The Graffiti Artists - The Double-crested Cormorant

There is no shortage of disparaging labels cast upon the Double-crested Cormorant (Phalacrocorax auritus). The heavy-bodied, diving piscivore has been called a nuisance, a villain, a monster and a fish terrorist, mostly by fishermen and mostly undeserved. I call them nature’s graffiti artists. Their roost is their canvas. Their feces and cloaca is their paint and paintbrush.

The name cormorant comes from the Latin “corvus” and “marinus” or Raven of the Sea. Considering the large congregations of birds that roost together, the fish-eating cormorant is seen as a threat to anglers and the fish they seek. While studies have shown that this threat is often exaggerated, cormorants can have an impact on the vegetation they roost upon as well as the other species that might inhabit the same trees (and usually lower than the canopy-loving cormorants).

Over the last few decades, the cormorant population in North America has dramatically increased, a heralded consequence of the ban of the harmful pesticide DDT. Like most fish-eating birds, cormorants suffered the effects of the chemical that bioaccumulated through the food chain and resulted in their inability to lay eggs with sufficiently calcified shells. Cormorants, eagles, osprey, pelicans and others would attempt to incubate their eggs and crush them instead. 

Here in South Florida I have seen a colony of 40-50 cormorants routinely roosting in the same Pond Apple (Annona glabra) trees and over time, the acidic feces they leave behind has defoliated the trees. The herons and egrets that might have nested here are forced to find a more suitable location.

In the 10,000 islands of the Everglades National Park, the cormorants, with hooked beak held high, sit upon the channel markers and leave the tell tale white washing upon the signs, inadvertent artistry that remains on display when the cormorants fly off and then swim for a meal.

Call them vandals of vegetation if you must but I prefer to look at the droppings left behind as a clue as to who was here when the bird is not. 

What's Your Wingspan? - The American White Pelican

As our boat rounded a sandbar in the 10,000 islands portion of the Everglades, I noticed a flock of twenty five, massive American White Pelicans (Pelecanus erythrorhynchos) resting and preening their feathers on an ephemeral tidal island. As the boat navigated around the backside, a flock of Double-crested Cormorants (Phalacrocorax auritus) came into view along the waters edge and the contrast in size between the birds was stunning. I considered for a moment that this was a different, smaller species of cormorant, but the white pelicans are just that big.

The Double-crested Cormorant is not a small bird. With a wing-span over 50 inches and weighing over five pounds, the heavy-bodied diving bird is a conspicuous sight in the water, on power lines and in flight. When standing next to the American White Pelican, they look tiny.

The American White Pelican is the Airbus of birds. They can weigh up to twenty pounds and have a wingspan over nine feet wide. In Florida there is no bigger bird. Consider your “wingspan” is roughly your height. Mine would be five feet nine inches. I’m only nine inches taller than a White Pelican.

Long, broad wings allow the pelicans to reduce energy use by taking advantage of thermal updrafts and wave lift. As warm air rises, it creates a column of warm air that pelicans and other soaring birds can use to their advantage and rise to higher heights. Wind pushed up and over waves also provides a lift for many birds gliding over water.

Most of the White Pelicans use their wingspan to their advantage as they migrate south from the northern plains and eastern Rockies in the US and Canada. Many spend the winter here in Florida where they work in teams, paddling on the surface and steering fish into shallow water where they can scoop them up with their pouched beak. It’s an entirely different strategy then that of the Brown Pelicans (Pelecanus occidentalis) who dive from the air into the water to capture their prey.
Above me, a flock of fifty or more White Pelicans soars above the Everglades. I envy their view. If only I had a wider wingspan.