WALTERS J (1983) Short announcements: Early laying of Great Tits Pams major. LIMOSA 56 (2): 60-60.

At a sewage farm in Amsterdam the dates of first egg laying in Great Tits appeared to be earlier than in other Dutch nest-box populations under more natural conditions (fig. 1). It is suggested that the milder microclimate at the sewage farm was favorable for early development of sufficient natural food, whereas in winter much food was supplied by man. The size of the first clutches compares favorably with those in the other areas, but the number of fledglings was lower

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