The Emu and Crocodile

Australian Endotherm: THE EMU Scientific Name: Dromaius novaehollandiae Located throughout Australia, not in Tasmania. Habitat: -Grasslands, open woodlands, savvanah woodlands. - Semi- Arid conditions - Areas that are open with some plant covering.

ADAPTATION 1- Feathers are long, with two feathers sharing one shaft. In cold temperatures: -Emu will plump its feathers up to trap a layer of air inside the thick covering. - This heat insulates the emu, keeping the internal temperature more stable.

The feathers also have another adaptation of having black tips. The black tips absorb the heat from the sun. The long feather, with the absorption of sun rays at the end, occurs far from the skin. Tip absorbs it, and stops this heat from contacting the skin. This allows the emu, to stay cool during the strong heat of the day.

ADAPTATION 2- The emu pants when the endotherm needs to cool down - internal temperature is too hot. Behavioural adaptation. Excess heat is lost by evaporation, moisture takes heat from body. Emu don’t have sweat glands. Emu breathes faster, pants and allows more moisture to be evaporated from lungs and mouth, a cooling effect as heat is expelled. Also have nasal passages which are folded, for breathing in cooler temperatures - keeps moisture and heat in the body. EMU PANTING TO EVAPORATE MOISTURE AND LOSE HEAT

ADAPTATION 3- The emu adapts to the semi-arid conditions by using its small wings to cool down their body using the small wings which are not used for flight. The wings are flapped and this cools the animal down by pushing cool air through the long feathers to cool the surface. Will receive cool air through their long feathers as they are actively walking,and will also flap their wings which will provide greater cooling eventually through to the skin of the emu. LOCATION OF SMALL WINGS

Australian Ectotherm: THE CROCODILE Scientific Name: Crocodylidae. Two Species in Australia: -Freshwater: Johnstones Crocodile -Saltwater: Estuarine crocodile Found in the warm tropical areas of Northern Australia: Northern Territory, Queensland and Western Australia. Habitat: -Freshwater: Can live closer inland in: lakes, rivers. Live close to banks and swampy areas for shelter/hunting etc. - Saltwater: Usually close to or on coast, and can also live in estuaries, wetlands, swampy regions and rivers. Lives near swampy regions/banks for survival.

ADAPTATION 1- Positions itself on the bank in a sunny position and sun-bask. Will increase the ectotherms internal temperature as heat is absorbed. Sun baking, on a hot surface and in a sunny position allows a large amount of suns rays to be absorbed as heat energy. Quick increase in temperature so it can continue with hunting and other processes. Flattens itself on the hot surface

ADAPTATION 2- To withstand the hot temperatures of the Northern Territory, especially in summer the crocodile stays in the water throughout the day to keep as cool as possible. Keeps the crocodile from overheating in the day as water not greatly effected from the ambient temperatures due to its high heat capacity. The temperature can change in the environment yet the water the crocodile stays in will be minimally effected. When temperatures drop in the night time, the crocodile can now comfortably move onto the bank and hunt for their prey without becoming overheated. STAYS IN WATER DURING HEAT OF DAY AT NIGHT, WHEN TEMPERATURES ARE LOWER, GOES HUNTING

ADAPTATION 3- Adaptation of opening its jaw/mouth greatly. When ambient temperature is high the crocodile will move onto the bank and will largely open its jaw. Cools the crocodile down, as evaporation of moisture and heat occurs from the crocodile, due to the large surface area of the crocodiles mouth. Large surface area allows large amount of heat can be lost to keep its head cool.

Bibliography Books 1) Judith, Brotherton. Mudie, Kate. Heinemann Biology second Edition. 2004: Heinemann 2) Hill, Jennifer. Alford, Diane. Excel: HSC Biology. 2012: Pascal Press. Internet Sites 20/11/2012. Title: Emu. 20/11/2012. Title: Habitat of Emus. Elizabeth Jennings. Date Visited: 21/11/2012. Title: The Emu: Dromaius novaehollandiae. Andrew Moon. Date Visited: 21/11/2012. Title: Nature Notes – Emu. Date Visited: 21/11/2012. Title: Emu. Date Visited: 21/11/2012. Title: The adaptive significance of dark plumage for birds in desert environments. Jennifer, M Ward. Date Visited: 21/11/2012. Title: Emu. Toronto Zoo.

Internet Sites Date Visited: 22/11/2012 : Salt-water Crocodile, Estuarine Crocodile. Author: Australian Government website. Date Visited: 22/11/2012 : Saltwater crocodile. Date Visited: 22/11/2012 Australian Saltwater Crocodile Facts. Date Visited: 22/11/2012: Freshwater Crocodile. Author: Chris Hosking. Date Visited: 22/11/2012: Saltwater Crocodile wp/barbara/adapt.html wp/barbara/adapt.html Date Visited: 22/11/2012: Adaptations.