Answer:
Henry should go to the field and make observations in nature.
Explanation:
The best way of studing an animal behaviour is in the field. So when studing different techniques that perching birds use to build their nest, the first thing to do is to previously study the perching species that inhabit in the study area for a better identification and recognition. Learn about their biology and ecology is as important as learning about their physic characteristics, because in that way the investigator knows what the animals looks like and where to find the animal. After this, the investigator is ready to go to the field and make direct observations in nature. This is a descriptive work, so the observer does not need to build a model or to perform a control experiment.
