The Effects in Animal Development From Differences in Testing Environment edit
We are creating this page for our Honors Seminar, at the University of Maryland, College Park. The authors are Brandon, Dan, Oren, and Val. Our question is "What are the effects of animal development from differences in diverse testing environments?".
Introduction edit
Most researchers would agree that a human’s character and unique responses to certain physical stimuli arise from an association between their genes and environmental stimuli. Our research aims at better understanding the environmental side of this theory within non-human animals by addressing the different techniques of animal experiments: those within the lab and those in the wild. Just as humans living in their hometown would develop and learn differently from those living in a cave, non-human animals that live in laboratories develop and act quite differently from those living in their natural environments; these differences extend to their cognitive, social, and behavioral abilities. In analyzing the differences between experimental results in the respective settings, our group hopes to determine the effects of natural versus artificial environments on the behavior and characteristics of the general non-human animal. This study pertains to animals of higher cognition, including birds, dolphins, and non-human mammals.
Lab Research Data edit
Research of animals in a laboratory environment is defined as any form of controlled research over animals. This includes confining animals in a caged environment, restricting animal interaction and contact with other animals of the same type, and promoting development of animal's skills and traits in order to analyze a particular feature or ability of the animal.
An animal that has widely been researched in the laboratory environment is the bottle-nosed dolphin. Dolphins maintained in oceanaria or in research facilities can readily transfer their social awareness and responsivity to the human caregivers. If the caregivers acknowledge and give proper attention to the social nature of the dolphin, a strong interest in humans can develop that allows for a close and cooperative long-term working relationship between the two species(9). Though it takes a tremendous amount of effort and hard-work, by successfully maintaining a dolphin within a laboratory research environment scientists were successful in more effectively learning about many unique aspects of the species including visual processes, sensory integration, memory and concept formation, imitation, and language learning.
In an experiment, scientists utilized non-human primates that aided scientists to attain data about non-human primate recognition. Individually housed chimpanzees were confronted with a full-length mirror outside their cages... The chimpanzees initially reacted as if they were seeing another chimpanzee and engages in a variety of social displays directed toward the reflection. Soon the chimpanzees began using the mirror to respond to themselves by engaging in mirror-mediated facial and bodily movements and self-directed responses such as grooming parts of the body only visible in the mirror. This transition gave the impression that the chimpanzees had learned to recognize themselves(9). This laboratory experiment was effective in providing information about self-recognition, self-awareness, and mental state attribution of non-human primates.
Wild Research Data edit
Research of animals in a wild environment is defined as any form of unrestrained research of animals. This includes behavioral or social research of animals in a natural setting with minimal human contact.
Research in the wild is sometimes preferable and often beneficial, as studies have shown that changes in the environment of animals have effects on brain structure, physiology, and behavior, including things such as recovering from illness and injury, and which genes are expressed(10).
In one experiment, enacted by two animal behavior specialists from the San Diego Zoo, the urine of free-range female black bears was tested for differing endocrine levels during breeding season, in hopes to better understand the basic reproductive biology of black bears and provide a detailed characterization of their estrous cycle. The two researchers traveled to the Black Hills of South Dakota and trained five wild female black bears to associate urination with a positive reward, such as honey-sweetened water. These noninvasive procedures were performed without chemicals, physical harm, and were not performed in any kind of lab environment. The experiment went quite successfully, as the researchers were able to acquire many urine samples every day(12).
One way researchers are able to study animals is through the use of radio telemetry; a strategy which is simple and does not harm the subjects. Animals are typically captured and either attached or surgically connected to a radio transmitter. They are then released back into their natural habitat, unaware that the researchers now have the opportunity to know their whereabouts, heart rate, brain waves, blood pressure, and even body temperature, without any form of contact involved. Researchers can observe from nearby locations and receive this information through radio waves(11).
Studying animals in the wild has taught researchers many things that were formerly misunderstood through research in the lab, that led to unusual behavior by the animals. For example, it has been observed in the wild that animal's heart rates do not always speed up when frightened, rather they may slow down instead. For instance, when rabbits hide from a predator, they lower their heart rates by 25 percent, as opposed to increasing it if they had decided to run away. Additionally, when an alligator is frightened, it's heart rate slows down two beats a minute as it dives under the water(11).
Interesting Discoveries Made Through Research in the Wild(11).
-Groundhogs' heart rate and breathing rate are often not synchronized, which is said to help the animal make more "economical" use of the limited oxygen in their burrows
-When an Alligator is still, the temperature of the core of its body rises more slowly than that of its back which is being hit by the sun. Yet, when it is moving, its core temperature increases more rapidly due to muscles forcing warm blood from the back into general circulation.
-When an alligator is in the water, its body temperature is higher than the surrounding water temperatures, which revealed to researches that some large reptiles (not just mammals) use internal heat production even while being cold-blooded.
Advantages to Lab Research / Disadvantages to Wild Research edit
In researching animals in a laboratory, scientists can attain much more useful information about the animal. In a particular animal experiment, primates, including rhesus monkeys, vervet monkeys, and squirrel monkeys, were taken from their wild environments and brought to a lab for more invasive neuro-physical research. Specific research in the brains of wild primates revealed a lot about the reactions to certain stimuli and their associated social behaviors. The direct link to these behaviors is the visual and auditory acuity of the monkeys. For example, the temporal cortex helps identify the hierarchy of the monkeys based on visual cues. These include facial features of an individual monkey (processed through the inferior temporal cortex), as well as facial expressions and gaze direction (processed through the superior temporal cortex). With sounds (specifically vocalizations), monkeys are capable of distinguishing individual monkeys, their relationships, and dominance and reproductive status of individual monkeys(1). Only through lab research methods could the scientists attain such data and make complex conclusions on the biological features of the monkeys.
Captivity also provides a way of preserving or repopulating threatened or endangered species. Not only does captivity preserve these breeds to promote genetic diversity, it also provides for laboratory research of the special characteristics and abilities of the species. Without these characteristics, the animal will lose its uniqueness and importance in an environment and an important scientific discovery could be missed. For example, North Ronaldsay sheep are valued because of their diet of seaweed. No other sheep have this diet, which makes it special(8).
In a lab setting, variables can be controlled and monitored to very finite levels. This is very useful for testing very specific data. Such advantages include promoting, manipulating, or avoiding any type of visual or auditory stimuli which may cause certain undesirable or unwanted behaviors, or may lead to distractions(4). It also minimizes any error from interactions with an outside factor
Disadvantages to Lab Research / Advantages to Wild Research edit
There are many benefits to researching animals in the wild setting versus in a laboratory. An important benefit is that wild research allows researchers to observe animals' natural behavior and techniques without disturbing their growth and development. An example of a wild animal skill includes "survival effects," techniques that include animals' recognition of their natural environment and the ability to adapt to changes in their setting. Domesticated and laboratory animals are much less likely to develop such skills(2). There is also the aspect of "natural suffering" (suffering from natural circumstances) which is a result of not living in a caged environment where everything is controlled and monitored. Wild animals experience difficulties that domesticated and lab research animals are spared from, including starvation, dehydration, and predation. A lack of interactions with other non-research animals may affect the test subjects in ways not replicable in lab settings(2). These interactions may provide pivotal roles in the development of animals. This could cause research data about a particular animal to be inaccurate or even false. There is a group of people that feel that the animal is subordinated to the ecosystem, so removing the animal from its environment damages the ecosystem more so than removing the animal from its habitat(2). For example, by removing the linx predator from the New Zealand forest/ wooded ecosystem, the hare prey population will grow unbounded and would throw off the entire balance in the ecosystem(7). In order to maintain equilibrium in the environment the less-intrusive wild research method would be preferred in the forest/ wooded ecosystem of New Zealand.
Marc Hauser also made the point of “socioecologically sensible neuroscience” which demands that researchers take note that an animal’s brain is suited for the socioecological problems that the animal is expected to experience(1). Should an animal be removed from it's natural environment, there could be effects on how the brain that will disrupt certain natural behaviors of the animal, which may also disrupt other behaviors and functions. This means that if an animal is removed from its wild environment and placed in a laboratory setting, the new location could influence behaviors of the animal that would cause inconsistencies and inaccuracies in the collection of data pertaining to the animal. It is possible that the laboratory control marmosets, although considerably more enriched than monkeys reared in the traditional lab for the developmental studies, nevertheless remained deprived of the experiences that adult marmosets require to maintain “normal” brain structure like that in the wild.
In 2005, a group of scientists from Princeton University assessed dendritic architecture, dendritic spines, and synaptic proteins in adult marmosets housed in either a standard laboratory cage or in one of two differentially complex habitats; they were hoping to establish a dissonance in the cognitive abilities of primates located in a traditional lab setting, slightly more complex environments, and the wild. A month-long stay in either complex environment enhanced the length and complexity of the dendritic tree and increased dendritic spine density and synaptic protein levels in the hippocampus and prefrontal cortex, whereas those left in traditional lab environments showed obvious volumetric decreases of the dendritic spine and synapse in brain regions important for cognition. Despite the length and complexity of the dentritic tree in the marmosets raised in the complex environments, the researchers found that these laboratory control primates were still living in deprived conditions relative to the wild (13).
There are also many detriments to keeping an animal in captivity. Obviously, being exposed to a different environment will bring out differing and potentially abnormal behaviors. One of the big disadvantages to having a captive environment is the enrichment necessity for the animal. The need for stimulation is tied to the development of abnormal behaviors, especially in captured animals such as bears. There is an innate desire to occupy ourselves with something, and we can get agitated if we are not properly stimulated. Bears too have that same desire. In an experiment, when bears were given enough stimuli to satisfy their time, they did not display any abnormal behavior. Such stimuli such as play and foraging has kept the animals from reaching a stressful state, and thus prevented any abnormal behaviors from developing. This can be directly associated with having a lab versus a wild environment. Obviously, a wild environment can expose the animal to novel and constantly varying number of stimuli, where as a laboratory setting can only expose an animal to so much(3). In addition, the cost of maintaining the animal in captivity requires a large budget to provide for food, housing, equipment, sanitation, and other necessities.
Conclusion edit
There are many concerns about animal welfare when it comes to studying in the lab as opposed to the wild. While environmental enrichment has been introduced to try to counter this concern, some studies have shown that putting animals in a complex environment could have negative effects, as opposed to the positive ones mentioned above. These effects include negative issues that have to do with memory, reversing learning deficits, etc. Thus, while enrichment may contain preferable utilities for the animals, it is not a guarantee for the well being of the animal, and actually can be physically detrimental(10).
The efforts of researchers in finding the most suitable testing environment is a big issue in animal studies. Research in the wild can often be difficult, while research in labs can be detrimental to the animals welfare, not to mention that it may conclude in unnatural results. Attempts at improving the emotional states of these animals through environment enrichment may be a step in the right direction; however, it is not yet sufficient since we cannot measure the animals emotions, and thus cannot determine if it is even valuable for either the animals or the research in which they are used(10). Also, variability can be very difficult to control, and therefore small environmental differences should be noted and not be underestimated to have significant effects on research.
There are many benefits and consequences for choosing either a lab or wild setting. When choosing an environment, proper care must be given in terms of what is being tested and what is the best way to get that data. However, there are some ways to get the benefits of both. Enrichment in the lab setting has been a hotly debated topic recently. Enrichment helps the animal as well, providing better well-being, and thus minimizing abnormal behaviors and providing better results and conclusions. Enrichment in the lab setting also helps researching “species specific behavior than in standard laboratory”(5). With mice, researchers scattered food to mimic the actual environment and structured the environment with climbing accessories, shelters/refuges, and exercise devices. All of these methods were more affective then just making the space bigger. They believed it gave the mice a sense of control over their surroundings, which lowered stress levels. Another experiment involved three rhesus monkeys in an animal house facility, where they were given almost complete autonomy. The facility was continuously connected to a computer that controlled a laboratory-type task and the distribution of regular monkey chow as reward. This was significant because the studied animals were able to work on their own time and by their own standards, in their home environment. This study provided much more data than others that were done in intervals of time in manipulated settings. It was found that when the monkeys participated in “self-initiated manipulatory activity,” the number of motor stereotypes was reduced. This showed that this type of testing was beneficial both to the animals and to the researchers(6).
References edit
(1) Ghazanfar1, Asif A. and Laurie R. Santos. "Primate brains in the wild: the sensory bases for social interactions." Nature Publishing Group. August 2004. <http://www.nature.com/nrn/journal/v5/n8/execsumm/nrn1473.html>.
(2) Swart, Jac. A.A. "THE WILD ANIMAL AS A RESEARCH ANIMAL." Journal of Agricultural and Environmental Ethics. March 15, 2003. <http://www.springerlink.com/content/nu020g4p11130185/fulltext.pdf?page=1>.
(3) “The Detrimental Effects of Captivity on the Behaviour of Wild Animals,” TSWCA, <http://www.tscwa.org/research/stereobears.pdf>.
(4) Waitt, C and Honess, P. “Interactions With Research Animals: Psychological Testing in the Home Cage Environment” International Journal of Primatology. 27 (Feb2006): 189-190
(5) Van de Weerd, H and Baumans, V. “Evaluation of Environmental Enrichment for Laboratory Mice.” Animal Welfare Information Center Bulletin 9.3.4 (1999): 1-2
(6) Preilowski, B and Michael Reger and Hans Engele. “Combining Scientific Experimentations With Conventional Housing: A Pilot Study With Rhesus Monkeys.” American Journal of Primatology 14.3 (1988): 223-234
(7)
Orians, G. H., W. K. Purves, and H. C. Heller. "Trophic Links: Predation and
Parasitism." GlobalChange. University of Michigan, 2 Nov. 2005. Web. 7 Dec.
2009. <http://www.globalchange.umich.edu/globalchange1/current/lectures/predation/predation.html>.
(8) Hardy, Donna Fitzroy. "The Role of the Domestic Animal in the Zoo," International Zoo News, December 1999, <http://www.anapsid.org/roleofzoos.html>.
(9) Bekoff, Marc, Colin Allen, and Gordon M. Burghardt. The Cognitive Animal. Cambrige: Bradford Book, 2002. Print.
(10) Benefial A, Willie Dong and William Greenough. “Mandatory “Enriched” Housing of Laboratory Animals: The Need for Evidence Based Evaluation.” Institute for Laboratory Animal Research 46.2 (2008): 1
(11) Arehart-Treichel, J. “Monitoring the Physiology of Animals in the Wild.” Science News 116.11 (1979): 186-187
(12) "You will catch more bears with honey than vinegar." You will catch more bears with honey than vinegar. San Diego Zoo. <http://www.sandiegozoo.org/help_wildlife/story_bears.html>.
(13) Kozorovitskiy, Yevgenia. "Experience induces structural and biochemical changes in the adult primate brain." Proceeding of the National Academy of Sciences of the United States of America. 2005. Princeton University. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1297690/>.