Birds communicate in a variety of ways, including through vocalizations. Many species of birds are known to sing during the day, filling the air with beautiful birdsong. But what about at night? Do birds continue to vocalize when the sun goes down?
Summary
Yes, many species of birds do vocalize at night. Nocturnal bird vocalizations serve a variety of functions, including defending territories, attracting mates, navigating, and communicating with flock members. The songs and calls of nocturnal birds are often simpler and less melodious than daytime birdsong. Some examples of birds that vocalize at night include owls, nightjars, potoos, some shorebirds, and more. The ability to vocalize at night likely provides an adaptive advantage to these species.
Do all birds vocalize at night?
No, not all species of birds vocalize at night. Many predominantly daytime species like songbirds are mostly quiet at night. However, a considerable number of bird species worldwide do vocalize during nighttime hours.
Birds can be generally categorized as diurnal (active during the day), nocturnal (active at night), or crepuscular (active during twilight hours). Species that are nocturnal or crepuscular are the most likely to vocalize at night.
Some examples of birds that vocalize at night include:
- Owls
- Nightjars
- Potoos
- Whip-poor-wills
- Nighthawks
- Some shorebirds like woodcocks
- Some seabirds like shearwaters and petrels
- Some hummingbird species
- Rails
- Woodpeckers
- Grebes
- Cormorants
- Herons
- Some songbird species like thrushes, European robins, nightingales
So while not universal among all bird species, nocturnal vocalizations are common in a wide array of bird groups spread across different habitats.
What types of vocalizations do nocturnal birds make?
Nocturnal bird vocalizations can take many forms, from the hoots and screeches of owls to the bizarre booms of potoos. Here are some examples of common nocturnal bird calls:
- Owls – Owls produce a wide range of vocalizations including hoots, screeches, barks, whistles, and shrieks. These can communicate territorial boundaries, attract mates, or defend nest sites.
- Nightjars – Also known as goatsuckers, nightjars produce distinctive “churring” or repetitive croaking calls to defend territories and attract mates.
- Potoos – These rainforest birds produce booming, bellow-like calls that can travel long distances.
- Whip-poor-wills and nighthawks – Named for their calls, these related bird groups produce loud, repetitive vocalizations.
- Rails – Marsh-dwelling rails are often very vocal at night, producing a variety of grunts, growls, and loud calls.
- Grebes – Grebes perform elaborate vocal duets and visual displays between breeding pairs at night.
In most cases, nocturnal bird vocalizations are simpler in structure and less melodious than the elaborate daytime songs of birds like thrushes and warblers. But they are no less impressive as acoustic communication displays!
Why do some birds vocalize at night?
Nocturnal vocalizations likely serve a variety of functions for different bird species:
- Defending territories – Loud calls announce a bird’s presence and ward off territorial intruders.
- Attracting mates – Vocalizations draw the attention of potential mates.
- Coordinating breeding – Duetting or coordinated vocal displays may help synchronize breeding between pairs.
- Navigating – Calls may help birds navigate and maintain contact in darkness.
- Avoiding predation – Quieter contact calls help flock members stay in touch to reduce risks.
- Locating prey – Some owls and nightjars use echolocation calls to help find prey.
Being able to vocalize at night likely provides a selective advantage to nocturnal bird species. It allows them to effectively exploit dark hours when diurnal predators and competitors are less active. Nocturnal vocalization helps birds communicate when vision is limited.
How do bird vocalizations differ between day and night?
There are some notable differences between daytime birdsong and nocturnal bird vocalizations:
- Nocturnal vocalizations are often louder and carry further to be audible in darkness.
- Nocturnal calls may be more simple, repetitive, and less melodious than daytime birdsong.
- Some crepuscular birds like owls and nightjars have specialized anatomy to produce resonant hoots and churrs.
- Daytime birdsong functions more to defend breeding territories and attract mates.
- Nocturnal calls emphasize flock communication and navigation.
- Birds may use specific dawn and dusk transition calls.
However, there are exceptions where daytime-singing songbirds like robins and thrushes will also vocalize at night. Overall though, nocturnal bird species tend to have simpler vocalizations adapted for low-light conditions.
Do bird vocalizations at night bother people?
Whether nocturnal bird vocalizations are perceived as bothersome depends on the species and the listener’s tolerance.
Some birds like owls and nightjars only vocalize for a few hours at dawn and dusk. But other species like Northern Mockingbirds may sing repeatedly through the night during breeding season. This can become an annoyance to light-sleeping people.
Birds that vocalize near human residences at night include:
- Northern Mockingbirds
- American Robins
- Common Nighthawks
- Killdeer
- Mourning Doves
- Owls
- European Starlings
- Blue Jays
- Northern Flickers
- Common Loons
In most cases, closing windows, using earplugs, or employing noise-masking devices can help block nuisance bird calls at night. Removing vegetation or food sources near nesting areas may also discourage nighttime vocalizations.
But in general, the night songs of birds are a natural part of the soundscape that provide listeners with an appreciation of nature.
Do bird vocalizations serve as cues for seasonal change?
Yes, increased vocalizations by birds at night can signal important seasonal changes:
- Early dawn choruses – Birds singing earlier before sunrise in spring marks the start of breeding season.
- Seasonal migrants – Nocturnal calls overhead may indicate migrating flocks passing over.
- Territorial defense – Increased nocturnal calling by males defending territories signifies the onset of breeding activity.
- Nest preparation – Vocalizations may coordinate nest-building and other breeding behaviors between pairs.
- Transition calls – Unique vocalizations at dawn and dusk help regulate circadian rhythms.
So paying attention to the nighttime vocalizations of birds can provide clues about important seasonal and behavioral changes occurring within bird populations.
How can you identify bird species by vocalizations at night?
Identifying species by vocalizations takes practice, but here are some tips for deciphering those nocturnal calls:
- Note the time of occurrence – Is it dusk, dawn, or full night?
- Note sound qualities – Loud or soft? High or low pitch? Unique tonal qualities?
- Note any repetitive patterns – Number of notes, regular repetition, rhythmic pace.
- Compare regional bird species lists – Which common birds match the location and vocalization?
- Use audio identification resources – Compare recordings to nail down difficult IDs.
- Remember distinctive mnemonics – “Who cooks for you?” (Barred Owl), “Teacher, teacher, teacher” (Whip-poor-will).
With attentive listening skills and some study, people can learn to identify many secretive nocturnal birds by vocalizations alone.
Do other animals vocalize at night?
Yes, many other animal species vocalize at night in addition to birds, including:
- Insects – crickets, katydids, cicadas
- Amphibians – frogs, toads
- Mammals – coyotes, foxes, wolves
- Primates – bush babies, night monkeys, chimpanzees
- Bats
- Whales and dolphins
- Fishes
Nocturnal vocalizing is a common strategy across the animal kingdom. Under cover of darkness, animals exploit acoustic communication to facilitate courtship, defend territories, navigate, hunt prey, and maintain group cohesion.
Paying attention to who is vocalizing at night provides great insights into hidden biological activities happening while humans sleep.
Conclusion
Many bird species across diverse groups vocalize at night to take advantage of darkness when diurnal competitors sleep. Owls, nightjars, rails, seabirds, waterbirds, and some songbirds are just a few groups that frequently vocalize after sunset.
Nocturnal bird vocalizations serve important functions like attracting mates, defending territories, navigating, avoiding predators, and coordinating flock activities. Calls tend to be loud, repetitive, far-carrying, and simpler in structure than daylight birdsong.
Listening carefully to the nighttime soundscape reveals the hidden world of birds that are active in darkness. With practice, many species can be identified by their distinctive nocturnal vocalizations alone.