A device and a method are provided for detecting and indicating a preparatory phase of birthing a bovine or equine animal. The device is configured to be attached to the tail of the bovine or equine animal. The device contains elements configured to: measure components of acceleration of the device according to at least one axis, such as three orthogonal axes process the measurements of the components, to detect an occurrence of the preparatory phase generate a radio communication signal configured in case the occurrence is detected and transmit the generated signal to a collector forming a relay or to a terminal.