Improving the efficiency of routing methods in wireless networks of telemetry systems

Одна из основных проблем построения автоматизированных систем телеметрии и управления – организация надежной связи между удаленными объектами и пунктами сбора информации. Использование беспроводных самоорганизующихся сетей является наиболее приемлемым решением данной задачи. Подобные сети характеризуются: высокой надежностью и живучестью; достаточной пропускной способностью; низкой стоимостью эксплуатации; простотой перемещения и оперативностью развертывания. В настоящее время разработано множество алгоритмов и протоколов, обеспечивающих автоматическое конфигурирование таких сетей. Однако, несмотря на обилие разработанных алгоритмов и протоколов существует необходимость создания новых протоколов, оптимальных для решения поставленной задачи при заданной топологии сети. В работе предложен алгоритм поиска кратчайшего пути маршрутизации в телеметрической беспроводной сети. Представлен пример поиска оптимального пути в случае выхода из строя одного из транзитных узлов системы телеметрии. Реализация алгоритма позволяет существенно упростить поиск нового маршрута и сократить временные затраты на восстановление целостности сети, что в конечном итоге увеличивает пропускную способность сети. One of the main problems of building automated telemetry and control systems is the organization of reliable communication between remote objects and information collection points. The most acceptable solution to this problem is the use of wireless self-organizing networks. Such networks are characterized by high reliability and survivability, sufficient bandwidth, low operating costs, ease of movement and speed of deployment. Currently, many algorithms and protocols have been developed that provide automatic configuration of such networks. However, despite the abundance of developed algorithms and protocols, there is a need to create new protocols that are optimal for solving the problem at a given network topology. The paper proposes an algorithm for finding the shortest routing path in a telemetric wireless network. An example of finding the optimal path in the event of failure of one transit node of the telemetry system is presented. The implementation of the algorithm makes it possible to significantly simplify the search for a new route and reduce the time spent on restoring the integrity of the network, which ultimately increases the network throughput.

Workflow for constructing social networks from automated telemetry systems

1.Advances in datalogging technologies have provided a way to monitor the movement of individual animals at unprecedented spatial and temporal scales, both large and small. When used in conjunction with social network analyses, these data can provide insight into fine scale associative behaviors. The variety of technologies demand continuous progress in workflows to translate data streams from automated systems to social networks, based on biologically relevant metrics. 2.Here we present a workflow for generating flexible association matrices from automated radio-telemetry data that can be parsed into both spatial and temporal dimensions. These can then be used to generate and compare social networks across space and time.3.We illustrate this workflow using data collected from an automated telemetry study of acorn woodpeckers (Melanerpes formicivorus), a cooperatively breeding bird. The data were collected continuously over two years at base stations placed within social group territories. We use this system to demonstrate how this flexible data structure can be used to answer a number of biological questions, specifically 1) how assortative are social associations at the population scale, 2) how do association patterns among territory visitors vary across territories, 3) and how does seasonality affect assortative affiliation within groups?4.This flexible method allows one to generate social networks that can be used to ask a variety of biological questions pertinent to a wide range of animal systems, exploiting the investigative power that can be gained by using automated radio-telemetry in conjunction with social network analyses.

Captive-reared migratory monarch butterflies show natural orientation when released in the wild

Eastern North American migratory monarch butterflies (Danaus plexippus) have faced sharp declines over the last two decades. Although captive rearing has been used as an important tool for engaging the public and supplementing conservation efforts, a recent study that tested monarchs in a flight simulator suggested that captive-reared monarchs lose their capacity to orient southward during fall migration to their Mexican overwintering sites. We raised offspring of wild-caught monarchs on swamp milkweed (Asclepias incarnata) and, after eclosion, individuals were either tested in a flight simulator or radio-tracked in the wild using array of over 100 automated telemetry towers. While only 33% (7/39) of monarchs tested in the flight simulator showed strong southeast to southwest orientation, 97% (28/29) of the radio-tracked individuals were detected by automated towers south or southeast of the release site, up to 200 km away. Our results suggest that, though captive rearing of monarch butterflies may cause temporary disorientation, proper orientation is likely re-established after exposure to natural skylight cues.

Evidence for spring stopover refuelling in migrating silver-haired bats (Lasionycteris noctivagans)

Migrating animals must acquire sufficient fuel to sustain migratory movement, but how time is allocated to achieve this can vary greatly. The fuel strategies used by migrating bats are not well understood and have not been investigated during the spring when insectivorous bats face low food abundance. Migrating silver-haired bats (Lasionycteris noctivagans (Le Conte, 1831)) were captured at a stopover site in Long Point, Ontario, Canada, in April and May of 2012–2014. We followed the movements of 40 bats outfitted with radio transmitters using an automated telemetry array and examined the effects of ambient temperature, fat stores, and sex on stopover duration. As seen previously in autumn, most bats departed the evening following capture, but one-third of bats used multiday stopovers. Extended stopover was associated with lower ambient temperature. There was no effect of sex or fat at capture on stopover departure probability. Bats captured closer to dawn had greater fat mass and lean mass than those captured early in the night, a trend indicative of fuel deposition at this site. This is the first study to provide evidence that bats use stopover habitat for refuelling.

Testosterone modulates status-specific patterns of cooperation in a social network

SummaryStable cooperation requires plasticity whereby individuals are able to express competitive or cooperative behaviors depending on social context. To date, however, the physiological mechanisms that underlie behavioral variation in cooperative systems are poorly understood. We studied hormone-mediated behavior in the wire-tailed manakin (Pipra filicauda), a gregarious songbird whose cooperative partnerships are crucial for fitness. We used automated telemetry to monitor > 36,000 cooperative interactions among male manakins over three field seasons, and we examined how circulating testosterone affects cooperation using > 500 hormone samples. Observational data show that in non-territorial floater males, high testosterone is associated with increased cooperative behaviors and subsequent ascension to territorial status. In territory-holding males, however, both observational and experimental evidence demonstrate that high testosterone antagonizes cooperation. Moreover, circulating testosterone explains significant variation (2-8%) in social behavior within each status class. Collectively, our findings show that the hormonal control of cooperation depends on a male’s social status. We propose that the status-dependent reorganization of hormone-regulatory pathways can facilitate stable cooperative partnerships, and thus provide direct fitness benefits for males.