The Hooded Vulture Necrosyrtes monachus (Temminck 1823)

Physical appearance. The Hooded vulture (Necrosyrtes monachus) is another small vulture, only marginally larger than the Egyptian vulture. Anderson and Horwitz (2008) describe the Hooded vulture and the Egyptian vulture as the same length (66 cm) and weight (1.9 kg). The largest individuals are found in South Africa, with smaller birds found in the more northerly parts of its range (Snow 1978; Mundy et al. 1992). The average length is 62-72 cm (25-28 in) long, have a wingspan of 155-165 cm (61-65 in) and a body weight of 1.5-2.6 kg (3.3-5.7 lbs) (Ferguson-Lees and Christie 2001). The coloration is brown, with brownish to whitish down on the crown and the back of the neck, and pinkish to greyish skin on the face and throat. There is also a brown feather ruff on the lower neck. The underparts are whitish, streaked with brown (Fig. 2.2 a,b,c).

Fig. 2.2. Hooded Vulture

Classification. The Hooded vulture is the only species of the Genus Necrosyrtes (Gloger, 1841). Some investigators recognize a second subspecies, N. m. pileatus, occurring throughout the range outside West Africa, with the nominate subspecies classified as Necrosyrtes monachus monachus, and limited to West Africa. Kemp (1994: 126) noted that 'Two subspecies sometimes recognized, with nominate race in W. Africa and rest of range covered by race pileatus, but variation only in size... from small in W to large in S'. Other authors write that it should be monotypic (Brown and Amadon 1968). In the past, it was placed with the Egyptian vulture in the Genus Neophron due to perceived morphological similarities (e.g., Britton 1980; Louette 1981; Nikolaus 1987; Gore 1990). This classification was however rejected by cytochrome b gene studies (Wink 1995), and studies using the sequences of two mitochondrial genes and one nuclear intron (Lerner and Mindell 2005). The results of these studies were that the Hooded vulture is more likely to be related to the clade of true Old World vultures, Aegypiinae, including Aegypius, Gyps, Sarcogyps, Trigonoceps and Torgos, and less likely related to the Neophron-Gypaetus clade, Gypaetinae. Studies have not clarified the link of Necrosyrtes to Aegypiinae, but it is possible it diverged 3 to 5 million years BP, from the Genus Gyps, commonly considered its nearest relatives (Wink 1995).

Foraging. Hooded vultures, unlike some other larger vultures are often associated with human settlements. They are also common in desert, coastal land, grassland, wooded savanna and forest edge (Ferguson-Lees and Christie 2001). Wacher et al. (2013: 195) write that 'the distribution of human activity is clearly significant to Hooded Vultures in West Africa, but the interaction is less clear-cut for larger species.' Buij et al. (2013: 240) write of 'the greater abundance of Hooded vultures in the areas with little natural habitat and high human populations.' This species has been recorded in high altitudes up to 4,000 m, but is commonest below 1,800 m (BirdLife International 2012). In the Masai Mara National Park, the Hooded vultures, similar to the Egyptian vulture, compared to the larger vultures 'have a more varied diet, using several food sources other than carrion, but when feeding at a carcass tend to peck on scraps' (Kendall et al. 2012: 525). Hooded vultures were also more likely to associate with Egyptian vultures at kills, despite their similar feeding habits, than with the other larger vultures.

Breeding. The Hooded vulture is usually a tree nester, commonly nesting in stick nests in colonies on palm trees. Daneel (1984) gives examples of nesting from Kruger National Park South Africa. These were located in trees, namely Jackalberry or African Ebony Diospyros mespiliformis Hochst. ex A. DC. and sycamore fig or fig-mulberry Ficus sycomorus L. trees. Both of these trees may reach over 20 m in height.

The breeding period of the Hooded vulture varies regionally. In Northeast Africa most birds breed from October to June. Breeding in West Africa and Kenya occurs mainly from November to July, but may take place all year. In southern Africa, most breeding takes place from May to December. One egg is laid, and the incubation period lasts 46-54 days, with a fledging period of 80-130 days (Ferguson-Lees and Christie 2001) (Fig. 2.2d).

Population status. The population distribution of the Hooded vulture is shown in Fig. 2.2e. The Hooded vulture is mostly resident across most if its range. It is fairly common in the Sahelian countries (Senegal, southern Mauritania, Niger, Chad, and Sudan, South Sudan, Ethiopia and western Somalia), southward to northern Namibia and Botswana, Zimbabwe, southern Mozambique and South Africa (Ferguson-Lees and Christie 2001).

Recently, the population has declined across its range (Ogada and Buij 2011). Indirect poisoning, killings for capture for human food or 'bushmeat' or traditional medicine, and deliberate persecution are the main factors for this decline (Ogada and Buij 2011). The indirect poisoning is usually due to the use of carbofuran pesticides in dead livestock to poison mammalian predators (Otieno et al. 2010; Kendall 2012).

Hooded vulture meat is reportedly sold as chicken in some places. Intentional poisoning of vultures may be carried out by poachers to hide the locations of their kills. Secondary poisoning occurs when vultures ingest meat from carcasses laced with carbofuran pesticides (Otieno et al. 2010; Kendall 2012). Improved abattoir hygiene and garbage disposal, and land conversion to more developed uses also affect vultures (Ogada and Buij 2011). The Hooded vulture may also acquire and die from avian influenza (H5N1), possibly from feeding on dead domestic poultry; 'Hooded vultures could potentially be vectors or sentinels of influenza subtype H5N1, as are cats and swans elsewhere' (Ducatez et al. 2007: 611).