Tag Archives: conservation

Pygmy Three-Toed Sloths……


(repost because this is the most common blog to turn up in search engines and my friend just became head vet at DWA)

Isla Escudo is home to this pygmy sloth, one of four species of three-toed sloths. These folivores (suborder: Folivora), also known as Escudo sloths are not only smaller than mainland species, but they are considerably more docile. They are  threatened by the loss of mangrove habitat, and are  consumed by local fisherman. The fisherman will camp out on the island and cut down mangroves for fire. They feed on these xenarthrans when fishing is deemed unsuccessful. By the way, the brown-throated three-toed sloth may still be the only publicly displayed three-toed sloth in the US.  You can see one at the Dallas World Aquarium and Zoo, Texas.  Although sloths are known for their menacing claws I do remember a colleague who was seriously bitten by a two-toed sloth.

Dr. Jordan Schaul, Zoo Keeper Emeritus

Jungle Yellow Fever

I’m scheduled to give a talk to an audience at the Beardsley Zoo in Connecticut next month on topics relevant to ecological health and conservation medicine. These emerging field disciplines are popular right now, just as veterinary epidemiology has become a hot topic among interdisciplinary collection-based research programs.  They are not just popular. These health science disciplines are vital areas for researching the implications of the human-wildlife interface in regions of the world where wildlife coexists closely with human populations.

While perusing wildlife health resources I realized that I missed some recent epizootics or at least notable reports of disease outbreaks in wildlife.  The Wildlife Conservation Society just released some news regarding the cause of a 2007-2008 die-off  among two of the 9 extant species of howler monkeys.  Altogether 59 monkeys in northeastern Argentina succumbed to this arbovirus (arthropod-borne virus) some of which were a subspecies of brown howler monkeys (Alouatta guariba).  Although found in relatively high densities even in fragmented habitat, hunting and disease have impacted otherwise sustainable populations of these large leaf-eating monkeys.

Muller, Frankfurt Zoo

Jungle Yellow Fever refers to the sylvatic or wild life cycle which persists with in New World monkey populations in forest habitat.  The acute viral hemmorhagic disease which has it’s origins in Africa is also now endemic in Latin America. Infected Old World primates are typically asymptomatic, but the virus takes it’s toll on the more susceptible Central and South American primates which have not co-evolved with the disease.  Aedes spp. mosquitoes serve as vectors of this viral pathogen and if they feed on unvaccinated populations of humans, the disease is easily transmitted and may persist in “urban” transmission cycles.

Yellow fever refers to the jaundice that affects some human patients. The disease, if not treated, can be lethal.  As people continue to encroach upon wild lands and deforestation rates increase in tropical regions, the potential for the sylvatic disease transmission cycle to evolve into an intermediate and/or urban transmission cycle becomes increasingly likely.  As people and monkeys increasingly attempt to co-exist, threats to human health from Yellow Fever will persist without the intervention of immunization  and mosquito control programs.   Yellow fever exemplifies a human health risk that can be assessed and addressed though surveillance programs targeted at wild primates.  In this case brown howler monkey populations which are already threatened by human activities serve as indicators of disease outbreaks in areas inhabited by humans.

Some zoos in Latin America, including facilities in Belize warn people not to purchase monkey as pets, mentioning several reasons, one of which is concern over diseases like Yellow Fever.  Yellow fever like all arboviruses is considered a zoonotic disease because the transmission cycle involves   insect vectors and people. However,  no direct transmission occurs between primates and people.

According to ISIS  the only pair of  brown howler monkeys (Alouatta guariba guaribaNorthern Brown Howler) in captivity (on record) are housed at the  Fundacao Zoo-Botan. de Belo Horizonto. I believe the animal photographed above is a red howler monkey.

“We’ll Skip the Small Mammal Building”


Rarely do you hear the zoo visitor soliciting directions to the small mammal exhibits from docents, guest services, or other zoo personnel.  Most people are eager to get right to the big guys.  Guests hastily try to orient themselves with respect to some key locales with the help of the printed zoo maps.  They are challenging for some people to use at first, but they are actually quite useful if you have some patience. Yes, some people are most eager to visit the restroom, the gift shop, or perhaps the restaurant.  Others quickly embark on a journey to see the high-profile species. Among these people some are too excited to fumble with the schematic map and  start following patrons who appear to know where they are going. Although many seek out the quickest route to the mega-fauna on display (e.g., big cats, apes, marine mammals, and elephants, etc.), a few are probably more systematic in their approach to comprehensive zoo animal viewing.

But once the visitors, regardless of their interests or enthusiasm, catch site of the crowds hovering over something seemingly insignificant, their curiosity over rides the impulse to pass up anything of potential interest and temptation leads them to follow others.

BBC News

The most popular exhibits that may serve as the impetus for visiting the zoo in the first place may eventually take a back seat to the lesser known and underappreciated displays of charismatic min-fauna.  By the time you leave the zoo, your party may have all but forgotten the lions and tigers and bears. While reflecting on your zoo visit the interest in mega-fauna is  somehow superseded by discussion of meerkats, and prairie dogs, and naked mole rats.  These semi-fossorial and fossorial species are highly social, perceived as “cute” and their high energy levels make them particularly interesting to watch. Even those distracted by ADHD or cotton candy find these animals to be fascinating. Their impromptu “pop up” performances are riveting.

True fossorial mammals live their entire lives virtually underground, but due to some fantastic exhibit design zoos now offer subterranean viewing of these eusocial, true fossorial mammals.  The African mole rats or blesmols, including the naked mole rat (which is commonly displayed in zoos) use their incisors to dig through soil.  The smallest of  the fossorial rodents may burrow at a rate of 4m/h. This energy expenditure comes at a cost, but indicates just how much energy these animals can expend in a short period of time. To restore energy small mammals are typically voracious eaters and consume a lot of food .

Energy expenditure is determined by body size, climate, and foraging habits.  The physiological parameters considered in the measurement of the metabolic activity and the general energetics of small endotherms (animals that regulate their own body temperature) must be considered when comparing wild animals to zoo animals. Even captive small mammals will be quite active and captivating to watch. The abundance and distribution of food resources in captivity are far different from what is available to wild animals.  This may permit visitors with more of an opportunity to observe a certain spectrum of behaviors.  This is purely speculation.

Without concern for predators or other coteries (harems) of prairie dogs, the behavioral repertoire of captive prairie dogs may differ or be limited compared to wild prairie dogs. None-the-less, their social interactions are most interesting.  I should mention that prairie dogs are very important to prairie ecosystems, and they are actually ground squirrels. They do bark like dogs.

Today prairie dog exhibits allow kids and adults to view these animals under ground and are also designed to simulate fossorial activities.  I first worked with a black-tailed prairie dog enclosure with a bottomless enclosure.  In an effort to deter the animals from burrowing out of the exhibit, I placed long white, plastic tubes above ground to encourage the animals to spend more time at the surface. This alone won’t discourage burrowing activity, but it provides secure above ground retreats.

Black-tailed prairie dogs which one numbered in the billions were candidates for the endangered species list. They are highly susceptible to plague and human activity has heavily fragmented their habitat.  Today they are commonly displayed in zoos. A mentor of mine, Dr. Penny Bernstein began studying black-tailed prairie dog communicative behavior at the Philadelphia Zoo in the 1970′s.  The Philadelphia Zoo continued to study the behavior of these animals as have other living institutions.  More recently, the Denver Zoo has dedicated an entire day to prairie dog awareness.  A good reference for prairie dog information is the following website http://www.prairedogcoalition.org

Dr.  Jordan Schaul, Zoo Keeper Emeritus

The Bear That Could Pace

I recently visited the Large Animal Clinical Science’s web page hosted by the  Western College of Veterinary Medicine (Canada). While scrolling down the page, a link to an applied ethology resource caught my attention.  Behavioral science resources are now more commonly made available for veterinary faculty and students, but often these resources are limited to the discussion of domesticated species. Applied behavior as it relates to exotic, zoo animal, and alternative livestock may be neglected to some degree.  If anything, animal health programs may dedicate more educational resources to the emerging field of behavioral genomics.

As I perused the topics I came across some information concerning the  manifestation of stereotypic behavior in zoo carnivores and primates.  The topic was was addressed in some detail and the information was relatively current.  Nothing  I read would surprise the zoo professional. In general, stereotypies in these taxa have received much attention in zoo science and applied animal welfare publications.   Again, this is pretty common knowledge.  I don’t argue that efforts should be made to mitigate aberrant behavior.  Many investigators have examined the possible etiologies of stereotypic pacing.  Not everyone agrees on what causes it or how to address it.  But it may be just as important to consider how serious these aberrant behaviors are in the context of a larger picture -a more comprehensive evaluation of an individual animal’s quality of life.

At one extreme laboratory animals have exhibited self-mutilation and reduced reproductive success.  However, zoos were the first to examine captivity-induced stereotypic behavior and they were the first living institutions to address this concern.  Enrichment programs have reduced stereotypies in the species that have been the subject of intense study by more than 50%.  Most of these subjects include the intelligent charismatic species such as bears, elephants, and primates.

Zoos, aquariums and marine parks provide quite the hospitable environment for their collection animals.  If we consider the quality of life of captive born and reared animals compared to the challenges facing their wild counterparts, our perspectives and attitudes may change.

Wild animals face  increasingly compromised natural environments as a consequence of habitat encroachment and fragmentation which exacerbate the daily struggles to find food and mates, raise offspring and defend territories. Captivity starts to look pretty good.

I remember that I used to bite my nails before big exams, but no one ever called social services. I don’t dismiss that fact that some captive animals may exhibit aberrant behavior, but I also know that we don’t home school children with restless leg syndrome just because they are known to tap their feet incessantly in school.  They may be more of a distraction to others than a risk to themselves.  We can’t eliminate environmental stressors altogether.

In my opinion zoo life is a pretty good deal.  The arranged marriage issue is the only thing that I would want to negotiate, but I think that animals are much less discriminating in regards to choosing mates. In captivity the  mate selection for both the sire and dam consists of unrelated, well fed, conspecifics in good body condition, not to mention that available partners are most likely to be pathogen free.   In the wild, you’d have to sort through a lot of goldfish before you find some Koi.  In captivity the studbook keeper serves as one heck of a matchmaker.   I digress….

I’ve seen a more than a few bears pace in my time and I’m really quite impressed with the extensive amount of research that has been conducted on stereotypic behavior in an effort to improve the psychological well-being of these animals.  I also remember how often keepers inadvertently may have reinforced this behavior in an attempt to stop it.  I may have done it myself. It’s amazing how an animal may appear to be in a “zone” or stupor as it repetitively follows the same figure eight pattern as part of an apparent  appetitive behavior.  However, they may snap out of it quite readily and come to life, if you will.  They may smell their keeper or see or hear them in front of the exhibit.  I often wondered if this pacing routine was just a ploy to get the attention of a caregiver.  Polar bears may not look like they are always thinking, but I was always thinking they are.

I mentioned behavioral genomics earlier and wanted to direct your attention to the following article:  Genomics Meets Ethology I have been interested in genetic predisposition to communicable pathogen resistance in zoo animal populations, but I also have been very interested in a genetic predisposition to stress tolerance and perhaps aberrant behaviors such as stereotypies.  It may be very controversial to exclude individuals from participation in breeding programs because of pacing behavior or other unwanted behaviors, but it has been looked at with much greater frequency in domestic livestock.

Dr. Jordan Schaul, Zoo Keeper Emeritus

Photo by J.Schaul (http://www.bearkeepers.net)- view with Int. Expl.

Engelbert Humperdinck Supports Same-Sex Marriage in Pelagic Seabirds

Can Animals be Gay? New York Times (April 2, 2010)

It’s truly none of my business whether or not people with different sexual preferences choose to commit to marriage.  In fact, I think that everyone should try it at least once, and some have endeavored to try it many times.  No one cares whether I condone or endorse it, but I do know that the divorce rate among some pelagic seabirds that have entered into committed relations with same-sex partners is particularly low. And yes, biologists do refer to the frequency of break-ups of such unions in the animal kingdom as divorce rates.

Text books have recently broached the subject of same-sex relations in the animal kingdom because it’s much more common than we once thought and evolutionary biologists, and sociobiologists now recognize these relationships as important factors that drive evolution.   Same-sex unions play a role in cooperative breeding strategies, they help mediate intrasexual conflict, and they facilitate social bonding. These partnerships are documented in courtship behavior, pair bonding and copulation in species as wide-ranging as mammals, birds, reptiles, amphibians, and insects. Even one of our closest simian relative, the bonobo or pygmy chimpanzee is known to engage in these kinds of partnerships. Invertebrates such as molluscs and nematodes also participate in such behavior. As a medical zoologist, applied nematology of parasitic species in zoo animals is an interest of mine, but I can’t say that I have observed same sex relations among roundworms that I’m aware of.

The spheniscid penguins at the San Francisco Zoo elicited world-wide attention as have other penguin couples at the Central Park and Bremerhaven zoos .  I don’t know what transpired in Manhattan or in Germany, but partners Harry and Pepper are the two Magellanic penguins at the San Francisco Zoo who were broken up by a female penguin (technically called a hen) by the name of Linda.  Harry and Pepper entered into a romantic relationship in 2003 and spent several years together before splitting up.

Magellanics are spheniscid penguins native to Argentina, Chile and the Falkland Islands. They are closely related to black-footed (jackass) penguins of South Africa and the Humboldt penguins (Peruvian penguins) of the Chilean and Peruvian coastlines.   All three species are common in captivity.  Temperate penguins are not only popular exhibit animals, but anyone who has worked with them can share fond memories of these birds. And many keepers bare the scars of their painful bites as I can.  The spectrum of docility in these captive birds ranges quite a bit.  I don’t want to suggest that these penguins are inherently vicious.  Some are great animal ambassadors and commonly participate in hands-on education programs. Careful monitoring of imprinted animals is always considered.

Only the keepers may be able to provide the intricate social dynamics and genealogy of a particular captive colony.  San Francisco Zoo keeper, Anthony Brown, is quite a knowledgeable and seasoned zoo professional. Perhaps he can share more details and insight into the particular love triangle involving Harry, Pepper and Linda. He could als0 share more about the sociobiology of these temperate penguin species in general. I myself have worked with different penguin species, but among spheniscid birds, I have only been privileged to work with a  colony of 40 black-footed penguins.  I wouldn’t be surprised if we overlooked some of these atypical partnerships in the colony that I worked with.  They were a blast to take care of.  Even if you have a feather phobia I recommend that you find an opportunity to work with these little guys.

Spheniscid penguins may be a bit more promiscuous than Antarctic and sub-Antarctic penguins in captivity and in the wild. I can’t speak to that claim, but they certainly are more liberal in their romantic interests than some pelagic sea birds.  Laysan albatrosses, for instance, live about twice as long as spheniscid penguins and they may remain in monogamous same-sex relationships for their entire lifespan (approx. 60 yrs).   This brings us to crooner, and world- acclaimed recording artist Engelbert Humperdinck. One of his more recent hits Lesbian Seagull became a pop culture sensation.  Nearing 75, the legend also known as the “King of Romance” shared his appreciation for all kinds of romance with this tribute to same-sex partnerships in seagulls.

Dr. Jordan Schaul, Zoo Keeper Emeritus