Konrad Lorenz, the Nobel prize, carried out long term behavioural studies on hand-reared greylag geese to allow close approximation. His geese - which were individually named - lived free but did not migrate, so he could study them year round. Lorenz describes geese behaviour in detail in his book 'Here I am - where are you?' Lorenz first discovered the phenomenon of imprinting on geese, by which newborn birds attach themselves to the first moving object they see after hatching. The description of his first, serendipitous, realisation of imprinting is quite moving:
'After the first gosling had hatched and dried, I was unable to resist the temptation of removing the delightful creature from under the foster mother and taking a closer look. As I did so, it gazed at me and soon began to utter its single syllable lost calls [...] I answered with a few comforting sounds. [...] Eventually, however, I had enough of this babysitting and placed the gosling back under the wings of the brooding domestic goose and started to leave. I should have known better.'
The gosling started making distress calls and when Lorenz starts moving away, it follows him. Lorenz did a lot of babysitting from then on!
The Greylag goose triumph ceremony (from one of Lorenz's papers on the behaviour of the Greylag geese).