1 Module # 6 Component # 7 Sparrowhawks & Goshawks and the Gymnogene Sparrowhawks and Goshawks There are nine Southern African species in this group, these are the: Ovambo Sparrowhawk Little Sparrowhawk Redbreasted Sparrowhawk Black Sparrowhawk Little Banded Goshawk Dark Chanting Goshawks Gabar Goshawk African Goshawk Pale Chanting Goshawk are also quite shy, and are not easily observed. Sparrowhawks are true hawks, characterised by slender bodies, rounded wings, long tails, small sharp beaks and long bare legs and toes tipped with needle sharp talons. This general morphology gives Sparrowhawks great manoeuvrability in pursuing prey. Most hunt other birds, chasing and catching them on the wing. They The Goshawks by contrast are not at all secretive, often perched conspicuously along road sides. They are also lethargic hunters, taking their prey on the ground.
2 Little Sparrow-hawk - Accipiter minullus Vital Statistics Wingspan Weight Preferred prey Incubation period Clutch size Status Nesting site Nestling period Hunting success Habitat 50 cm [20 in] 70-100 g [ 3-4 ounces.] Small bird specialist 28-32 days 2 eggs Common resident Upper branches of trees 26 days Less than 50% of each attempt Evergreen forests and savanna woodland
3 Description This species is second only to the Pygmy Falcon in being the smallest Southern African bird of prey, measuring 23 to 25 cm [9 ½ in] from beak tip to tail if laid down flat. The bird has a light grey breast finely barred with a light rufous brown. Their wings and back are slate grey, while the tail is black with two distinct white eye spots and a narrow white strip on the base. Its eyes, cere and legs are yellow and bill is black. Females are larger than their male counterparts. The juveniles have heavy brown spotting on its underparts. Their upperparts are brown. The eyes are pale grey, but legs and cere are yellow. Its moult into the adult plumage takes place in its second year, with no intermediate moult stages.
4 Courtship and Reproduction Courtship behaviour begins about six weeks before the pair begin building a nest. Display flights consist of flying around while carrying nesting material. Nests are placed in the upper branches of trees, with the actual building being carried out mostly by the female. Nests or at least the same trees are used successively. The nest site is aggressively defended within at least 40 m [130 ft] of the nest. Normally two eggs are laid, mostly in October (early summer). There is usually a 48-hour delay between eggs being laid. The incubation is shared but the male is only responsible for around 25 % of it. He will hunt for both, thoroughly decapitating, plucking and eviscerating birds before delivering them. She may continue to hunt while he is on the nest. Incubation periods vary between 28 and 32 days. The nestlings begin vigorous wing exercises at 17 days and start flying at 26 days. The young will remain in the nest vicinity initially, but it is unknown when they become independent.
5 Hunting An often-asked question pertaining to this diminutive raptor is how do birds that only weigh 70-100 grams [3 4 ounces] compete in the world as predators, when they themselves are potential prey, from other bird eating species? The answer to this is their stealth coupled with their startling flying dexterity. Their preferred prey are other birds, up to their own size, and their favoured mode of hunting is ambush. They frequently perch unobtrusively near a popular watering or feeding site of other birds, and await an opportunity. When they deem their chances good, they shoot from their cover to grasp their prey. They are more unsuccessful than not, but when they miss, they simply return to cover and await the prey s return. Occasionally they will take lizards and insects. Little Sparrowhawks have an unusually broad habitat tolerance. They may be found from evergreen forests, through a range of woodlands and savannas to semi-arid areas.
6 Little Banded Goshawk - Accipiter badius Vital Statistics Wingspan Weight Preferred prey Incubation period Clutch size Status Nesting site Nestling period Hunting success Habitat 58 cm [23 in] 100-150 g [3-4 ounces.] Small lizards 28-30 days 2-3 eggs Common resident Tree tops 32 days Greater than 50 % of each attempt Open Grassland and Savanna Woodland
7 Description The upperparts of the adults are blue - grey and their white underparts are finely barred with russet horizontally, including their throat. Legs, feet and cere are yellow, and beaks are black. One very distinctive feature of this diminutive raptor is its very striking cherry red eyes. When its grey tail is spread, four black bars are visible. The sexes are mainly distinguished by the basis of their behaviour during the breeding season. Juveniles are brown on their upperparts, and their breasts are covered in broad russet splotches. The rest of their underparts are broadly russet barred. Their legs, feet, cere and eyes are all yellow, and their beak is black. Adult plumage is acquired by the age of two years, but individuals may breed while still in an intermediate moult stage.
8 Courtship and Reproduction Courtship between Little Banded Goshawks consists of a variety of flight displays. These include soaring in circles above the treetops, chasing flights through the trees and the male also flies near the perched female with nesting material, in a similar fashion to the Little Sparrowhawk. During both activities, both birds call noisily. Feeding of the female by the male is also a regular feature of the courtship. Their nests are usually flimsy affairs, generally not lasting to the following breeding season, and most nests are discarded in favour of new ones rather than repairing the old ones. Both sexes build them. Eggs are laid for the most part in October, and a clutch size of 2-3 eggs is the norm. The female takes most of the responsibility for incubating the eggs, while the male feeds her. He may bring up to seven items of food daily. He does not bring the prey to the nest, but rather alights near it and calls the female to him. During this time, she does not hunt at all. The male stays away from the nest for most of the day, presumably hunting, but even at night he does not roost anywhere near the nest. Incubation takes between 28 and 30 days, and after three weeks of hatching the nestlings are jumping to branches adjacent to the nest, and are beginning wing exercises. The males sole task during this period is to supply food, which he may do up to ten times daily. Curiously he still delivers it in the same manner as he did while the female was incubating. It remains her task to tear it up and distribute it to the nestlings. The young birds begin flying about 32 days after hatching, and after three weeks can hunt themselves, although they are still fed by the female. At five weeks, they are no longer dependent on their parents, and disperse from the nest area shortly afterward.
9 Hunting Outside of Southern Africa, the Little Banded Goshawk has the name "Shikra", derived from the Hindu word for hunter. The favoured prey of these small raptors is lizards which consist of over 70 % of what they catch. They will also take other birds, small mammals such as mice and even bats, geckoes, agamas, frogs, snakes, and even rob fledglings from their nests. Their main mode of hunting is from a concealed branch close to the ground. When the chosen prey is sighted, they attempt to catch it with a quick dive to the ground.
10 Gymnogene - Polyboroides typus The last of the diurnal or day time raptors to be detailed is the Gymnogene. This very peculiar bird of prey has been put in the group known as the Harriers and allied species. However, it probably merits its own specific taxonomic group, being put here for bearing some similarity to the harriers but more for want of a better place. We have included it here mainly since it is a very enigmatic and interesting bird. It is not a common raptor, which we believe makes knowing about it, more important when you are lucky enough to see it.
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12 Vital Statistics Wingspan Weight Preferred prey Incubation period Clutch size Status Nesting site Nestling period Hunting success Habitat 160 cm [64 in] 0.95-1.4kg Bird eggs and variable generalist 35 days 1-2 eggs Uncommon Trees, bushes or cliffs 50 days Greater than 50 % of each attempt Open Grassland and Savanna Woodland
13 Description Happily, this unusual bird is described so, due to both behaviour and morphology, and is thus easy to identify. The upperparts of the adults are a bluish grey, as is the head and breast. Below the breast, its underparts are finely barred black and white. The tail is black with a broad white bar across the middle, and can be seen from above or below. The Gymnogene s bill, eyes and talons are black, contrasting with yellow legs, feet and cere. Its head is also distinctive as being disproportionately small in comparison to its body, and its face is unfeathered and a pale yellow. Juveniles are uniformly dark brown. Their eyes, bill and bare facial skin are black. The legs and feet are yellow. Change to the adult plumage may take one of two routes. In some individuals, the upperparts of their back and wings begin to change first, while others begin the transformation with their head and breast plumage modifying first. Either way it takes about two years to assume its full adult colouration.
14 Courtship and Reproduction The bare skin on the faces of Gymnogenes can be indicative of their imminent breeding, as they flush red as if they were blushing. This is preceded by some nuptial displays. These consist of flight displays which culminate in the male diving at the female who turns and extends her feet to his. They generally touch claws briefly and then continue soaring. During this time, the males also feed the females, depositing prey in their nest or delivering the prey to her directly. Gymnogenes show little consistency in their choice of nest site, which may be in a tree canopy or at its base. They also construct nests in bushes or on cliff ledges. They may also take over nests of other species, but this is rare. Both birds contribute to the nest building, and when they are together on the nest their faces flush red. Eggs are laid from September to November, and one or two may be laid. Their eggs are very distinctive, having a basic creamy colour overlaid with a red wash. The male incubates for about 10 % of the time, and feeds the female. She also hunts for herself while he is on the nest. They are also seen to flush whenever a change-over in incubation occurs. Eggs take 35 days to hatch. When two chicks are present, Cainism readily occurs, with the first-born nestling often killing its sibling or simply competing with it for food, thus letting it starve. Nestling periods average at 50 days, and the birds generally leave the nest area within a week.
15 Hunting and Feeding The peculiarity of this species manifests itself mostly in its choice and acquisition of prey. This is aided by a unique morphological characteristic, which is its ability to bend its knee joint in both directions. This "double - jointedness" enables the bird to fit its long legs into tree holes and nests to extract nestlings and eggs. Its unusually small head and bare face also aid it in sticking its head into small crevices to find food. Using this hunting or foraging technique, just about everything found is taken. This includes dormice, bats, lizards, snakes, frogs, insects and a variety of other unsuspecting animals. The birds are also very agile, and contort themselves to reach even the most inaccessible of animal homes. This includes hanging upside down to reach into weaver nests and the homes that swifts, swallows and sparrows who often build under the eaves of buildings. These various adaptations of the Gymnogene have enabled it to fill an ecological niche, where it has little or no competition from other raptors.