1. Different Places Different Diets Different Places Different Diets Feeding habits and diet of the Water-rat Rakali Hydromys chrysogaster in the waters of City of Port Phillip Andrew McCutcheon - Earthcare St Kilda Inc

2. Feeding habits and diet of rakali n They are amphibious hunters of mostly aquatic and marine organisms. They also hunt on land. n Diet consists of larger aquatic insects, crustaceans, molluscs, fish, frogs, birds and even aquatic plants. n They are opportunistic and will quickly adapt to other types of food if there is a shortage of the normal or preferred food source. n They hunt or forage for food by running on waters edge, wading in shallow water or swimming and diving in water to a depth of 2 metres. n Prey is generally taken to a feeding platform such as a rock or log in or beside the water. They will frequently use moored boats for this purpose.

3. How can we find out what rakali eat? n Direct Observation n Analyse food left on feeding platforms - middens Middens provide a good indication of prey species that exist in a particular habitat area. Middens provide a good indication of prey species that exist in a particular habitat area.

4. Rakali eating Red Swimmer Crab - 25 0ctober 04

5. Rakali resting - Note abundant whiskers

6. Partially webbed hind-foot

7. Swimming Rakali

8. Four Habitat Areas in City of Port Phillip n St Kilda Harbour n Elwood Canal & Point Ormond shore n Albert Park Lake n East shore of Webb Dock & Port Melbourne Foreshore

9. St Kilda Harbour n Sheltered and exposed marine habitat n Habitat subject to heavy storms battering breakwater n Populations can be reduced or vanish after storms and/or heavy rain producing flows of turbid/ polluted water from the Yarra River and drains n Prey species consist of crabs, European Fanworms, fish and possibly baby penguins. Red Swimmer Crabs are the preferred diet. n Main threats are heavy storms, floods and water pollution impacting on prey.

10. Inside of breakwater - St Kilda Harbour

11. Pier and breakwater - St Kilda Harbour

12. Rakali eating Red Swimmer Crab - 25 0ctober 04

13. Floodwater from Yarra after storm - 2 February 05

14. Turbid water 3 days later - 5 February 05

15. Rakali midden with small Common Shore Crab - 23 march 05

16. Rakali midden with small clam and European Fan Worms - 23 March 05

17. Rakali midden with European Fan Worms - 23 March 05

18. Rakali feeding on European Fan Worm - 23 March 05

19. Rakali midden with European Fan Worms - 1 May 05

20. Midden with Common Shore Crab & Fanworm- 2 October 05

21. Midden with Common Shore Crabs - 16 October 05

22. Rakali feeding on Sea lettuce - 16 October 05

23. Elwood Canal & Point Ormond shore n Freshwater surface drain, tidal canal and exposed marine habitat n Habitat subject to complete inundation and rapid change of water quality (salinity, turbidity) after heavy rain n Populations can be reduced or vanish after storms and/or heavy rain n Prey species not fully known as there are no middens. Fish and aquatic insects are the most likely diet. n Main threats are heavy floods and water pollution

24. Elster Creek

25. Elwood Canal -High tide

26. Elwood Canal -Low tide

27. Elwood Canal -Very low tide

28. Foreshore north of Pt Ormond

29. Silverfish (Hardyhead)

30. Baby Black Bream

31. Sea lettuce

32. Albert Park Lake n Freshwater Lake with island n Gunn Island appears to be the land based refuge for rakali. n Habitat subject to little change as water level is regulated, and stormwater pollution minimised by pollution control ponds. n Prey species not fully known as there are no middens. Yabbies and aquatic insects are the most likely diet. n Main threats appear to be water pollution impacting on prey

33. The Point - Albert Park Lake

34. Pollution control pond - Albert Park Lake

35. Yabby

36. East shore of Webb Dock & Sandridge Beach (Port Melbourne) n Exposed marine habitat n Habitat subject to heavy storms battering rock armor and groynes n Rakali show great variation in diet. Prey species consist of crabs, mussels, European Fanworms, and possibly fish. No single species appears to form a preferred diet. n Main threats appear to be heavy storms.

37. Webb Dock East Park

38. Sandridge Beach Groyne

39. Midden with Mussels - 1 October 05

40. Midden with small Spider Crab - 1 October 05

41. Midden with small Red Swimmer Crab - 1 October 05

42. Why is it important to find out what rakali eat? n To obtain a better understanding as to how they survive in our urban environment, in what are primarily man made habitats. n To determine the diversity of aquatic or marine species that live in our marine or aquatic habitats. n Rakali are good indicators of whether our marine and aquatic ecosystems are in a healthy environmental condition.