Help please

1- In a 2014 study, Grossi, Larach, Canals, Vsquez, and Iriarte-Diaz connected weighted sticks to the back of 4 domestic chickens to mimic the tail of a dinosaur and recorded the chicken both walking and standing.They concluded that the manner in which these chickens with dinosaur-like tails then walked in a manner consistent with to the theorized manner in which non-avian dinosaurs walked.What is the population of this study?

2- Peter Pan is studying the migration patterns of pixies.As part of this research, he counts the number of pixies over Mermaid Lagoon on 16 randomly selected days.What is the sampleof this study?