In a feeding relationship, the higher trophic level animals can be described as predators. There are two approaches to analyzing the effect of predators on lower-level organisms: exclusion of predators or direct counting of the loss of prey items by predators. In New Zealand, reducing the threat to endemic species by excluding invasive predator species is practiced on various scales. Experiments can be carried out with eggs laid as prey in artificial nests. The number of bites on prey reflects the strength of predation pressure. In the forests, browsing pressure is of economic importance. Measurement methods are addressed. However, large herbivores’ browsing effect on vegetation can also be utilized for nature conservation. We also discuss the extent to which top carnivores control the density of prey populations.