Sensor:
Acceleration

No Thumbnail Available
Name
Acceleration
External ID
acceleration
Is Location Sensor

Filters

2016 - 201912020 - 20211
Reset filters

Settings

search.filters.applied.f.scientificName: Anser albifrons ×

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Data package
    Data from: Longer days enable higher diurnal activity for migratory birds [greater white-fronted geese]
    (2021-03-24) Kölzsch, Andrea; Müskens, Gerhard J.D.M.; Moonen, Sander; Kruckenberg, Helmut; Glazov, Peter; Wikelski, Martin
    (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.
  • No Thumbnail Available
    Data package
    Data from: Scaring waterfowl as a management tool: how much more do geese forage after disturbance?
    (2016-05-20) Kölzsch, Andrea; Müskens, Gerhard J.D.M.; Nolet, Bart A.; Wikelski, Martin
    (1) With increasing numbers of many herbivorous waterfowl species, often foraging on farmland, the conflict with agriculture has intensified. One popular management tool is to scare birds off the land, often in association with shooting. However, the energy costs of flying are considerably higher than those of resting. Therefore, when birds fly off after a disturbance, they use extra energy that subsequently needs to be compensated. (2) We used the white-fronted goose Anser albifrons, the most common (grass-eating) species wintering in western Europe, as a model species. We measured flight durations by high-frequency accelerometer recordings over 2 × 24 h in 9 focal geese that were only incidentally disturbed. We also made direct observations on these days to determine whether the flight durations were reliably recorded. Using both a simple and a more realistic model of the energy balance, we calculated the extra grass consumption resulting from additional intentional disturbances. (3) On average, the geese flew daily 2 × 323 s (from and to their roosting sites at 3200 m), and furthermore took to the air 5.3 times during a day (and 1.9 times a night). Multiplied with the average flight durations of 195 s, this gives a total flying time of almost 0.6 h day-1 and a total foraging time of 7.4 h day-1. The extra foraging time needed to compensate for additional intentional disturbances strongly depends on the frequency of such disturbances and the following flight duration. If, for example, flights when intentionally disturbed are twice as long (2 × 195 s), the extra foraging time will be 3.7% day-1 (2.3–3.2% day-1 in the more realistic model) for each intentional disturbance, and the geese will no longer be able to cover their energy requirements when intentionally disturbed six times per day. (4) Synthesis and applications. Recent experiments suggest that geese have to be scared frequently in order to reduce goose visitation to particular fields. With an intentional disturbance rate e.g. of five times a day, the birds’ compensation for the increased energy expenditure will lead to a higher overall consumption of grass of 11.5–16 % day-1. Accommodation schemes have to take such increases in total grass consumption into account when deciding on the refuge areas to be set aside.