"After nearly a decade of…

"After nearly a decade of annual cormorant culls, Parks Canada is close to stabilizing the number of birds taking up residence on Lake Erie's Middle Island, where their nesting and fecal matter threaten vegetation at Canada's most southern point.

The birds threaten the health of nine different species-at-risk on the island owned by Parks Canada.

ix thousand nests were reported on the island — the southernmost point in Canada — when the cull began in 2008. As many as 25,000 birds would flock to the island each year, breaking branches, eating leaves, defecating everywhere and destroying rare Carolinian forest.

Today, the number of nests has been reduced to 1,794. A healthy balance between cormorants and wildlife can be achieved with about 1,100 nests on the island, according to Parks Canada. Middle Island is 18.5 hectares (46 acres) in size.

https://www.cbc.ca/news/canada/windsor/cormorant-culls-stabilizing-midd…

There appears no natural controls over the expanding number of comorants on the lake. I am concerned that their guano kills trees and environment; their diet takes many fish and they crowd out other species.

I would like to know the biologist's view on why the bird population is so large; what the natural controls are and what the appropriate balance is.