THE HIDDEN LIFE OF PEAFOWL

[Resolution]

When we think of a peacock something extraordinarily beautiful, even ornamental comes to mind.
No matter the setting, an image of a strutting bird with outspread "tail fan" endures.


In Western Culture the peacock serves as the ubiquitous symbol of vanity. A bird that reveals its plumage for no other reason than admiration. But surely, there must be more to a peacock's life than showing off and boasting of its beauty?

 

[new 2 pfowl]

Funny how humans never tire of projecting their abstractions onto the natural world.
"Vanity" being a quality exclusive to humans, and "Beauty" being a (constantly shifting and completely subjective) idea manufactured by humans.
Aren't the things people would call "vanity" or "beauty" in peacocks really just their intuitive focus on, and the encoded messages they transmit about, their reproductive potential?
(of course one could argue that this is also true for humans...)

 

[AquaEyes]

Possessing vanity requires self-awareness. Behaviors associated with vanity do not require the actor to be capable of vanity. In other words, if vain people are spending a lot of time in the mirror, and peacocks spend a lot of time looking at their reflections, it is not necessarily the case that both are doing it for the same reasons. Humans have a huge prefrontal cortex compared to other species, and this allows for behavior that either overrides or doesn't require the motivations and drives arising from lower-order processing.

It is more likely that the pattern of oceli in peacocks' trains has a stimulatory effect upon their nervous system, triggering the hypothalamus to start the chain of events that leads to hormone surges that affect breeding behavior. Males who happened upon this stimulus-response set by chance through an aberration in their plumage, and thus attracted more female attention, managed to secure more offspring, and thus initiated the sexual selection that operated to confer an advantage to males with ever more elaborate plumage displays.

The fact that oceli-patterns are found in other related species indicates an inherent predisposition for this stimulus-response set, and other species have independently evolved other ways in which males impress females with oceli-pattern displays. Possibly through runaway selection, those females who were more strongly attracted to oceli-patterns also mated with males with greater oceli-pattern displays, and thus had offspring which inherited not only the genes for greater oceli-pattern expression, but also those for greater oceli-pattern attraction.

The extent to which the male plumage display can be exaggerated becomes tempered by any decrease in predatory evasion, disease/parasite susceptibility, feeding, inter-male aggression, etc. Thus while trains even more extreme than those we find in peafowl today would likely stimulate females even more, the males who would possess them would face increased mortality from the handicap such a train would engender. Peafowl of the Pavo genus live in habitats that are open enough to allow movement of males with long trains, but the Congo peafowl live in denser jungles, where such a display would seriously restrict movement, and thus had a stronger negative selective pressure upon it.

 

[Resolution]

Sometimes I think peacocks can see miles into the sky. They can always make out the tiniest specks of movement even when they didn't seem to be paying attention a few moments before...

Four Fold Truths

In order to learn about the life history of these birds it's important to gain a vantage point from their perspective.

A wildlife trail within prime peafowl habitat. Note the height of surrounding vegetation;
the proximity of an isolated of considerable height. Note uneven distribution of
vegetative mass. Forbs closest to the ground are denser and grow more horizontally
as they crowd toward sunlight provided by the path itself. Taller vegetation grows more
vertically.

Compared with many bird species, peafowl are highly sedentary. Unless disturbed or driven out, they will remain within a specific area their entire lives. Territories are handed down from father to son and from brother to brother for generations. The same is true for females naturally and in most species, the female has ultimate deciding factor. For this moment I'd like to focus on the male of the species as decoding his life history is paramount to understanding hers and by extension the entire family flock, the species, genus and phylogentic family peafowl belong to.


Adult male peafowl spend many hours of every day perched high on their favorite tree ( or barn or outbuilding).
Imagine how much energy it requires for a bird this size with such extensive surface area to move to and from an emergent tree hundreds of feet high.

Prime habitat of every genus and species of the Peafowl family is marked by a single environmental feature unusual amongst true Galliformes and common amongst the Craciformes. They require special roosting trees that are isolated from all others either by height or space. These 'motherland trees' are generally species which grow well above the upper canopy of primary forest. This altitude of the forest is known as the overstory.

Due to their size and vulnerability to birds of prey, junglefowl, francolins, pheasants, partridge and grouse perch closer to the ground, generally hidden within dense vegetation.Conversely, Monals and Turkeys seek out similar exposed features in their respective habitats as home bases. Both Monals and Turkeys are similar to peafowl in that as a rule, they generally have more to fear from nocturnal ground predators than from nocturnal birds of prey.


This is prime Indian Peafowl habitat. Note the presence of isolated emergent trees standing throughout the tropical savannah. While peafowl forage and nest within these tropical grasslands, the most important feature for the long-term survivability of any naturally selected population is the presence of these emergent trees.

Peafowl of the genus Pavo inhabit more open woodland habitats than those in the three remaining genera of the Pavonids. Their ancestors lived in primary old growth forests just as the four argus species and Congo peafowl do today but the habitats of the Proto-Pavo ancestor transformed over time. These regions became exponentially drier. Deep broadleaf evergreen and tropical rain forest gave way to open deciduous forest ecosystems. Tropical deciduous trees are the dominant feature of their habitats. India's dry deciduous forests are semi-arid for several months every year. South East Asia's forests are a bit more diverse and complex. More on the later. Regardless, ancient emergent trees still stand in open tropical savannah, as they've endured countless generations -one stable component within an otherwise highly dynamic mosaic of fragmented forests.


Even when deep forest biomes dominated the landscape these towering giants were never particularly common. They have witnessed the rise and fall of whole forest ecosystems and still they endure. These emergent tree species are many millions of years old with origins in Gondwanaland but have proliferated and diversified only since the Eocene~ 50 Million Years Ago. According to molecular and fossil data, Peafowls are ~ 35 Million Years old. The deep forest habitats that once dominated the majority of Southern and South East Asia began to dry out and open up ~20 Million Years Ago.
Peafowl species of the genus Pavo evolved in concert with changing habitats.
One attribute of their most ancient haunts, those emergent trees endured in concert. The seeds and drupes of these giant trees are often consumed by the birds. Peafowl disperse their seeds, which have been primed for germination in their digestive systems.

Isn't it fitting that peafowl have remained roosting on their trees all this time?

Recap:
Peafowl inhabit ecosystems marked by the presence of giant isolated trees.
The astonishing scale of these trees with their great height enables the birds to sleep at night safe from terrestrial predators. They also spend the majority of their hours on these mother trees throughout the rainy season, which lasts for a few months. They take shelter on these trees when forced to take flight by terrestrial foes.
Adult males remain on these trees for many more hours of the day year round than females and juveniles.
These trees enable adult males to act as sentinels over their families 365 days of the year for the full decade or more that the average wild male peafowl will live. These emergent trees are one of the most important attributes of the peafowl habitat. Fresh moving water is equally important.


A new question arises. If these emergent trees are so important to peafowl and most Gallinaceous birds avoid exposed resting places, how is it that peafowl avoid aerial predators? Is this confidence shared by peafowl of both genders, of all ages and developmental phases or is this limited to adult, train-bearing males?

 

[Resolution]

Have a peek into the private life of the wild Siamese Imperator, Pavo imperator siamensis.