Effect of supplemental food on the breeding of blue and great tits in Mediterranean habitats

  • Published source details Clamens A. & Isenmann P. (1989) Effect of supplemental food on the breeding of blue and great tits in Mediterranean habitats. Ornis Scandinavica, 20, 36-42.


This study is summarised as evidence for the following.

Action Category

Provide supplementary food for songbirds to increase reproductive success

Action Link
Bird Conservation
  1. Provide supplementary food for songbirds to increase reproductive success

    A cross-over study in a coppiced oak forest in southern France in 1986-7 (Clamens & Isenmann 1989) found that blue tit Parus caeruleus and great tit P. major pairs in an area provided with supplementary food started laying clutches significantly earlier than pairs in a control (unfed) area (1986: 9 pairs in a 10 ha fed area laid six days earlier than 26 pairs in a 50 ha control area; 1987: 15 pairs in a 30 ha fed area laid five days earlier than 18 pairs in a 30 ha control area). However there were no significant differences in clutch size or the number of young hatched between treatments (average of 9.2 eggs/clutch for 24 fed clutchea vs. 8.3-9.1 eggs/clutch for 44 controls) and, in 1987, significantly fewer chicks fledged from blue tit nests in fed areas than control areas (average of 3.0 chicks/nest for 11 fed pairs vs. 6.3 chicks/nest for 15 controls). There was no significant difference in productivity in 1986 (7.1 chicks/nest for seven from fed areas vs. 7.3 chicks/nest for 23 controls). The authors suggest this could be due to fed clutches hatching before the peak in natural food in 1987.


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