Understanding how individuals manage costs during the migration period is challenging because individuals are difficult to follow between sites; the advent of hybrid Global Positioning Systemacceleration （ACC） track...Understanding how individuals manage costs during the migration period is challenging because individuals are difficult to follow between sites; the advent of hybrid Global Positioning Systemacceleration （ACC） tracking devices enables researchers to link spatial and temporal attributes of avian migration with behavior for the first time ever. We fitted these devices on male Greenland white-fronted geese Anser albifrons flavirostris wintering at 2 sites （Loch Ken, Scotland and Wexford, Ireland） to understand whether birds migrating further during spring fed more on winter- ing and staging areas in advance of migration episodes. Although Irish birds flew significantly further （ca. 300 kin） than Scottish birds during spring, their cumulative hours of migratory flight, flight speed during migration, and overall dynamic body ACC （i.e., a proxy for energy expenditure） were not significantly different. Further, Irish birds did not feed significantly more or expend significantly more energy in advance of migration episodes. These results suggest broad individual plasticity in this species, although Scottish birds arriving on breeding areas in Greenland with greater energy stores （because they migrated less） may be better prepared for food scarcity, which might increase their reproductive success.展开更多
The ability to fly is crucial for migratory insects.Consequently,the accumulation of damage on the wings over time can affect survival,especially for species that travel long distances.We examined the frequency of irr...The ability to fly is crucial for migratory insects.Consequently,the accumulation of damage on the wings over time can affect survival,especially for species that travel long distances.We examined the frequency of irreversible wing damage in the migratory butterfly Vanessa cardui to explore the effect of wing structure on wing damage frequency,as well as the mechanisms that might mitigate wing damage.An exceptionally high migration rate driven by high precipitation levels in their larval habitats in the winter of 2018–2019 provided us with an excellent opportunity to collect data on the frequency of naturally occurring wing damage associated with long-distance flights.Digital images of 135 individuals of V.cardui were collected and analyzed in Germany.The results show that the hindwings experienced a greater frequency of damage than the forewings.Moreover,forewings experienced more severe damage on the lateral margin,whereas hindwings experienced more damage on the trailing margin.The frequency of wing margin damage was higher in the painted lady butterfly than in the migrating monarch butterfly and in the butterfly Pontia occidentalis following artificially induced wing collisions.The results of this study could be used in future comparative studies of patterns of wing damage in butterflies and other insects.Additional studies are needed to clarify whether the strategies for coping with wing damage differ between migratory and nonmigratory species.展开更多
文摘Understanding how individuals manage costs during the migration period is challenging because individuals are difficult to follow between sites; the advent of hybrid Global Positioning Systemacceleration （ACC） tracking devices enables researchers to link spatial and temporal attributes of avian migration with behavior for the first time ever. We fitted these devices on male Greenland white-fronted geese Anser albifrons flavirostris wintering at 2 sites （Loch Ken, Scotland and Wexford, Ireland） to understand whether birds migrating further during spring fed more on winter- ing and staging areas in advance of migration episodes. Although Irish birds flew significantly further （ca. 300 kin） than Scottish birds during spring, their cumulative hours of migratory flight, flight speed during migration, and overall dynamic body ACC （i.e., a proxy for energy expenditure） were not significantly different. Further, Irish birds did not feed significantly more or expend significantly more energy in advance of migration episodes. These results suggest broad individual plasticity in this species, although Scottish birds arriving on breeding areas in Greenland with greater energy stores （because they migrated less） may be better prepared for food scarcity, which might increase their reproductive success.
文摘The ability to fly is crucial for migratory insects.Consequently,the accumulation of damage on the wings over time can affect survival,especially for species that travel long distances.We examined the frequency of irreversible wing damage in the migratory butterfly Vanessa cardui to explore the effect of wing structure on wing damage frequency,as well as the mechanisms that might mitigate wing damage.An exceptionally high migration rate driven by high precipitation levels in their larval habitats in the winter of 2018–2019 provided us with an excellent opportunity to collect data on the frequency of naturally occurring wing damage associated with long-distance flights.Digital images of 135 individuals of V.cardui were collected and analyzed in Germany.The results show that the hindwings experienced a greater frequency of damage than the forewings.Moreover,forewings experienced more severe damage on the lateral margin,whereas hindwings experienced more damage on the trailing margin.The frequency of wing margin damage was higher in the painted lady butterfly than in the migrating monarch butterfly and in the butterfly Pontia occidentalis following artificially induced wing collisions.The results of this study could be used in future comparative studies of patterns of wing damage in butterflies and other insects.Additional studies are needed to clarify whether the strategies for coping with wing damage differ between migratory and nonmigratory species.
