Recall the previous lesson, focusing on camouflage and mimicry, and how it supports animals to survive.

Display the demonstration copy of the Little penguin Resource sheet and read the information about little penguins.

Ask students to draw a reasoned claim based on this information, and in reference to what they have learned about camouflage, about the possible advantages of the little penguins’ specific colouring.

As required, explain that:

• the blue/black feathers on their back help them camouflage when in deeper water, making it difficult for birds of prey to spot them from above.
• when viewed from below, their white belly blends with the bright, sunlit sea above, making it difficult for predators below them in the water to see them.
• being dark across the back and light on the front is known as counter-shading.

Ask if they are aware of any other animals that use this two-toned colour strategy, e.g. whales, birds, snakes and lizards, deer. It is a common camouflage strategy found in the animal kingdom.

Discuss other structural adaptations that students can see in the images and think may increase the little penguins’ chances of survival.

Draw students’ attention to the location where little penguins typically live, the cold waters of Southern Australia and New Zealand (both close to Antarctica).

Pose the question: What adaptations might little penguins have developed to help keep them warm in the cold southern oceans?

Discuss what students already know about feathers, fur and blubber and list animals that have them. Record their ideas in the class science journal.

If required, define “blubber”: the thick layer of fat that sits directly under the skin of marine animals, including mammals such as whales, seals and dolphins and birds such as penguins. Polar bears also have blubber whilst not strictly marine animals. Blubber insulates heat keeping the animal warm, stores energy and increases buoyancy.

Note for students that little penguins have both blubber and feathers, and explain that in this investigation they will work in teams to explore how animals keep warm in cold climates by creating mittens to compare the insulating effect of feathers, fur and blubber.

Display and examine the materials that students have available to use as insulation for the investigation and determine which ones are the best models for feathers, fur and blubber and why.

• Feathers: craft feathers, feather boa, doonah/duvet feathers and down (soft fluffy feathers beneath a bird’s outer feathers).
• Fur: wool, faux fur, old vintage fur from coat/hat.
• Blubber: vegetable shortening such as Copha, animal shortening such as Fairy or Superfry, or regular butter or margarine. 
   

Explain and model how to create the mittens by creating one or two “blubber” mittens that will be shared between groups to reduce wastage:

1. Place a sandwich-sized plastic bag inside another bag of the same size.
   • Sandwich-sized resealable bags are ideal. Turning the inside bag inside out means the resealing mechanism can still be used to help seal the bags.
2. Put a large amount of the insulating material between each side of the two layers of plastic.
3. Seal the edges of the bags together so the insulating material cannot escape.
   • Grey electrical tape/gaffer tape is ideal for this as it is wide and waterproof.
4. Manipulate the insulating material between the bags so it is spread out in an even layer.

Discuss and determine:

• why plastic bags are being used.
  • As this is a model exploring the insulating effect of blubber, feathers, and fur in water, there has to be a means of ensuring that the mittens are waterproof. Plastic is the best material to ensure this.
• how students will undertake the investigation.
  • Students will place a hand inside each mitten in turn, then place this hand/mitten into a bowl of iced water for a set period of time.
• how students might collect fair, accurate and comparable data.
  • Determine how long each hand/mitten can stay in the iced water.
  • Take temperature readings of the water to ensure it is at the same/similar temperature when each mitten is placed in the water.
  • If the temperature of the water rises significantly, add more ice until the temperature returns to the same baseline as when the first test was carried out.
  • Determine how students will rate the effectiveness of each insulating material.
    • For example, will they dip their hands simultaneously in the iced water with a different insulator on each hand? Will they leave one hand ungloved as a comparison? Will they use a thermometer (without touching the bulb at the base, as this will affect the reading)? Will they rate the “coldness” after an elapsed time? Will they take notes?

Allow teams time to make their feather and fur mittens, carry out their investigation, and record observations and results using the agreed-upon method.

Optional: Teams take photos during their investigation.

Allow teams to share their results and the methods they used to compare the insulating properties of feathers, fur and blubber.

Determine if one was a more successful insulator and why/why not.

Consider how some animals, like the little penguins, have more than one insulating feature (feathers and blubber). List other animals the students think also have multiple insulating features, and any animals that only utilise one (and why they think that might be the case).

Discuss challenges and limitations that students faced during the investigation, such as differences in judgement about warmth/cold, variations in scoring and changing water temperatures over time.

Show the video How do whales, penguins, and polar bears keep warm? (3:44).

Optionally:

• explain and discuss the following:
  • Little penguins have both feathers and a thin layer of blubber to keep them warm.
  • Larger penguins, like emperor penguins, have more blubber to survive colder conditions in Antarctica.
  • Little penguins have many more feathers than other birds, around 10,000 in total. The feathers interlock to trap warm air and create a waterproof layer. The trapped air also helps with buoyancy.
  • Penguins have an oil gland near their tail and spend a significant amount of time oiling their feathers by running their beak through the feathers to distribute the oil. This is known as preening and assists with waterproofing. 
• show the video Little blue penguins (1:14) for an explanation of moulting and the importance of feathers.
• show the video 10 things you didn’t know about Australia’s little penguin (7:39) to explore more structural features and behavioural adaptations of little penguins, including three eyelids and crossing beaches in groups.
• show the live video feed Little penguin burrow camera at Phillips Island to observe penguin features and behaviours (such as preening) in real time.
• consider (or research) if the animals found during Lesson 2’s habitat survey can warm themselves or if they are affected by the environmental temperature. Discuss how this affects their need for insulating layers such as feathers and fur.

Reflect on the lesson  

You might:

• add vocabulary related to body covering and surviving cold temperatures to the class word wall or glossary.
• add to the W and H sections of the TWLH chart.
• review what’s been added to the class science journal during the lesson, determining if the ideas are supported by evidence, if further investigation or research is required to confirm them or making additions and amendments where needed.