When I was a child in the mid-1960's, there were only 17 Whooping Cranes left in the Aransas area, the Brown pelicans were gone, as well as the Roseate Spoonbills. Fortunately, the latter two were able to abide elsewhere. The problem with the birds disappearances? DDT. The pesticide ran off the fields in
rainwater, into the bays, and into the food chain. The effect it had upon the birds was to weaken the shell so that it broke long before the chick was ready to hatch. The disastrous effects of DDT upon the wildlife, particularly the birds, was documented in Silent Spring by Rachel Carson in 1962. This was the beginning of the Environmentalist Movement and ultimately led to the banning of DDT in 1972 as well.
Today, there are two colonies of Whooping Cranes; an Eastern colony, and the Aransas Colony, which is the only migratory colony, and migrates from Canada to Aransas, a journey of about 2,700 miles. I believe the latest count of the Aransas colony is 190, so they're still considered endangered. Interestingly enough, a Whooper from the Eastern colony took a side trip to Nashville recently. For this Texas coastal girl, that seemed very out of order!
Also, in my childhood, I remember the seeing the pink flocks of Roseate Spoonbills, and thrilled at the explosion of color in the marshes or along the shoreline. They're back, too, but not in the numbers that I remember. It's not as unusual, however, to see them as it is the Whooping Cranes. The Brown Pelicans are back, and the White pelicans have just decided to move in en masse. I guess Florida got too crowded for them. The stately Blue Herons never left, and probably never will. They are an amusing bird to watch - especially when they are teaching their young how to feed, but that's a blog for another day.