All animal societies can be viewed as networks of interconnected individuals, linked by social, spatial, temporal, and other relationships. By studying the links of association between individuals we can derive unique insights into the workings of the society, and better understand the various behavioral strategies that individuals use to enhance their success. The study of animal social networks requires that associations between individuals be continuously monitored for extended periods of time. The task of determining social associations and movement patterns is usually attempted via direct observation methods. However, in many cases, observation is not feasible, especially when animals must be continuously monitored for long periods of time, when animals behave cryptically (as they often do), or when animals are out of sight of observers.
The Encounternet project will result in a miniaturized tag device for social network and behavioral studies. This microprocessor-based digital radio tag technology allows autonomous monitoring of the proximity of each tagged animal to all other nearby tagged individuals on a continuous basis. Encounternet consists of two components: small groving node transceiver tags mounted on animals, and collection node devices placed at fixed locations in the field. The roving node tags will weigh approximately 1g, allowing placement on small animals such as song birds, rodents, and reptiles, and will employ energy harvesting technology to extend their lifespan. To achieve the desired encounter monitoring functionality and enable a significant improvement in miniaturization, Encounternet will utilize integrated circuit advances in wireless transceivers, a new social network monitoring radio protocol design, and an energy harvesting low voltage solar powertrain to augment battery power.
For behavioral recording, Encounternet tags can be equipped with a variety of sensors, including accelerometers, microphones, and light monitors. Sensor-equipped tags can be configured to wirelessly stream sensor data to a receiver or store it in onboard non-volatile memory for later retrieval. This technology allows researchers to acquire an enormous amount of rich information about study animals, their spatial movement patterns, behavior, even physiological state, which would be impossible to acquire using conventional analog tracking technology, allowing animal movements, social association, and behavior to be monitored on a continuous basis for the entire study period.
The development of Encounternet will promote outreach in the following ways. A prototype network will be deployed in field tests with various collaborators who study animal social behavior. Although Encounternet is intended for small animal social network research, it can be applied to a wide variety of applications, including disease vector species interaction, below-ground social interactions in fossorial species, and spatial/temporal decision making processes in herds and flocks. Tours of the Discovery Park (Seattle, WA) prototype deployment will be given to groups of high-school students to promote interest in both technology and nature.
Intellectual Merit: The Encounternet project was conceived as a technological solution for a large class of animal research tracking and behavioral monitoring problems that had not been addressed by any commercially available products. At the time we started the project, there was no apparent commercial interest in offering a very small, flexible proximity logging smart radio tag for use in animal research. The lack of this class of device was particularly limiting to avian researchers, but also to those who studied small mammals and reptiles. Furthermore, no company had developed, or were developing, the completely automated wireless base station data collection system that we had conceived. Additionally, although several other academic groups may have been developing similar "smart tag" technology, most were focused on larger sensor-oriented devices and none of them appeared to be moving beyond simple and unpractical "proof of concept" designs that had limited real-world application. After 5 years, Encounternet is still the only radio tag in the sub-10 gram range that can perform proximity logging, and no other radio tracking system that we are aware of offers features such as automated base station logging and tag data downloading, wireless base station and tag data downloading, Wireless re-configuration of tags deployed on animals, wireless firmware updates, custom firmware design, sensor add-on capabilities, etc. that require tag-tag proximity logging for social network monitoring. To date, 10 Encounternet systems have been shipped to researchers who have used them all over the world (over 600 devices in total) Although some of the systems have been or are being used in small pilot experiments, others have produced striking results that would not have been not possible without Encounternet. Two Encounternet based research articles have been published, and to our knowledge there are at least two or three others in preparation. Other Encounternet users are still collecting and/or analyzing acquired data. We believe that Encounternet has been proven flexible enough for use on numerous other research designs and has definitely not yet reached its full potential. Broader impacts: Why is Encounternet unique? What we learned in the course of the Encounternet project (sometimes through hard lessons) was that there is a vast difference between demonstrating an idea in a laboratory, or even in the field as a limited pilot deployment, and achieving a robust working system that can be safely placed into the hands of biologists who want to use the technology. The amount of effort required to get a device to the "real world" has been enormous. The hardware design for the parts of Encounternet (master node, base stations, and tags) were not technically difficult to implement, although we have designed many circuit revisions over the course of the project to solve various emergent problems. However, it took much more effort, and most of the project’s man-hours, to implement and debug a radio communication protocol and integrated device firmware set that was robust and that could meet the needs of a range of research goals. This effort is probably beyond the means of most research labs, and telemetry equipment manufacturer’s budgets. The IDBR grant that funded Encounternet has resulted in a proven useful research tool that would not otherwise have been likely. Over the last three years, Encounternet has been used in a wide range of species, from small birds like great tits and long tailed manakins, larger birds such as crows and Galapagos hawks, aquatic mammals like river otters and Galapagos sea lions, and spawning salmon in fresh water. Research goals and methods have also varied widely, from studies that monitor visits by tagged birds to lek mating sites using base stations, studies that constantly locate tagged birds using base station arrays, and to experiments
