#ecosystem development

This week we're interested in sonar: the echolocation ability used by bats, shrews, and some cave-dwelling birds, and of course, whales, dolphins, and porpoises. It's useful for everything from hunting to navigation. Do you have any species in your world that use sonar? What are they?

The world contains a few very slow-growing things. Cacti grow very slowly indeed, making cactus 'forests' a treasure of nature. The very oldest creatures in the world at the stromatolites of Australia; aside from those, humans are pretty much the slowest to mature. What if something else in your world matures more slowly? What in your world is slow-growing, and why?

Today we're talking parasites! Parasites can be anything from creepy to outright deadly, and they're not just animals. Did you know that plants can be parasites? Fascinatingly, parasitic plants can also be a means of "communication" between individual plants; there's a study that shows parasitic dodder can share signals from one host plant being attacked by insects to others in its parasite "network" -- so that the plants not yet chewed on can begin synthesizing noxious compounds before the insect pests spread to them. What parasites exist in your world?

Apex predators are impressive: lions, tigers, crocodiles, sharks. Yet, there's more to an ecosystem than these top predators. Smaller, perhaps omnivorous, creatures live out their lives too, such as weasels, snakes, or civet cats. What are your mid-tier predators?

Humans take great pride in our intelligence, yet intelligence isn't necessary to successfully survive into adulthood and pass on one's genes. We do rather *like* knowing that there are other intelligent animals around: great apes, crows, parrots, dolphins - there are a few of them around. What clever species exist in your world?