Life Cycles Teacher Resource Booklet 3

LIFE CYCLES TEACHER RESOURCE BOOKLET

THIS BOOKLET COMPLEMENTS THE LIFE CYCLES KIT WHICH CAN BE BORROWED FROM QUEENSLAND MUSUEM LOANS. Phone (07) 3406 8344 or http://www.qm.qld.gov.au/education/loans

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Teacher Notes LIFE CYCLES

Overview

This QM Loans kit investigates the different reproductive processes and life cycles in some animals. It examines abrupt and gradual metamorphosis. Information on insect, fish, reptile, bird, and marsupial life cycles is explored. Students investigate adaptations, and the relationship between living things and their environment.

Resources:

Australian Science Curriculum:

Science Understanding – Year 3 - Life Cycles

Life cycles and reproductive processes of animals.

Science Understanding – Year 7 – Growth and Reproduction

Structures and processes involved with animal growth and reproduction.

Content Elaborations:

Life cycles – observing living things as they develop through their lifecycles; raising silkworms to moths and grubs to beetles; caterpillar to butterfly; tadpole to frog.

Growth and Reproduction – different stages of growth such as changes in size; metamorphosis; larva-pupa-nymph stages; structural changes, maturation, caring for young.

Science Inquiry Skills – Year 3 Students

• make predictions to be tested

• collaboratively plan and conduct investigations

• test simple cause-effect relationships

• identify elements of a fair test

Year 7

• design fair tests identifying variables to be changed and to be measured

• collect and organise data, information and evidence

• draw conclusions that are supported by evidence

• identify and use safe practices

Science as a Human Endeavour

Science and Culture – Year 3 Students

• research or interview to understand Aboriginal or Torres Strait Islander peoples’ knowledge of the local natural environment. e.g. knowledge of the characteristics and life cycles of local animals

Engage:

1. What do we mean by the term ‘life cycle’?

2. Think of some animals that go through different stages in their life cycle? The stages may not look like the adult stage. Give examples and name any stages in their life cycle.

3. What do you think are some of the factors that influence how quickly these animals go through these phases? i.e. would life cycles always take the same time from egg to adult?

4. Why do you think animals have these stages in their life cycle?

Specimens:

Butterfly: Life Cycle + box Frog: Metamorphosis + box Grasshopper/Locust: Life cycle stages Bird, nest & egg Possum - Ringtail, study skin Shark: Egg Case Stromb: juvenile & adult Turtle of python eggs

Model:

Possum – Ringtail, pouch young

Cards:

9 descriptor cards

Books:

The Life Cycle of the Monarch Butterfly

Panels:

Birdwing Butterflies: Fact Sheet Giant Wood Moth and Witchetty Grubs: Fact Sheet Stick Insects: Fact Sheet

Posters

Butterflies Frogs: Amphibious Vertebrates

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Explore:

In the loans kit there are several animals with varied life cycles.

Activities:

1. Firstly, raise your own animals to observe so that you can see the changes they go through in their life cycle. i.e. construct and leave out the Fly Trap; collect some frog’s eggs from a supplier such as The Frog Society, or a local pond. (It is important that you return the adult frogs to the habitat from which they came.) How will you look after your tadpoles responsibly and ethically?

2. Work through each of the cards that go with the objects in the kit. Organise your data by creating a flow chart showing the stages in the life cycle of each animal. Label each stage and note any interesting points about the animal. e.g. butterfly; insect; frog; fish; reptile; bird; and marsupial.

3. Examine the bird, nest & egg sets. Birds, mammals and a few reptiles spend a lot of time and energy caring for their young. Make a list of the activities that parent birds do before, and after, the eggs hatch. How does this help the young to survive?

4. Research different models of care. Do male and female parent birds care equally for the young? Find some examples of cases where this does not occur.

5. Find out how the temperature of the surroundings affects the sex of the offspring in turtles and crocodiles.

Additional Activities:

1. Raising Silkworms

Silkworm eggs can be obtained from some pet stores and kept in the fridge until the next Spring season. Caterpillars will emerge in the warmer weather and feed voraciously on mulberry leaves. A constant, fresh supply of these leaves is needed. Students may like to devise ways for removing, storing and using the silk from the cocoons.

2. Forensic Entomology (for older students)

Investigate how forensic entomologists estimate the time of death using: temperature; environmental conditions; and the life cycle stage of insects infesting a corpse.

Explain:

1. Read out to your students the articles “Frogs on the Dinosaur Path” and “Toad fight croaks.”

a. Summarise the main points made in the articles.

b. Debate the topics: ‘Pollution is the cause of a decline in our frog populations’; and ‘Cane Toads should be exterminated.’

c. Discuss what you consider to be the best way of reducing the cane toad problem.

Elaborate:

1. Plan and carry out an investigation in the classroom, to test the effect of temperature on the speed that frogs (or mosquitoes or blowflies), go through metamorphosis. Construct a hypothesis.

What elements of a fair test will you need to consider? What safe practices will you have to use? What data will you collect?

Are there any ethical issues you need to consider?

2. Imagine you are a research scientist. You suspect that the reason for the decline in frog populations is because of the Chytrid fungus that lives on the skin of frogs. How could you test this suggestion?

What elements of a fair test will you need to consider?

What data would you collect and how would you record it? What results would support this hypothesis?

Evaluate:

Write up a report of No. 1 above. How well did your investigation go? Are there any things you could do to improve it?

Work through the QCAT worksheets on Life Cycles.

There are some good activities/assessment tasks on Life cycles on the QSA Website – QCAR Online Assessment Bank. Go to

https://qcar.qsa.qld.edu.au/assessmentbank/ and then the specific link for the Year 5/6 assessment task, on Life Cycles and Investigating Stage of Growth is as follows:

https://qcar.qsa.qld.edu.au/assessmentbank/html/package.html?uid=A0000009618

Queensland Museum 2010 3

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FROGS IN THE GARDEN FACT SHEET

Introduction

Brisbane is a haven for frogs. About thirty-six different species have made their homes among the lush, subtropical habitats of the greater Brisbane area.

Many people are concerned about declines in frog populations. Frequently, they reminisce about the ‘old days’ when the outhouse was home to big smiling Green Tree Frogs and raucous croaking could be heard from the downpipes on a rainy summer afternoon. Invariably, such reminiscence is followed by … 'but we don’t see them any more'. Often Cane Toads are blamed for local frog extinctions. However, although Cane Toads may have some impact on native frogs, undoubtedly, the main factor in frog declines within the suburbs, is a loss of suitable habitat. Frogs’ most favoured breeding sites – bodies of still water – have been drained for mosquito control or to make way for housing.

In recent years naturalists and scientists have also detected a disturbing decrease in both the numbers and kinds of frogs worldwide. Observers have found that some frogs have apparently disappeared in the wild or become very rare. Two frogs from the rainforests of south-eastern Queensland near Brisbane are now feared extinct. These are the Southern Platypus Frog (Rheobatrachus silus) and the Southern Day Frog (Taudactylus diurnus). Recent research suggests a virulent water-born pathogen, a chytrid fungus, may be responsible.

Although there is good reason to be concerned about the future of local frog populations, there is much that can be done to assist their recovery in disturbed areas. Adopting a 'frog-friendly' approach to gardening can create habitats in which native frogs live and breed. We can help re-establish local frogs in our gardens by providing a pond and appropriate landscaping.

Creating a frog-friendly garden

Frogs require environments in which the adults can breed, the tadpoles can develop and the young can mature. By creating suitable habitats in your garden

you can encourage thriving populations of frogs and other wildlife.

1.The most important factor in making a garden frog-friendly is creating a complex bush-like setting. This will have a variety of local native ground covers, grasses, shrubs and small to large trees, offering protection from wind and sun, and providing food for insects, which in turn feed the frogs.

2. With very few exceptions, frogs must visit water to breed. Try to establish a pond in your garden that the adults can access. A permanent pond, with well-vegetated landscaped banks, can be both visually appealing and attractive to frogs. A potential mosquito problem can be avoided by stocking with blue-eyes, small native fish that thrive on mosquito larvae. Contact a local aquarium regarding these fish.

3. An alternative to a permanent pond, and one which is often more appealing to the frogs, is a temporary water body. Following heavy rain it is common to see frogs largely ignoring creeks and ponds, in favour of water-filled ditches and depressions. A low-lying part of the garden, lined with an impermeable layer of plastic or clay and covered with soil and vegetation, can be a haven for breeding frogs when it fills during the summer rainy season. Such a depression would need to hold water for about 6 weeks. If the level drops too sharply before the tadpoles have developed it can be topped up with a little hose water.

4. Tadpoles feed on algae and other organic matter in the water. A typical outdoor pond environment will normally offer all the nourishment they need, so adding extra food is usually unnecessary and may foul the water.

5. Provide perches so the newly metamorphosed frogs can leave the water. Floating waterlily leaves and protruding branches are ideal, as they also offer shade. Tree frogs can climb smooth vertical surfaces, but ground dwelling frogs need a rough slope when their time comes to leave.

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6. The time taken to develop from tadpole to frog depends on such factors as species, temperature, population density, surface area of the water and day length. It usually takes 2–12 weeks, but during winter metamorphosis may be suspended or prolonged. Tadpoles born towards the end of summer may undergo little or no development until the following spring. For this reason, a lengthy or suspended metamorphosis should be no cause for alarm.

7. Once they leave the pond the young frogs have other requirements. They now eat small insects and they need the shelter of rocks, logs, leaf litter and thick vegetation. A good compost heap, lush foliage and plenty of ground cover will encourage them to reside in your area.

8. Discourage toads. Eliminating them from your garden will do the frogs and other wildlife, a favour. Densely vegetated pond edges will discourage Cane Toads from laying eggs. Remember, not all frogs are green so contact the Queensland Museum for further information on toad identification and eradication procedures.

9. Try to impart your ‘froggy’ enthusiasm to neighbours. With more households improving their gardens, there is a greater chance of creating broad, suitable habitats across Brisbane rather than widely separated islands in suburbia.

Rearing tadpoles

Metamorphosis from tadpole to frog is one of the natural wonders we can all appreciate and watching the process can help us understand our wildlife and the need to protect it.

1. If you wish to rear tadpoles under close observation you must care for them properly and, most importantly, obtain and release them locally.

2. You must start with a suitable container such as an aquarium, plastic garbage bin or paddling pool. If outdoors, keep it in three quarters shade.

3. Fresh water is essential. Try to take local water from an unpolluted pond or stream. If using tap water let it stand in an open, wide-mouthed container for 5 – 7 days. This will remove the chlorine which, in pure tap water, is at toxic levels for tadpoles. It is a good idea to keep spare de-chlorinated tap water on hand.

4. Tadpoles will eat lettuce boiled for 5–10 minutes, and will also take flaked fish food. Too much of either will foul the water; not enough and they will turn on each other. Try a little of both, and if the water becomes polluted replace it with spare stock and reduce the quantity of food. A small amount every 2–3 days is usually sufficient.

5. As with the outdoor pond, provide perches so the young frogs can leave the water.

6. It must be remembered that all Queensland frogs are protected by law under the Nature Conservation Act and Regulations. Before attempting to keep frogs, tadpoles or their eggs you should contact Queensland National Parks and Wildlife Service.

Important things to avoid

1. Do not move frogs or tadpoles from one area to another, whether between suburbs, or even between adjacent ponds or creeks. The chytrid fungus, which may be responsible for frog declines and extinctions, is easily spread in water and affects the outer layer of skin. In some populations, mortality may be 100 per cent. Unnecessary transportation of amphibians can speed the spread of this fungus and other pathogens to the detriment of our frogs.

2. For the same reason fish, such as blue-eyes used to control mosquito larvae, should never be released into local waterways. Fish supplied by a pet shop are unlikely to originate from your area.

3. Avoid using pesticides in and around the house as these may poison local frogs and their food.

4. However tempting it may be, we do not recommend you stock your frog pond or garden. When the environment is wrong, nothing you can do will keep the frogs in, but if the conditions are right nothing will keep them out. If you create a frog-friendly yard there is every reason to expect that, within a year or so, you will awake one wet night to hear something going ‘toc’ or ‘plonk’ at the bottom of your garden.

5. Avoid raising Cane Toads. Toad tadpoles are small and uniformly black or very dark grey in colour. The common Striped Marsh Frog can have very dark tadpoles, but these metamorphose at a larger size than Cane Toads. Some other native frogs have small, dark tadpoles, but these rarely breed in backyard ponds. If there is any doubt, the dark belly of the Cane Toad tadpole is diagnostic. The native species have pale or translucent bellies.

Further Information BARKER, J., GRIGG, G., & TYLER, M., 1995. A Field Guide to Australian Frogs. Surrey Beatty & Sons, Sydney

BERGER, L., SPEARE, R., DASZAK, P., GREEN, D.E., CUNNINGHAM, A.A., GOGGIN, C.L., SLOCOMBE, R., RAGAN, M.A., HYATT, A.D., MCDONALD, K.R., HINES, H.B., LIPS, K.R., MARANTELLI, G. & PARKES, H., 1998. Chytridiomycosis causes amphibian mortality associated with population declines in the rainforests of Australia and Central America. Proceedings of the National Academy of Sciences 95: 9031-6.

CASEY, K., 1996. Attracting Frogs to Your Garden. Kimberley Publications, Upper Mt Gravatt, QLD.

ROBINSON, M., 1993. A Field Guide to Frogs of Australia from Port Augusta to Fraser Island Including Tasmania. Australian Museum/Reed Books, Chatswood, NSW.

RYAN, M. (Ed.), 1995. Wildlife of Greater Brisbane. Queensland Museum, Brisbane.

RYAN, M. (Ed.), 2000. Wildlife of Tropical North Queensland. Queensland Museum, Brisbane.

Authors: Steve Wilson & Eric Vanderduys September, 2000 Queensland Museum PO Box 3300 SOUTH BRISBANE Q 4101 Phone: (07) 3840 7555

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How to Make a Fly Trap

Instructions

Materials

• 2 litre plastic soft drink bottles

• Heavy scissors

• 60 cm lengths of string

• Hole punch

• Bait: Raw meat soaked in a small amount of water (or old beer); old piece of fruit, like ripe banana

• Cotton ball

Making the Fly Trap

1. Using 2 litre plastic soft drink bottles remove the labels and rinse out with water. 2. With heavy scissors separate the top of the bottle from the bottom (see diagram). The

cut may need to be started with a Stanley knife or kitchen knife. Your teacher will do this.

3. Invert the top into the bottom part of the bottle. 4. On opposite sides of the container, punch holes using a hole punch. 5. Lace 60 cm of string through the holes and tie with a secure knot to create a hanger or use string

or use with paper clips attached to each end, if students are not ready to tie the string.

Trapping Flies

• To add the bait, slide the top up the string and drop in the bait. If your bait is runny, place a piece of paper (or wire screen) under the bait so that insects do not drown.

• Set trap in a tree so that rodents (or children) will not be enticed. To protect the flies from heat stress, place the trap in a shaded area. Depending on the weather, season, the bait and the amount of time the trap is left outside, the trap may attract other insects. Be watchful for honey bees.

Observing Flies

• After a few days, flies may be seen mating. Over the next week or so watch for the hatching of the eggs and their development into larvae (maggots), then pupae, and finally see the adult flies.

• After completing the observation, place the containers in a large bag and put in the bin.

Adapted from Wisconsin Bottle Biology Project.

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Courtesy of THE SUNDAY MAIL, Brisbane 24/08/2008

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Courtesy of THE SUNDAY MAIL, Brisbane 14/09/2008

by Suellen Hinde


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Documents

Life Cycles Teacher Resource Booklet 3