A wireless tracking device, comprising: a locating device configured to determine a geographic location of the wireless tracking device; at least one sensor configured to generate a sensor signal, the sensor signal representing a condition or a property associated with the wireless tracking device; at least one controller coupled to the location device and the at least one sensor, the at least one controller configured to: generate a message indicating the geographic location and the condition or the property associated with the wireless tracking device, place the wireless tracking device in a hibernation mode for a predetermined amount of time, switch the wireless tracking device to an active mode in response to receiving, from the at least one sensor, a sensor signal indicating a change exceeding a first sensitivity corresponding to a first external event, wherein the active mode consumes more power than the hibernation mode, increase the sensitivity for detecting an event by the at least one sensor to a second sensitivity while the wireless tracking device is in the active mode, and maintain the wireless tracking device in the active mode in response to receiving a sensor signal indicating a change exceeding the i second sensitivity corresponding to a second external event; and a communication module configured to send the message via a wireless network; wherein the locating device and the communication module are configured to operate in the active mode but not in the hibernation mode and to be intermittently operated in the active mode. a locating device configured to determine a geographic location of the wireless tracking device; at least one sensor configured to generate a sensor signal, the sensor signal representing a condition or a property associated with the wireless tracking device; at least one controller coupled to the location device and the at least one sensor, the at least one controller configured to: generate a message indicating the geographic location and the condition or the property associated with the wireless tracking device, place the wireless tracking device in a hibernation mode for a predetermined amount of time, switch the wireless tracking device to an active mode in response to receiving, from the at least one sensor, a sensor signal indicating a change exceeding a first sensitivity corresponding to a first external event, wherein the active mode consumes more power than the hibernation mode, increase the sensitivity for detecting an event by the at least one sensor to a second sensitivity while the wireless tracking device is in the active mode, and maintain the wireless tracking device in the active mode in response to receiving a sensor signal indicating a change exceeding the i second sensitivity corresponding to a second external event; and a communication module configured to send the message via a wireless network; generate a message indicating the geographic location and the condition or the property associated with the wireless tracking device, place the wireless tracking device in a hibernation mode for a predetermined amount of time, switch the wireless tracking device to an active mode in response to receiving, from the at least one sensor, a sensor signal indicating a change exceeding a first sensitivity corresponding to a first external event, wherein the active mode consumes more power than the hibernation mode, increase the sensitivity for detecting an event by the at least one sensor to a second sensitivity while the wireless tracking device is in the active mode, and maintain the wireless tracking device in the active mode in response to receiving a sensor signal indicating a change exceeding the i second sensitivity corresponding to a second external event; and a communication module configured to send the message via a wireless network; wherein the locating device and the communication module are configured to operate in the active mode but not in the hibernation mode and to be intermittently operated in the active mode.