HOW DO BIRDS SENSE COLD WEATHER COMING?

some duck and geese migrate when the weather finally turns cold enough but most birds leave long before the winter comes marsh warblers start to migrate in july their bodies tell them when to go as changes.

A hormones cause them to put on fat ready for the journey the final trigger to move is the length of the day which gets shorter in autumn and longer in spring.

img credits: https://www.shutterstock.com/video/clip-8436802-stock-footage-winter-pack-of-ducks-on-open-water-near-the-coast.html

Thanks You! Maraming Salamat po!