How Birds Know the Time and Why Barn Swallows Stick to the Schedule


Depending on where you live, you might be getting ready to “fall back” this weekend – that is, setting your clock back an hour to mark the start of Daylight Savings Time. Yay for an extra hour of sleep! Lucky for us humans we have alarm clocks to keep us on track, but that’s not the case in the animal kingdom. Have you ever seen a time-telling turtle?! We sure haven’t!

Keeping track of time is really important for lots of animals, especially the ones that migrate, since they cover a lot of distance at certain times of the year and always have to keep on schedule! Some of the most impressive long distance migrators are Monarch butterflies, which travel 4,000 km and humpback whales, which travel over 9,800 km. There are over 4,000 bird species in North America that move south in the fall and return north in the spring. That’s over 5 billion birds on the go heading in the same direction, and most of them at the same time, creating some very crowded skies!

barn swallow flying

Without an alarm clock to remind them, how can all these birds tell when it’s time to migrate? Most migratory birds use the length of the day, the availability of food and their hormones to tell them what time of year it is. Thanks to these internal alarm clocks North American birds know when it is the fall and time to head south to their wintering grounds and when it is spring and time to migrate north to their breeding grounds.

Barn Swallows on the Move

barn swallow map
Barn swallows breed in the blue area and migrate south in the fall to the orange area.

Barn swallows are one of the migratory songbirds that know when it is time to get moving by the length of the day, what food is around and their hormones. As the weather begins to warm up and the days get longer with the onset of spring, barn swallows and other North American songbird species use these cues or signals to tell them it is time to head north to breed. Special hormones or chemicals in their bodies also tell the birds that it is time to migrate by preparing the birds to mate. As winter ends and spring approaches most barn swallows start their migration journey north, leaving their wintering grounds in South and Central America in February and arriving at their summer breeding grounds by late April to early May. That’s three months on the road or … sky, a long migration for a small bird to make. For lots of birds, including barn swallows, they make this trip so they can have and raise their young in a relatively safe place; talk about dedicated parents! For songbirds like the barn swallow, North America is the perfect nursery for their young. There are tons of insects to feed them and there are less threats to their nests when compared to more southern tropical climates. The breeding season only lasts three and a half months, so by August it’s time to pack up and head out again, arriving back in South and Central America in November – right about now!

Unfortunately for us humans, our internal clocks aren’t quite as incredible as the barn swallow’s, so don’t forget to set your clocks back this weekend if you live somewhere that participates in Daylight Savings Time! Maybe you’ll think about the barn swallow’s amazing migration when you do, or maybe you’ll have visions of the monarch’s epic journey instead – let us know what your favourite migratory animal is in the comments!


  1. Hi my name is AlexisJane nice to meet you I live on earth and tricks I love the animals because know how to put on pictures for admissions I don’t know please or makes fun of me because my full name is I am a native I love animals so much at school from nine I don’t want anyone Hurt the trailer even within trouble I don’t Madame that’s why am I want of them don’t let me give up or are you busy nature is more important than one else Thanks like natures in a minute because that’s that’s what they think and I don’t like it that’s how much I love animals I don’t want them to even fully animals my friends even say well bullies or say to me that there’s no such thing as Earth rangers And I’m like Earth rangers exist


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