Two papers published recently in BirdLife International's quarterly birding journal highlight a problem faced by conservationists trying to save bird species - poor breeding seasons caused by natural events. Heavy rainfall in Indonesia is thought to have hampered breeding efforts of the critically endangered yellow-crested cockatoo, where a crucial population of 60 birds fledged only one chick last season.
Similarly, botfly larvae in Brazil lowered the breeding success of two species of flycatchers. The campo suiriri had only one-third of nests successfully producing fledglings, with the chapada flycatcher being successful in only one-tenth of nests.
BirdLife conclude "Both these studies in very different parts of the world seem to show how different natural conditions can lead to low reproductive output - something that is very difficult for conservationists to mitigate against... Clearly though, good breeding years can never be taken for granted."