Cormorants: A Vital Component of the Great Lakes Basin
Invasive Fish Consumption
A cormorant diet consists of very large numbers of primarily invasive fish, such as alewives and round gobies, as well as other non-commercial, non-forage species. Cormorants have no substantial ecological impact on fish populations, including those of sport fish and commercial species in the Great Lakes Basin.
Skillful Eco-Engineers
Cormorants are a keystone, ecosystem engineering species that maintains, modifies and creates habitat. Changes in the composition of vegetation in and around bird colonies globally is a sign of a vibrant natural ecosystem. Beavers, bison, prairie dogs and elephants are other examples of well known eco-engineering species.
Beneficial to Other Waterbirds
Cormorants share habitat with other colonial waterbirds, such as herons, egrets and pelicans. They can create conditions favourable to these and species. Cormorants nest on a relatively tiny percentage of islands, shorelines and peninsulas, as well as on inland lakes and rivers, in the Great Lakes Basin.
Shifting Baseline Syndrome
More than 100 years ago John James Audubon observed a single cormorant flock he estimated to number one million birds. In later years, cormorant numbers were decimated by pesticide poisoning and human persecution.
Some people today think there are too many cormorants. They didn't see many cormorants in the 1960s, 70s and 80s (since they were nearly wiped out), so not having them around was perceived as normal. These people see the return of cormorants as abnormal, when the reality is that the absence of cormorants is what is abnormal.
This perspective about what is normal is called Shifting Baseline Syndrome (SBS) and it has led some people, including wildlife managers, to support the reduction or elimination of cormorants. Watch a fascinating video - Forgetting Nature - that describes the phenomenon in more detail.
Succession: Dynamic Nature at Work
A process in which a disturbance, such as wildfires, hurricanes, wildlife or human alterations, causes vegetation to be modified or destroyed, followed by regrowth, until the next disturbance comes and the cycle repeats itself. (video to be posted soon).
Predator - Prey Cycles: The Way that Nature Works
When prey species rapidly multiply, the number of predators increase. The predators eventually eat enough prey that the prey population goes down. Predator numbers then decrease because of less food being available and the cycle repeats itself.
Trophic Cascades: Powerful Ecological Phenomenon
Predators of all kinds - such as the wolves in this video, and other animals - can have important, crucial, healthy effects on the ecosystems they inhabit. This video explains how wolves in Yellowstone brought their system into a more natural state.