This has been tested by comparing predation rates at artificial nests with and without playbacks of bird begging calls.

The problem is that these birds suffer high nest predation rates and so not all the offspring from a nest can be sampled.

During a survey, it was apparent that cats killed Kakapo with a predation rate of 56% per annum.

Breeding success in the period under review was often poor and observers have frequently remarked on a high predation rate after hatching.

The predation rate is low, since the islands are protected from terrestrial predators, but in some years there have been high losses caused by owls.

Nevertheless, topi tend to have a low predation rate when other species are around.

Therefore, clutch size in southern areas cannot be explained by predation rates or food delivery.

As a result of their high predation rate, these lizards are very prolific breeders.

Additional factors including high predation rates due to human disturbances and climate-driven changes in ocean conditions are also considered important now.

By increasing brood size, predation rate per individual decreases as a result of dilution effects.