The hostile encounter between a Black-thighed Falconet (Microhierax fringillarius) and a Spectacled Spiderhunter (https://rimbakiara.blogspot.com/2026/03/falconet-vs-spiderhunter.html) which ended in the Falconet flying into the taman and not off and away as he would typically had probably foretold that he had set up a presence in the taman.
For the next couple of weeks I did not notice any unusual activity or increased presence of a pair of Falconets which unfortunately meant that I did not monitor their movements.
And then one morning I saw a female Falconet feasting on a bat joined later by the male who came with a butterfly.
Perhaps even the Spotted Dove knew then of the potential threat this pair of Falconets would pose if the pair decided to nest in the taman as it tried to intimidate off the lone Falconet, to no avail.
And then it happened as I tracked the male as it flew down, and into a hole in a branch!
A surveillance was initiated.
The soon-to-be parent
During the period from mid March onwards, ie after the pair was observed to enter and exit the cavity nest albeit not regularly, I was still uncertain whether the pair had started incubation. This was because they were constantly indulging in courtship behaviours like allopreening, courtship feeding, and even copulation.
An insect prey was offered by the male to the female who in turn offered it back to the male, and then watched him enjoy it. Was this courtship?
It's playtime as the couple indulged in a bath together in the hollow of a tree on a hot day.
The male remained behind for some 'me' time.
During this period the pair also engaged in copulation.
Allopreening happened frequently. This kind of preening which typically takes place on the head or neck is one of the most adorable characteristics of the black-thighed falconets.
Anytime, anywhere.
Preening was most required too following long periods cooped inside the nest to fluff off parasites and mites acquired in the cavity nest.
And then it's the female's turn to show some affection for its mate, and self-rejuvenation.
Signs of incubation were deduced in late March when the pair took turns to be inside the nest but it was the female who tended to stay longer inside the nest compared to the male who normally remained inside for less time before he emerged to fly off and not to return until a couple of hours later.
When he returned with a catch he would give an alert cry and would either fly straight into the nest with the prey or the female would emerge to take the prey from him.
The nest was not left alone; there's always one on the watch outside when none was inside the nest.
Preening came naturally whenever the pair got together.
However the female or male left alone inside the nest could be seen to fly out regularly too to take a breather.
The female exiting to stretch and preen by herself.
Preys were normally delivered whole directly into the nest and whoever did so would exit almost immediately.
The male delivering food to the female.
It was mainly a drop-and-go delivery, this time of a dragonfly.
Making another rather clumsy entrance with a dragonfly catch.
Sometimes the male would call out to the female to exit the nest to receive his prey offer.
It was not uncommon for the male to consume a prey himself while outside the nest.
The male constantly displayed impatience as it emerged from the nest to look out for the female, also frequently leaving the nest when she could not be seen in the vicinity. However he would remain in the immediate vicinity.
Fluffing and stretching after emerging from the nest.
Food for the pair were primarily small preys such as moths, butterflies, beetles and dragonflies. Occasionally there were dead birds eaten on the perch outside the nest.
A carpenter bee prey in the early morning.
Most times it's not easy to identify the prey when what's left was just a piece of feather when the falconet was spotted or what was being brought was a plucked bird.
At other time it was evident what was devoured earlier.
Sometimes it felt like a prey was simply too pretty to be caught!!
When a catch was not completely eaten by one in the nest, it was taken out to be finished off by the other.
Unfortunately this beetle was dropped as it had been observed too before of other half-eaten preys in similar circumstances, due to clumsiness!?
At this stage, squirrels and birds like woodpeckers, mynas, magpie robins were seen regularly to attempt to check out the hole nest, going near or even managing to almost peer into the hole whilst one bird was inside the nest.
A Common Flameback was braver when it came to checking out the nest.
And a week later this one was at it again.
And then after almost 4 weeks' incubation I was able to made a reasonable conclusion that chicks had been hatched.
Some general observations and deductions:
1. It is uncommon for a pair of Black-thighed Falconets to nest in such a low and open or exposed branch that hang over a rather busy walkway in an urban park; the nest is less than 15ft high. This cavity nest was probably used by woodpeckers or barbets before as this park regularly plays host to these nesting species.
In addition, this pair could be deduced as first time parents as they had nested independently away from other falconets, perhaps due to their ignorance of typical black-thighed falconets' communal nesting and subsequent communal chick-feeding.
The cavity nest was probably chosen because of the eye-level and open perch available directly across the nest. The falconets could fly straight into the nest from any of the perches across the nest or even from one particular distant open perch.
(Interestingly, approximately a month after the falconets made the hole their nest, a pair of Banded Woodpeckers came to excavate and occupy a cavity nest just about 6ft above the falconets' nest on the very same branch!)
[AI overview:
Habitat: forest edges, secondary growth, plantations, wooded river valleys and clearings .... They favour open or semi-open woodland with perches for hunting.
Nest sites: they do not build exposed stick nests. Instead they nest in cavities - natural tree holes, old woodpecker/barbet cavities - hollow bamboo internodes, and occasionally fissures or crevices in dead trees. In some areas they've been reported using holes in earthen banks or abandoned termite nests, though tree cavities are most typical.
Site choice factors: entrance size, depth and dryness of cavity, concealment from predators, proximity to good hunting perches and abundant prey (small birds, large insects.
Nest: falconets do not construct an elaborate nest lining. They may remove loose debris and occasionally line the cavity with few feathers or plant fibres, but often leave the cavity largely bare. There is little to no nest-building visible compared with passerines.]
2. The pair of falconets took about 3-4 weeks to incubate. They displayed typical courtship behaviours like courtship feeding, allopreening, playful pursuits around the nest area before and during incubation, vibrant and rapid high-pitched exchanges when coming together in or outside the nest, and copulation.
It was the female that spent most of the time in the nest whilst the male would deliver food to her or call her out to offer her the catch. The male spent less time in the nest and sometimes disappeared for a few hours before returning to perch opposite the nest.
[AI overview:
Displays: courtship includes short aerial chases and fast direct flights between perches; conspicuous calling (high thin whistles) during flights; mutual chasing may include rapid direction changes and swoops.
Courtship feeding: males commonly present prey to females at perches and at the nest entrance (food transfer). This food-offering functions both to strengthen the pair bond and to provision the female during incubation. Mutual preening and and close perching are reported around nest sites.
Allopreening: Allopreening refers to a social grooming behavior in birds where one individual uses its beak to clean, groom, and arrange the feathers of another bird. It most commonly takes place on the head and neck, areas that are difficult for the receiving bird to reach on its own.Beyond basic hygiene, allopreening serves vital social and biological functions within the avian world.
Strengthening Bonds: It is heavily practiced by mated pairs to build and maintain strong partnerships. It is also common among flock members to solidify group cohesion.
Parasite Control: It helps remove ticks, mites, and dead skin particles that can accumulate in hard-to-reach areas.
Relieving Tension: In larger flocks, this mutual grooming ritual can help defuse aggression and reduce conflict between birds.
Egg-laying and clutch size: reported clutches typically range from 2 to 5 eggs, most commonly 2-4.
Egg appearance: eggs are generally pale, often whitish or buff with fine speckling (description varies with source)
Incubation: incubation is primarily by the female, though the male returns frequently to feed her and may incubate briefly. Reported incubation periods in Microhierax species are roughly in the order of 20-30+ days, exact figures for M. friggillarius may vary by site and are not universally consistent in literature.
Attendance: the female stays in the cavity for long stretches, leaving briefly to to be fed by the male or to hunt, especially early or late in the day.]
3. Both birds displayed continued intense alertness and aggressiveness at being watched, bobbing their heads and staring at the camera lens if aimed at them. Once, the female left the nest to fly and flutter directly in front of my camera lens, an uncommon behaviour.
On another test occasion, I lingered outside the nest with the camera aimed at the hole entrance, the female flew out, swooped down brushing past my lower legs before she flew into the nest to exit immediately again, perched and 'eye-balled' me.
A final test occasion was planting myself right opposite of the nest entrance, aimed my camera at the entrance, and within seconds her head popped out, and she flew out right over my head that I had to duck!
On one occasion this heightened wariness was displayed too with other birds close-by when the female arrived with a dead chick. She was plucking the feathers of a dead bird as if ready to take it into the nest. However, with a Black-naped Oriole foraging close-by, and as if to not reveal the nest, she flew off to a distant perch and finished off the bird prey by herself!
She only returned an hour later to the nest with a beetle prey.
Another strategy was to delay entering the nest with preys whenever there were birds in the immediate vicinity of the nest.
And it’s the female that’s always the aggressive one.
Both male and female were always on the alert before entering or exiting the nest.
Male
Female
Even during copulation the male was aware of being watched!
During preening, watching from afar.
Exiting with a discard.
Whilst on perch.
At bath!
Aggression
Playtime
