Secretarybird

Secretarybirds are not generally gregarious aside from pairs and their offspring. They usually roost in trees of the genus Acacia or Balanites, or even introduced pine trees in South Africa. They set off 1–2 hours after dawn, generally after spending some time preening. Mated pairs roost together but may forage separately, though often remaining in sight of one another. They pace around at a speed of 2.5–3 km/h (1.6–1.9 mph), taking 120 steps per minute on average. After spending much of the day on the ground, secretarybirds return at dusk, moving downwind before flying in upwind. Birds encountered singly are often unattached males, their territories generally in less suitable areas. Conversely, larger groups of up to 50 individuals may be present at an area with a localised resource such as a waterhole in a dry area or an irruption of rodents or locusts fleeing a fire. Secretarybirds soar with their primary feathers splayed to manage turbulence. Their wings can flap, though in a slow laborious manner and requiring uplift to be sustained, otherwise they can become exhausted. In the heat of the day, they use thermals to rise up to 3,800 m (12,500 ft) above the ground. The lifespan is thought to be 10 to 15 years in the wild, with the oldest confirmed by banding to be 5 years from a nestling banded on 23 July 2011 in Bloemfontein and recovered 440 km (270 mi) away in Mpumalanga on 7 June 2016, and up to 19 years in captivity.

The secretarybird is endemic to sub-Saharan Africa and is generally non-migratory, though it may be locally nomadic as it follows rainfall and the resulting abundance of prey. Its range extends from Senegal to Somalia and south to Cape Province, South Africa. The species is also found at a variety of elevations, from the coastal plains to the highlands. The secretarybird prefers open grasslands, savannas and shrubland (Karoo) rather than forests and dense shrubbery that may impede its cursorial existence. More specifically, it prefers areas with grass under 0.5 m (1 ft 8 in) high and avoids those with grass over 1 m (3 ft 3 in) high. It is rarer in grasslands in northern parts of its range that otherwise appear similar to areas in southern Africa where it is abundant, suggesting it may avoid hotter regions. It also avoids deserts.

In 1968 the species became protected under the African Convention on the Conservation of Nature and Natural Resources. The International Union for the Conservation of Nature (IUCN) listed the secretarybird in 2016 as a vulnerable species, due to a recent rapid decline across its entire range. Although widespread, the species is thinly distributed across its range; its population has been estimated in 2016 to be anywhere between 6,700 and 67,000 individuals. Long term monitoring across South Africa between 1987 and 2013 has shown that populations have declined across the country, even in protected areas such as Kruger National Park due to bush encroachment, an increase in the tall vegetation cover, resulting in loss of open habitat that the species prefers. As a population, the secretarybird is mainly threatened by loss of habitat due to fragmentation by roads and development and overgrazing of grasslands by livestock. Some adaptation to altered areas has been recorded but the trend is for decline.