井下切割形成的巢状钢屑团
... bird-foot delta 鸟足状三角洲 bird-nesting 井下切割形成的巢状钢屑团 bird-track 鸟迹 ...
Oology (or oölogy) is a branch of ornithology studying bird eggs, nests and breeding behaviour. The word is derived from the Greek "oion", meaning egg. Oology can also refer to the hobby of collecting wild birds' eggs, sometimes called egg collecting, birdnesting or egging, which is now illegal in many jurisdictions.