Maintaining
a Balance
Biology – Stage 6
Zoo Education is a
partnership between:
© Taronga Zoo Education Centre 2011
These sheets may be reproduced for
teaching purposes. Permission to reproduce
them for other purposes may be obtained
from Taronga Zoo Education Centre.
1
Maintaining a Balance
Zoo
Education
This resource is to be used as part of an excursion to Taronga Zoo. The
resource and related workshop is linked to the NSW School Curriculum and has
been developed in consultation with Department of Education and Training
Curriculum Coordinators and NSW School Teachers. It is a comprehensive kit of
information and activities designed to ensure maximum benefit to you during
your excursion to Taronga Zoo.
Contents
Introduction
3
NSW School Curriculum Links
3
Excursion Options
4
Prior Knowledge and Experience
4
Pre-visit Activities
5
At the Zoo
6
Taronga Zoo – Stage 6 Education Resource
2
NSW School Curriculum Links
Stage 6 Biology
9.2 Maintaining a Balance
Taronga Zoo exhibits a range of animals which will enable students to develop
an excellent understanding of the adaptations animals have to maintain a
balance within the narrow limits for survival.
The activities detailed in this resource address the following syllabus related
topics:
•
Compare responses of named Australian ectothermic and endothermic
organisms to changes in the ambient temperature and explain how these
responses assist temperature regulation.
•
Analyse information from secondary sources to describe adaptations and
responses that have occurred in Australian organisms to assist temperature
regulation.
•
Analyse information from secondary sources to compare and explain the
differences in urine concentration of terrestrial animals, marine fish and
freshwater fish.
•
Use available evidence to explain the relationship between the conservation
of water and the production and excretion of concentrated nitrogenous
wastes in a range of Australian insects and terrestrial mammals.
The ‘Maintaining a Balance’ excursion to Taronga Zoo also provides students
opportunities to further develop skills in communicating information and
understanding, scientific thinking, problem solving and working individually and in
teams.
3
Excursion Options
Option One
-
Students present pre-prepared talks in groups to the class using an
animal and its exhibit as a visual aide
Students take notes on provided worksheets
Zoo Educator provides extra information and or clarification
Hands on encounters with animals
Student worksheet trail in Zoo grounds
Option Two
-
Zoo Educator presents information
Students take notes on provided worksheets
Hands on encounters with animals
Student worksheet trail in Zoo grounds
Prior Knowledge and Understanding
It would be most beneficial if students had the following prior knowledge and
understanding before their visit to the Zoo.
-
the maintainence of a constant internal environment is important for
optimal metabolic efficiency
homeostasis
endothermic and ectothermic
the process of diffusion and osmosis
passive and active transport
the role of the kidney
the processes of filtration and reabsorption in the mammalian nephron
4
Pre-visit Activity
If your class chooses Excursion Option One – ‘Student Presentations’, the
following activity must be completed before the students visit Taronga Zoo on
their excursion.
Pre-Zoo research task
During the lesson on your Taronga Zoo excursion day, your students (in groups)
will be asked to present information to the rest of their class. It is essential that
the groups come prepared with their presentation.
Divide the class into 5 groups and assign each group one of the following
animals:
- Green Tree Frog
- Short-beaked Echidna
- Shingleback Lizard
- Red Kangaroo
- Saltwater Crocodile
Groups of students are to prepare a talk (duration 5 mins), describing the
adaptations or responses of their given animal that assist with temperature
regulation and water conservation.
Things to consider:
-
-
-
the talk will be presented with the actual animal in view, so reference to
the animal, its surroundings, enclosure provisions and its behaviour must
be made. Some of this cannot be pre-prepared (eg. behaviour of animal,
features of exhibit).
Time will be given before the presentation to study the animal’s enclosure
and surroundings in order collect ‘evidence’ to support the information
being provided, eg. find kangaroo faeces, shade structures, interpret the
animal’s behaviour.
Further information and discussion will be provided by the Zoo Educator
after each presentation.
5
At the Zoo
There are two options available for this excursion:
1. Student Presentations
2. Lesson with Zoo Educator
Both options are approx 60 minutes duration and include animal encounters.
(see page 4 for details on these options)
Seal Presentation
Seals are exceptional thermoregulators, needing to cope with temperature
extremes both in water and on land. Watching this special presentation will
provide students with an excellent opportunity to extract information about seal
thermoregulation from expert marine mammal keepers.
A notes page is provided for students at the back of this rescource.
Presentation time: This presentation is subject to staff availablity. Please
contact Taronga Zoo’s Education Centre to confirm.
Excursion Worksheets
Copy the following worksheets for your students to complete in their free time at
the Zoo. The questioning is designed to have students apply their knowledge of
thermoregulation and water balance from a captive husbandry point of view.
Students will also be challenged on their ethical attitudes towards keeping
animals in captivity.
6
Koala
Provide possible explanations for the koala facts given below in relation to
thermoregulation and/or water balance.
Core temperature - 35-36Cº.
Brain size – 0.2% of body weight
Koala is an Aboriginal word
meaning ‘no drink’
.………………………………………
……………………………………….
Water intake – 400ml per day
Activity – nocturnal, sleeps 18hrs per day
…………………………………..
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No sweat glands, do not pant
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Back fur – very high insulation
Chest fur- low insulation
………………………………………
Posture – temperature dependant
……………………………………….
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Faeces – dry pellets
Urine – highly concentrated urea
……………………………………………
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Describe features of the exhibit that assist in the thermoregulation of the koala.
………………………………………………………………………………………………
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Suggest what Zookeepers could do to avoid heat stress in koalas on a 40Cº day.
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7
Corroboree Frog
Fertilised eggs rapidly enlarge
as they fill with water
……………………………………
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Lays eggs in sphagnum moss
…………………………………………
Changes posture when basking
……………………………………
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Uric acid is stored when the frog is
out of water
…………………………………………
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Tadpoles hatch in winter, already with hind
legs and without gills
……………………………………………………
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Tadpole growth-rate slows over winter months
……………………………………………………
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The Corroboree Frog exhibit is kept at a temperature of 5Cº. These tiny frogs
can survive comfortably in temperatures ranging from 0Cº to 30Cº. Suggest a
reason for the deliberate lowering of the temperature of the frogs’ surroundings.
………………………………………………………………………………………………
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8
Black-headed Python
Head section is black
……………………………………………………
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Found in arid conditions
Incubation - coil around eggs and ‘shiver’
…………………………………………………
………………………………………….........
Feeding – greatly reduced in cooler
months
………………………………
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Behaviour - nocturnal in warm weather,
diurnal in cold weather
…………………………………………………
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Basking behaviour
………………………………………………………………
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Lacks sensory heat pits for detecting
endothermic prey
…………………………………………………
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Skin is impermeable
…………………………………………………
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Many snakes are ambush predators, spending up to 3 weeks lying motionless to
fool potential prey into approaching. Give an explaination as to how a snake can
do this yet also thermoregulate so that their body temp is high enough to digest
prey.
………………………………………………………………………………………………
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Some Australian snakes give birth to live young (the eggs hatch before they
young emerge). Hypothesize why this may be an adaptation to cope with cold
temperatures.
9
Asian Elephant
Ear flapping – blood temp drops over
8Cº as it passes through the ears
………………………………
………………………………
Throat pouch – contains stored
water which can be drawn out
by trunk
………………………
………………………
Core temperature - 36-37Cº
Skin surface area is twice as
large as needed
……………………
……………………
250 litres of water consumed
daily
………………………
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Skin – 3cm thick on legs and back, paper
thin on chest and abdomen
…………………………………
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Dust bathing behaviour
………………………
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Sweat glands only found between
toes
……………………………
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An elephant weighing 2000000g has a skin surface of roughly 100000 cm².
A rat weighing 300g has a body surface of 300 cm².
Compare the surface area to volume ratios of these two mammals.
………………………………………………………………………………………………
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Make a general statement comparing the ability of large and small animals to
give up their heat?
………………………………………………………………………………………………
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Use this information to postulate what would happen if elephants did have sweat
glands all over their body rather than large ears.
………………………………………………………………………………………………
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10
Andean Condor
Birds do not sweat
Spreads wings in morning
Body temperature drops by several degrees overnight
…………………………………………………………
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Fluff feathers when cold, smooth
feathers when hot
Many folds of bare skin on head
…………………………………………
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Retracts bare head into tuft of neck feathers when flying
at high altitudes
………………………………………………………………
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Defecates on legs in hot weather
……………………………………………………………………
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Countercurrent heat exchange in feet
………………………………………………………………
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When an Andean Condor drops down to ground for feeding its body may
experience a temperature shift from l2Cº to 40Cº. How do you think Andean
Condors cope with this extreme?
………………………………………………………………………………………………
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11
Maintaining a Balance
Zoo
Education
Snow Leopard
Sheds coat annually
Temperature - can tolerate 50 Cº
below zero
…………………………………………
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Altitude – 1500 - 5000 m
…………………………………………
Fur on body – 5cm long
Fur on tail – 8cm long
…………………………………………………
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Small ears
………………………………………………
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Enlarged upper nasal chamber
and sinuses
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Tail – 1 m long
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Fur covered toe pads
…………………………………………………………………
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Observe the Snow Leopards and note any thermoregulatory behaviour.
………………………………………………………………………………………………
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What features of the Snow Leopard exhibit are designed to reduce the incidence
of heat stress.
………………………………………………………………………………………………
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How might these Snow Leopards cope (in terms of thermoregulation) if they were
removed from the Zoo and placed in the Himalayas tomorrow?
………………………………………………………………………………………………
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12
Maintaining a Balance
Zoo
Education
A long way from home
Locate a Zoo animal that is originally from a location/climate markedly different to
the climate and conditions found in Sydney.
1. Draw the animal in
its exhibit.
2. Label the animal with
possible responses the
animal may have had in
order to cope with its
new environment.
3. Label the features of
the exhibit that have
attempted to assist the
animal’s ability to cope in
its new environment.
Do you feel the animal is suitable for Sydney’s Taronga Zoo? Explain.
………………………………………………………………………………………………
………………………………………………………………………………………………
Find out why the animal is part of the Zoo collection.
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13
Maintaining a Balance
Zoo
Education
Seal Presentation Notes
14
Maintaining a Balance
Zoo
Education
Short-beaked Echidna
15
Maintaining a Balance
Zoo
Education
Red Kangaroo
16
Maintaining a Balance
Zoo
Education
Green Tree Frog
17
Maintaining a Balance
Zoo
Education
Shingleback Lizard
18
Maintaining a Balance
Zoo
Education
Saltwater Crocodile
19