Numerical Data on African Birds' Behaviour at the Nest: Hirundo S. Smithii Leach, the Wire-Tailed Swallow.

Abstract

The observations on which this series of papers is based have been made almost entirely by Africans who are able to read and write Swahili. Equipped with note-book, pencil, and ordinary watch, they have made observations for continuous spells of five hours and upwards in the day, and noted the time at which every event occurred, especially the arrival and departure of parent birds. Compared with mechanical systems of recording, the use of African observers has the obvious disadvantage of human fallibility. But I am satisfied from the frequent surprise visits that I paid and from the short spells of watching I was able!, to do myself, that the Africans' records are faithful; and their work has the great advantage over mechanical records that as they became interested; which they did to a surprising and gratifying degree, they began to amplify their bare records of standard events with notes that were often significant. It may be added that the average cost of the observations is less than 1 ½ per hour.