What is a keystone species? Perhaps you know what that term means. But in case you want to find out, the National Geographic shows us a film and some words about keystone species.
My fellow blogger skepticalsquirrel mentioned in a comment to my post about wolves (Canis lupus) that ‘the wolf was a keystone species’ in Yellowstone National Park in the USA. The National Geographic article doesn’t talk of wolves but it does talk of mountain lions and sea stars (predators) as well as hummingbirds (pollinators). It’s paradoxical, but true, that a species eating herbivores can be crucial to the herbivores’ survival.
I’m reminded of the Newfoundland cod (Gadus morhua), mentioned by the same skepticalsquirrel (who should be renamed excellentsquirrel) in comments to my post about the North Sea cod. The Newfoundland cod was a keystone species, as shown by the way its overfishing led to a dramatic shift in that fishery’s ecosystem.
The story of the Newfoundland fishery isn’t over. A few months ago the Globe and Mail told us that cod was making a comeback in Newfoundland. As EqFe pointed out in a comment to my cod post, making a comeback isn’t the same as having *made* a comeback. But it’s encouraging. Apparently the Newfoundland proto-recovery is attributed to rising ocean temperatures.