Differences in Reproductive Investment between Male and Female Syrian Woodpeckers Dendrocopos syriacus (Hemprich and Ehrenberg, 1833) in a Newly-colonised Area

作者：Michalczuk Jerzy^*; Michalczuk Monika

来源：Acta Zoologica Bulgarica, 2016, 68(1): 77-84.

• parental care
• costs of reproduction
• primary cavity nesters

The reproductive investment of 14 pairs of Syrian woodpecker Dendrocopos syriacus was studied in the newly-colonised area of SE Poland in 2003-2006. The birds devoted ay. 62.5% of their time to nest hole excavation, which varied between 44.7% of the time spent in April (before the egg laying) and 84.0% in May (during the breeding season). Nest construction was largely carried out by the male, with av.88.0% share of participation in this activity. In April, the share of male participation in nest construction averaged 96.8% and fell to 77.3% in May. Clutches were incubated 97.2% of the day time, shared equally by the pair members. The share of male and female participation in feeding was similar, too. In each successive fourth seven-day periods of nestling's life, one nestling received on average, respectively, 1.08, 1.86, 2.62, and 2.90 (average 2.12) food deliveries per hour. The involvement of both pair members in nest excavation during the breeding season and the participation of the female in this activity reduced the construction time of new nest holes, and simultaneously accelerated renesting. Additional costs of Syrian woodpecker reproduction at the northern limit of the species range may also result from an increased investment in egg incubation. This may be due to the greater thermal requirements of this southern species when breeding in the cooler climate of central Europe.

• 出版日期2016-3