Predator Prey Counts in a cardboard
habitat.
A very scientific study of the bakery animal.
text
& photographs by Martha Jordan
Introduction by her dog who's smarter than she is.
I'm a
herding dog. That's what I do. I can herd anything. I can make
little animals do my bidding. I could eat them if I wanted to.
I make them go here and there, squeaking little pinheads that
they are. Why? Because I can herd anything. What? The Bumble
Ball episode? I don't want to talk about that.
Love, Tucker Jordan
decorated by President Bush,
"Take Pride in America" award for volunteer work with
the US Fish and Wildlife Service for... you guessed it. Herding.
(Migratory waterfowl, not Bumble Balls.)
How many times have you passed the cookie aisle at your favorite
grocery and looked down to see the Barnum's Animals Crackers
boxes stacked neatly on the shelf? You probably passed by without
a second thought except nostalgic ones of a glass of milk when
you were a child. Nostalgia aside, I decided that as a wildlife
biologist it was time to give this battered subject its just
due. So, while I started out to do an exhaustive study, I ended
up with a study that I found exhausting. Nonetheless, what follows
are the results of my labors and those of the fortunate people
who brought their own milk, or latte, or tea and sat down to
help me crunch the numbers.
I noted that in each box purchased there were three common
factors:
1) several species of animals of both predator and prey types
were present,
2) some of the animals were whole, others broken and some
animal pieces at the bottom of the box, and
3) no matter how many animals are contained in the habitat,
at some point in time all animals are predated within the habitat.
I began a study of the box habitat phenomenon looking at the
question: What is the predator/prey relationship of animal cookies
in cardboard habitats?
When designing this study I originally had in mind simply
looking at the predator-prey relationship in Barnum's Animal
Crackers (BAC) representing small flocks in boxes. However, on
a visit to Costco I noticed that these animals also came in a
larger, see through plastic habitat Stauffer's Animal Crackers
Originals (SACO) or large herds in bulk containers. It was imperative
that I modify the study to attempt to shed light on the clearly
visible fact that very few animals appeared to be predated within
this large herd. Therefore, I looked at two main questions to
attempt to shed light on this issue:
1) Are prey species more vulnerable to attack in large herds
versus smaller flocks? and
2) Are there other predation factors that are present that
affect either or both of these populations?
Within each habitat type I examined the species diversity,
predator/prey ratio, the type of prey taken and how many predators
were injured.
Two types of BAC small flocks were found- vanilla and chocolate,
likely variants of the same species. There were a variable number
of animals found in the samples of the same habit type, vanilla
20, 26, and 22. The chocolate sample had 17 animals. Each sample
contained 10 different species out of a possible 14 species known
to exist in this habitat type. The species were
1) prey species: kangaroo, monkey, gorilla, giraffe rhinoceros,
hippopotamus, camel, sheep, zebra, buffalo, bear, and
2) predator species: lion, mountain lion, tiger.
In both the vanilla and chocolate races, I found the predator/prey
percent to be 79 percent prey species and 21 percent predators.
This appears to be a healthy balance of more prey species than
predators. However, within these small vanilla flocks there appears
to be a higher proportion of mortality in predators during the
hunt. Between 30 and 45 percent of animals killed were predators
compared to 55 to 73 percent prey species. The chocolate animal
cookies seem to fare better in their box habitat. Of the 17 animals
present, 13 were entire and 4 were predated, 2 prey and 2 predators.
This is 23% predation level compared with the 42-45% predation
level in vanilla animal cookies. The predator/prey ratio of death
was 1:1 in the chocolate variety versus 30 to 45% predators in
the vanilla variety. It appeared that animals were killed but
not eaten since the entire animal could be found, although definitely
not in one piece. It does appear that chocolate predators find
their prey more challenging.
The may be pure speculation but one possibility is that chocolate
cookies can hide more easily (camouflage) in their darkened habitat
and thus escape detection and/or are less prone to attack by
predators due to this night camouflage. This subject may deserve
further research. However, it definitely appears that the act
of observation sheds light on the situation and therefore these
animals become equally subject to predation by other creatures.
In the chocolate's habitat there were no random pieces of carnage.
The SACO herd had 992 animals of 12 species of which 10 were
prey and 2 predator species. The animals found were:
1) prey: hippopotamus, donkey, buffalo, elephant, rhinoceros,
goat, camel, bear, horse and cow, and
2) predator: cat and lion.
It appears that there is less diversity in the larger herd
with the camel at 90 being most abundant animal. Most species
were between 70 and 84 individual animals, the goat being the
exception at 58. Both the lion and cat were abundant with 80
and 70 individuals respectively for a total of 16 percent of
the population. While every species, including the predators
suffered mortality, the horse (12) and elephant (13) were the
most common prey killed. There were 47 prey species, compared
to 7 predator species found dead. This is 5 percent and less
than one percent of the population respectively.
It is known that there is safety in large numbers, or why
would wildebeests form such vast herds on the plains. Therefore,
it seems reasonable that due to the large size of the herd and
the relatively low number of predators in the population that
mortality will be, and is in fact, lower in the large SACO herd
than the BAC flocks.
Active predation among animals
was observed for the first time. I observed, and photographed,
a cat taking a horse and carrying it off (see photo). While I
witnessed several attempts by prey species to attempt escape
by one individual hiding behind another (cookies fused front
to back) and hiding under each other (one on the back of another),
no other acts of actual predation were observed.
Are there other predation factors that are present that affect
either or both of these populations? There appears to be an outside
influence on the predation and eventual extinction of animals
within each of these habitats. During the course of my research
I observed what happens when animals leave their natural habitat
and go exploring. It appears that they are 100 percent predated
either by large bipedal organisms or smaller, four-legged hairy
beasts that dart quickly when they hear one of the cookie animals
drop to the floor due to gravitational forces then go scooting
across the floor in a vain attempt at escape. The bi-pedal predators
are voracious, they are frequently seen putting their appendages
into the habitat and harassing the quarry until it leaves the
area - both predator and prey species are equally vulnerable
to these random attacks. In the smaller flocks all of the animals
will be quickly predated in this manner. The larger herds, likely
due to the numbers of animals, require many such encounters,
but eventually they are all eaten. Perhaps there need to be discussions
with the U.S. Fish and Wildlife Service regarding possible listing
under the Endangered Species Act? At the very least it is more
food for thought.
Biologist
Martha Jordan is a regular contibutor to Get Lost Magazine. She
channels little swans who like to tell whopper tales.
|