Data from: Longer days enable higher diurnal activity for migratory birds [Himalayan griffons]

Sherub S, Wikelski M. 2021. Data from: Longer days enable higher diurnal activity for migratory birds [Himalayan griffons]. Movebank Data Repository.
(1) Seasonal geophysical cycles strongly influence the activity of life on Earth because they affect environmental conditions like temperature, precipitation, and daylength. An increase in daylight availability during summer is especially enhanced when animals migrate along a latitudinal gradient. Yet, the question of how daylength (i.e. daylight availability) influences the activity patterns of long‐distance, latitudinal migrants is still unclear. (2) Here, we ask whether migration provides benefits to long‐distance migrants by enabling them to increase their diurnal movement activities due to an increase in daylight availability. To answer this question, we tested whether four vastly different species of long‐distance migratory birds--two arctic migrants and two mid‐latitude migrants--can capitalise on day length changes by adjusting their daily activity. (3) We quantified the relationship between daily activity (measured using accelerometer data) and day length, and estimated each species' daily activity patterns. In addition, we evaluated the role of day length as an ultimate driver of bird migration. (4) All four species exhibited longer activity periods during days with more daylight hours, showing a strong positive relationship between total daily activity and day length. The slope of this relationship varied between the different species, with activity increasing 1.5‐fold on average when migrating from wintering to breeding grounds. Underlying mechanisms of these relationships reveal two distinct patterns of daily activity. Flying foragers showed increasing activity patterns, i.e. their daytime activities rose uniformly up to solar noon and decreased until dusk, thereby exhibiting a season‐specific activity slope. In contrast, ground foragers showed a constant activity pattern, whereby they immediately increased their activity to a certain level and maintained this level throughout the day. (5) Our study reveals that long days allow birds to prolong their activity and increase their total daily activity. These findings highlight that daylight availability could be an additional ultimate cause of bird migration and act as a selective agent for the evolution of migration.
Gyps himalayensis,animal behavior,animal movement,animal tracking,avian migration,bio-logging,GSM telemetry,Gyps himalayensis,Himalayan vulture,life history,seasonality
Gyps himalayensis
Himalayan Vulture
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DOIs of related Publications
  title = {Data from: Longer days enable higher diurnal activity for migratory birds [Himalayan griffons]},
  author = {Sherub, S and Wikelski, M},
  year = {2021},
  URL = {},
  doi = {doi:10.5441/001/1.4n2501f5},
  publisher = {Movebank data repository}
ID  - doi:10.5441/001/1.4n2501f5
T1  - Data from: Longer days enable higher diurnal activity for migratory birds [Himalayan griffons]
AU  - Sherub, Sherub
AU  - Wikelski, Martin
Y1  - 2021/03/24
KW  - Gyps himalayensis
KW  - accelerometer
KW  - animal behavior
KW  - animal movement
KW  - animal tracking
KW  - avian migration
KW  - bio-logging
KW  - GSM telemetry
KW  - Gyps himalayensis
KW  - Himalayan vulture
KW  - life history
KW  - seasonality
KW  - Gyps himalayensis
PB  - Movebank data repository
UR  -
DO  - doi:10.5441/001/1.4n2501f5
ER  -