Anhingas Nesting

 

Monday, 31 August 2020

Watching Anhingas

Onn June 21,2020, a pair of anhingas decided to build a nest on a low-hanging branch of an oak tree over a pond outside our bedroom window.  They prefer a location over water from 6 to 20 feet off the ground.

Anhingas live in Florida year-round. They are also called "water turkeys" because of a turkey-like fantail. Some call them "snakebirds" because they can appear to be a water snake with only a long black neck and head above water. Anhinga means "Devilbird" in the Brazilian Tupi language. When we get a visit from a flock of 15-to-20 anhingas, they swim side-by-side underwater, along the length of the pond, surfacing with the small fish they spear with their sharp beaks.

The males tend the nest during incubation (in July) an average of 55% of the time, compared to 45% for the female. The darker male gathers about 81% of the nesting material. This male seems good at ripping off tough oak twigs and branches. When it rains, the adults spread their wings over the nest to keep the eggs and chicks dry.

Here is a video of the adults building their nest over two days in late June.

Anhingas can dive 60 feet deep, soar with the thermals, and fly flat and level very fast...they have a flat, cross-shaped appearance in flight.  The male anhinga has black head feathers. The female has a white head and chest feathers. Their feathers are not waterproof, which enables them to dive deep for food.

 Two to six eggs are laid every other day after the nest is complete. The eggs hatch in two weeks. This nest had three eggs and after another six weeks, the chicks are expected to have feathers capable of supporting flight.

Here is a video from early August. The video shows the hatched chicks feeding. Both adults work hard tag-team feed the growing chicks. They fly off and spearfish. Then they regurgitate the fish and the chicks seem to stick their heads way down their parent's throats to eat. The parents provide all the water and food that the chicks need to survive. The smallest chick died as it became progressively less active and unable to compete with its siblings for food.  

Aug. 19, 2020: They look ready to fly. There is much wing-flapping going on. The adults seem to be trying to entice the chicks higher in the tree. remaining two chicks left the nest for good and began to
explore the oak tree. They are taking short hops of a few feet between branches and getting high into the top of the tree. The adults return to feed them where they find them.

Humans learn to walk with little steps first and anhingas must do the same. I was expecting a sudden and dramatic departure flight from the nest, but short practice hops to train first makes more sense.

Observing this reproduction process from my bedroom during Pandemic isolation has enabled me to discover things about the meaning of life. These birds are a brilliant self-replicating design with an incredible history of lucky functional improvements. Life is the meaning of life.

The two surviving chicks "fledged" on August 27th and August 29th.  The first flight of the second chick was to crash land in another oak tree about 100 yards away from the nest. I was unable to videotape this event, but I observed it happen. The adult female returned to feed the remaining chick and the chick flew back to the nest very gracefully to receive lunch. 

The nest is empty. The chicks may build their own nest after two or three winters. There are 200-300 breeding pairs of anhinga in west-central Florida. We were lucky to have one outside our bedroom window.