Tockus nasutus nasutus African Gray Class: Aves. Order: . Family: Bucerotidae. Other names: Gray hornbill, hornbill

Physical Description: Male—dun-colored with a central light stripe from hind neck to rump; head, throat, neck more or less gray with a broad white stripe over eye to nape; wing feathers and coverts (feathers covering the bases of the quills of the wings and tail) edged with whitish; outer tail feathers tipped white; underside creamy white; bill black with a splash of cream at base of upper mandible. Female—smaller, bill is colored red at tip, and greater part of the upper mandible is yellow. are about 18 inches, males being larger than females. The wingspan of the gray hornbill is 7.5- 10 inches and weighs 5-9oz.

Diet in the Wild: eggs and nestlings, insects, rodents, lizards, frogs, supplemented with small fruit and seeds especially during the dry season.

Diet at the Zoo: Apples, papayas, grapes, hard-boiled eggs, mealworms, softbill diet, pinkie mice

Habitat & Range: Sub-Saharan and Eastern Africa into Arabia, living in open woodlands and tree hollows

Life Span: Up to 25 years

Perils in the wild: of prey, some carnivores, man, habitat destruction

Physical Adaptations:  Hornbills have huge, two-tiered beaks that cause the birds to appear top-heavy. The bill is long forming dexterous forceps. The cutting edges are serrated for breaking up food.  The casque surmounting the bill is a narrow ridge that may reinforce the upper mandible. In spite of its heavy appearance, the structure is a light skin of keratin overlying a bony support. The beak itself is honeycombed with air chambers, making it as light as a sponge. The casque possibly serves as a means of visual recognition but may be used in amplifying calls, in fighting, or to knock down fruit.  The hornbill is one of the few birds that have eyelashes to shield them from sun, dust, and debris. There eyelashes are actually modified feathers.  Only bird group (hornbills) in which the first two neck vertebrae are fused to support the skull  Stocky body has air sacs under the skin over the back and shoulder area which may cushion the female from injury in her cramped nest  The tail is used as a rudder in flight. It also serves as a prop, bracing the male while he clings to the nest-hole entrance.  Strong feet provide a secure grip, particularly for the male as he perches to feed his mate through the slit in the nest hole.

Behavioral Adaptations:  Diurnal  Live in monogamous pairs 09/04/2012

 Eat most of their food from trees, but possess great aerial skills for catching food while flying. They follow herds of zebras, monkeys, baboons, to take advantage of the disturbed insects. Rarely dig for insect larvae or eats from ground  Can fly at speeds reaching around 18 MPH.  Hornbills have been known to wipe their food back and forth over a perch or along the ground to clean the item of unwanted coverings, like hairy caterpillars, slimy toads, or juicy fruits.

Reproduction and Development:  Nesting African grey hornbills are monogamous, and their nesting habits are unique. Natural cavities are used.  Two to five dull white eggs are laid at considerable intervals in any suitable hollow in a tree. Incubation for hornbills in general requires around 24 days depending upon the size of the species.  The female seals herself inside the nest, leaving only a narrow vertical slit through which the male will feed her and the young and through which she will forcibly expel droppings. At first she uses mud (while working from the outside) and later her own droppings mixed with food remains and feathers. In some species the male assists by bringing lumps of mud or sticky foods. The female undergoes a molt of all her flight and tail feathers at the time of egg laying. These are re-grown by the time she emerges from the nest. The incubation period is quite lengthy, and the young mature slowly. Her mate brings her food as often as 10-20 times a day.  When the chicks are about half grown, the female breaks out of the nest and helps the male to feed the nestlings. The nestlings need an insect each, every 10 minutes. The male needs help from his mate to provide sufficient food for their brood. In order to protect themselves from predators, as soon as the female leaves, young grey hornbills once again seal up the nest, breaking their way out only when they are ready to fledge.

Additional Information:  These birds are sometimes called “Fire birds”, because when the fires sweep across the plains, the insects rise into the air attracting these birds from miles away to attend the feast.  African Grey Hornbills can catch bees in flight and de-venom them before eating.  The African Grey Hornbill doesn’t like to be on the ground much. They prefer to sit in trees where they find most of their food. They rest at night and return to the same tree again and again, this tree is called a sleeping tree.

Conservation Status: Least Concern

Conservation Efforts: Currently not endangered, habitat loss is their main concern.

Sources:  Cincinnati Zoo & Botanical Gardens  http://www.mangoverde.com/birdsound/images/00000008793.jpg  The Hornbills by Alan Kemp  http://www.pittsburghzoo.org/animal.aspx?id=74  http://www.biodiversityexplorer.org/birds/bucerotidae/tockus_nasutus.htm  http://www.twycrosszoo.org/african-grey-hornbill.aspx

09/04/2012