Steph Harris
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stephharris.bsky.social
Steph Harris
@stephharris.bsky.social
Researcher at Bangor University @sosbangor.bsky.social working on seabird movement and energetics. Interested in animal movement, behaviour and demography. She/her
Special thanks to @bardseybirdobs.bsky.social and @copelandbirdobs.bsky.social for their incredible support and being wonderful places to spend time with Manx shearwaters! Thanks also to project SHEAR and my brilliant co-author team!
January 15, 2025 at 10:29 AM
We enjoyed thinking about how being both wind-efficient and target-oriented might together help shape colony foraging ranges...

If birds learn their foraging landscape over time, but prevailing winds influence where they get to know best, windscape effects should persist even on calm days
January 15, 2025 at 10:29 AM
Manxies are generally quite wind selective (as we'd expect, for a shear soarer), but they often reject being efficient - esp. on return to the colony, if winds aren't too high, or when embarking on a long flight

Collectively, these suggest birds trade off wind-efficiency vs. reaching known targets
January 15, 2025 at 10:29 AM
We estimated flight costs under different wind conditions using accelerometry and measured the wind selectivity of shearwater flight decisions - did they choose the cheapest available path given the wind, or were they prioritising something else?
January 15, 2025 at 10:29 AM
Manx shearwaters seem to fall somewhere in between - they show some evidence of targeted foraging movements, but have a strong preference for flying in a crosswind direction for dynamic soaring

So how does a seabird both wind-efficient and target-oriented make foraging decisions?
January 15, 2025 at 10:29 AM
Some seabirds (esp. Procellariiformes) have wind-assisted foraging strategies, with some closely following the most wind-efficient path to fly fast & cheap, encountering prey at random as they go

Meanwhile, other seabirds seem to target memorised foraging areas, flying directly to prey hotspots
January 15, 2025 at 10:29 AM