CAPTIVE BEARS
Knee-Deep in
Bear
Scat
I was
knee-deep in
bear
scat when I first considered the prospects of studying
parasites in bears. I suspect that few people wake up
on a given morning with any ambition of studying the
patterns of
helminth
infections in captive bears. I guess I'm an exception.
I had rotated through various keeper routines at a large
regional zoo while concurrently pursuing a graduate
degree in parasite ecology. I eventually decided to
settle down and work more regularly with bears &
pinnipeds. Some
people can watch apes and elephants all day, but my
favorite charismatic
mega-vertebrates were bears. I was still
conducting research on
helminth
infra-communities of stream fishes and free-living
herpetiles for my
master's degree. However, my intellectual interest in
pathogen-mediated competition in
ectotherms had no
real connection to my career in zoo animal husbandry or
my future interest in the conservation of endangered
mammals. The giant ball of round worms that I
encountered following my first administration of
anti-helminthics to a
parasitized
bear,
served as a pivotal point in my career as a
parasitologist, and
subsequently determined my fate would be in the fields
of parasitology and
scatology. After
completing my master's degree, I decided to revisit
parasitology from a
new perspective. Rather than pursue opportunities to
conduct field studies of
icthyofauna and
herpetofauna, I embraced the emerging field of
captive wildlife
epizootiology and the possibility of improving
the health and welfare of captive animals through the
control and eradication of persistent pathogens. I
simply became passionate about ridding bears of
roundworms. As would
be expected, I never found a great abundance of
endo-parasites in
wildlife, but I was certainly surprised to learn just
how many worms could take up residence in the intestines
of an otherwise "healthy looking" zoo
bear.
Without pharmacological intervention, I learned that
bears could accumulate and harbor lethal quantities of
worms, due to highly contaminated
bear
enclosures.
Hence, my
passion for
bear
conservation and the welfare of these zoo animal
ambassadors, in conjunction with an appreciation
for parasitic and symbiotic
helminth communities
in wildlife, served as the impetus for embarking on an
unusual and unlikely PhD dissertation. After discussion
with zoo clinicians and some cursory investigations of
published work, I was out soliciting zoos for
bear
scat. I was amazed at all the paperwork involved. Sure
I was familiar with permit applications for field work,
but I had no idea that the abundance of
bear
scat that once provided me with great job security,
would become so challenging to obtain.
Although I
currently study parasites in captive and free ranging
bears, 123 zoos have agreed to participate in a study
involving roundworm control. I have not yet examined
the feces of all 450 individual animals, representing
all 8 species of bears, but I do have a lot of scat, as
well as health records and husbandry protocols provided
to me by keepers, curators, and veterinarians from zoos
nearby and on continents far away.
Imperiled
species of mega-predators
may benefit to a great degree from zoo-based
conservation education programs. Captive bears are
ambassadors for their free-ranging counterparts. These
animals can't be released into the wild, but they are of
great value
to conservation educators. Through
their display in naturalistic, mixed species exhibits,
zoos enrich the lives of animals, and subsequently these
animals enrich the experience for the zoo visitor. These
environmentally enriched enclosures elicit natural
behaviors and are designed to display wildlife in
naturalistic settings. The exhibition of bears in zoos
will hopefully engender a respect for our natural
heritage and the very animals we must increasingly learn
to co-exist with. However, with progress comes
compromise. Although the health care and welfare of zoo
animals are top priorities for captive wildlife
managers, there are some drawbacks to displaying captive
wildlife in naturalistic enclosures.
Today's naturalistic exhibits are more
conducive to infectious pathogen survival and
persistence. Older facilities were designed to
facilitate cleaning and enclosure maintenance. Today's
facilities are more "animal friendly," but not
necessarily as "keeper friendly" as facilities of years
past. In many ways we continue to improve animal
welfare. At the same time, we may sacrifice some of the
most basic aspects of animal care and management with
regard to basic husbandry and preventive medicine.
Zoos can not readily sanitize and
disinfect the
"new-age" enclosures with diverse substrates and natural
flora.
The
primary objective of my
helminth
control study is to develop enclosure-specific control
strategies for reducing
bear
roundworms (
Baylisascaris
transfuga)
infections in captive
bear
populations and reducing parasite contamination in their
enclosures. This includes the development of husbandry
protocols for individual facilities. I hope to reduce
the need for frequent
parasiticidal treatment through the
implementation of sanitation and
disinfection
practices which target this particular pathogen.
Hopefully, these efforts will reduce the need to
routinely administer
antihelminthics in captive bears for roundworm
control. Many zoos administer
antihelminthics with
enough frequency to warrant concern for drug resistance
in parasites. Hence, the rotation of antihelminthics
has been implemented in zoo animal preventive medicine
programs much like it has in the livestock industries
for the purposes of discouraging drug resistance in
parasites.
In addition,
bear
roundworms can cause
illness or death in other endangered and threatened zoo
species. Similar to the roundworm of raccoons ( B.
procyonis), the
bear
roundworm has been implicated in larval
migrans syndromes in
non-carnivoran
captive wildlife and could potentially present a public
health concern.
Although B.
transfuga can
threaten the health of captive bears and other wildlife,
there is still a paucity of information regarding the
prevalence, intensity and persistence of B.
transfuga and
effective control strategies in captive
bear
populations. I invite any captive wildlife managers and
field researchers to contact me. I'd love to look at
your
bear
scat!
