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Each spring, nature lovers eagerly greet the signs

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that winter is finally coming to an end.

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As the days grow warmer,

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the flowers and trees start to bloom,

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and the world comes alive

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with the melodious call of birds

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in search of a new mate.

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But where have these enchanting sounds

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been hiding all winter?

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For almost 200 species of song birds,

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their winters have been spent

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down in the tropical climates

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of Central and South America.

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While this may sound ideal,

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it involves one of the most perilous journeys

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known in the entire animal kingdom.

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This journey is called migration,

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and for song birds,

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this can involve travelling somewhere

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between a few hundred to almost 7,000 miles

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in a period of several weeks

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to four months.

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Birds spend weeks preparing

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for the intense journey

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by gorging on large quantities of food,

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sometimes doubling their weight

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prior to departure.

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While flying, birds can lose

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almost one percent of their body weight an hour,

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so packing on the pounds is crucial to their survival.

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However, more than the physical stress,

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migrating birds are now facing

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a new source of hardship:

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landscape change.

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Just imagine you're the one

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getting ready to take a trip.

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You've packed the car

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with everything you think you need,

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fueled up the tank,

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eaten a huge breakfast,

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and hit the road.

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You've taken this journey before.

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You know all your favorite rest stops

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and little back-alley diners to grab a bite.

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Everything is planned out.

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But just as your fuel gauge starts

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dipping into the red zone,

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you pass by what should have been a gas station,

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except it's closed.

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"Not a problem," you think,

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"The next one can't be too far away."

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But then that next station never appears.

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Unfortunately, as you continue on your route,

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the reality of the situation starts to set in.

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More and more stations are closed

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or just erased from your map.

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All of a sudden, your routine trip

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has become a desperate search

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just to find somewhere safe to rest

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and refuel for the night.

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This scenario has become the reality

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for the majority of migrating song birds

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as human land development continues unchecked.

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Humans are altering important stop-over sites

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that birds have been using for generations.

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As migrators pass over the continent,

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they run a gauntlet of dangers,

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including pesticide ingestion in rural farmlands,

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habitat loss in suburban developments,

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as well as disorientation from light pollution,

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and even structure collision

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with tall, reflective glass buildings in cities.

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Of the estimated 20 billion individual birds

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that comprise the fall population,

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only about half will return

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to breed the following spring.

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Almost one billion of these deaths

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are attributed just to building collisions.

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With such astounding yearly losses,

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humans risk more than just the loss

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of the beautiful colors and songs of birds,

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they also play an important role in the ecosystem.

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Birds help with insect control,

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pollination,

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and disbursing seeds throughout the landscape.

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Without birds, the natural world

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would be a very different place.

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Although birds face an on-going threat

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from human land development,

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there are actions that we can all take to help.

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Many countries and local governements

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have already passed important laws

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that restrict the use of poisonous pesticides.

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By using more natural, plant-based products,

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we can maintain our farms and gardens

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without the dangerous side effects.

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In addition, as our global populations continue to grow

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and people need places to call home,

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green spaces can offer both bird habitat

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as well as a peaceful and natural place

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for us to enjoy.

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Small changes at home

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can also make a huge difference.

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By hanging up feeders

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and building bird houses in outdoor areas,

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we can provide much-needed food and safety

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during long migrations.

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Turning out lights in suburban

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and urban environments

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can also help birds

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that look for stars to navigate.

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With our help, these sky travellers

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can reach their destination safely,

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and hopefully keep returning year after year.