The two extant families of monotremes, the platypus and echidna, have distinct habitat preferences and distributions:
1. Platypus (Ornithorhynchus anatinus):
- The platypus is semi-aquatic and is primarily found in eastern Australia.
- It inhabits freshwater rivers, streams, and lakes.
- Their burrows, known as "platypus burrows", are built along riverbanks with soft soil and vegetation.
- The burrows can have multiple entrances and can be quite complex.
2. Echidnas (Tachyglossidae family):
- There are four species of echidna, three found in Australia (short-beaked, long-beaked, and Western Australian) and one in New Guinea (Sir David's long-beaked echidna).
- Echidnas occupy diverse habitats, including temperate forests, woodlands, grasslands, deserts, and alpine regions.
- They burrow underground and create simple nests or shelters made of leaves and twigs.
Overall, egg-laying mammals are found in specific habitats within these geographic regions:
- Australia: Platypus in freshwater habitats and echidnas across various terrestrial habitats.
- New Guinea: Sir David's long-beaked echidna in the montane forests of the island.