02
Aug

Why do birds open their mouths? It is so much more than just eating……

Two days ago, our heat index hit 115°F.  Miserable does not even begin to describe how awful it was outside.  When it is that hot and humid, birds become very quiet.  They sit in shady places – where they might catch a breeze or two – and occasionally pant.  Here are photos of birds who are panting.  Notice their relaxed bodies.  None are scraping their tummies on the ground in a submissive behavior.  None have their necks outstretched in an aggressive manner.  Their beaks are straight out or pointed down – none are pointed towards the sky.  These are all indications that these birds are panting:

Pied Heron. Photo by David Clode on Unsplash.
Great Kiskadee. Photo by Dieny Portinanni on Unsplash.
Great Egrets. Photo by Getty Images on Unsplash.
Great Blue Heron. Photo by Getty Images on Unsplash.

 

 

 

 

 

 

 

On a hot, or hot and humid, day, when you see birds sitting quietly with relaxed bodies, open beaks, and they are not engaging another bird, most often they are panting.  This is an indication the bird is overheated and panting is their attempt to regulate their body temperature.  Birds lack sweat glands and panting is their primary method for cooling off a bit.  This is called thermoregulation.  Panting causes the moisture in their air sacs and respiratory tracts to evaporate – called evaporative cooling.  A bird not only opens its beak, but it also rapidly moves its throat.  If you see a bird doing what you think is panting and can get a good look through your binoculars, you might see the throat feathers quivering – just like they often do when a bird is singing.  The difference is posture.  A singing bird most often holds its body erect and will often tip its beak up – towards the sky.  A panting bird has a more relaxed body, and its beak is most often pointing straight out or down – not tipped toward the sky.  Panting is normal behavior for birds on hot and hot and humid days.  This is one of the reasons bird baths* are helpful – bathing also helps birds keep cool.

Birds open their beaks for other reasons besides panting.  Juveniles open their beaks when they see their parents – this is part of begging for food.  Birds can open and shut their beaks – often with a clicking or snapping noise – when either defending their spot or aggressively trying to take a spot from another bird. Birds often open their beaks as part of their mating rituals or as a greeting to a mate which reinforces the pair bond.  Just like we humans do.  When my husband, Cleon, comes home after being away the entire day, he greets me with a hug and a kiss and that strengthens/reinforces our pair bond.  When in flocks, birds will open their beaks to make sounds other than singing in order to communicate with other members of the flock or group.  And of course they open their beaks to sing.

There are other body clues that will help you decide what a bird is actually doing when it opens its beak.  Here are photos of juveniles begging for food.  Look at their body positions.  Just having an open beak does not signal begging behavior – the entire body will be involved:

A juvenile European Starling with its mouth open and begging the parent for food. Notice how its neck is retracted and its down is a bit fluffed out – all part of begging behavior.  Photo by Ruyan Ayten on Unsplash.
The female House Sparrow is on the right and her two juveniles are begging for food. Notice the crouched position both juveniles have. This, plus the open beak, is the begging posture of many juveniles.  Photo by Andrey Tikhonovskiy on Unsplash.
An unknown parent bird with a fledgling just out of the nest by photographer Nikola Tomasic on Unsplash. I uploaded this photo to the Merlin app and the app suggested Northern Flicker. Merlin is not aways right – this is definitely not a Northern Flicker. But the point I wanted to make with this photo is for you to observe the behavior/posture of the fledgling. An excellent example of begging behavior complete with fluttering wings and open beak.
And here is an exception – the body is not involved in the begging behavior.  But is there any other interpretation possible?  The juvenile is standing right in front of its parent with mouth open wide.  If that does not say “Feed me!”, I don’t know what does.  This is a magpie with its juvenile. Photo by Rae Wallis on Unsplash.

 

 

 

 

 

 

 

 

When juveniles want their parents to feed them, they assume a submissive position.  They hunker down so their tummies are either touching the ground or very close to it.  They retract their necks, often flutter their wings, often fluff out their feathers, often tilt their heads upward, and always open their beaks WIDE.  Interestingly, this is both submissive and aggressive.  Their behavior and positions of their bodies are all submissive.  But they often follow their parents around in a very aggressive manner – they hound them.  They will not let them alone.  And often this behavior is accompanied by loud sounds – Blue Jay juveniles are real screamers.  And this is a tug of war. The juveniles want fed NOW by their parents – they do not want to search out their own food.  And the parents instinctively know that the juveniles MUST begin to get their own food in order to survive as adults.  Does any of this sound familiar?

 

Birds often open and shut their beaks when being aggressive:

Two Neotropic Cormorants showing aggression. It could be the one in the water wants to sit on that post – exactly where the other cormorant is sitting. Notice the outstretched necks and wings – all part of an aggressive posture. Photo by Steve Smith on Unsplash.
Two European Starlings in what looks like a pretty serious tussle. Photo by Delia Giandeini on Unsplash.
Northern Gannets at a nest site. I can just imagine this screaming match: “Get off my rock!” “What do you mean? YOUR rock? This is MY rock!” Photo by Zdenek Machnace on Unsplash.
One bird giving another a piece of its mind? Look at the postures. The bird with the open beak is stretched out towards the other who is slightly crouched in a more submissive position. Maybe cringing? Photo by Joshua J. Cotten on Unsplash.

 

 

 

 

 

 

 

 

 

 

 

Opening beaks as part of a mating ritual or reinforcing the pair bond:

Australian Ibises. A mated pair greeting each other. Photo by Saketh Upadhya on Unsplash.
Common Cranes come together in a dance as part of their mating ritual. Photo by Getty Images on Unsplash.
A mated pair of European Bee-eaters.  Besides opening their beaks as part of a mating/greeting ritual, the male will often offer the female a choice morsel which she will accept. Photo by Zdenek Machacek on Unsplash.

 

 

 

 

 

 

 

 

 

Communication with each other – you can observe this more easily when birds are in flocks – or groups:

Laughing Gulls are always chatty – and loud! Photo by Paco Adame on Unsplash.
Great White Pelicans. Sometimes birds all talk at once! Photo by cphotos on Unsplash.

 

 

 

 

 

 

 

And last but not least, birds open their mouths when singing.  Many tilt their heads up which opens the throat so they can really belt out that song!  Notice that when singing, the body is held straight up and more stiffly.  We do that, too.  When you are playing your favorite song and singing in the shower – or when washing dishes as Cleon does – notice your own body posture.  You are most likely more upright and stiff – possibly your head is straight or looking up.  Singing birds are most often on prominent perches – they sing to advertise themselves or their territory.  We human beings who are not professional singers, generally do our singing when we are hidden – behind closed doors, in the car alone, in the shower.  But in our minds – aren’t we belting out our favorite song in public to a huge number of cheering fans?  Just like these birds.  Opening their beaks and singing and singing to anyone or anything within earshot!

A White-crowned Sparrow. Photo by Michelle Tresemer on Unsplash.
Song Sparrows are always as conspicuous as they can be when singing. Photo by an unknown photographer on Unsplash.
Meadowlark. Photo by Jeffrey Hamilton on Unsplash.
Carolina Wren – a big-time singer. Incredible volume from a small bird! Photo by Ryk Naves on Unsplash.

 

 

 

 

 

 

 

 

 

To summarize, why do birds open their beaks?

Juveniles begging their parents for food:

White-throated Sparrows. Photo by Anish Lakkapragada on Unsplash.
Juvenile Barn Swallows. We do not need to see a parent to know these fledglings are all begging for food. Seeing all these open beaks must be daunting for any parent! Photo by Lia Maaskant on Unslash.

 

 

 

 

 

 

Aggression.  Defense:

Pygmy Cormorants. Besides their open beaks, both birds’ postures just scream aggression. I don’t know what they are fighting about, but for them? This is serious business. Photo by Zdenek Machacek on Unsplash.

 

 

 

 

 

Mating ritual or reinforcing a pair bond:

Moss-backed Tanagers.  You can see the male has his beak open slightly and the female has gently laid her beak within. From the posture of both birds, from our perspective as human beings, this looks like a loving gesture. Photo by Zdenek Machacek on Unsplash.

 

 

 

 

 

 

 

 

Communication within the flock or group:

Merlin IDed these as Black-headed Gulls. Photo by Lucius Hunter on Unsplash.
Great Black-backed Gulls. Birds in flocks often ‘talk’ all at once. Photo by Javier Flemate Lopez on Unsplash.

 

 

 

 

 

 

Best of all – singing!

Red-winged Blackbird. I can just hear the ‘Conk-la-reeeee!!!!’ Can’t you? It may not be the most melodic bird song, but it is always enthusiastic and loud! Photo by Econaturalist on Unsplash.

 

 

 

 

 

 

 

 

 

And on hot, sunny days birds open their beaks to pant – remember, they do not have sweat glands and so this is one of the few ways they have to cool themselves.

American Robin. Notice the relaxed posture – no signs of aggression nor is this bird singing. The beak is only slightly open – not opened all the way as the robin does when it is singing. This bird is panting. Photo by Gennady Zakharin on Unsplash.

 

 

 

 

 

 

 

 

Happy Birding!  Linda

P.S.  Cleon was finally able to finish his squirrel tower.  You can see it on the back left of the bird feeder livestream.  He did make it primarily for the squirrels, but I am also hoping some of the birds will peck on the cobs.  I am watching for Blue Jays and Mourning Doves.  If we get inundated with Common Grackles and European Starlings as we approach fall, we may remove the corn cobs during the day for a few weeks.  We are fortunate in that we do not have grackles and starlings all the time – their flocks are here in September and October.  So, this is an experiment.  We also have raccoons …….. not sure how this will all work out.  More on our raccoons next week!

I have added Golden Alexanders (Zizia aurea) to the Landscaping and Gardening for Birds and wildlife section of this website.  Here is the link:  Golden Alexanders (Zizia aurea)

*If you live in an area that is plagued with mosquitoes in summer – we do! – here are some tips for bird baths.  Scroll through the information on bird feeders until you come to bird baths:  Bird Baths and Mosquitoes