Jacksonville Zoo's Cranes Raise Adopted Chick
March 24, 2017
Keepers at Jacksonville Zoo recently discovered the egg their Wattled Cranes were sitting on was not fertilized. They contacted their friends at White Oak Conservation for assistance. White Oak happened to have a pair of Wattled Cranes who laid an extra egg.
The average clutch size of the Wattled Crane is thought to be the smallest of any of the world's cranes. Generally, in a nest of two or more eggs, only one chick will survive to hatch or fledge. Therefore, removing the extra egg was a possible ‘saving grace’ for the chick inside.
As a first step, keepers at Jacksonville Zoo decided to swap out the non-viable egg from their nest to a dummy egg, until they knew White Oak’s extra egg was close to hatching. When that time came, keepers at Jacksonville placed the egg in their birds’ nest. The egg hatched on March 5th, and they now have a healthy male chick!
The cranes are raising the ‘adopted’ chick as their own, and visitors to Jacksonville Zoo can see the new family at the African Boardwalk exhibit!
Photo Credits: Rob Bixby
The Wattled Crane (Grus carunculata) is a large bird found in Africa, south of the Sahara Desert.
It is the largest crane in Africa, at a height of up to 175 cm (5.74 ft) and is the second tallest species of crane, after the Sarus Crane. The wingspan is 230–260 cm (7.5–8.5 ft), the length is typically 120 cm (3.9 ft) and weight is 6.4–7.9 kg (14–17 lb) in females, 7.5–9 kg (17–20 lb) in males.
The Wattled Crane is native to eleven sub-Saharan countries in Africa, including an isolated population in the highlands of Ethiopia. More than half of the world’s Wattled Cranes occur in Zambia, but the single largest concentration occurs in the Okavango Delta of Botswana.
All cranes are omnivorous. The principal food of the Wattled Crane is mainly aquatic: tubers and rhizomes of submerged sedges and water lilies. It is one of the more herbivorous of extant cranes. The other primary portion of the diet consists of aquatic insects. They will supplement the diet with snails, amphibians and snakes when the opportunity arises. Roughly 90% of foraging done by this species occurs in shallow waters. They typically forage by digging vigorously with their bill into the muddy soil. On occasion, it will eat grain and grass seed as well.
Wattled Cranes commence their breeding season around April. Most nests are sloppily crushed impressions of grass along the border of a marsh. Eggs are laid approximately 3 weeks after the nests are built. The average clutch size of the species is reportedly the smallest of any of the world's cranes, with an average of 1.6 eggs. Even if there are two eggs, usually only one chick successfully survives to hatch or fledge. The incubation period, roughly 33 to 36 days, is on average the longest of any crane and both parents participate. The chicks are immediately fed by both parents, which take shifts. After around 80 days, the offspring start to forage with their parents. At the first sign of any danger, the parents force their young into tall grasses to hide. The fledging period occurs at 100–150 days, the longest it takes any crane to fledge. The young remain with their parents for up to a year (when the next breeding period starts) and may gather in flocks with unrelated juveniles.
The Wattled Crane is currently classified as “Vulnerable” by the IUCN. Destruction, alteration, and degradation of wetland habitats constitute the most significant threats to the bird.