Vandalur zoo ostrich has good exchange value in other zoos

By Balasubramani Muniyandi Published on Sep 15, 2018 01:09 PM IST

"Ostrich is one of our most prized possessions. It has an exchange value on a par with that of carnivores in the zoo," says the veterinarians at Arignar Anna Zoological Park, popularly known as Vandalur zoo.

"We have good reproduction rate which makes our ostriches all the more sought after in other zoos. The management set-up here is top-notch, which is the result of the efforts taken by zoo director S Yuvaraj and deputy director Sudha Ramen," said veterinarian K Sridhar.

He said utmost care is given to the ostriches. "In the wild, these birds, which belong to the Ratite family, are well-adapted to the environment in which they have evolved. We have tried to replicate it as much as we can and ensured that their movement is not restricted."

He said a special feed is brought from TANUVAS (Tamil Nadu Veterinary and Animal Sciences University) and is given to the birds here.

"Apart from this, we also give sprouts, green leaves which help keep the birds healthy," he added.

BREEDING SEASON

Another veterinarian, Pa Kalaignan, said, "We show minimum interference with the birds - especially during the breeding period. A pinkish skank will be formed in the legs of the male bird which indicates the breeding season. Both male and female birds take part in the hatching process and they roam as couples during this period."

"Female ostriches lay about 15 eggs per breeding-season, which is once a year, and only after they have laid enough to cover with their bodies and wings will they start to incubate them," Kalaignan added.

Veterinarian Boon Allwin said, "Vandalur zoo is the only place in India where breeding of the ostrich is done naturally with high success rate."

"The breeding season’s length largely depends on food availability, bird condition and weather. Approximately, two months prior to the beginning of the breeding season, birds should be separated into breeding pairs. Groups of one male and two female birds can also be penned together. Bird condition is important as unhealthy and improperly conditioned birds will often be less productive," he added.

IN THE WILD

Kalaignan said in the wild, the ostrich has to face a variety of predators which includes lions, leopards, spotted hyenas and cheetahs.

"Adult ostriches can outrun most predators and, hence, it is mostly attacked in ambush. If the nest or young ones are threatened, either or both the parents may create a distraction, feigning injury. However, they may sometimes fiercely fight predators, especially when chicks are being defended," he said.

TEMPERATURE BALANCE

Since they are found in the Savanna and desert regions, they maintain a body temperature of about 38.1 to 39.7 degrees Celsius. Like every other bird, ostrich too lacks sweat glands, so, they heavily rely upon increased evaporation from the respiratory system for heat transfer.

Unlike other birds, Ostrich is able to dissipate heat through panting. During hyperpnea ostriches pant at a respiratory rate of 40-60 cycles per minute, versus their resting rate of 6-12 cycles per minute. The temperature of their beak, neck surfaces, lower legs, feet and toes are regulated through heat exchange with the environment.

CHALLENGES

Ostrich lives in habitats that are dry and hot and this poses a challenge to its water consumption. Also, the ostrich is a ground bird and cannot fly to find water sources, making it all the more difficult for it.

BIGGEST EGG

Ostrich’s is the biggest and hardest egg. In fact, it is so hard that at times ostriches lay eggs standing and they do not break even if they fall from that height. The chicks cannot break open the egg on their own. They will be assisted by the parents who peck the egg from the outside. The timing of this has to be accurate failing which the egg will not hatch properly. This egg is highly proteinous and is an easy source of energy for other animals and, hence, it is very vulnerable.

NO HEAD IN SAND

The vets said contrary to popular belief, ostriches do not bury their heads in sand to avoid danger.

"This may have been a misunderstanding of their sticking their heads in the sand to swallow sand and pebbles to help digest their fibrous food. Another possible origin for the myth lies in the fact that ostriches keep their eggs in holes in the sand instead of nests, and must rotate them using their beaks during incubation; digging the hole, placing the eggs, and rotating them might each be mistaken for an attempt to bury their heads in the sand," they explained.

NO DRINK TROUBLE

Common ostriches can go without water for several days, using metabolic water and moisture in ingested plants, but they enjoy liquid water and frequently take baths where it is available.

MATING DANCE

During the breeding season, the cock performs with his wings, alternating wing beats, until he attracts a mate. He will maintain privacy by driving away all intruders. They graze together until their behaviour is synchronised; then the feeding becomes secondary. The cock will then excitedly flap alternate wings again, and start poking on the ground with his bill. He will then violently flap his wings to symbolically clear out a nest in the soil. Then, while the hen runs a circle around him with lowered wings, he will wind his head in a spiral motion. She will drop to the ground and he will mount for copulation.

SOME STUNNING FACTS

Running Speed - 50-70 miles per hour

Eye vision - up to 12 km in deserts

Lifespan - 60-70 years

Productive age - 30-40 years

Incubation period - 42-44 days

Male features - ht 7-8 ft, wt 130-150 kg

Female features - ht 6-7 ft, wt 120-130 kg

Egg weight - 1,300 to 1,500 g

Ideal chick weight - 850 g

NEXT BIG THING

Now that we have covered the largest mammal on earth - elephant, the largest bird - ostrich, we will now shift focus to biggest water animal - hippopotamus. Stay with us to know about the largest water mammal at Vandalur zoo in our next Zoo Tales in News Today edition of 22 September.