used custom software to gather the acoustic sounds of male and female Vervet monkeys from East Africa and male Vervet monkey from South Africa. The point of the experiment was to gather the acoustic sounds of these monkeys when stimulated by the presence of snakes (mainly [[Pythonidae|Python]]), raptors, terrestrial animals (mostly Leopards), and aggression. Then to determine if the calls could be distinguished with a known context.
▲''The experiment determined that while the Vervet monkeys were able to categorize different predators and members of different social groups, however their ability to communicate specific threats is not proven. The chirps and barks that Vervet monkeys make as an eagle swoop’s in are the same chirps and barks that are made in moments of high arousal. Similarly, the barks made for leopards are the same that are made during aggressive interactions''. ''The environment that they exist in is too complex for their ability to communicate about everything in their environment specifically.''.<ref>{{Cite journal|last1=Price|first1=Tabitha|last2=Wadewitz|first2=Philip|last3=Cheney|first3=Dorothy|last4=Seyfarth|first4=Robert|last5=Hammerschmidt|first5=Kurt|last6=Fischer|first6=Julia|date=2015-08-19|title=Vervets revisited: A quantitative analysis of alarm call structure and context specificity|journal=Scientific Reports|language=en|volume=5|issue=1|pages=13220|doi=10.1038/srep13220 |pmid=26286236| pmc=4541072 |bibcode=2015NatSR...513220P|issn=2045-2322}}</ref>
In an experiment conducted by Dr. Julia Fischer, a [[Unmanned aerial vehicle|drone]] was flown over Vervet monkeys and recorded the sounds produced. The Vervet monkeys made alarm calls that were almost identical to the eagle calls of East African Vervets. 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. Dr. Fischer concluded that Vervet monkeys can be exposed to a new threat once and understand what it means.
It is still debated whether or not Vervet monkeys are actually aware of what the alarm calls mean.
▲It is still debated whether or not Vervet monkeys are actually aware of what the alarm calls mean. ''One side of the argument is that the monkeys give alarm calls because they are simply excited. The other side of the argument is that the alarm calls create mental representation of predators in the listeners minds.'' 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.<ref name=":5" />
Ultimately there is not enough evidence to support whether or not the calls are simply identifying a threat or calling for specific action due to the threat.
Line 77 ⟶ 73:
=== Sexual selection for predator-specific alarm signals ===
In [[guenon]]s, selection is responsible for the evolution of predator-specific alarm calls from loud calls. Loud calls travel long distances, greater than that of the home range, and can be used as beneficial alarm calls to warn conspecifics or showcase their awareness of and deter a predator.<ref>{{Cite journal|last=Smith|first=J Maynard|date= February 1965 |title=Reviews|journal=Heredity|volume=20|issue=1|pages=147|doi=10.1038/hdy.1965.20|issn=0018-067X|doi-access=free}}</ref><ref>{{Cite journal|last=Flasskamp|first=A.|date=1994|title=The Adaptive Significance of Avian Mobbing V. An Experimental Test of the 'Move On' Hypothesis|journal=Ethology|language=en|volume=96|issue=4|pages=322–333|doi=10.1111/j.1439-0310.1994.tb01020.x|bibcode=1994Ethol..96..322F |issn=1439-0310}}</ref><ref name=":9">{{Cite book|title=The Guenons: Diversity and Adaptation in African Monkeys|last=Glenn, Mary E.|date=2004|publisher=Springer US|isbn=978-0-306-47346-3|oclc=853270856}}</ref> A spectrogram of a subadult male call shows that the call is a composition of elements from a female alarm call and male loud call, suggesting the transition from the latter to the former during puberty and suggesting that alarm calls gave rise to loud calls through [[sexual selection]].<ref name=":9" /> Evidence of sexual selection in loud calls includes structural adaptations for long-range communication, co-incidence of loud calls and sexual maturity, and sexual dimorphism in loud calls.<ref name=":9" />
=== Controversy over the semantic properties of alarm calls ===
Line 87 ⟶ 83:
=== Receiver knowledge ===
Alarm signalling varies depending on the receiver's knowledge of a certain threat. Chimpanzees are significantly more likely to produce an alarm call when conspecifics are unaware of a potential threat or were not nearby when a previous alarm call was emitted.<ref name=":1">{{Cite journal|last1=Crockford|first1=Catherine|last2=Wittig|first2=Roman M.|last3=Mundry|first3=Roger|last4=Zuberbühler|first4=Klaus|date= January 2012 |title=Wild Chimpanzees Inform Ignorant Group Members of Danger|journal=Current Biology|volume=22|issue=2|pages=142–146|doi=10.1016/j.cub.2011.11.053|pmid=22209531|issn=0960-9822|doi-access=free|hdl=10023/4314|hdl-access=free}}</ref> 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.<ref name=":2">{{Cite journal|last1=Crockford|first1=Catherine|last2=Wittig|first2=Roman M.|last3=Zuberbühler|first3=Klaus|date= November 2017 |title=Vocalizing in chimpanzees is influenced by social-cognitive processes|journal=Science Advances|volume=3|issue=11|pages=e1701742|doi=10.1126/sciadv.1701742|pmid=29152569|pmc=5687857|issn=2375-2548|bibcode=2017SciA....3E1742C}}</ref> In a recent{{When|date=June 2021}} experiment, caller chimpanzees were shown a fake snake as a predator and were played pre-recorded calls from receivers. Some receivers emitted calls that were snake-related, and therefore represented receivers with knowledge of the predator, while other receivers emitted calls that were not snake-related, and therefore represented receivers without knowledge of the predator.<ref name=":2" /> In response to the non-snake-related calls from receivers, the signallers increased their vocal and nonvocal signalling and coupled it with increased receiver monitoring.<ref name=":2" />
=== Caller age ===
Line 110 ⟶ 106:
==Alarm pheromones==
Alarm signals need not be communicated only by [[Hearing (sense)|auditory]] means. For example, many animals may use [[Chemoreception|chemosensory]] alarm signals, communicated by chemicals known as [[pheromone]]s. Minnows and catfish release alarm pheromones (''[[Schreckstoff]]'') when injured, which cause nearby fish to hide in dense schools near the bottom.<ref>Campbell, N. & Reece, J. 2004. ''Biology'' 7th Edition - Benjamin Cummings {{ISBN|0-8053-7146-X}}</ref> At least two species of freshwater fish produce chemicals known as disturbance cues, which initiates a coordinated antipredator defence by increasing group cohesion in response to fish predators.<ref>{{Cite journal|last1=Crane|first1=Adam L.|last2=Feyten|first2=Laurence E. A.|last3=Ramnarine|first3=Indar W.|last4=Brown|first4=Grant E.|date=2020-05-01|title=High-risk environments promote chemical disturbance signalling among socially familiar Trinidadian guppies|url=https://doi.org/10.1007/s00442-020-04652-6|journal=Oecologia|language=en|volume=193|issue=1|pages=89–95|doi=10.1007/s00442-020-04652-6|pmid=32296954|bibcode=2020Oecol.193...89C|s2cid=215775310|issn=1432-1939}}</ref><ref>{{Cite journal|last1=
Deceptive chemical alarm signals are also employed. For example, the wild potato, ''[[Solanum berthaultii]]'', emits the aphid alarm-pheromone, (E)-β-[[farnesene]], from its leaves, which functions as a repellent against the green peach aphid, ''[[Myzus persicae]]''.<ref>{{cite journal |last1=Gibson |first1=R.W. |last2=Pickett |first2=J.A. |s2cid=4345998 |year=1983 |title=Wild potato repels aphids by release of aphid alarm pheromone|journal=Nature |volume=302 |issue= 5909|pages=608–609 |doi=10.1038/302608a0 |bibcode=1983Natur.302..608G }}</ref>
| |||