Perceptual trap
Encyclopedia
A perceptual trap is an ecological
scenario in which environmental change
, typically anthropogenic
, leads an organism to avoid an otherwise high-quality habitat
. The concept is related to that of an ecological trap, in which environmental change causes preference towards a low-quality habitat.
, James Battin did not distinguish between high-quality habitats that are preferred or avoided, labelling both "sources." The latter scenario, in which a high-quality habitat is avoided, was first recognised as an important phenonmenon in 2007 by Gilroy and Sutherland, who described them as "undervalued resources." The term "perceptual trap" was first proposed by Michael Patten and Jeffrey Kelly in a 2010 article.
against ecological traps, but not necessarily against perceptual traps, as Allee effect
s may restrict a population’s ability to establish itself.
To support the concept of a perceptual trap, Patten and Kelly cited a study of the Lesser Prairie Chicken
(Tympanuchus pallidicinctus). The species' natural environment, shinnery oak grassland
, is often treated with the herbicide
tebuthiuron
to increase grass cover for cattle grazing
. Herbicide treatment resulted in less shrub cover, a habitat cue that caused female lesser prairie-chickens to avoid the habitat in favour of untreated areas. However, females who nested in herbicide-treated areas achieved comparable nesting successes and clutch sizes to those in untreated areas. Patten and Kelly suggest that the adverse effects of tebuthiuron treatment on nesting success are countered by various effects, such as greater nest concealment through increased grass cover. Therefore, female birds are erroneously avoiding a high-quality habitat. Patten and Kelly also cited as a possible perceptual trap the cases of the Spotted Towhee
(Pipilo maculatus) and Rufous-crowned Sparrow
(Aimophila ruficeps), which tend to avoid habitat fragments, even though birds nesting in habitat fragments achieve increased nesting success due to a reduction in snake
predation.
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
scenario in which environmental change
Environmental change
Environmental change is defined as a change or disturbance of the environment by natural ecological processes, and is described in the following articles:*Climate change*Environment...
, typically anthropogenic
Anthropogenic
Human impact on the environment or anthropogenic impact on the environment includes impacts on biophysical environments, biodiversity and other resources. The term anthropogenic designates an effect or object resulting from human activity. The term was first used in the technical sense by Russian...
, leads an organism to avoid an otherwise high-quality habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
. The concept is related to that of an ecological trap, in which environmental change causes preference towards a low-quality habitat.
History
In a 2004 article discussing source-sink dynamicsSource-sink dynamics
Source-sink dynamics is a theoretical model used by ecologists to describe how variation in habitat quality may affect the population growth or decline of organisms....
, James Battin did not distinguish between high-quality habitats that are preferred or avoided, labelling both "sources." The latter scenario, in which a high-quality habitat is avoided, was first recognised as an important phenonmenon in 2007 by Gilroy and Sutherland, who described them as "undervalued resources." The term "perceptual trap" was first proposed by Michael Patten and Jeffrey Kelly in a 2010 article.
Description
Animals use discrete environmental cues to select habitat. A perceptual trap occurs if change in an environmental cue leads an organism to avoid a high-quality habitat. It differs, therefore, from simple habitat avoidance, which may be a correct decision given the habitat's quality. The concept of a perceptual trap is related to that of an ecological trap, in which environmental change causes preference towards a low-quality habitat. There is expected to be strong natural selectionNatural selection
Natural selection is the nonrandom process by which biologic traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution....
against ecological traps, but not necessarily against perceptual traps, as Allee effect
Allee effect
The Allee effect is a phenomenon in biology characterized by a positive correlation between population density and the per capita population growth rate in very small populations.-Description:...
s may restrict a population’s ability to establish itself.
Examples
Lesser Prairie Chicken
The Lesser Prairie Chicken, Tympanuchus pallidicinctus, a species in the grouse family, is slightly smaller and paler than its near relative the Greater Prairie Chicken...
(Tympanuchus pallidicinctus). The species' natural environment, shinnery oak grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
, is often treated with the herbicide
Herbicide
Herbicides, also commonly known as weedkillers, are pesticides used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant...
tebuthiuron
Tebuthiuron
Tebuthiuron is a nonselective broad spectrum herbicide of the urea class. It is used in a number of herbicides manufactured by Dow AgroSciences, and is sold under several trade names, depending on the formulation. It is used to control weeds, woody and herbaceous plants, and sugar cane...
to increase grass cover for cattle grazing
Grazing
Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...
. Herbicide treatment resulted in less shrub cover, a habitat cue that caused female lesser prairie-chickens to avoid the habitat in favour of untreated areas. However, females who nested in herbicide-treated areas achieved comparable nesting successes and clutch sizes to those in untreated areas. Patten and Kelly suggest that the adverse effects of tebuthiuron treatment on nesting success are countered by various effects, such as greater nest concealment through increased grass cover. Therefore, female birds are erroneously avoiding a high-quality habitat. Patten and Kelly also cited as a possible perceptual trap the cases of the Spotted Towhee
Spotted Towhee
The Spotted Towhee is a large New World sparrow. The taxonomy of the towhees has been debated in recent decades, and formerly this bird and the Eastern Towhee were considered a single species, the Rufous-sided Towhee...
(Pipilo maculatus) and Rufous-crowned Sparrow
Rufous-crowned Sparrow
The Rufous-crowned Sparrow, Aimophila ruficeps, is a smallish American sparrow. This passerine is primarily found across the Southwestern United States and much of the interior of Mexico, south to the transverse mountain range, and to the Pacific coast to the southwest of the transverse range. Its...
(Aimophila ruficeps), which tend to avoid habitat fragments, even though birds nesting in habitat fragments achieve increased nesting success due to a reduction in snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
predation.