Many avian enthusiasts are fascinated by flight. Indeed, an enchantment with this breathtaking phenomenon often converts bird fanciers in the first place.
Similarly, the question of how parrots and other birds sustain respiration while flying baffled mankind for years before modern science shed light on this rather complex subject.
We’re still learning today, and new and valuable insights are constantly surfacing.
We’ll swoop through some common queries relating to the avian respiratory system, soar through the gas exchange process, and finally discuss how birds can breathe at high altitudes.
Do Parrots Breathe Through Their Beaks?
No, a parrot does not breathe through its beak under normal circumstances. However, open-mouth breathing (an acutely concerning sign) may occur when parrots are unwell or very distressed.
If your parrot opens its beak to breathe, it signifies medical or psychological distress.
This means you must remove your parrot from any stressful stimuli or cease handling immediately and allow your bird to calm down.
Seek advice from a vet if there are no obvious environmental stressors present, as this may indicate a medical cause for open-mouth breathing, such as respiratory disease.
Now that we’ve established that parrots do not normally breathe through their beaks, how (and where) do they take in air for respiration?
Under normal circumstances, birds inhale air through their nares (or ‘nose holes’), situated just above (at the base of) the beak in most avian species.
There are exceptions to this rule. For example, the nares in Kiwis are situated at the very tip of the beak.
In psittacine species, the nares are covered by a horny structure known as the operculum, which protects the nasal cavity.
Air breathed in through the nares passes through the nasal cavity, choana, oropharynx, larynx and then the trachea to eventually reach the two mainstem bronchi and the lower respiratory tract, where gas exchange occurs.
How Do Parrots Obtain Oxygen?
Let’s first run through an overview of airflow through the avian respiratory system.
Our journey starts at the nares, where the air is inhaled.
This air is warmed, moistened and filtered in your bird’s nasal cavities before passing through the choana, oropharynx, larynx, and into the trachea (windpipe).
After a short distance, the trachea bifurcates (splits into two branches). As an interesting aside, at the level of tracheal bifurcation, you’ll find the syrinx (vocal organ) in many avian species, including parrots.
The bifurcation of the trachea results in two main stems or “primary” bronchi, one of which branches towards each lung. The primary bronchi traverse the lungs and empty into the abdominal air sacs.
Within the lungs (throughout this traversing portion), each primary bronchus gives rise to numerous secondary bronchi, which further branch into tertiary bronchi (also known as ‘parabronchi’). From these tertiary or parabronchi, air capillaries arise.
Next, we must focus on the lower respiratory system, where gas exchange occurs. Gas exchange refers to the influx of oxygen into the bloodstream and removing carbon dioxide into the airways to exhale.
Unlike in mammals (where gas exchange occurs at the alveoli of the lungs), in parrots and other birds, the process occurs within specialized structures called air capillaries.
Air capillaries can be mentally pictured as tiny air-containing tubes from the bird’s tertiary bronchi.
They are smaller and finer than mammalian alveoli, with a thinner blood-gas barrier. This is the barrier between the air-containing spaces and the bloodstream, where gas exchange occurs.
The overall result of this is improved respiratory efficiency compared to mammalian species.
Parrots obtain oxygen from inhaled air in their air capillaries. Oxygen in the air capillaries moves into closely adjacent blood capillaries, and carbon dioxide in their blood capillaries moves into the air capillaries, ready to be exhaled.
How Does A Parrot’s Respiratory System Enable Them To Fly?
Even at rest, birds have higher oxygen consumption rates than other vertebrates. As if this was not impressive enough, oxygen consumption often increases during flight.
Of course, this means that a very high rate of gas exchange is required to provide the bird with sufficient oxygen to sustain this phenomenal feat.
Several clever evolutionary adaptations allow birds (including parrots) to achieve efficient gas exchange.
As mentioned, birds possess air capillaries rather than alveoli, resulting in more effective gas exchange. The lack of alveoli also means less “dead space” within the avian respiratory system, resulting in more efficient respiration.
Birds also possess several pneumatized bones, which serve the dual purpose of bestowing a lighter skeleton and providing additional air-containing spaces (extensions of the air sacs).
Avian air sacs serve as reservoirs, allowing parrots and other birds to maintain continuous unidirectional airflow through the lungs.
So, pneumatized bones and air sacs also help enable a parrot to fly.
How Do Parrots Breathe At High Altitudes?
Parrots are not high-altitude birds, and almost all parrots are non-migratory.
There are only two exceptions to this rather sedentary lifestyle: the swift parrot (Lathamus discolor) and the orange-bellied parrot (Neophema chryogaster).
The vast majority of parrot species abide permanently in lowland tropical forest environments. Regarding their anatomy and physiology, parrots are built for relatively short bursts of low-altitude flight.
Certainly, we cannot include parrots with high-altitude birds, such as cranes and condors.
Birds that live at high altitudes all the time have adapted to the lower oxygen conditions by increasing the amount of hemoglobin (the oxygen-carrying molecule in the blood) that each red blood cell contains.
This adaptation is permanent and constant. On the other hand, migrant birds (i.e., those who are ‘just visiting’ high altitudes) will adapt temporarily by producing more red blood cells only while needed.
This allows a greater blood oxygen-carrying capacity. However, the downside is thicker blood, which increases the risk of blood clots.
