Like human infants, all baby birds depend on signaling to let their parents know that they are hungry. However, birds have a clutch size of 2 to 10 eggs, depending on their species, and there’s usually more than one baby per brood.
Birds know which baby to feed through a hatchling’s vocalization, behavioral displays, and physical postures, like stretching, collectively known as begging. They also rely on structural signals to determine which baby to feed, influencing their survival chances.
Birds Know Which Baby To Feed Based on Nestlings’ Begging
Baby birds are classified into three categories:
- Hatchlings: recently hatched, eyes are closed
- Nestlings: from a couple of days old until fledging
- Fledglings: develops feathers, down, and plume
Baby birds beg for food whenever they are hungry, which is usually several times a day. Here’s a general feeding habit of most baby birds, irrespective of species:
- Hatchlings: 6 to 10 times per day
- Nestlings: 5 to 6 times per day
- Fledglings: 2 to 3 times per day
All baby birds beg for food, which usually comprises the following acts:
- Vocalization, which includes chirping, crying, or screeching.
- Stretching and opening the mouth widely.
- Behavioral displays, like jostling and moving.
Parent birds will feed every baby in sequence and continue to do so as long as the nestlings are begging, subject to food availability.
Some nestlings may beg more than others and will scream more or move towards the food by pushing their siblings.
The parents, in these cases, might first feed the baby that begs the most and then proceed with feeding the other nestlings.
However, parent birds don’t rely only on the nestlings’ begging to feed their babies.
Most parent birds use discretion and feed their babies based on practical compulsions, like food availability.
Parent birds will also assess the condition of their babies to decide who gets fed first or more.
Birds May Feed the Biggest and Healthiest Baby During Scarcity
Parental instinct in animals, including humans, favors feeding the weaker baby and the one that cries the most for food.
The latter could also be due to individual appetite and behavior. Not all baby birds beg identically, despite being equally hungry.
But parent birds use other signals, too.
Birds assess the growth and health of their nestlings.
The size of a hatchling or nestling is a reliable indicator of growth and overall health, while beak coloration is another indicator.
If any of the indicators are distinct, parent birds may favor or ignore a baby based on the implication.
Parent birds may feed scrawny nestlings first before attending to healthier babies whenever there’s sufficient food available.
In contrast, they might prioritize the bigger and healthier nestlings during scarcity.
Generally, birds encounter two types of threats in the wild:
- Environmental unpredictability: weather, potential predators, and surrounding factors
- Environmental quality: food availability, which determines nutrition
Parent birds favor bigger and healthier nestlings while feeding in an unpredictable environment because these babies have a better chance of survival, effectively carrying the genes forward.
The same preference applies to environmental quality. If food is scarce or the quality or nutrition is low, parent birds are likely to favor the healthier nestlings.
They may even ignore the begging of the weaker babies in such cases.
Studies have revealed that birds may force-feed their healthier babies even if they aren’t too eager or begging during scarcity or unpredictability.
Conversely, parent birds may feed the weaker babies first and more frequently if there’s ample food and there is no apparent environment unpredictability.
Baby Birds May Be Dishonest When They Beg or Signal for Food
While parent birds naturally adopt the Darwinian evolutionary theory to facilitate the survival of the fittest, the babies aren’t necessarily honest all the time when begging for food.
Some studies have revealed the fact that the nestlings of many species can falsely beg for food and eat more.
The dishonest begging is often due to competition, which is typical due to the brood sizes of many avian species.
The begging intensity is directly proportional to the brood size, which might mean that a larger brood’s nestlings are likely to indulge in more intense and sometimes dishonest begging.
Some nestlings may be deceptive in their begging intensity due to the following factors:
- Brood hierarchy
- Genetic relatedness
- Sibling rivalry
Baby birds don’t have identical begging intensities.
A hungrier bird is expected to vocalize more intensely, display overt behavioral postures, and might even push its siblings to get to the food.
In such cases, the parent birds know which baby to feed first or a bit more than the others.
But some nestlings beg intensely even when they are less hungry than their siblings, or they are probably fed already.
A brood with asynchronous hatching may have a hierarchy that influences this deceptive begging among some nestlings.
In such cases, the parent birds may respond to the false but intense begging or use structural signals and assessment to feed their nestlings.
Genetic relatedness usually pertains to bird species with multiple broods and nestlings with step siblings.
The other scenario when genetics influence or trigger false begging is if a brood has a hatchling of another avian species.
Irrespective of these differences, the natural tendency, and the eventual objective are the same, survival.
The fundamental reality of survival is also the foundation for avian siblicide.
Some birds are known to kill their siblings in the brood, including but not limited to the following:
- Black eagles
- Blue-footed booby
- Egrets
- Ospreys
- Pelicans
However, false begging, jostling for space and food, and other behavioral tendencies of varying intensities aren’t limited to the birds known for avian siblicide.
Real-time factors, including food availability and environmental stability, may trigger deceptive behavior and feeding habits.
That said, all such issues are only relevant in the wild.
If you are feeding a few baby birds, you can simply follow the daily routine and provide just enough food to the nestlings based on their age, size, and species.
Kaytee Exact Baby Bird Food (available on Amazon) is a vet-approved and recommended instant formula.
The pack has dozens of essential ingredients for the optimum growth and nourishment of baby birds of numerous small species.
You should always follow the feeding and weaning instructions.