короткие ночные полеты птиц и летучих мышей
Уже довольно старая статья 2011 года в PLOS ONE, но вновь и вновь заставляет задуматься о механизме этого явления. Большое количество птиц было прослежено, и многие из исчезнувших из-под контроля были вновь обнаружены. У некоторых видов до половины стартов заканчивались этими короткими разнонаправленными полетами.
Жаль, что авторы на анализировали эти короткие полеты совместно с метеорологическими параметрами (сила и направление ветра на разных высотах в дни стартов).
Естественно, возникают аналогии с разнонаправленной ориентацией птиц в клетках Эмлена.
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0027054#pone-0027054-g003
Landscape Movements of Migratory Birds and Bats Reveal an Expanded Scale of Stopover.
Many species of birds and bats undertake seasonal migrations between breeding and over-wintering sites. En-route, migrants alternate periods of flight with time spent at stopover - the time and space where individuals rest and refuel for subsequent flights. We assessed the spatial scale of movements made by migrants during stopover by using an array of automated telemetry receivers with multiple antennae to track the daily location of individuals over a geographic area ~20×40 km. We tracked the movements of 322 individuals of seven migratory vertebrate species (5 passerines, 1 owl and 1 bat) during spring and fall migratory stopover on and adjacent to a large lake peninsula. Our results show that many individuals leaving their capture site relocate within the same landscape at some point during stopover, moving as much as 30 km distant from their site of initial capture. We show that many apparent nocturnal departures from stopover sites are not a resumption of migration in the strictest sense, but are instead relocations that represent continued stopover at a broader spatial scale.
Жаль, что авторы на анализировали эти короткие полеты совместно с метеорологическими параметрами (сила и направление ветра на разных высотах в дни стартов).
Естественно, возникают аналогии с разнонаправленной ориентацией птиц в клетках Эмлена.
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0027054#pone-0027054-g003
Landscape Movements of Migratory Birds and Bats Reveal an Expanded Scale of Stopover.
Many species of birds and bats undertake seasonal migrations between breeding and over-wintering sites. En-route, migrants alternate periods of flight with time spent at stopover - the time and space where individuals rest and refuel for subsequent flights. We assessed the spatial scale of movements made by migrants during stopover by using an array of automated telemetry receivers with multiple antennae to track the daily location of individuals over a geographic area ~20×40 km. We tracked the movements of 322 individuals of seven migratory vertebrate species (5 passerines, 1 owl and 1 bat) during spring and fall migratory stopover on and adjacent to a large lake peninsula. Our results show that many individuals leaving their capture site relocate within the same landscape at some point during stopover, moving as much as 30 km distant from their site of initial capture. We show that many apparent nocturnal departures from stopover sites are not a resumption of migration in the strictest sense, but are instead relocations that represent continued stopover at a broader spatial scale.