Herbivores, Carnivores &
Constrictor Jaws – Teacher Notes
VCE Biology Unit 1:
Unity and Diversity
Area of Study 2:
Functioning Organisms
Werribee
Open Range Zoo
PO Box 460
Werribee
Victoria 3030
Australia
T 61 3 9731 9601
F 61 3 9731 9644
zoo.org.au/learning
Introduction
Herbivores, Carnivores and Constrictor Jaws is designed to meet the requirements of the Schoolassessed Coursework (SAC) component for Outcome 2 (practical activity). It addresses the key
knowledge and skills related to VCE Biology Unit One, with particular emphasis on the diet, dentition
and digestion of animals.
Aims
This program aims to:
• investigate the common requirements of herbivores, omnivores and carnivores
• examine the relationship between diet, dentition, hunting/foraging behaviour, body structure
and habitat
• observe, identify and describe the adaptations in specific animals for obtaining and processing
nutrients and removing wastes
• compare and classify animals based on their diet and how they process nutrients
• develop some of the skills required when investigating living organisms and in collecting,
analysing and presenting data.
At the Zoo
Herbivores, Carnivores and Constrictor Jaws consists of a guided safari tour, a Discovery Session
with an Education Officer and a self guided walk around the African Walking Trail. Allow
approximately 4 hours for your visit to Werribee Open Range Zoo.
The safari tour allows students to make observations and gain knowledge of the structural and
behavioural adaptations of a variety of herbivores. The Discovery Session involves observation of
structural, behavioural and physiological adaptations of herbviores, carnivores and omnivores
through the interaction with various animals and examination of skulls and scats.
The first-hand data collected by students may be used to complete an assessment task in the form
of a practical activity or research report.
NB. It is suggested that students work in groups of two on the Safari Tour to ensure an
effective observation and recording of behavioural and structural adaptations.
Planning your visit
The Student Trail are available at
www.zoo.org.au/Learning/Programs/VCE/Werribee/Herbivores_Carnivores. We ask teachers to
please download and print the Student Trail for students to complete whilst at the Zoo.
Prior to the visit a Zoo Education Officer will contact the organising teacher to discuss the
particular requirements of the session. It is beneficial that students have some background
information on diet and digestion prior to the Zoo visit, however it is not essential.
Check out what you can do to Fight Extinction at Act Wild www.actwild.org.au
Herbivores, Carnivores and Constrictor Jaws Teacher notes
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Answers to student trail
The Discovery Session
Skull Analysis
1.
By analysing skulls we can learn about an animal’s way of life. Observe the skulls provided
and circle the most correct response in the table below:
The skulls of various animals will be observed with a Zoo Educator. General information about the
skull morphology typical of herbivores, carnivores and omnivores is listed below:
Table 1:
Diet group:
Dentition:
Mandible
(lower jaw)
length:
Carnivore
Incisors needed
for stripping the
flesh from
carcasses. All
carnivores,
except Sloth
Bears have 6
upper and lower
incisors. Molars
modified to sharp
teeth
(Carnassial
teeth), which
slice off meat.
Food is
swallowed
without chewing.
Canines for
gripping and
puncturing prey.
Exclusive meat
eaters tend to
have a shorter
mandible.
Diastema:
The gap
between the
incisors and
molars.
May be present
to accommodate
large canines.
Eye
position:
Forward facing to
enable accurate
detection of
location and
distance away
from prey.
Saggital
crest:
A ridge
extending
Present in
carnivores.
Strong muscles
needed for biting
Herbivore
High number of
molars, ridged for
chewing herbage.
Incisors usually
present, however
members of the
Order Artiodactyla
have no upper
incisors, instead a
bony plate is used
for tearing off the
grasses. If canines
are present they
may be modified as
incisors or retained
for fighting.
Omnivore
Low crowned
molars. Incisors
and canines
present. Incisors
are used for
tearing off food
and may be used
for grooming in
animals such as
primates.
Long deep
mandible needed
for large muscle
attachment.
Necessary for
chewing large
amounts of
herbage.
Present in
herbivores. It is the
gap between the
incisors and
molars. Needed to
move around large
quantities of food to
enable easier
mastication.
Usually high on the
head and located
to the side. Give a
broad view while
feeding, enabling
the animal to look
out for predators.
Usually not
pronounced.
However if
pronounced may
Relatively short
mandible
compared to a
herbivore.
Usually not
present.
Usually forward
facing.
Pronounced in
some omnivores,
eg. Baboons,
particularly the
Herbivores, Carnivores and Constrictor Jaws Teacher notes
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along the
skull. It is a
site for
muscle
attachment.
down on prey.
indicate the animal
uses a forceful bite
to obtain food or as
a form of
aggression.
Zygomatic
Arch:
The arch of
bone beneath
the eye
sometimes
referred to as
the “cheek”
bone.
Name of
Animal:
Strong and wide
for the
attachment of
large muscles. It
gives the jaw
power needed to
bite down on
prey.
Strong and wide to
accommodate
large jaw muscles
needed for regular
chewing of
herbage.
males. A strong
muscle
attachment is
needed for a
powerful jaw. The
jaw may
sometimes be
used for
aggression rather
than catching
prey.
Will vary
according to diet.
A diet of soft food
will not need a
strong zygomatic
arch, however a
diet of tougher
foods will.
Rodent Skull
incisors
diastema
zygomatic arch
molars
mandible
2.
After completing the skull analysis above explain how we can determine an animal’s diet
by examining the structure of its skull and teeth.
By examining skull structure we can look at sites of muscle attachment which can give us
information about the type of food an animal may eat and its way of life. Teeth structure will also
give us this information.
Refer to the table above for structures typical of animals from each of the main dietary groups.
Herbivores, Carnivores and Constrictor Jaws Teacher notes
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Scats
3. Observe the scats provided.
a. Draw and describe the scats of different animals.
b. Table 2:
Sample
Observations, e.g. size, particles
present
Dietary group, e.g.
carnivore, herbivore,
ruminant, etc.
Herbivore
Ruminant
Giraffe
Herbivore
Non-ruminant
Zebra
Carnivore scats may contain evidence of bones, feathers and fur.
Omnivore scats may also include animal remains as well as digested plant material.
Non-ruminant scats contain a large proportion of undigested plant material.
Ruminant scats may display some evidence of plant material but will mainly consist of well
digested plant material.
c.
What can you learn about animals by looking at their scats?
A range of factors can be learnt from examining scats such as the food preferences of the animal,
food availability, predatory behaviour, the range of its territory, water availability, health, and the
variety of plants and animals that exist within its habitat.
Safari Tour
The Escarpment: Broad Observations
4.
Select a herd of animals for observation.
a.
How many individuals are in the group?
b.
Estimate how many of these individuals are feeding at the one time.
It would be unusual to observe all the members of a herd feeding at once. Some may feed while
others are looking out for any threats.
To complete questions 5-15 you are required to select an individual animal to observe which is
grazing within a group.
Herbivores, Carnivores and Constrictor Jaws Teacher notes
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Feeding
5.
Describe how the grass is cropped by the animal (where possible, describe the action of the
jaw, lips, tongue and teeth).
Depending on the species observed, the method of cropping
will vary:
-Zebras have a mobile upper lip, which they use to gather a
tuft of grass before biting it off with a scissor-like action
between their upper and lower incisors.
-White Rhinoceros crop the grass by gripping and tearing it
with their broad lips. They do not have upper or lower
incisors.
-Giraffe have a diet predominantly of leaves of acacia trees
and bushes. Their selective and dexterous tongues (up to
30cm in length) are used to hold small twigs and to strip
them of leaves. Giraffes have incisors on the lower jaw only.
6.
Explain how the head structure of the animal you are observing is suited to a herbivorous diet.
Students should describe the long and relatively large muzzle common to the herbivores on the
plain. The herbage consumed by herbivores is of low digestibility and low energy value compared
with meat and fruit. This means that herbivores must eat proportionately greater volumes of food to
sustain themselves than do other non-herbivorous animals. This necessitates the animal will
spending a large proportion of its daily routine engaged in the eating (and digestion) of food. A
large jaw can accommodate many teeth required for chewing. Herbage is difficult to chew and so
strong muscles are required to cope with many hours of daily chewing. The teeth wear down over
the life of the animal. Such teeth (and muscles) can be accommodated in a large jaw.
The jaw is muscled and articulated so it is able to move in a sweeping, grinding motion. Students
may see the giraffes chewing without having recently ingested any food. These animals are
ruminants, and chew their food twice. Refer to the Teacher Resource material
www.zoo.org.au/Learning/Programs/VCE/Werribee/Herbivores_Carnivores
Body Structure
7. Draw a rough sketch showing the body proportions of your selected animal.
8.
How does the size of the abdomen of the animal you have selected to observe compare with
other animals you have seen today?
Herbivores can be characterised generally as having large
abdomens. Of course there is much variation between
herbivore species.
The digestibility and energy content of grass and leaves are
relatively low; therefore large volumes of food and a large
digestive system are required for the animal to obtain
adequate nutrition.
9.
After listening to your guide and making your own observations describe how the body
proportions of young animals differ from those of older animals.
Herbivores, Carnivores and Constrictor Jaws Teacher notes
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The body proportions of younger animals generally vary from those of adults in that leg length is
relatively longer in the young. This is especially true for animals such as zebras, where leg length
in juveniles is almost the same as in adults.
The initial diet of young animals is milk, which is easily digested, obviating the need for a large
abdomen. Predators are especially dangerous for young animals. In animals such as zebras,
fleeing is their best defence and for this, long legs are important. Young rhinos have body
proportions similar to those of an adult.
10.
Suggest for what purpose the animal’s tail is used.
Tails are important fly swats - with large quantities of dung produced, it is very important that the
animal avoid fly infestation (‘fly blow’) which can be fatal in severe cases. The base of the tail
protects the soft tissue of the vulva (in females) and the anus from sunburn and skin cancers. The
tail may also be used as a signaling device for danger, sexual receptiveness, a sign of dominance
or for other communication within the group.
11.
How many toes does the animal have on each foot?
The number of toes on herbivores is important to the study of the evolution of herbivore species.
Refer to the Teacher Resource material at
www.zoo.org.au/Learning/Programs/VCE/Werribee/Herbivores_Carnivores for the number of toes
present on various animals.
12.
Is this animal a ruminant or non-ruminant? Provide a reason to support your answer.
Refer to the Teacher Resource Material for information on the ruminants and non-ruminants.
13. Draw a profile of the head of the animal you have been observing, marking in mouth, eye and ear
positions.
14.
Suggest how the relative positions of the mouth, eyes and ears may help the animal to avoid
predation.
The relative positions of mouth, ears and eyes on the herbivore’s head are significant in that they
allow the animal to maximise vigilance for predators whilst feeding. When the animal is feeding,
the eyes are high off the ground and, being located to the side of the head, allow the grazing
animal to maintain a broad view of the surrounding terrain. The ears are independently mobile,
allowing sounds to be detected through 360 degrees.
The rhinoceros’ large size is usually an effective deterrent to predators although there are many
documented cases of lions killing an individual. These animals are most susceptible in young and
old age, and when injured. Mothers fiercely protect young rhinos. The physique of a young
rhinoceros make escape by fleeing practically impossible. Pairs of rhinos at Werribee Open Range
Zoo have been observed sitting near each other facing in opposite directions. This may be a
defensive behaviour.
15.
Which other structural and behavioural features does the animal have to help it avoid
predation?
Animals such as the giraffe are usually safe from predators due to their size, but they are
vulnerable when bending down to drink, or to browse on low bushes. At such times lions are able
to seize the giraffe’s neck and topple the animal. Group cooperation in avoidance of predators is
important. Not all individuals are grazing at the one time, so there are eyes alert to danger at all
times. Warning sounds are made when a predator is sighted (or smelt, or heard) to which the herd
immediately responds by raising their heads and being prepared to take flight.
Herbivores, Carnivores and Constrictor Jaws Teacher notes
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African Walking Trail (self guided)
Lion (Panthera leo)
16.
How do lions detect their prey?
Forward facing eyes, mobile ears and wet nose are used to detect prey animals.
17.
Spend a few minutes observing the lions. Describe their behaviour.
Lions spend about 20 hours a day resting.
18.
Suggest a hypothesis to explain why lions spend so much time being inactive.
Possible hypotheses might include lions rest for long periods:
-in order to conserve energy for the effort required to catch and kill prey
-because there is no available food in their exhibit
-because a long time is required to digest their food.
Discuss the feasibility of each of these.
Cheetah (Acinonyx jubatus)
19. Observe the Cheetah closely. On the diagram below label, with a brief description, the structural
adaptations it has that would be considered an advantage for capturing prey.
20. Once a Cheetah has made a kill, hyenas and lions move in very quickly to take over the food.
Suggest some strategies the Cheetah may use to maximise the amount of meat it consumes
before it is taken over by a scavenger:
- devour large quantities of food within a short period of time
- drag food under cover
- swallow food without chewing it.
21. Zebras may spend up to 60% of their day grazing on food, while Cheetahs may not eat anything
all day. Explain why there is such a large difference between the amount of time these animals
spend eating.
Grass contains less energy than meat; therefore zebras need
to spend a lot more time eating to obtain their energy
requirements.
Herbivores, Carnivores and Constrictor Jaws Teacher notes
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Meerkat (Suricata suricatta)
The diet of the Meerkat consists of buried invertebrates such as beetle larvae, crickets, scorpions;
and small vertebrates such as snakes, birds and mice. Its water requirements are obtained by
eating melons, roots and tubers.
22. Spend some time observing the Meerkats. On the diagram below label, with a brief description,
the structural adaptations that may enable the Meerkat to find and capture prey.
23. The main predators of the Meerkat are hawks and eagles. How does their behaviour help them to
avoid being preyed upon by these animals?
- males take it in turns to keep a look out for predators. They give an alarm call when they spot a
predator
- stand on their hind legs to locate danger
- run into burrows when threatened.
Conclusions
24. Compare ruminants and non ruminants by completing the table below:
Table 3:
Comparative amounts
Time spent eating:
Nutrition derived from
herbage eaten:
Time take to digest herbage:
Quality of herbage digested:
Location of microbes in
digestive system needed to
break down cellulose:
Consumption of water:
Cud chewing:
Examples:
Ruminants
high / low
high / low
Non ruminants
high / low
high / low
large / small
high / low
foregut / hindgut
large / small
high / low
foregut / hindgut
high / low
present / absent
bison / giraffe / rhinoceros /
deer /antelope / zebra / camel
/ hippopotamus
high / low
present / absent
bison / giraffe / rhinoceros /
deer /antelope / zebra / camel
/ hippopotamus
Herbivores, Carnivores and Constrictor Jaws Teacher notes
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25a. The skulls and digestive systems below are representative of a carnivore, omnivore
and two types of herbivore; ruminant and non-ruminant. Draw a line to match the skulls
with the digestive systems.
Skull
Digestive System
A
1
B
2
C
3
D
4
25b. The skulls and digestive systems above belong to the zebra, giraffe, chimpanzee and cheetah.
Label the skulls and digestive systems you have matched together with each of these animal names.
Give reasons for your choices.
A2 Cheetah. The cheetah is a carnivore. The skull clearly shows the canines and carnassial teeth
typical of a carnivore. The digestive system is relatively short in comparison to the other digestive
systems as meat is easier to digest than plant material.
B3 Zebra. The zebra is a non-ruminant herbivore. The skull has a large number of molars and a
diastema common to herbivores. It also has upper and lower incisors typical of a hindgut
fermenter.The digestive system is long, needed to digest the large amounts of plant material ingested.
It has a large caecum which holds the bacteria which play an important role in the fermentation of
plant material.
C4 Chimpanzee. The chimpanzee is an omnivore. The skull has the molars, canines and incisors
typical of an omnivore. It has a relatively short digestive system compared to the herbivores, but
longer than a carnivore. It also has an appendix commonly found in apes.
D1 Giraffe. The giraffe is a ruminant herbivore. The skull has the large number of molars and
diastema typical to a herbivore. It is also lacking in upper incisors, a characteristic of ruminants. The
digestive system is long to assist with the digestion of plant material. It also has a 4 chambered
stomach found in ruminants.
Herbivores, Carnivores and Constrictor Jaws Teacher notes
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26. Identify and describe the role of the different kinds of vertebrate teeth.
27. Use specific examples to compare the digestive systems of :
a.
Ruminant and non-ruminant.
b.
Herbivore and Carnivore.
28.
Refer to two selected examples you observed today to explain how structural adaptations
related to acquiring and processing food assist an animal’s chances of survival. Include one example
of an herbivore and one example of a carnivore.
Conservation Action - Beads for Wildlife (Additional activity)
29. What impact would the introduction of domestic animals (such as Cattle and Goats) have on the
wild populations of Zebras and Lions of the Melako Conservancy in Northern Kenya?
Cattle and Goats compete for food and water with grazing Grevy’s Zebra – the larger the
number in the herd the greater the challenge for the zebra to access sufficient food close to a
water source. The Maasai herdsmen hold their wealth in cattle, thus the more cattle are owned
the richer the herdsman is considered to be. Should a Lion kill a cow, the herdsmen retaliate
by killing the Lion in order to protect the stock and their wealth. The cattle is also a food source
for the Maasai and less cattle becomes a food security issue.
30. Rank the following animals from 1 to 10 in order of importance to the Maasai people of Melako.
Your ranking should consider 1 being the most important to 10 the least important. Suggest why.
4
9
6
7
8
2
10
1
3
5
Elephant
Lion
Zebra
Rabbit
Bee
Cow
Baboon
Chicken
Giraffe
Camel
- good for tourism
- dangerous
- harmless and good for tourism
- food (meat)
- honey
- food (meat, milk, blood)
- cheeky
- food (meat and eggs)
- good for tourism
- transport, drought tolerant, food (meat and milk)
31. How can African Bead work help preserve the Endangered Grevy’s Zebra of Melako?
Zoos Victoria is committed to saving the Endangered Grevy’s Zebra from extinction with the help of
the Northern Rangelands Trust and the Grevy’s Zebra Trust in Northern Kenya.
Through purchasing African beadwork from the women of Melako the number of cattle required by the
Massai has dropped. This additional income has meant more children have had an opportunity to go
to school and vegetables have been able to be purchased at market improving local diets. Less cattle
and goats owned by the Maasai has meant less competition for food and water for the Grevy’s Zebra
and less predation by lions on domestic stock.
32. What can you do to help Zoos Victoria and Grevy’s Zebra?
By purchasing beadwork from the Safari Shop you not only have a souvenir of your day at Werribee
Open Range Zoo you are helping to save a species.
You can also create a Mash-Up on the ActWild website to tell your friends and family about the Beads
for Wildlife community conservation campaign. Visit www.actwild.org.au
Herbivores, Carnivores and Constrictor Jaws Teacher notes
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Glossary
Adaptation:
A feature that an organism has to help it to survive, it may be structural,
behavioural or physiological.
Canines:
The pointed conical teeth located between the incisors and the first molars.
Carnassial teeth:
Molars that are modified to have sharp edges for cutting flesh. Found in
carnivores.
Carnivore:
An animal that eats meat.
Dentition:
The type, number, and arrangement of a set of teeth.
Herbivore:
An animal that eats plants.
Incisor:
A tooth adapted for cutting or gnawing, located at the front of the mouth.
Molar:
A tooth with a broad crown used to grind food.
Non-ruminant:
Odd toed ungulates of the Order Perissodactyla. One chamber stomach.
Includes horses, zebras and rhinoceros.
Omnivore:
An animal that eats both meat and plants.
Pre-molars:
The teeth that occur on either side of the upper and lower jaw, behind the
canines(in the case off carnivores) or in front of the incisors and in front of the
molars.
Ruminant:
Even toed ungulates of the Order Artiodactyla. The stomach is divided into
four components. Partially digested food is regurgitated and chewed again
(chewing the cud). Includes cattle, deer, antelope, giraffe.
Scat:
Faeces.
Ungulate:
A hoofed animal.
Herbivores, Carnivores and Constrictor Jaws Teacher notes
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