Why rooster crowing isn’t that impressive, and chickens get jet lag like the rest of us.

Circadian rhythms and jet lag.  There, cyclic crowing behavior explained.

Quite a lot of people are discussing this study from Japan examining the effect of light on the crowing behavior of roosters. The authors observed several birds in experimental conditions where light intensity and duration were controlled, taking observations with audio recorders and cameras. The scenarios presented were a daylight cycle of 12 hours of light and dim light respectively, and constant dim light. Observations were recorded for a period of 14 days, producing this graph.

So many reporters on the study have run with this, making declarations about what great timekeepers roosters are, and how cool it is that they don’t need the sun to know when dawn is.

Well, approximately when dawn is.

“Under dimLL conditions, a free-running rhythm of crowing was observed with a period of 23.7 ± 0.1 h (n = 4), but this free-running rhythmicity gradually damped out”

Interesting, so the sun is unnecessary until it’s been gone for a while, then we start to get some variation. This dampening effect is even more obvious when you place testosterone implants in the roosters.

Testosterone implant roosters calling out “Bro, do you even lift?”

Don’t get me wrong, the fact that Roosters have this accurate of a circadian clock is impressive! It’s very interesting biologically, but it’s not some infallible atomic clock. While many news sites are toting that Roosters are independent of the sun, the opposite is true. Circadian rhythms are directly calibrated primarily by light cycling, with temperature being another important environmental cue. To confirm the roosters knew what time it was, the authors examined the effect of light or recorded crowing sounds at different times of day. They found that there were fewer crowing behaviors at random dawn times than at the “correct time” of day.

This doesn’t mean the roosters know it’s 5pm, but their circadian rhythm is telling them that it isn’t dawn. However, the sun still “came up” so we witness some halfhearted crowing. Anyone who has ever traveled out of their timezone knows exactly how this feels: these roosters have jet lag. While the sun may be coming up, their circadian clocks are telling them that it feels like a different time of day, so they crow in response to the light, but with reluctance and confusion, much in the same way you sleepily get up on vacation when the Louvre opens, even though it feels like 5PM to you.

“But Austin,” you tell me, “aren’t you anthropomorphizing?” While I admit roosters may not empathize with trans-Atlantic vacations, we know that chickens are dependent on daylight to calibrate their biological rhythms because we do it all the time. We increase egg production by simulating summer lighting year round, and alter feed intake in broilers by changing their daylight cycle. We also use this trick to bring mares into heat.

The loss of rhythm observed in 24 hour dim light is likely to become more and more sporadic, and even more so if the roosters were housed singly (as there is some group consensus due to competitive crowing). I would propose that if you could keep the roosters on a light cycle that progressively moved forward an hour a day until dawn was at 2pm, the roosters would crow with the same strict rhythm independent of the actual sun. If the authors of the study choose to pursue this hypothesis, an easy test would be to simply progress their artificial sun’s rise and fall over time.

Alternatively, we could fly several roosters with us to Paris, and see if they wake us up before the Louvre opens.

ResearchBlogging.org

Shimmura, T., & Yoshimura, T. (2013). Circadian clock determines the timing of rooster crowing Current Biology, 23 (6) DOI: 10.1016/j.cub.2013.02.015

Do cats in shelters acclimate faster if given a bunkmate?

Lucy is currently up for adoption at Heartland Humane Society (Corvallis) and is housed singly.

This article is one of many that I’m currently reviewing to build the introduction for the original research I plan to complete this summer/fall. This is the first of several posts discussing shelter cats to come in the next several weeks.

This study by Kessler and Turner (1997) took a look at the stress levels of cats introduced to a shelter/boarding facility-type environment over the first two weeks of their stay, and cross-examined those housed alone, in pairs, and in groups. 45 homeless animals that had already been at the facilities for some time were selected as a control, and 140 animals staying for temporary boarding were observed for the first two weeks of their stay.

Overall, the authors were able to conclude that in a two week stay, two-thirds of the cats acclimated very well, and after two weeks their stress levels, while still higher, were very comparable to the control. They suggest that other options be explored by the owners of the other third, with a special emphasis on the 4% of the cats who were extremely stressed even after a two week stay.

I endorse this wholeheartedly as I often watched animals for owners as a job when I was much younger. While they may be given more brief human contact, working out a deal with a house-sitter or neighbor to take care of your pets while you are away can be much less stressful for them than if they are placed in an unfamiliar environment with strange people and animals. You reduce their risk of exposure to disease, and help some young lad save money for college (I did…though some of it bought movie popcorn).

The more surprising conclusion was that housing the cats singly, pairs, or groups appeared to have no influence on the stress levels of the animals. There appears to be a slightly faster decline in stress for group housed cats on the authors’ graph, however it isn’t addressed, and the difference is minimal.

The conclusions have merit, but I have several problems with the selection of control animals in this study, namely, the fact that they aren’t representative of the experimental group. The biggest problem is that only homeless shelter cats were used for the control, and only boarding cats for the experimental group, where  either all homeless shelter cats or all boarding cats should have been included. The second large flaw I see is that all of the control animals were housed in groups of 6 to eight, effectively ruining any comparisons you may want to make when looking at the other housing situations. In a study named Stress and Adaptation of Cats (Felis silvestris catus) Housed Singly, in Pairs, and in Groups, you would think the control would use all of those situations.

The authors briefly mentioned the stress caused by cats that may be less social, or housed with familiar animals versus strangers, but were unable to control those factors with the way the data was collected and prepared. When it comes down to it, the control group just wasn’t…controlled. They were unable to fully examine how quickly single or pair cats acclimated to the boarding facility because you couldn’t compare them to a control cat in the same situation.

Kessler and Turner have another study (1999) examining stress levels of shelter cats in terms of animal density and cage size. Interestingly enough, they found that group density was “highly correlated with the stress level of animals housed in groups”, indicating that we should have seen some differences from the study above as well. That research was done two years after the 1997 study, so perhaps the authors also thought that those questions remained unanswered from the original study. I’ll be looking out for some newer research on the subject and may chime in on it again soon.

 

ResearchBlogging.org

M R Kessler, & D C Turner (1997). Stress and Adaptation of Cats (Felis Silvestris Catus) Housed Singly, in Pairs and in Groups in Boarding Catteries Animal Welfare, 6, 243-254

M R Kessler, & D C Turner (1999). Effects of Density and Cage Size on Stress in Domestic Cats (Felis Silvestris Catus) Housed in Animal Shelters and Boarding Catteries Animal Welfare, 8, 259-267

 

If you’re interested in the cat featured in this post, head on over to Heatland Humane Society to meet him!

Newsworthy: University of Georgia is characterizing flock vocalizations as a stress indicator.

Hey all, taking a quick break from blogging as I’m busy with a personal research project I’ll report here on ASR soon, but I wanted to add a quick post for anyone subscribing to RSS or wondering if I’m still alive.

This article on ScienceDaily details a study going on at the University of Georgia, in which they’re recording flock vocalizations to find distinct patterns that can be associated with temperature levels, ammonia concentrations, and other detrimental environmental factors. This has possible implications not only for the welfare of the birds but for the efficiency of the operation.One example of a financial incentive that the article provided is that current ammonia detectors are expensive and short-lived, and if a computer instead could “listen” to the flock and identify specific vocalization changes related to ammonia levels those detectors could be made obsolete.

It’s a cool article, and an awesome example of how agriculture continues to keep up with technology. Check it out and I’ll be back to regular posting as soon as my other personal project is on it’s way!

Article Review: Animal Play and Animal Welfare

Today’s article comes again from sciencedirect, and it’s the last literature review I’ll do for a while. It discusses play as an indicator for good welfare in captive and production animals. The challenges associated with understanding the motivations of play, and a brief history of landmark studies concerning play behaviors.

Temple Grandin writes that play in dogs may be training for different social situations. She supports this because dominant animals will change roles to a subordinate position and vice versa. In this way dogs and others would be ready to handle new situations outside of their norm. One benefit of play the article mentions supports this theory, that it’s sheer variability and fluidity may prepare animals for the unexpected. While the rest of their survival and social behaviors are predictable and procedural, play constantly creates new challenges and situations to react to that aren’t life or death. I think this makes sense, but I also think it’s even broader than Grandin puts it. Playful bucking and jumping by cattle, goats, sheep, and horses doesn’t seem to be play behavior related to dominance or social skills. To address this, the article lists several schools of thought as to the main purpose of play.

The first category believes in long-term benefits resulting from play. This includes benefits such as somatic development (differentiating muscle fibers, motor skills, etc.), proficiency in species specific behaviors (hunting, sex behaviors, etc.), and general improved physical and emotional flexibility across novel situations (social changes, new environments, anything new). There’s a lot of research supporting this school, but it doesn’t completely answer the question. Adult animals still play, even those that have sexual experience or have no need to hunt. This thinking largely explains why we see so much more expression of playing behaviors in juvenile animals, and is well supported. This sometimes doesn’t pan out well welfare wise, as experience with sexual or aggressive behaviors may not benefit say, your neutered indoor cat.

The second category is more recent, and proposes that play provides primarily immediate benefits to the animal. The first idea is that play provides/communicates information about the immediate environment it finds itself in. This may be information concerning other group members, its effectiveness physically in that situation, or its current level of development. Another idea is that play is self medicating; as it’s been proven that play releases natural opioids (Pellis & Pellis, 2009). Finally, play may be used for social communication. An animal can reinforce its status, reduce tension, or “break the ice” with a strange animal. I like this theory, but just like the other one, it doesn’t provide a complete picture. It sounds like a cop-out, but I think the reality is a mixture of the two thoughts. Behavior is rarely black and white, and I’m convinced by the research on both sides of the debate. What will be interesting is when we single out species specific behaviors and determine if they reflect the immediate benefits as opposed to the long term benefits. Dogs aren’t a good model because the pedomorphism nature of their evolution makes them predisposed to juvenile play their entire lives.

The bulk of the article relates all of the information to the use of play as an indicator of good welfare. It’s not a new idea, and the article provided a very comprehensive pros and cons list. The pros being that play is contagious, it releases opioids, it doesn’t occur in depressed or ill animals, and animals appear to enjoy it. The cons being that it’s extremely variable between species and individuals, and that occasionally it can increase in frequency to respond to stress (lending evidence in support of the second theory). Eventually, play is identified as a decent indicator of good welfare, and promoter of animal contentment. I agree with the conclusion, and also with the final statement that we have many questions left to ask.

Suzanne D.E. Held, & Marek Spinka (2011). Animal Play and Animal Welfare Animal Behaviour (81), 891-899

Newsworthy: “White Coat Effect” and Dog Appeasing Pheromone

It’s tough being a big guy in veterinary medicine. I’m not sure why so many dogs don’t like guys, but its going to be a big hurdle for me as my work continues with both small and large animals. Just today I met someone’s dachshund who did nothing but chase my ankles barking, growling, and snapping his teeth. Any attention or efforts to be friendly only seemed to increase his wrath, and ignoring him completely just encouraged him to be more brave (and not in an investigative way, more of a tactical strike way). Most dogs who dislike men aren’t so overtly aggressive, and just feel uneasy or fearful. One of the ways we try to make these dogs more at ease, in many situations, is to use Dog Appeasing Pheromone. I’ve often suggested that I wear a DAP collar myself so that I can exude a calming presence and change my smell profile, because once they see me and decide to become anxious, DAP won’t do much good.

I was thinking about methods for calming animals after reading this article about the “White Coat Effect” in greyhounds. Just like in humans, greyhounds and other dogs get anxiety and higher blood pressure in response to the stimulus of the veterinary clinic and veterinarians. Anything from the smell of latex, seeing white coats and scrubs, or a combination of several factors could be the stimulus. Not every dog reacts this way, but I imagine most do to varying degrees. Whenever we get a high strung dog, we would spray the counter or a towel with DAP, and hope it helps. One of our veterinarians swears by it for her own dogs (border collies mostly), and I think that it makes a difference.

There are a couple studies that support the use of DAP in creating a calmer environment in different situations, and really, anything helps. For my part, I just try to do the obvious things to make myself less scary: look smaller, don’t face the animal, slow movements, soft voice etc.. My newest thing has been observational learning, so for example, if I can talk to the owner or interact with their other, less fearful animal, before even approaching the nervous dog/cat, I’m hoping that they may not generalize me as just another man.

All I can really hope for is that if I work long term in a clinic someday, I can build a relationship with both the clients and their animals. It may be that there will just be some patients that will be better served by seeing a female veterinarian, and that’s okay, not everyone can be a perfect fit. Hopefully though, working with larger animals will be a better fit for me as a veterinarian, and I’ve got a few more years to decide on my approach to alleviate the fear associated with my white coat.

Book: Animals in Translation (Grandin)

That’s right, I’ve finally finished the book that everyone else has already read. When I first saw Temple Grandin speak at Oregon State and glanced through some of her research, I wanted to read one of her books that not everyone had read. So I picked up Animals Make Us Human. I immensely enjoyed that book, but had no idea that Animals in Translation was so popular for a reason. AMUH takes the principals discussed in the first book and uses them to analyze the quality of care you provide your household pets. Whereas Animals in Translation goes deep into the science and assumptions Grandin makes using her experiences in animal handling and Autism. She then quickly backs all of it up with an extensive review of relevant literature.

There’s a critic on the back of the book that says “there’s a wow on almost every page” and I believe them. There’s a lot of crossover between the two books, but Translation is much more science oriented and acts as a manifesto of Grandin’s observations and conclusions of the perceptive worlds (and umwelts) of animals. It reads like a great pop science book, and keeps the information from getting dull by relating it all to the author’s anecdotal evidence and personal experiences.

As well constructed as the arguments in the book are however, Grandin makes a lot of assumptions. I’m inclined to agree with pretty much all of them, but many times she attacks the certainty of scientists who believe animals can’t do things. I agree more progress has been made assuming possibilities instead of negatives, but I’m sometimes uncomfortable with how certain she believes her own conclusions are. You can’t call out other people for not having satisfactorily proven their conclusions, and then state yours with the same conviction. That being said, she does make all of her statements with a careful amount of humility, and always follows them with something along the lines of “this hasn’t been examined/proven yet, but I believe we will soon see studies that support it”. She’s especially careful when the supporting research is conflicting, and makes suggestions on how future studies could get more consistent data.

I love her examination of brain structure to explain the differences, and similarities, of animals to humans. Using Autism in terms of frontal lobe function seems like an appropriate model for the animal brain, and her hyper specificity theories seem to align perfectly with animal behaviors concerning fear. The black box manages to provide evidence to support most of her theories, and gives them weight across multiple disciplines. The chapters concerning fear were especially interesting, and I’m curious if I can run experiments on my roommates using hard-wired phobias, though they’ve probably already been exposed to them all.

What I really want to do now, is find a book that disputes some of Grandin’s theories. I’m afraid that the arguments she makes are so charismatic and I’m so prepared to agree that I don’t analyze them rigorously enough. I’d like to see writing from someone with a similar amount of education and experience, but with different views, so I can make my own judgments. As of now I’m pretty sure I agree with Grandin on all fronts, but until I receive a conflicting argument I can’t rely on that impression.

Temple Grandin and Dr. James Males at Oregon State University

Like I said, the book was fantastic, and if you’re at all interested in animals, behavior, or just pop science, you need to pick it up. I highly recommend reading animals in translation first. I’ve got one more Grandin book on my shelf I want to read, Humane Livestock Handling, which includes some of her systems that are used in slaughtering facilities across the nation and how to operate them. I’m excited to dig into it, but for now it’s going to sit on the shelf while I read something different. I’ve been reading behavior and cattle literature a lot lately, so I’m looking for something a little different before I start another book in that vein.

Book: Domestic Animal Behavior for Veterinarians and Animal Scientists – Katherine A. Houpt

After a year-and-a-half of on and off reading, I’ve finally finished Domestic Animal Behavior for Veterinarians and Animal Scientists, 4th edition. It’s only about 400 pages, but it’s technically a textbook, and by no means light reading. I got through it by taking it a couple pages at a time, which allowed me to process the information and apply it to things I was learning and reading elsewhere.

It was a great resource for me, as someone who has few experiences working with production animals, to learn common behaviors and methods of correction for domestic species I was less familiar with. I’m sure a lot of it is common knowledge to someone who grew up around cattle, horses, sheep, and swine. But for someone like me who hasn’t spent years observing those animals, the book provided a lot of observations that I haven’t been able to see myself. Grazing and sexual behaviors were particularly interesting to me, and were covered well.

One of my favorite parts of the book was its depth. Each chapter is specific to one behavior aspect (e.g. “Communication”, “Aggression and Social Structure”, “Circadian Rhythms and Sleep”, and “Food and Water Intake”), then breaks it down by species, and then further breaks it down based on problems specific to that species, finally discussing relevant studies. I actually spent quite a few lunch breaks at the clinic last summer reading this book and asking the veterinarians questions.

The language and voice of the book tends to be pretty abstract, but occasionally makes suggestions to scientists studying/raising the species being discussed. The arguments are very compelling when they are immediately preceded by an experiment summary that supports them. The book also does a great job of identifying gaps in the reviewed literature, and asks great questions about continuity. It often seems to be giving a big hint or nudge to animal researchers to explore a specific topic.

Overall, I highly recommend this textbook for anyone interested in behavior or may want to learn more about domestic species. It covers a ton of the physiology and pharmacology behind the decisions animals make, and is a great example of technical but achievable language that animal science/veterinary students should be familiar with. I’ll definitely be keeping it as a desk reference and referring to it whenever starting a project with a new species.

Research: Effects of disposition and acclimation to human handling on feedlot performance and carcass characteristics of feeder steers

So as I’ve mentioned before, this summer/fall I’ll be interning at the Eastern Oregon Agricultural Research Station (EOARC) in Burns, Oregon under Dr. Reinaldo Cooke. So my next few blog posts leading up to that will concern the research that we will be conducting, as well as a brief look at previous similar experiments that have been conducted at the station or elsewhere.

The first one is one that I’ve actually discussed on this blog before, and it concerns the effects of disposition and acclimation to human handling on cattle in all life stages. Previous research has examined heifers and cows, looking mostly at reproduction, performance, and temperament (note, there has been more recent research on the subject, however it is not yet published online). The new proposal that I will get to help work on will be concerning steers and feedlot performance.

The overall purpose of the study isn’t to find anything drastically new, as calm disposition has already been shown to be beneficial for general and feedlot performance in other settings. Primarily the goal is to examine cow/calf operations as they are used in Oregon (large rangeland scenarios, not drylots), promote selection for calm disposition as a production trait, and show that acclimation to handling is a possible and beneficial way to attain higher yields (in terms of carcass quality).

In terms of the methods, I’m still reading and rereading all of these so that I’m very familiar with the experiments we will be running. As far as the acclimation process goes, we’re going to be spending time with the experimental group for two hours, three times a week before they go to the feedlot. During that time we will run them through basic handling procedures, and during feeding times we will walk around in close proximity to further acclimate them to our presence. At the end of the 60 days at the EOARC they’ll take a 24 hour truck ride (to simulate transport that would normally be long and stressful for most of Oregon cattle) then head to the feedlot in Boardman. The control group will remain free to graze during this time without excess human contact to keep them non-acclimated.

The quantitative data we will be collecting (at multiple points during the experiment) will include: cortisol, inflammatory proteins, IGF-1 (Insulin like Growth Factor), weight gain, feed intake, feed efficiency, health condition, morbidity and mortality, and several carcass characteristics. Our evaluation of cattle disposition will also be quantitative, as it will be evaluated based on chute exit velocity and chute score.

A quick note on exit velocity, when I visited the EOARC, Reinaldo showed me the infrared sensor that they use to measure chute exit velocity. I think that similar devices are used to measure fastballs. I just thought it was really cool. There are a lot of other experiments on temperament out there that examine exit velocity, it’s well proven as a method for determining excitability/temperament/disposition. I just think it’s really cool, and pretty brilliant.

I imagine that we’ll find the expected results, and that the acclimated steers will be less stressed and better producers than the control group. I’m also curious whether this is the last in the series examining this effect, or if there’s still another age group or factor to analyze. This effect on dairy cows has already been examined, so what could be left? There’s nothing except the feedlot. Given the compact and efficient nature of the feedlot, I don’t think it’s financially viable to take the time to further acclimate the animals to the human presence. Hopefully, the acclimation routine done in the cow/calf operation beforehand will be sufficient to promote better performance on the feedlot, and this study will examine just that. I’ll definitely be asking Reinaldo what his future proposals will be, and maybe even get to participate in that thinking process.

Click here to view the actual research proposal.

Article Review: Sources of Stress in Captivity, Part II

Took me forever to get around to reading the rest of this article, this last term was pretty heavy. But nonetheless I haven’t forgotten about this thing, and it’s not like I have to keep an update schedule for my breathlessly waiting readers on here. So with that, let’s get back into it.

The second half of the article focused on more biotic and behavioral stressors, still mostly from a zoo perspective. This half was much more interesting, as the abiotic factors discussed in the first half were pretty simple. That’s not to say that they weren’t well explored and there wasn’t any new information presented, but I’m pretty sure it wasn’t hard for them to come to the conclusion that if we cook our captive animals on concrete on a hot day that it’ll cause stress. One of the neatest things when they were examining behavioral stress was that they always identified when a certain stressor was used as the definition of stress in other studies. Things such as separation from conspecifics and invasive handling were not only examined, but identified as the state of being “stressed” in other studies.

Both at the beginning and the end of this section they really hit the nail on the head for stress in capitivity.

“…the primary difference between such stimuli in nature and the same stimuli in captivity is in the animal’s ability to control it’s exposure to these stimuli…confinement in captivity brings with it a host of other potential stressors, largely in the form of restricted choice” (Morgan and Tromberg, 2007)

Like in The Matrix, it’s a problem of choice. Whether that’s removal of the choice to retreat from people or animals, of feeding time and meal composition, of which animals it shares space with, of mate selection, and obviously of home range/habitat selection. That’s the reason for stress in captivity as broadly defined as it can be. It makes sense, but they touch upon it again later when they discuss the roles of predictability for environment enrichment. Animals when given a choice will chose a predictable schedule over unpredictability, but there are conflicting results as to which one provides more benefits. Novelty  has been shown to be necessary for environmental enrichment: the provision of toys in stall horses greatly reduces stall vices/stereotypies such as cribbing and swaying. Stereotypies are also reduced in pigs with long pieces of straw to chew (see Grandin for perspective on this behavior). Novelty comes up in the article when discussing controlled things such as feeding and cleaning times, and uncontrolled factors like the number and behavior of visitors to zoos.

Human contact is discussed thoroughly as a stressor and enrichment. Social and domesticated species have been shown to benefit greatly from human contact, however other species display obvious detrimental effects.

“In one review of black rhinocerous breeding success in US zoos, animal mortality was positively correlated with the degree of public access to the animals.” (Morgan and Tromberg, 2007)

The only real trend is that the effect of human contact creates wildly different effects based on its nature. If the contact is social or feed associated, it can be great, but across the board, negative contact whether in treatment, handling, or painful/invasive medical procedures will make future contact with people a negative and stressful experience. The article does take a moment to clarify what they thought created a pleasant experience.

“Part of what pleasant handling appears to involve is meeting the animal on its own terms.” (Morgan and Tromberg, 2007)

Grandin talks about this a lot with how animals approach novelty with caution. They enjoy novelty because it turns on the SEEKING blue ribbon emotion, but if that novelty moves beyond what they’re ready to explore, they crank on the FEAR emotion and the novel thing becomes stressful.

So, given everything examined, how do we fix it? That depends on your goals. If you want to create a zoo/farm that keeps the animals at the same stress level as them living in the wild, you better work at Yellowstone (and even then!). It’s really not going to happen. So let’s say we set some reasonable goals, like wanting to reduce pacing stereotypies in our larger animals. So, how do we identify the stressors in those enclosures?

“Many of the stressors reviewed above produce the same or very similar effects on animals…This ambiguity makes such behavioral and physiological responses unreliable symptoms for troubleshooting a given captive situation” (Morgan and Tromberg, 2007)

All we get is that something is wrong, but have no idea what. It’s like saying a person or animal has nausea, diarrhea, and fever. Helpful, we now know it could be one of a thousand issues that all cause those symptoms, more information is needed to make an appropriate diagnosis. In all honesty, other than some simple species specific observations, it comes down to individuals. Some will do better in captivity than others, and some will respond to changes you make to minimize stress better than others. The article mentions that if your goal is a conservation effort, captivity can promote learned helplessness, which results in the loss of adaptive coping strategies. There’s a lot of issues with conservation efforts: loss of genetic diversity (cheetahs), over-success (grey wolves), and loss of natural adaptability and wild behaviors (pandas). Learned helplessness can be useful or at least non-detrimental with respect to domesticated species, but anything you intend on reintroducing to the wild may have issues.

Perhaps (unless it’s a conservation effort) we should just resign ourselves to the fact that when we put animals in a zoo, we are domesticating them. Part of the lure of the zoo is to see wildlife in a controlled setting, but there’s an oxymoron there. Wildlife is out of our control, deer that have problems giving birth die, and predators won’t discriminate between a keystone species and other food options (oh if only we could keep all the salmon to ourselves). Maybe the new direction should be not to impersonate nature, but promote behaviors that inherently make zoo life less stressful for those animals. The article briefly mentions “contrafreeloading” behavior, in which animals will choose to work for a food reward even when it is offered freely. I want to bring up circus animals and how, even though many inhumane techniques have been used to teach them the tricks they do, many of them have been selected for their willingness to do a shapeable behavior or to work with items. We could be selecting our zoo animals for their willingness to participate with handlers and items, and we could provide enrichment through allowing them to work for their rewards. This is accepted with marine mammal exhibits where wild whales, dolphins, sea lions, and anything else we can seemingly fit in a tank receives enrichment in this way (not to say that swimming stereotypies still don’t exist). You can’t argue that we’re attempting to keep their wild habitat and behaviors with three shows a day jumping through hoops. I would need to read more on the subject to provide a supported discussion, but that’s my feeling. And that’s the end of that article, I highly recommend reading through it, but be prepared for a grind, it’s a long one.

Article Review: Sources of Stress in Captivity, Part I

I’ve been hanging onto this review of literature for a long time, it’s about 40 pages long, so I’ve slowly gotten about half way through in my spare time. I’ve decided to break down my thoughts into two posts, not only for the length of the article, but so that I don’t have to essentially write an essay all at once.

Most of the article is written from a zoo perspective, but they do take time to review bits of literature pertaining to domestic livestock. One of my favorite things about this article so far is how they chose to define stress and stressors.

“Stress will be defined as the experience of having intrinsic or extrinsic demands that exceed an individual’s resources for responding to those demands.”

“A ‘stressor’ is anything that challenges homeostasis…in this case may be an actual physical challenge to homeostasis (such as exposure to a sudden change in temperature, physical restraint, or combat) or the threat of such a challenge (such as a direct stare from a more dominant individual, or the approach of a human with handling gloves). In either case, stressors result in a cascade of physiological events designed to prepare the body for homeostatic challenge – the so-called ‘fight or flight’ response.”

I immediately read that first definition of stress and said to myself “yes, that’s what it is”. Mostly in terms of whenever I want to define how I feel stressed. But in reality, I was much more impressed with the definition provided because “stress” is such a catch all term for essentially anything wrong with an animal or it’s environment. I remember working at the animal shelter and being told that most of the diarrhea we saw in healthy cats and dogs in the shelter was a result of “stress.” While that may have been true in many cases, the employees, myself included, used the word stress to essentially explain any question proposed by visitors regarding abnormal behavior from the animals. We gave them the assumption that we knew something they didn’t, and usually the issue was dropped. Without a clear definition of what exactly “stress” meant to those shelter animals though, we had no way of asking the important question, what is causing this animal to be stressed?

We never thought, other than taking basic care of these animals to maintain health, hygiene, and human contact; about what we should be doing to keep them mentally sound. With all the behavior and minor health issues we crossed off as stress induced, we never made an attempt to cure that. It’s not that we didn’t care, but in hindsight it’s just something that wasn’t explored or audited. When I think about it now there was probably a lot of little things that we could have been done if we had just asked the question, instead of just assuming that all stress was inevitable.

I bring this up because I’m sure that other organizations, whether they be animal shelters, veterinary clinics, small farms, or large animal production facilities might have that same oversight. Just providing yourself with a concrete, identifiable definition of stress causes you to move onto the next big one, what are the stressors?

So far in the article I’ve read the sections on abiotic stressors, which included lighting, ambient temperature, sound (ranges and pressure), odors, and tactile interaction with the environment. These are actually harder to work with in my opinion, biotic factors are easier for us to understand and study from a physiological standpoint. Figuring out the umwelt of different species is something that Temple Grandin says she does by thinking in pictures, but I think it goes beyond that. The sheer amount of Olfactory cues that we can only observe animal reactions to tell me that the sensory overload our livestock animals receive every day is beyond something as simple as changing the lighting alone. It’s like explaining the instant assailment of information that flows into your mind when you look at a classroom. Or trying to explain how (literate) people can see words on highway signs and with a single look compute the meaning of those specific shapes. How can we get into the head of a cow and understand how that whiff of estrus urine translates into information?

Anyway, some of the bigger problems noted in the article were flicker rates in florescent lighting that animals can see, extremely high sound pressure in zoo and agricultural settings from both machinery and people (that doubles what would be found in a natural setting), and problems associated with the materials used to create habitats or bedding. As a potential start to a solution, at the end of the abiotic section they make recommendations on what sort of equipment (and where to get it) should be used to measure these factors and potential stressors. Identification of what we know is the first step, so that new options and unforeseen stressors become more obvious.

I’ll have much more to say on this article in part II, but I’ll leave these preliminary thoughts for now. Look for more on this from me soon.