 The wren (Troglodytes troglodytes) is a very active small bird, weighing around 00g - about half an ounce. This male has been building this nest for some weeks, however it will be one of several he builds in an attempt to woo a female. This one has chosen the build under the front overhang of a boat roof. Heron 0 This heron (Ardea cinerea) was later rewarded for its patience with a rather unfortunate pike (Esox lucius). The heron's simple technique is wait, then stab its beak through its prey skewer style. 