Depending on the characteristics of the environment it lives in, an animal species may develop a wide range of physical adaptations to help it survive there. But mental adaptations can occur as well, sometimes sparking the development of impressive cognitive abilities.
Tougher environments seem to spur the need for innovation and quick problem-solving.1 With hardships ranging from food scarcity to tricky navigation, harsh environments require animals to figure out solutions fast if they are to survive. These solutions may entail the expansion of hunting and foraging ranges, learning how to use tools, or even cleverly deceiving other animals.2
Scientists from the University of Nevada, Reno studied the cognitive differences between mountain chickadees that live in low and high elevations.3,4 When tested, the chickadees from higher elevations proved to have better problem-solving skills, figuring out how to unplug a tube holding a food reward at a much higher speed than the low-elevation chickadees. In another test, it was found that high-elevation chickadees also have better memories: they can more accurately remember where they’ve stashed food than the low-elevation chickadees could. They could remember these locations for longer as well. These superior abilities are likely directly linked to the environmental pressures of the birds’ high-elevation habitats.
Higher up, the winters last longer and see more snow, meaning that food is harder to find. Necessary skills for surviving the winters include learning how to find and access hard-to-reach food sources, and remembering where food caches are stored. Every season, the birds that don’t have these skills are more likely to perish, while those that do live on to pass down their genes.
Over time, this results in a population that has evolved the mental capacities to tackle the problems presented by the habitat. The scientists discovered that the high-elevation birds have evolved larger hippocampi than their low-elevation counterparts. The hippocampus is strongly linked to learning, memory, spatial memory, and navigation abilities.
The problem-solving disparity can also be found between animals that live in urban environments and those that live in rural areas.5,6 Researchers presented a mix of urban and rural bullfinches with a diverse lineup of food containers, all of which had unique mechanisms the birds would have to figure out in order to access the food. As was predicted, the city birds were better problem solvers. They routinely solved the container “puzzles” more quickly than the country birds.
This dynamic is the same between city raccoons and country raccoons.7 They have also been tested using a variety of containers holding food. City raccoons not only had more success breaking into the containers, but they were also more fearless about approaching and handling unfamiliar ones.
Urban raccoons in many areas are notorious for their dumpster-diving skills, being able to outsmart even trash bins that are designed to latch closed. This problem has created a demand for raccoon-proof trash containers. However, the introduction of such containers could lead to an arms race: as containers become more difficult to open, raccoons may continuously develop the smarts to conquer them. The likelihood of this seems great, considering that it’s theorized the urbanization (and, thus, complexification) of their habitats is largely responsible for their evolved level of intelligence in the first place.
The environmental influence on intelligence explains why there are such differences between animals of certain regions, and even entire continents. For instance, Australia’s general population of birds is renowned for being particularly intelligent, likely because the continent has perilous living conditions.8
Australian birds often face an unstable food supply. Due to the prevalence of wildfires, droughts, and other environmental challenges, the birds can’t count on the same food sources to be continuously available. They are often forced to improvise and find other means of feeding themselves.
A large number of Australian birds have a high brain-to-body size ratio, and as many as 18 of the continent’s bird species have been found to be tool-users. In many cases, they use these tools to obtain food. Some such cases of tool-use are highly surprising, like the reports of raptors picking up burning sticks and dropping them in fields to start wildfires.9 It’s thought that the raptors are starting the fires to drive out prey hiding in the grass. Once the flames ignite, the prey flee, making them easier to be snatched up by the hungry raptors.
The Role of Domestication and Captivity
It might surprise some to describe goats as “clever”, but it shouldn’t when you consider that wild goats have historically inhabited rugged areas, such as rocky mountains where food can be hard to reach and rough terrain must be navigated carefully.
Domestic goats perform very well at learning a two-step task involving the functioning of a lever to receive a food reward.10 Furthermore, the goats can quickly remember how to handle the lever when faced with it as many as 10 months later.
This was noteworthy to researchers because domestication generally reduces the need to learn and remember how to extract food. Domestic animals can usually rely on humans to provide them with a regular food supply. In this context, it’d be expected that the goats wouldn’t fare so well.
Domestication has been repeatedly linked to decreasing brain sizes in a number of animal species.10,11 Even first-generation guppies raised in captivity were found to have smaller brain sizes than wild-caught guppies.12 The limbic system is the brain region that has seen the most domestication-linked reductions throughout animal species; this brain region is associated with memory formation, long-term memory, and emotion.
Of course, smaller brains do not necessarily equal lower intelligence. Brain shrinkage can sometimes be attributed to a higher level of efficiency rather than a reduction of wits. But captivity does have other influences on animal brains. Researchers compared the brains of lab mice13 living in standard cages and those in cages enriched with objects like nests, exercise wheels, toys, and tunnels. They found that the mice living in the enriched environment had many more hippocampal neurons than the ones living in plain, featureless cages. Additionally, the enriched mice performed significantly better in a maze test.
These results suggest that environments offering stimulation and facilitation of natural behaviors can have a positive effect on the cognitive abilities of captive animals, while deprived environments may have a negative effect.
Living in a captive environment can remove pressures to develop cognitive abilities useful for survival. Naturally, the process of domestication can also be an influence on cognition, since humans may select for or against traits associated with intelligence, depending on their domestication goals.
More Immediate Effects
Temperature can have its own effects on cognitive performance.
For example, the intelligence of reptiles was long underestimated because they didn’t show impressive abilities in past tests. But when the lab conditions of those tests were examined,14 it was found that most were far too cold for the reptiles, making them slow and minimally responsive. When reptiles were kept in suitably warm environments, they performed far better. In fact, a tortoise tested in warm conditions excelled at solving a maze puzzle.15
“They seem to learn the quickest at body temperatures that are very uncomfortable for us.” Dr. Burghardt, a comparative psychologist, said of reptiles.
In humans, it’s already known that temperature has an effect on how well our brains process information.16 Exceedingly warm temperatures tend to make it harder for us to make complex decisions, and lower our general cognitive performance. This is also the case with temperatures that are particularly cold. Generally speaking, our brains work better at temperatures that are comfortably cool.
This is why, if you’ve ever taken a standardized test for school, you may have noticed that the testing rooms are often kept somewhat chilly. If human cognitive performance can be so strongly affected by ambient temperature, then it’s only natural that the same is true for animals of other species. So why aren’t more experiments done on animals including species-appropriate temperature controls?17
It’s crucial for science that captive animal subjects are given appropriate living conditions that accommodate their specific physiological and behavioral needs. Not doing so can significantly skew their performance in cognitive and physical performance assessments. Furthermore, the environmental factors they’ve been exposed to throughout their entire lives, not just the experiment periods, must be accounted for as well as possible when conducting any studies on animals. It’s only when we acknowledge the unique needs and experiences of animals that science can make better strides in understanding their minds.
This article was written by Amanda Pachniewska, founder & editor of Animal Cognition.
1 – Simon M. Reader, Julie Morand-Ferron, Emma Flynn
Animal and Human Innovation: Novel Problems and Novel Solutions
Biological Sciences, The Royal Society
2 – Richard William Byrne, A. Whiten
Cognitive Evolution in Primates: Evidence from Tactical Deception
3 – Dovid Y. Kozlovsky, Carrie L. Branch, Vladimir S. Pravosudov
Problem-Solving Ability and Response to Novelty in Mountain Chickadees (Poecile gambeli) from Different Elevations
Behavioral Ecology and Sociobiology
4 – Dovid Y. Kozlovsky, Carrie L. Branch, Cody A. Freas, Vladimir S. Pravosudov
Elevation-Related Differences in Novel Environment Exploration and Social Dominance in Food-Caching Mountain Chickadees
Behavioral Ecology and Sociobiology
5 – Jean-Nicolas Audet, Simon Ducatez, Louis Lefebvre
The Town Bird and the Country Bird: Problem Solving and Immunocompetence Vary with Urbanization
6 – Rachel Baxter
City Birds Smarter, Bolder than Country Counterparts
7 – Jude Isabella
The Intelligent Life of the City Raccoon
8 – Gisela Kaplan
Bird Brained and Brilliant: Australia’s Avians are Smarter than You Think
9 – Amanda Pachniewska
Ruthless Raptors Use Fire, Prisons & Mind Games
10 – Elodie F. Briefer, Samaah Haque, Luigi Baciadonna, Alan G. McElligott
Goats Excel at Learning and Remembering a Highly Novel Cognitive Task
Frontiers in Zoology
11 – Kruska, DC
On the evolutionary significance of encephalization in some eutherian mammals: effects of adaptive radiation, domestication and feralization.
Brain Behav Evol.
12 – James G. Burns, Arthy Saravanan, F. Helen Rodd
Rearing Environment Affects the Brain Size of Guppies: Lab-Reared Guppies have Smaller Brains than Wild-Caught Guppies
13 – Gerd Kempermann, H. Georg Kuhn, Fred H. Gage
More Hippocampal Neurons in Adult Mice Living in an Enriched Environment
14 – Emily Anthes
Coldblooded Does Not Mean Stupid
The New York Times
15 – Amanda Pachniewska
Tortoises Can Master Mazes
16 – John Brewer
Effect of Extreme Environmental Conditions on Decision Making Ability of Active Referees and Goal Line Officials
University of Bedfordshire
17 – Bonnie L. Hylander, Elizabeth A. Repasky
Thermoneutrality, Mice, and Cancer: A Heated Opinion
Trends in Cancer