Happy Valentine’s Day!
It’s that time of year when everyone is expected to start
thinking flowers, candy, and – above all – romance! Unless, of course, you work in a zoo or
aquarium. If you do, everyday is
Valentine’s Day, and romance is always in the air! (Along with various unique
aromas and the attendant flies)…
It may not seem it at first glance, but zoos are always
concerned about romance – at least among their charges. Romance among the human occupants is
something entirely different (maybe more on that in a later post…). Long gone are the days when zoos filled their
collections by placing orders with Frank Buck, Carl Hagenbeck, and other animal
dealers. To be sure, some animals in zoo
collections do still come from the wild, but fewer and fewer, especially among
the larger mammals. Part of this is the
difficulty in navigating the permit process and international laws. Part of it is a reflection of the fact that
there really isn’t much of a “wild” to pull animals from anymore.
End result: in many cases, if zoos and aquariums want
animals, whether for education programs, exhibition, or future reintroduction
programs, they have to breed them.
So, you take a daddy animal and a mommy animal, put them in
a cage together, give them a chance to know one another, and boom, you get a
baby, right? The stork (conveniently
found in the exhibit next door) pops over with a bundle in its beak. Not quite…
Come to think of it, who brings the storks' baby?
For some species, captive breeding is extremely easy. This is true of domestic animals (they wouldn’t
be domesticated if they were hard to breed).
To a lesser degree, it’s also true many of the large, popular zoo
animals, such as lions, giraffes, and zebras.
I’m pretty sure that I could take a lion and lioness, keep them in the
cramped spare room in my apartment, add food and water, and a few months later
I’d have cubs. For prolific species, the
concern is overpopulation – if everyone bred all the time and pumped out cute
babies for display, we’d quickly have a problem of those cute babies growing up
and having nowhere to place them… which leads to tough decisions that we’d all
rather avoid.
Other species can prove difficult to breed for a variety of
reasons. The first captive birth of a
gorilla occurred in 1956, with Colo at the Columbus Zoo. That year also saw the first captive birth of
cheetahs since the days of the Moghal Empire, when Akbar the Great’s hunting
cheetahs produced a litter (and to be fair, he had 1000 cheetahs… someone was bound to give birth). The Sumatran rhino calf born at the
Cincinnati Zoo in 2001 was the first captive birth in well over a century. But why are these species harder to
breed? A lion is a cat, and a cheetah is
a cat… what’s the difference?
If a species isn’t breeding in captivity, it usually means
that some essential ingredient is missing from the occasion. For clouded leopards, it turned out to be
privacy. Most zoos use to house their big cats
all together in one building. Clouded
leopards turned out to be easily stressed by the presence of bigger, scarier
cats in close quarters and that impaired their breeding. Given quarters removed from the lions and
tigers, with a few other changes (such as taller enclosures – they like to be
up high), breeding success improved.
For flamingos, the opposite proved true. Flamingos in the wild breed in massive flocks
of thousands upon thousands of birds, and it turns out that they are most
likely to breed in large congregations.
The more flamingos a zoo has in its flock, the more likely they are to
breed, with 40 appearing to be the magic number where success becomes most
likely. Can’t accommodate forty
flamingos? Don’t worry – some zoos have
used strategically placed mirrors to trick flamingos into thinking they are
part of a bigger flock.
Tomato frogs take it a step further – scientists at one zoo
found that females are stimulated to release eggs by the jarring of several
males clambering on top of her, trying to push each other out of the way (if
you only have one male, it turns out that you can recreate this affect by
holding the male on top of the female and wiggling him vigorously).
In some animals, reproductive success is triggered by
changes in their environment. Many birds
base their breeding seasons of changes in day length; for these species, zoos
may alter the light cycle with artificial lighting. For reptiles and amphibians, changes in
temperature may be the cue that is missing – many zoos chill their reptiles
prior to breeding.
In some species, the female will mate with any eligible
suitor. In some (like cheetahs), she may
be choosier, and do best when she has a variety of options. In some species, males and females stay
together year round. In others, novelty
is a turn-on, and the pair should only be brought together for breeding, and
then separated again. Absence makes the
heart grow fonder, and all that.
Romance at the zoo isn’t allowed to go rampant and
unchecked. Many species displayed in
zoos are part of Species Survival Programs – carefully managed breeding
programs where matings are planned out to maximize the genetic health and
sustainability of the population. It
sounds better if you try thinking of it as Match.com for rhinos and
pandas.
At present time, there are about a dozen species at my zoo
that we are attempting to breed. They
range from large carnivores to waterfowl.
Some of them will take care of themselves on their own – all I’ll need
to do is keep them fed and happy. Some
might require a little coaxing – putting out nesting material, minimizing
disturbances, upping their diets. Some I’ll
have to wait, either for prospective mates to be introduced peaceably (not easy
with some species), in others for one partner or the other to come of age. Any progress will be duly noted, and husbandry
and routines will be changed based on the outcomes. If there are resultant offspring, there will
be more changes still.
Keeping track of it all is a job in itself. No way that we could do it all just on one
day in February. I guess it’s a good
thing that for a zookeeper, everyday is Valentine’s Day!
PS: Want to learn more? Many zoos host "Sex at the Zoo" (not as naughty as it sounds) programs around this time of year. Check and see if your local zoo has one!
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