The booklet is part of a series which tests some skills biologists use in their investigations. A series of diagrams of a biological community over a period of 10 years indicates an increasing bird mortality, and students are asked to choose a puzzling event that they would want to investigate if they were biologists. A scrambled programed text format is used to direct students to sets of questions concerning possible investigative procedures. Students are asked to indicate the order in which they would carry out a number of suggested steps in an investigative strategy. Some options include choosing and reading related literature; extracts from a number of works are included. These readings are to be rated according to their usefulness to the student. Part B (SE 011 337) contains a series of questions related to possible experiments testing one of the possibilities offered in this booklet. Students are allowed 55 minutes for this test. (AL)