Desert Birds
Desert birds are some of the most clever survivors of any desert wildlife. With no fur and no underground burrows, they cannot easily escape the heat, so they have evolved different strategies: flying to find water, staying in deep shade during the day, or migrating to follow seasonal rains. Some species (like the sandgrouse) make daily flights of up to 80 km to drink water and bring it back to their chicks.
- Iconic desert birdRoadrunnerFast-running cuckoo of North America
- Water carrierSandgrouseSoaks belly feathers for chicks
- MigratingMany speciesUse deserts as routes between continents
- Heat dumpBig beakLoses heat through bare skin areas
- Famous owlElf owlSmallest owl, lives in saguaro cacti
- Hidden by dayMost speciesActive at dawn and dusk
How fast can a roadrunner run?
The greater roadrunner can sprint at up to 32 km/h, fast enough to chase down lizards, snakes and even small birds. The bigger ostrich (of African grasslands) is the fastest running bird at over 70 km/h.
How do desert birds survive?
Desert birds use a mix of strategies:
- Be active at dawn and dusk. Many desert birds rest in deep shade during the hottest hours, then become active in the cooler morning and evening light.
- Pant instead of sweat. Birds do not have sweat glands, but many desert species pant rapidly when overheated, using the evaporation of moisture from their throat to cool down.
- Flutter their throat skin. Some birds (vultures, owls, doves) have a featherless throat patch they can vibrate to lose heat, called "gular fluttering".
- Use big beaks for cooling. The toco toucan and the desert thrasher have unusually large beaks with rich blood supply, which act as heat radiators.
- Travel for water. Many desert birds fly long distances every day to reach water sources, then back to feed in dry areas.
- Be light-coloured. Most desert birds are pale tan, sandy or grey, reflecting more sunlight than darker colours.
The famous roadrunner
The greater roadrunner of the American Southwest is one of the most distinctive desert birds. It is a large ground-dwelling cuckoo with long legs, a long tail and a distinctive crest. Although it can fly, the roadrunner prefers to run, sprinting at up to 32 km per hour to chase down lizards, snakes (including small rattlesnakes), insects, scorpions and other small animals. The famous Roadrunner cartoon character is a wild exaggeration of the real bird (which says nothing like "meep meep") but the running speed is fairly accurate.
The elf owl
The elf owl of the Sonoran Desert is the smallest owl in the world, just 13 to 14 cm tall (about the size of a sparrow). It lives in nest holes carved into saguaro cacti by woodpeckers, perfectly safe from most ground predators behind the cactus's spiky exterior. The elf owl hunts insects, scorpions and small lizards at night, using its excellent hearing and silent flight.
Migrating through deserts
Many bird species do not live in deserts year-round but pass through them on long migrations between summer breeding grounds and winter ranges. The Sahara Desert is a major obstacle for migratory songbirds travelling between Europe and tropical Africa. Some birds fly straight across (a non-stop journey of 1,500 km or more, often at night), while others island-hop between oases. The deserts of central Asia and the Middle East are similarly crossed by birds moving between Russia, India and Africa.
Deeper dive: avian water economy, gular fluttering and the desert migration bottleneck
Birds face unique challenges in maintaining their water balance in deserts compared to mammals. Birds excrete their nitrogenous waste as uric acid (a white paste rather than dissolved urea like in mammal urine), which requires far less water to flush from the body. This is part of why so many bird species have successfully colonised arid environments. Many desert bird species can also tolerate higher body temperatures than mammals; while mammal body temperature normally fluctuates within a couple of degrees, some desert birds can let their temperature rise by 5 °C or more during the day, then cool back down at night. This "controlled hyperthermia" reduces the temperature gradient between bird and environment, slowing heat absorption and avoiding the need to use water for evaporative cooling.
Gular fluttering is an unusual cooling technique used by many desert and tropical birds. The bird vibrates its throat muscles to rapidly move air over the moist mucus membranes of the throat, increasing evaporation and shedding heat. The trick uses much less energy than panting (which involves whole-body muscle contractions) and lets the bird cool down without breathing hard enough to disrupt its blood gas balance. Vultures, owls, nightjars, pelicans and many other birds use this technique. The featherless skin on the throat of vultures and condors is partly an adaptation for efficient gular fluttering. Some species can also extend the technique by displaying the inside of the mouth, with the help of brightly-coloured "gape" tissues that may have evolved as a thermal display.
The Sahara crossing is one of the most demanding events in the life of a migratory songbird. Each spring and autumn, hundreds of millions of European songbirds cross the Sahara on their way between European breeding grounds and African winter ranges. Many fly the 1,500 to 2,000 km crossing non-stop, often at night and at altitudes of 3,000 to 5,000 metres where the air is cooler. Birds may lose 30 to 50% of their body weight on a single crossing, arriving at the African or European side dangerously thin and dehydrated. The few oases scattered across the Sahara provide essential stopover points for birds that cannot make the crossing in a single flight, and these oases support extraordinary concentrations of migrants for a few weeks each year. Climate change and habitat loss along the migration routes are making each crossing more difficult, contributing to long-term declines in many European songbird populations.
For other desert animals, see desert animals. For desert ecology generally, see desert ecosystems.