And because weissensee is such a deep forest , ornithologists doing serious birds of prey research show up to climb its trees and count the number of goshawk fledglings in cemetery nests .
In spring , caterpillars time their emergence to coincide with the bud burst of trees ; birds start nesting when they can feed those newly emerged caterpillars to their fledglings .
春天，毛毛虫的出现时间和树木的萌芽一致；鸟儿开始筑巢的时间要跟毛虫出现的时间吻合，用来哺育幼鸟。
The family is united and return to their nest where their roles are reversed as the fledglings guard their injured mother .
