Cormorants (Double Crested?) have just made their way up the Maumee River. I first knew them in Ireland where my father described them as ‘very dirty birds’.  Forty four years ago I saw none on Lake Ontario, then 10 years later I saw a few solitary birds off Toronto Islands.  Ten more years passed while the population increased to cloud-like flocks on the horizon.  Moving to Lake Erie 24 years ago I saw the whole cycle repeated as the invasion of the Great Lakes proceeded westward.  Now we saw about seventy of them perched on one tree on “Small Island” outside 341. Their droppings often kill the trees, as has happened at Lake Erie Islands, because of high ammonia content or just outright volume of guano, I’m not sure which.