A micro-tracking device for tracing action track of animals is disclosed. The micro-tracking device has a weight between 1 and 10 grams and is fastened on any animal's any position (especially a flight animal's concave ring portion between its body and tail), for capturing action track information (for...http://www.google.com/patents/US20080001815?utm_source=gb-gplus-sharePatent US20080001815 - Micro-tracking device for tracing action track of animals and method for using the same
