Supplementary feeding increases Tengmalm’s owl Aegolius funerus reproductive success in a peak vole year in western Finland

  • Published source details Korpimaki E. (1989) Breeding performance of Tengmalm's Owl Aegolius funer eus: effects of supplementary feeding in a peak vole year. Ibis, 131, 51-56


This study is summarised as evidence for the following.

Action Category

Provide supplementary food for owls to increase reproductive success

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

    A replicated, controlled trial in western Finland in spring 1986 (Korpimaki 1989) found that ten Tengmalm’s owl Aegolius funereus pairs supplied with supplementary food (50-60 g of dead laboratory mice Mus musculus provided daily) during the pre-laying and laying periods started laying earlier, had larger clutches and had higher hatching success than 15 control (unfed) pairs (fed pairs: clutches started on 24th March, 6.8 eggs/clutch, 98% hatching success; control pairs: clutches started on 30th March, 5.9 eggs/clutch, 82% hatching success). Fed pairs also had more fledglings in successful nesting attempts than controls (5.6 fledglings/successful nesting attempt for nine fed pairs vs. 4.0 fledglings/successful nesting attempt for 15 controls). There were no differences in egg dimensions or the weights of parents and fledglings between fed and control nests. The author notes that the study took place in a peak vole year, when naturally-occurring food was extremely plentiful.


Output references

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