A collection of organisms of different species that live together in the same place and time can be called an ecosystem. It is a ‘system’ because if one component of the system fails, it has an effect on all other parts. For example, fungi play a key role in nutrient recycling and decomposition, giving seedlings the resources they need to grow into trees. Trees provide food for animals in the form of leaves and nectar. As trees age they can form hollows, where animals can live and when branches drop, they become ground-dwelling shelters for mammals, reptiles and invertebrates. Without the invertebrates the reptiles would not have a reliable food source and without the reptiles the resident Kookaburra wouldn’t get the meaty nutrition it needs to survive and reproduce.
There are many ways to imagine and connect the dots within ecosystems, and the relationships vary widely depending on the environment. For example, a rockpool and forest are very different to look at but are nonetheless full of organisms that are dependent on each other.
Birds are one of the more easily visible components of an ecosystem. Measuring species diversity and abundance in birds gives us an idea of how well an ecosystem is doing with regard to provision of different types of habitat and what resources are available. For example, small perching birds such as wrens and robins need an adequate amount of shrubs and grasses to protect them from predators while nesting and foraging. Semi-aquatic birds such as cormorants, darters and spoonbills need relatively large and healthy aquatic ecosystems with sufficient areas for perching, nesting and basking.