Poison shyness
Poison shyness, also called conditioned food aversion, is the avoidance of a toxic substance by an animal that has previously ingested that substance. Animals learn an
In nature
For any organism to survive, it must have adaptive mechanisms to avoid toxicosis. In mammals, a variety of behavioral and physiological mechanisms have been identified that allow them to avoid being poisoned. First, there are innate rejection mechanisms such as the rejection of toxic materials that taste bitter. Second, there are other physiologically adaptive responses such as vomiting or alterations in the digestion and processing of toxic materials. Third, there are learned aversions to distinctive foods if ingestion is followed by illness.
A typical experiment tested food aversion learning in
The nematode
In pest control and conservation
Conditioned taste aversion has been widely used as a method of pest control and conservation. These aversions have been induced in both predator and prey species.[6]
Examples
Rodents: Rats and mice develop bait shyness very readily; it can persist for weeks or months and may be transferred to nontoxic foods of similar types.[7] Thus, if poisons are used for control they must provide no sensation of illness after ingestion. For this purpose, baits containing anticoagulants such as Warfarin were long used; they kill relatively slowly through internal bleeding, which is not associated with ingestion. More recently a highly potent toxin attacking the central nervous system, bromethalin, has been used. Again, with sub-lethal doses of this chemical, the animal cannot learn the association between the odour of the food and its toxicity, thereby preventing poison shyness from developing.[8]
Crows: Conditioned taste aversion has been used to control crow (
Quoll: In
Multiple predators: When surrogate eggs of the sandhill crane (Grus canadensis) were laced with an illness-producing substance, egg predation decreased in a location which contained multiple potential predators.[13]
Coyotes: Poisoned baits of meat left where coyotes can find them have been used to discourage coyotes from attacking sheep. Here, bait shyness is transferred from the pieces of meat to an aversion for live sheep.[14] Bait shyness may sometimes be location specific and not transferred to different localities.[15]
Livestock protection
Taste aversions have been developed in wolves, coyotes, and other canids to protect livestock and vulnerable wildlife.[16] In 1974, it was reported that coyotes (Canis latrans) learned to avoid hamburger after eating hamburger treated with lithium chloride and could transfer such a drug-induced aversion of LiCl-tainted sheep or rabbit (Sylvilagus sp.) flesh to the corresponding live prey.[17] Olfactory (cologne) and visual (a red collar on the sheep) cues increased the suppression of predation through conditioned learned aversion in coyotes, although this was for a limited duration.[14]
Grazing livestock frequently eat poisonous plants, and death often results. Behavioral adjustments by conditioned taste aversions may protect animals from over-ingestion of toxic plants. Three species of plants with different mechanisms of toxicity were tested for their ability to condition a taste aversion in sheep. Only woody aster conditioned a taste aversion indicating that conditioned aversions to selenium-containing plants help deter consumption of such plants by grazing ruminants.[18]
Crop protection
The cultivation of woody plants (olive trees, grapevines, fruit trees, etc.) can benefit from having animals e.g. sheep and goats, grazing the same area as their faeces nourish the soil thereby reducing the use of herbicides and fertilisers. However, these same animals sometimes eat the crops. Lithium chloride has been used to develop conditioned taste aversion to olive leaves and shoots in sheep and goats.[19]
List of animals
Below is an incomplete list of animals for which poison shyness or bait shyness has been documented in pest control:
- Possums[23]
- Brushtail possum (Trichosurus vulpecula)[24]
- Moles[citation needed]
- Voles[25]
- Mice
- Coyotes (Canis latrans)[14]
- Crows
- Carrion crows
- Ravens[15]
See also
References
- ^ .
- ISBN 0-478-14065-7.
- PMID 10454364.
- ^ "Researchers discover how worms pass knowledge of a pathogen to offspring". phys.org. Retrieved 11 October 2020.
- PMID 32908307.
- ^ Gustavson, C.R. (1977). "Comparative and field aspects of learned food aversions". In L.M. Barker; M.R. Best; M. Domjan (eds.). Learning Mechanisms in Food Selection. Waco, TX: Baylor University Press. p. 632.
- ^ Cowleys. "Rats, food, and bait shyness". Archived from the original on February 5, 2013. Retrieved May 22, 2013.
- PMID 8194072.
- S2CID 28393515.
- ^ Anon. "Taste aversion". Retrieved May 23, 2013.
- S2CID 85678374.
- .
- JSTOR 2425983.
- ^ a b c Sterner, R.T. (1995). Cue enhancement of lithium chloride-induced mutton/sheep aversions in coyotes. Great Plains Wildlife Damage Control Workshop Proceedings. Paper 451.
- ^ JSTOR 1521474.
- ISBN 9789061936145.
- S2CID 19911508.
- doi:10.1016/j.smallrumres.2010.02.009.)
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: CS1 maint: numeric names: authors list (link - .
- .
- . Retrieved 4 April 2015.
- ^ Prescott, C.V.; El-Amin, V.; Smith, R.H. (1992). "Calciferols and bait shyness in the laboratory rat". Proceedings of the Fifteenth Vertebrate Pest Conference 1992. University of Nebraska, Lincoln. Retrieved 4 April 2015.
- ^ "Properties of various poisons used to control possums". Controlling Possums in Westland. Retrieved May 22, 2013.
- ^ Ogilvie, S.C.; Thomas, M.D.; Fitzgerald, H.; Morgan, D.R. (1996). Sodium monofluoroacetate (1080) bait-shyness in a wild brushtail possum (Trichosurus vulpecula) population (PDF). Proc. 49th N.Z. Plant Protection Conf. 1996. pp. 143–146.
- ^ Wedge, R. "Vole poisons". Retrieved May 22, 2013.
- ^ Rao, A.M.K.M. & Prakash, I. (1980). "Bait shyness among the house mouse Mus musculus bactrianus to zinc phosphide and RH-787". Indian Journal of Experimental Biology. 18 (12): 1490–1491.
- JSTOR 3800520.