Each year, the arrival and departure of migratory birds herald the changing seasons and fill us with wonder for the natural world. Have you ever wondered about all the dangers they face en route between their breeding and overwintering grounds?
Birds face multiple threats during migration, from losing their way to running out of energy or falling prey to a hungry predator. However, the world’s birds face new threats as the human population grows and suitable habitats are degraded and transformed.
Growing awareness around the dangers migratory birds face and the active involvement of individuals, communities, and governments will be key to keeping our skies filled with the calls of migrating birds for generations to come.
In this guide, we’ll be taking a closer look at some of the major threats to migrating birds. Read along to learn about some of the old and new challenges our heroic feathered friends overcome to return to our areas each year.
Pictured: The Calliope Hummingbird is a long-distance migrant travelling around 5,000 miles each year
Flying long distances across varied landscapes is filled with potential dangers for migrating birds. Read on to learn about the natural challenges these birds face.
Migrating birds are vulnerable to many wild and feral predators while on migration. Many smaller species prefer to migrate at night when dangerous aerial predators like Peregrine Falcons are asleep, but they are not safe from attack while resting and foraging during the day.
Birds have evolved several strategies to avoid predators, including keen senses and vigilance, speed and agility, and safety in numbers when migrating in flocks.
Birds have the remarkable ability to navigate across immense distances, but sometimes, they get a little lost and never arrive at their destination.
Because they are so mobile, these unfortunate birds can turn up as vagrants far away from their usual habitat and sometimes even on the wrong continent!
Unfortunately, vagrant birds often die of exhaustion or fail to adapt to their new environment, although some do recover and make it back home.
Extreme natural events like high winds, dust storms, large hail, and heavy rain can make migration difficult or even deadly, especially where large sea crossings are involved.
Birds may stop to rest or change course to avoid these events when flying over land, but birds crossing large waterbodies may be exhausted when they find no safe place to shelter.
Many smaller bird species prefer to migrate at night when dangerous aerial predators like Peregrine Falcon (pictured) are asleep
The human population has increased roughly 8-fold in the last two centuries, causing massive changes to the natural habitats that birds evolved in. These changes have come too rapidly for most birds to adapt, leaving them vulnerable to many human-induced challenges.
Continue reading to learn about the new challenges facing migratory birds.
Birds evolved in a world where the moon and the stars were the only light source after sunset. These celestial bodies provide important navigational cues for migrating birds, but artificial light is creating havoc by confusing and causing them to veer off course or suffer fatal collisions.
Tall man-made structures with or without artificial light create a deadly obstacle for migrating birds. Structures such as lighthouses, towers, skyscrapers, and wind turbines can cause especially high mortalities.
Looking at satellite imagery of the Earth, it’s clear to see the impacts humans have on the environment. From the degradation of natural landscapes by overgrazing to monocultures of crops and forestry, human land-use practices severely alter the natural landscapes birds rely on.
In more extreme cases, urbanization and industrial developments severely fragment natural habitats, making it difficult for migrating birds to find resting and feeding areas on their journey.
Structures such as wind turbines are a deadly obstacle for migrating birds
The increased Carbon Dioxide levels and temperatures associated with accelerated climate change can affect migratory birds by altering the vegetation communities in their habitats and changing the timing of natural food source availability. This is causing marked changes in the timing and routes of migrating birds.
Pesticide use and pollution are affecting migratory birds and their food sources. Decreased invertebrate populations affect the entire ecosystem, including birds.
In some parts of the world, migrating birds face the threat of direct persecution, either for food, profit, to protect crops, or even for sport. Shooting, trapping, and poisoning all take their toll on birds as they migrate between their breeding and overwintering grounds.
Pictured: Mute Swan. Pesticide use and pollution are affecting migratory birds and their food sources
Migrating birds are not concerned with politics and national boundaries, yet these human constructs have important effects on their survival.
Laws and policies governing the protection of migrating birds may differ between nations, but the guidance of international conservation organizations and agreements can benefit migratory birds across their often extensive world ranges. The following international agreements and organizations benefit and protect migrating birds:
Also known as the Bonn Convention, the CMS is an international environmental treaty of the United Nations that provides for legal protection of migratory species in over 133 countries. It contributes by obligating member states to conserve habitats, protect migratory species, and manage risks that affect their migrations.
The Migratory Bird Treaty Act of 1918 federally protects over a thousand species of migratory birds. It was first enacted to protect North American migrants between the United States and Canada but has since expanded to include Japan, Russia, and Mexico.
Over 190 countries have joined the legally binding Paris Agreement, an international treaty that seeks to reduce global greenhouse gas emissions.
Ramsar is the name of an international treaty that protects over 2,400 wetlands worldwide. These sensitive environments are especially important for migrating wildfowl and shorebirds.
World Migratory Bird Day is celebrated on the second Saturday of May and October each year. It is an important tool for raising awareness and gathering support for the protection of migratory birds all over the world.
Lesser Falmingos (pictured) in a Ramsar protected wetland
While international initiatives are vital for the long-term protection of migratory birds, the importance of actions at a grass-roots level cannot be overstated.
Rather than waiting for others to champion their cause, we can all do our bit, and understanding the challenges faced by migrating birds is an essential first step toward conserving these precious creatures.
The following simple actions can make a difference:
Pictured: A small flock of Bar-tailed Godwits in-flight
Scientific research is a powerful tool that informs decision-making for the conservation of migratory birds. Fortunately, the growing body of work produced by students, professional scientists, and even members of the public through citizen science programs continues to provide important data.
Scientific research sheds light on every aspect of bird migration, including the challenges they face.
Recent findings, for example, have uncovered that migrating birds recover their immune systems during rest stops and that birds require more protein to fuel their flights than previously thought.
This kind of information may yet prove to have important implications in protecting migratory bird stopover sites and feeding areas.
Technological advancements are providing new ways of tracking and studying bird migrations. While old techniques like ringing/banding still have their place, new tools like drones and compact GPS tracking devices help scientists monitor bird movement in real time.
With increasingly powerful technology in our mobile devices, birdwatchers can also contribute meaningful data through citizen science platforms like iNaturalist and eBird that collect geographic and temporal information about bird movements.
Adélie Penguins (pictured) migrate on average around 8,100 miles (13,000 kilometres) every year
All around the world, bird watchers and nature lovers root for birds as they make their long and often dangerous annual migrations.
However, challenges and pitfalls ranging from predators and storms to global crises like climate change and habitat destruction are taking their toll on avians globally.
Only by understanding these threats and spreading awareness around the plight of migratory birds can we adequately conserve them now and into the future.
Fortunately, we can all help in our own way and, through small collective efforts, help our feathered friends return safely next spring.
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