SCHOPPERS J (1996) Short contributions: Tape recorder useful in breeding season surveys of Partridge Perdix perdix. LIMOSA 69 (4): 180-181.

Grey Partridge Perdix perdix The possible advantage of using a tape recorder in surveying Partridges was tested in three study areas (Duivensche Broek near Arnhem and Ossenwaard and Driedorpenpolder near Lobith, Netherlands) in spring 1994. The areas were visited 3, 3 and 2 times in the evening, resp., without using a recorder and just as many times with use of a recorder. Visits were brought between two hours before and 1.5 hours after sunset in March, April and May. Visits without and with recorder resulted in 23 and 75 observations, resp. When vocal reactions are considered exclusively (no sight records), there were 18 observations without, and 69 with use of the recorder. The advantage of using a recorder is best in March and April (5.4 and 4.2 times) and clearly less in May (2.4 times). Most reactions are heard between sunset and one hour after sunset (Fig. 1). Using a recorder is most advantageous before sunset (7.6 times higher; after sunset 'only' 2.6 times higher). When a recorder is used in sampling plots for breeding birds, territories found with the aid of a tape recorder should be recorded separately

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