Jenevieve Norton: Field Research in Beautiful Isla Boca Brava

View from Isla Boca Brava.

For the past six weeks, I have been on our field site in Isla Boca Brava, Panama. It has been incredible to finally see the birds I have studied for 2 years dancing before my eyes, or rather before my binoculars. I have loved seeing the other animals on the island such as howler monkeys, a huge variety of insects, and coyotes. It was a huge adjustment living on the island in the middle of the jungle as this is my first experience with field work, and I feel I have gained a lot of new skills for the field and for my life.

Male lance-tailed manakin caught during netting.

My favorite aspect of field work has been netting. We put very fine mist nets up in the forest to catch lance-tailed manakins. We do this to individually color-band the birds for later identification, confirm which birds are alive, collect blood samples, and gather information on characteristics such as molt patterns, parasite loads, and body condition throughout the season. I was able to assist the field techs in putting up and taking down nets. I was also able to scribe the measurements and any other notes about the birds we captured. Sometimes there would be “bycatch”, or birds other than the manakins, in the nets as well. This was a great opportunity for me to learn how to take birds out of the nets. I was able to take out a hummingbird and an antshrike out of the nets independently by the end of the field season. It was amazing to see the birds up close and learn how to collect relevant data in the field. 

Rufous-tailed hummingbird caught while netting for lance-tailed manakins.

Another part of field work I loved learning was how we collect information on the lance-tailed manakin chicks as they grow. Lance-tailed manakins typically lay two eggs in a nest, although single-egg nests are also possible. When a nest with two eggs in it is found, one of the eggs is taken back to the field house and placed in the incubator to develop in relative safety. This is done so that if the egg in the forest doesn’t survive, we can still collect genetic information from the nest based on the incubator egg. When the chick hatches, they are marked and a small blood sample is taken. The chick is then returned to the nest and the chicks are checked in intervals until they fledge.

12-day old manakins chicks, just after getting their bands.

I came onto the field site during the rainy season, so afternoon downpours happened quite often. When I was stuck inside, I spent my time working on my data analysis. I wanted to see if females who show fidelity to their mates are also more likely to show fidelity to their nesting sites. In order to investigate this, I went through every nest since 2000 that we had the bands of the female and her nest location over consecutive years and breeding seasons. In addition to having a nest every year, females can have multiple nests in the same breeding season. I calculated the distance between nests using the Pythagorean theorem and decided if a female switched or stayed at a site based on the GPS points of her nests. Our GPS accuracy is 6 meters, therefore, if the nest is over 12 meters away from the initial nest, then I deemed it to be in a new area and the female would not show nest-site fidelity. Then, I compared the sires of the chicks across and within years. From preliminary analyses, we found that mate fidelity and nest-site fidelity are not related. 

Beach view on Isla Boca Brava.

For the remainder of my time, I will learn lab techniques with the data we have collected in the field. I have also thought of a new hypothesis to test with the data I already have. I hypothesize that females may show nest-site fidelity to habitat conditions, instead of nest-site locations. I will compare factors such as nest height and how steep of a slope the nest was built on. I am looking forward to learning more and exploring more about fidelity in lance-tailed manakins.

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