Field Observation 2: Ecological Physiology

Weather: sunny, no wind,78 degrees F.
Habitat: Wakodahatchee Wetlands. Man-made wetlands that are the homes to a variety of species including Green Iguanas, American Alligators, Anhingas, Great Blue Herons, Tricolored Herons, and more.

In Florida, the seasons are not defined the same as they are here in Vermont and in the rest of New England. There, the winter is a dry season and the summer is the wet season. Winter is still hot during the day, but goes down to the lower temperatures at night.
At Wakodahatchee Wetlands in Florida, I observed Great Blue Herons raising their young. They were caring for a nest with two young chicks that looked almost old enough to learn to fly. The parents were still feeding their offspring, as they did not appear to have their flight feathers yet.
The next day on the beach in Jacksonville, I observed a siege of Great Blue Herons flying North. I found it interesting how different groups of the same species had such different plans within a 24hr period. Raising young is such a time consuming event, from mating to laying eggs to rearing the young and sending them off into the world. Migration on the other hand, is not an easy event either, nor is it something that they would be able to do with flightless chicks.
To survive the low temperatures of a northern winter, many birds including the Great Blue Heron, fly south. They return when the weather is warmer. When it becomes very cold in the South, or anywhere, birds may go into a hibernation-like state torpor. They may also huddle together, especially with their young in their nests. For the Great Blue Herons that I observed, I did not see them at night, as I visited the wetlands in the morning. I did see them spending a lot of time defending their nest from nearby Wood Storks(an actually drew blood from the stork at one point), hunting for food (to feed themselves and their chicks), and looking for branches and other nesting materials to make repairs to the nest as the babies grew. They were hunting and eating fish in the marshy area around their clump of trees.
At this time of year in Florida, the herons are eating mostly fish, as other organisms that they may consume, such as tadpoles and small lizards, may not all be available yet. In the dry season, larger fish that would provide a more fulfilling meal are not always available to the herons as they may be in deeper waters that are not easily accessible to the birds. At this point in mid-March, just about the middle of the dry season, the majority of fish available are likely to be tiny/newly hatched and so the bird would need to spend more time hunting to have the same intake.
Although it is unlikely that a Great Blue Heron would inhabit a snag, smaller birds such as a Scrub Jay would use them as nesting sites and for scoping out their territories. They can also be used as a place for foraging if there are insects or worms inside the wood.

Publicado el 20 de marzo de 2018 por