Birds have been sending warnings for thousands of years, communicating danger to each other and even to other species. There are many types of alarm and warning calls that birds use to alert others to predators, threats, and food sources. Understanding bird language can give humans insight into the natural world.
Alarm Calls
Birds have specific alarm calls that are used to signal immediate danger. These alarm calls are short, loud calls that alert other birds in the area to a predator or threat. Some common birds that use alarm calls include:
- Blue jays – When spotting a predator, blue jays will give a loud, ringing call that alerts other birds. They use specific calls for different threats like hawks, cats, humans.
- Chickadees – If chickadees detect a predator, they will give a high-pitched “chick-a-dee-dee” alarm call. This warns other birds in the area to be on high alert.
- Crows – Crows have various alarm calls for different predators like hawks, owls, cats. Their calls signal others to mob predators or flee the area.
- Woodpeckers – When woodpeckers see a predator, they make a loud “kyeah” call. This alerts other birds nearby to the danger.
Birds rely on these alarm calls to quickly communicate danger. The alarms call cause birds to freeze, flee the area, or mob the predator to drive it away. These warning calls are essential for bird survival.
Sentry Calls
Some birds take turns acting as sentries, watching for predators while others in their flock forage. Sentry birds will make sentry calls alerting their flock to potential threats. Common sentry birds include:
- American robins – Robins singing sentry calls from high perches indicate the area is free of predators.
- Pinyon jays – Sentinel jays sit atop trees and watch for predators, making quiet calls if any appear.
- White-browed sparrow weavers – Small flocks have one sentry who alerts the others to predators.
- Red-winged blackbirds – Males defend territories and act as sentries, signaling alarm if threats appear.
The sentry calls let the other birds know if it is safe to feed on the ground. If the sentry stops calling or makes an alarm call, the birds will freeze or flee to cover.
Flocking Calls
Some birds make flocking calls that communicate information to others in their group. Flocking calls help coordinate movements, foraging, and awareness. Some key flocking calls include:
- Crows – Crows make over 250 different calls including specific flocking calls like “koww” to signal the flock to regroup and “caw-caw” to indicate movement.
- Parrots – Parrots make contact calls allowing them to coordinate with their mate or flock while flying or foraging.
- Swallows – The short clicking calls swallows make help the flock stick together when feeding in flight.
- Shorebirds – Shorebirds like sandpipers and plovers make soft “wit” calls to maintain flock formation.
These flocking calls allow groups of birds to stay in contact, alert each other to food sources, and maintain awareness of movements within the flock.
Mobbing Calls
When small birds detect a predator, they often mob the intruder by diving at it while calling loudly. This mobbing behavior is meant to harass and drive the predator away. Some common mobbing callers include:
- Crows – Crows gather in mobs and dive bomb predators while screaming loudly to scare them off.
- Jays – Jays mob predators like hawks by gathering and making loud alarm calls.
- Chickadees & titmice – These small birds will recruit other birds to harass predators.
- Waxwings – Waxwings defend their flocks by mobbing predators with high-pitched calls.
By gathering and calling loudly, a mob of small birds can successfully drive away larger predators. The noisy mobbing calls serve to both harass predators and communicate the threat to other birds nearby.
Food Calls
Birds also make various food calls that alert others to good sources of food. Some examples include:
- Crows – Crows make a “tok-tok-tok” call to signal others to join a food source.
- Crossbills – These finches make a resonating “pip” call directing their flock to good conifer seed sources.
- Sparrows – Sparrows chatter or call softly to tell their flockmates about food.
- Wrens – Wrens make a buzzing “zreeee” sound to indicate a good food source nearby.
By sharing food call signals, birds can alert greater numbers of birds to good feeding areas. This helps the birds locate and share limited food resources effectively.
Distress Calls
When caught by a predator, many birds emit loud distress calls. These often attract other birds that may harass the predator to make it release its prey. Some common distress calls include:
- Blue jay – A high-pitched screaming call when threatened.
- Cardinal – Rising and falling shrieks when caught by cats or predators.
- Chickadee – Fast “dees” if caught by a predator.
- Finch – Loud repeated “peeps” to signal distress.
A bird’s distress call indicates an imminent threat. This stimulates mobbing behavior in other birds or may cause the predator to release the prey.
Duetting
Some mated pairs of birds perform duets together. These duets communicate different information to each other and other birds. Some examples of duetting birds include:
- Eastern screech-owls – male and female owl duets convey territory ownership and pair bonding information.
- Magpie-larks – mated pairs sing synchronized duets at dawn to defend their territory.
- Barred owlets – mates sing coordinated duets to strengthen their pair bond.
- Song sparrows – songs sung by mates help identify each other and their territory.
Bird duets can strengthen pair bonds, signal territorial boundaries, and share location information between mates. The cooperative duets require timing, coordination and learning between pairs.
Mimicry
Some birds have an impressive ability to mimic the calls of other bird species. This mimicry can serve different purposes:
- Deception – Some drongos mimic meerkat alarm calls to scare them away from food.
- Mimicry rings – Groups of species all mimic each other’s songs, like some Australian birds.
- Incubation calls – Female doves may mimic hawk calls to scare off others while incubating eggs.
- Mobbing – Small birds may mimic hawk calls to get other birds to mob a predator.
Mimicry demonstrates birds’ intelligence and vocal learning abilities. It allows them to manipulate other birds’ behavior for their own benefit during foraging, reproduction and defense.
Warning of Severe Weather
Some birds can detect changes in air pressure and scent that signify upcoming severe weather. Their calls may act as an early warning:
- Seagulls – Flocks may be heard calling as they evacuate inland before hurricanes or storms at sea.
- Crows & ravens – These corvids make agitated calls signaling rain and storms.
- Swallows – Their excited twittering indicates impending storms or tornadoes.
- Sparrows – Flocks will take cover in bushes or trees while calling loudly before storms.
Heeding these warning calls can give people time to take cover before severe weather hits an area. Birds’ sensitivity to pressure changes gives them early notice not obvious to humans.
Warning of Earthquakes
There are anecdotal reports of unusual bird calls and behavior preceding major earthquakes. Possible explanations include:
- They detect initial low-frequency seismic waves before quakes.
- Changes in electrical charge affect navigation abilities.
- They react to changes in groundwater levels or magnetic fields.
- Reactions to earthquake lights anomalies in the sky.
While more research is still needed, noted pre-earthquake bird behaviors include:
- Mass nighttime evacuation from usual roosts.
- Daytime flocking when normally more dispersed.
- Increased singing, chirping, alarming calls.
- Sudden interruption or silence in normal vocalizations.
- Disoriented navigation and mobility.
So animals may have sensory detection abilities exceeding our current technology. Monitoring bird behavior could one day provide warning to humans of imminent seismic activity.
Conclusion
Birds have a wide repertoire of alarm calls, warning signals, and distress cries. Their vocal communication warns others of danger, food sources, severe weather and possible earthquakes. Understanding bird language provides a window into avian intelligence, behaviors and awareness of the natural world. Heeding their warnings wisely can lead humans to safety and greater harmony with nature. Bird communication signals demonstrate we still have much more to learn about our feathered cohabitants on this planet.