The barn owl hunts primarily at dusk and at night for small mammals. I
have observed that this family of owls feeds on rats, which are
plentiful in Mumbai. The owl detects its prey using its optical and
acoustical skills. The concavity of the facial disc enables it to
collect sound waves and directs them to its ears, thereby blocking
ambient noises.
Very often, takeoff and landing of the family members are accompanied by the cries of the onlookers of their own clan
Off they go for their nightly hunt
Their flight is practically soundless. These owls have often flown past me, but I have heard absolutely nothing.
The velvety-thick serrated feathers on the front edges of the
owl’s wings combing through the air, reduce the noise during
flight.
Bottleneck at the entrance
Scanning the area before feeding
Homecoming with the prey.
I could observe that the prey was always carried in the beak. Only when
the beak was used for other tasks, the prey was held with the claws.
Fight for food
Marking the territory and attracting the female for mating begins
mostly from February. The mating call and the mating process depend on
the availability of food. In case of shortage of food, 60% of the older
owls do not even attempt this exercise. When the food supply is
abundant, the male owls mate with multiple female partners per season,
resulting in two or three nested offsprings. And that seems to have
taken place here, this year.
Calls accompany the start
When
the parent owls are out on a hunt, the offspring screech ceaselessly
all night long, despite the risk of attracting the attention of
predators. The latest theory is that the owlets, through their
screeching, signal each other of their hunger, thereby negotiating
their next meal. Instead of fighting for food, the owlets, upon their
parents’ return, convey to each other, their extent of hunger, as
well as their determination to stake their claim over the food.
Subsequently, priority is given to the hungrier owlets rather than the
stronger ones.
Often I could observe that their individual flight was also accompanied with a screech
Flight Observations
The drive for such behavior of the owlets, however, is not compassion.
It is purely a calculative move to enhance their chances of survival.
This is because the energy expended for the negotiations is less than
the cost involved in a fierce fight over food. At least, that is what Alexander Roulin,
Swiss Professor of the Department of Ecology and Evolution at the
University of Laussane, has theorised. He has recently published his
theory in the Evolutionary Ecology Research Journal.
While observing the owlets, the young researcher discovered that these
young ones make an awful lot of noise in the absence of their parents.
The number of cries can go up to as many as 1,800 cries per night. Even
I could have told him that!
The hunger calls of the owlets are at times accompanied by calls of
male owls declaring territorial boundaries (the highest intensity calls
can be heard between 3 and 4 o’clock at night). Then there are
other calls meant to impress and attract a mate, to which the females
regularly respond. Further, there are calls directing those of their
own clan to their nests. All these calls are so similar that they can
hardly be distinguished from each other. It is only the gentle hooting
of the owlets from the nest that is distinct. Owls can create a hell of
a racket at night, which is pretty much a mixture of whistling,
hissing, screeching and hooting! After over 2 months of constant noise,
finally there is peace again. The residents of the apartment complexes
across must surely have had enough of the owls. We will just have to
wait and see if they come back! Owls are supposed to be pretty loyal to
their respective territories.
The short sequences of this brief video (4:17 min) were recorded with the D3S
camera, ISO between 10.000 and 12.800, as well as with the help of a small flashlight.
One morning, I found this owlet dead on the ground right in front of the building. Its missing feathers
and some mud on its beak clearly indicate the fierce fight it must have had, as it landed on the hard floor.
