Field Observation: Social Behavior and Phenology

On March 8, 2020 from 9:30am to 11:00 am, I walked a loop with my grandfather in Naples, Florida that led us along the beach and then back on a paved trail near mangroves. The loop was approximately 2 miles long, and it took us almost exactly an hour and a half due to all the stops we made to observe the wildlife. The sun was out and there were some clouds in the sky, but the sky got more overcast as our walk proceeded.

The first bird we saw while walking on the beach was a white Ibis. I had never seen an Ibis before, and I had only recently discovered them via a picture I was sent by a friend who lives in Houston, Texas. This bird was alone on the shore, and was sticking its long pink beak into the sand to search for (assumingely) crabs or something of the sort. The legs of the bird were also a dark pink/red, and the body was all white. I think the white body offers an evolutionary advantage because it provides the bird with some cryptic coloration/camouflage against the sand. The bright color of the bill may also be advantageous for males to drive off other males and attract females? The wings also have black on the tips, which I'm assuming is to add strength to the flight feathers. The white ibis was also foraging at around 9:45am. Since Naples, FL is very southern and warm year-round, I assume this routine does not change much for the bird as the environmental conditions are relatively consistent. It does indicate though that the bird is diurnal rather than nocturnal, and there is no need to forage at a very specific time of day because it is digging its beak into the sand to find food anyway.

At around 10:05, we saw a large group of black skimmers on the beach right in front of the water. I found this to be quite strange because the beach was populated by people who were sitting no more than 10 ft away from the birds. However, the birds and the people really were not interacting at all. Most of the birds were either facing towards the water or away from the water. I figured that the birds facing towards the water were trying to face the wind so that they could retain their body heat. The sun was in the other direction though, so maybe the other birds were facing the sun so as to warm up? They seemed to be resting and drying/warming up after searching for fish in the ocean. These birds are also very funky looking- it doesn't look like they have eyes! The top of their head and their back is black, and there is a white ring around the beak that extends to the bird's stomach. The coloration of these birds seems to follow countershading, in which the white underneath has no pigment in it and reflects the surroundings. This would help the bird avoid predators via cryptic coloration, just without the energetic investment of producing melanin or other pigments. The beaks are red at the base and black at the tip, and the white strip of feather seems to accentuate the beak. These birds were also make lots of sounds, but it really just seemed like they were telling each other to give them their personal space. Whenever one of the birds was trying to move or walk through the pack, the others squawked at it.

At 10:30, we came across a human-made nesting pole for osprey. There was an adult in the nest along with two chicks. The chicks seems to be of decent size as we could see them while standing about 30 feet away. The pole was about 12 ft high, and the nest was perched perfectly on top of it. As we watched the family of osprey, the adult left the nest and flew around the mangroves in circles. It looked like it was searching for food, although I never actually saw it pick up/catch anything. This foraging behavior lines up with its cirannual rhythm because since the adult is raising chicks, it needs to provide for both itself and them. I am not familiar with the breeding season of osprey or most other birds in warmer climates, so I was kind of surprised to see a nest with chicks in the middle of March. Osprey have very interesting coloration... when their wings are folded in, they are just brown with white on their heads and undersides. This countershading seems important for osprey to blend in with their surroundings to avoid predators like owls and eagles. When they fly though, the undersides of their wings are striped. The chicks were also making little calls while the adult circled the nest, and it definitely seemed like these calls were meant to signify that they were hungry.

Around 10:50, we were back on a paved path walking towards the parking lot where we parked. One each side of the path, there are little stagnant rivers. This is where we saw alligators! Walking across the path was a very strange looking bird, which I identified to be an Anhinga. I had never seen a bird like this before, and when getting closer to it I thought it was injured because it was walking in such a strange and unbothered way. The bird started to move faster as we got closer, and then it scurried away to the edge of the water. The bird had a very long beak and fuzzy hairs around its head. The next was also very long, and after looking up the bird I learned that they are often referred to as snakebirds for this reason.

Publicado el marzo 24, 2020 05:25 TARDE por aneu