Ghrelin, corticosterone and the resumption of migration from stopover, an automated telemetry study

2018 ◽  
Vol 194 ◽  
pp. 450-455 ◽  
Author(s):  
Cas Eikenaar ◽  
Sven Hessler ◽  
Elmar Ballstaedt ◽  
Heiko Schmaljohann ◽  
Hiroyuki Kaiya
Keyword(s):  
2020 ◽  
Author(s):  
Alana A. E. Wilcox ◽  
Amy E. M. Newman ◽  
Nigel E. Raine ◽  
D. Ryan Norris

AbstractEastern 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.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Dmitry Kishkinev ◽  
Dominik Heyers ◽  
Bradley K. Woodworth ◽  
Greg W. Mitchell ◽  
Keith A. Hobson ◽  
...  

Author(s):  
Е.Е. Прозоровский ◽  
Ю.В. Редькин

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.


2017 ◽  
Vol 71 (2) ◽  
Author(s):  
Antonio Celis-Murillo ◽  
Wendy Schelsky ◽  
Thomas J. Benson ◽  
Matthew I. M. Louder ◽  
Michael P. Ward

2013 ◽  
Vol 47 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Jinelle H. Sperry ◽  
Michael P. Ward ◽  
Patrick J. Weatherhead

2019 ◽  
Vol 97 (11) ◽  
pp. 961-970 ◽  
Author(s):  
Kristin A. Jonasson ◽  
Christopher G. Guglielmo

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.


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