| |
|
Red-backed shrike (\kur{Lanius collurio}) versus Common cuckoo (\kur{Cuculus canorus}): Clutch variability and egg recognition
KRAUSOVÁ, Ladislava
In this work, using photography, I tested the red-backed shrike (Lanius collurio) intraclutch egg variability and compared it with the interclutch egg variability. The effect of colour, size, volume and maculation as well as chromatic and achromatic contrasts were evaluated. Moreover, I tested ability of the red-backed shrike to recognize artificial cuckoo eggs and artificial shrike eggs, evaluate the rejection rate of these eggs, and compare it with the rejection rate of conspecific eggs. I showed that shrikes have low intraclutch variability and high interclutch variability in all measured parameters. Such variability might be an adaptation against brood parasitism. In addition, I found out that the shrikes' ability to recognize and reject a parasitic egg is significantly higher than expected.
|
| |