The male hissed a warning and flapped his burnished wings at anything that got too close to the cage where his missus sat silently with their labour of love under her bosom.
A nest of gleaming black swan eggs, a first for the Capital’s zoo in more than two decades.
Cob, the male, will not tolerate any trespassing. Pen, the female, is equally alert. They will remain so for at least 40 days, until the incubation period is over and the little cygnets peck out of the hard-shell eggs.
But the large Australian wetland species’ paternal, counter-predatory instincts and skills are not enough to prevent black swan events that have besieged the zoo before. Snakes and mongooses had made a feast of their exotic eggs.
So, enter the nannies.
Zookeepers, smarting from a cruel bird flu virus last year, are more than eager to avoid any miscarriage of the good news that the black swan couple, brought from Thiruvananthapuram and Mysuru in 2014, has shared last week.
- They are native to the wetlands of south-west and eastern Australia
- The two swans that currently reside in Delhi zoo, were part of the two pairs of swans that came to the Delhi zoo in 2014 from Thiruvananthapuram in Kerala and Mysuru in Karnataka
- They have a life span of 25 to 33 years
- They lay around 4 to 8 eggs at a time
- The eggs are usually hatched after an incubation period of 35 to 40 days
- Both the female and male swans take turn to sit on the eggs during the incubation period
- Black swans mate for life
- They are the proverbial ‘night owls’ as they fly at night and rest during the day
- The birds are not considered endangered, as their conservation status is listed at ‘least concern
From zoo vets to janitors, everyone’s going through the nervousness of a first-time father when the wife is wheeled into the labour room. Officials are on their toes, trying to ensure safety of the eggs and health of the nesting birds with round-the-clock care and watch, food supplements and minimum interference near the cage. Guards are shooing away pesky crows.
“We have started giving them poultry eggs apart from the bird’s regular diet, which include pulses and grains,” a zookeeper said on Wednesday.
The zoo is expected to have a herd of hatchlings by mid-April. Until then, the biggest caretakers are the swans themselves.
“The eggs are hardly ever left unattended. If we try getting close to the female and her eggs, the male comes charging,” an attendant said.
Officials believe there are at least four eggs, but they cannot be sure.
“We don’t go too close to the nest, as this might disturb the birds. The slightest interference may halt the hatching process. The eggs can get damaged if we try to handle them, or the birds may not sit on it if they find any human smell on the eggs,” the zookeeper said.
Black swans were kept in a different, more open enclosure before 2014. But reports of snake and mongoose attacks have prompted authorities to accommodate the new pair in first enclosure on the left of the aviary.
“The zoo had a black swan breeding programme in the 1990s. Back then snakes and mongooses posed a big problem for the eggs and cygnets. Once a python ate all the eggs,” said Dr Panneerselvam, former veterinary officer of Delhi zoo.
Officials thought the new couple will break the jinx, but their hopes almost took flight as the pair didn’t lay a single egg in three years. Anxiety gave way to suspicion about the birds being of the same gender.
The swans put doubts to rest when zookeepers discovered their eggs almost a week ago.