One type of symbiosis is called mutualism. Which of the following is an example of mutualism? mangrove trees in swamps with long roots provide habitat for small fish which provide "fertilizer" to support the trees
lions hunt zebras and keep them from overgrazing the savanna
fleas bite dogs and other mammals, obtaining blood
birds ride on the back of wildebeest, eating the bugs that the wildebeest disturbs as it walks