Richard Despard Estes (December 26, 1927 - December 6, 2021) was a biologist specialising in the behaviour of mammals in mainland Africa. He was particularly interested in studying wildebeest. This interest led Rod East, the former co-chair of the Antelope Specialist Group of the IUCN-World Conservation Union, to dub him the 'Guru of Gnu.' [1] It has been suggested that Estes is responsible for most of the world's knowledge of wildebeest behaviour. [2] [3]
Estes chose to study wildebeest because he thought they were 'the most interesting' animals he knew, particularly in their rutting behaviour. He obtained his doctorate in the early 1960s with a thesis on the wildebeest of the Ngorongoro Crater, in which he advanced the theory that the females' estrus was triggered by the rumbling 'love call' of the males. Estes has spent most of the ensuing 40 years doing field work in Africa. In 2004 he began a project in cooperation with the Smithsonian Institution to test his early theory using new advances in molecular chemistry.
Estes has written two guides for travellers to Africa, The Behavior Guide to African Mammals (considered the standard reference of its kind) and The Safari Companion.
Estes lives in Peterborough, New Hampshire. [4]
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(help)[ title missing ]Jackals are medium-sized canids native to Africa and Eurasia. While the word "jackal" has historically been used for many canines of the subtribe canina, in modern use it most commonly refers to three species: the closely related black-backed jackal and side-striped jackal of sub-Saharan Africa, and the golden jackal of south-central Europe and Asia. The African golden wolf was also formerly considered as a jackal.
Wildebeest, also called gnu, are antelopes of the genus Connochaetes and native to Eastern and Southern Africa. They belong to the family Bovidae, which includes true antelopes, cattle, goats, sheep, and other even-toed horned ungulates. There are two species of wildebeest: the black wildebeest or white-tailed gnu, and the blue wildebeest or brindled gnu.
The glans is a vascular structure located at the tip of the penis in male mammals or a homologous genital structure of the clitoris in female mammals.
A bachelor herd is a herd of (usually) juvenile male animals who are still sexually immature or 'harem'-forming animals who have been thrown out of their parent groups but not yet formed a new family group. It may also refer to a group of males who are not currently territorial or mating with females.
The spotted hyena, also known as the laughing hyena, is a hyena species, currently classed as the sole extant member of the genus Crocuta, native to sub-Saharan Africa. It is listed as being of least concern by the IUCN due to its widespread range and large numbers estimated between 27,000 and 47,000 individuals. The species is, however, experiencing declines outside of protected areas due to habitat loss and poaching. Populations of Crocuta, usually considered a subspecies of Crocuta crocuta, known as cave hyenas, roamed across Eurasia for at least one million years until the end of the Late Pleistocene. The spotted hyena is the largest extant member of the Hyaenidae, and is further physically distinguished from other species by its vaguely bear-like build, rounded ears, less prominent mane, spotted pelt, more dual-purposed dentition, fewer nipples, and the presence of a pseudo-penis in the female. It is the only placental mammalian species where females lack an external vaginal opening, having a pseudo-penis instead.
The sable antelope is a large antelope which inhabits wooded savanna in East and Southern Africa, from the south of Kenya to South Africa, with a separated population in Angola.
The striped polecat, also called the African polecat, zoril, zorille, zorilla, Cape polecat, and African skunk, is a member of the family Mustelidae that resembles a skunk. The name "zorilla" comes from the Spanish word "zorillo", meaning "skunk", itself a diminutive form of the Spanish "zorro," "fox." It lives predominantly in dry and arid climates, such as the savannahs and open country of Central, Southern, and sub-Saharan Africa, excluding the Congo basin and the more coastal areas of West Africa.
The black wildebeest or white-tailed gnu is one of the two closely related wildebeest species. It is a member of the genus Connochaetes and family Bovidae. It was first described in 1780 by Eberhard August Wilhelm von Zimmermann. The black wildebeest is typically 170–220 cm (67–87 in) in head-and-body length, and the typical weight is 110–180 kg (240–400 lb). Males stand about 111–121 cm (44–48 in) at the shoulder, while the height of the females is 106–116 cm (42–46 in). The black wildebeest is characterised by its white, long, horse-like tail. It also has a dark brown to black coat and long, dark-coloured hair between its forelegs and under its belly.
The pelvic thrust is the thrusting motion of the pelvic region, which is used for a variety of activities, such as dance, exercise, or sexual activity.
The giant forest hog, the only member of its genus (Hylochoerus), is native to wooded habitats in Africa and is one of the largest wild members of the pig family, Suidae, along with a few subspecies of the wild boar. It was first described in 1904. The specific name honours Richard Meinertzhagen, who shot the type specimen in Kenya and had it shipped to the Natural History Museum in England.
The southern reedbuck, rietbok or common reedbuck is a diurnal antelope typically found in southern Africa. It was first described by Pieter Boddaert, a Dutch physician and naturalist, in 1785. It is placed in the genus Redunca and family Bovidae. This antelope has an average mass of 58 kg (128 lb) and a body length of about 134–167 cm (53–66 in).
The blue wildebeest, also called the common wildebeest, white-bearded gnu or brindled gnu, is a large antelope and one of the two species of wildebeest. It is placed in the genus Connochaetes and family Bovidae, and has a close taxonomic relationship with the black wildebeest. The blue wildebeest is known to have five subspecies. This broad-shouldered antelope has a muscular, front-heavy appearance, with a distinctive, robust muzzle. Young blue wildebeest are born tawny brown, and begin to take on their adult coloration at the age of 2 months. The adults' hues range from a deep slate or bluish-gray to light gray or even grayish-brown. Both sexes possess a pair of large curved horns.
The Ugandan kob is a subspecies of the kob, a type of antelope. It is found in sub-Saharan Africa in South Sudan, Uganda and the Democratic Republic of the Congo. The Ugandan kob is normally reddish-brown, differentiating it from other kob subspecies.
Grant's gazelle is a relatively large species of gazelle antelope, distributed from northern Tanzania to South Sudan and Ethiopia, and from the Kenyan coast to Lake Victoria. Its Swahili name is swala granti. It was named for a 19th-century British explorer, James Grant.
Hackles are the erectile plumage or hair in the neck area of some birds and mammals.
A gecker is a vocalization most often associated with infant primates. It is defined as a loud and distinct vocalization, which consists of a broken staccato noise. In 1965, Irven DeVore of the Center for Advanced Study in the Behavioral Sciences described geckering as a "single sharp yak sound", which may be repeated. It has also been characterized as "cackling." It is common in to all types of macaques, geckering is also associated with fearful jackals and mongooses. Patas monkeys have also been observed to gecker. In macaques, bickering is associated with spastic jerking of the body. Geckers are also commonly displayed in combination with grimaces.
The spotted hyena is the most carnivorous member of the Hyaenidae. Unlike its brown and striped cousins, the spotted hyena is primarily a predator rather than a scavenger. One of the earliest studies to demonstrate its hunting abilities was done by Hans Kruuk, a Dutch wildlife ecologist who showed through a 7-year study of hyena populations in Ngorongoro and Serengeti National Park during the 1960s that spotted hyenas hunt as much as lions, and with later studies this has been shown to be the average in all areas of Africa. However spotted hyenas remain mislabeled as scavengers, often even by ecologists and wildlife documentary channels.
In the biology of birds and mammals, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the moment of birth or hatching. Precocial species are normally nidifugous, meaning that they leave the nest shortly after birth or hatching. These categories form a continuum, without distinct gaps between them.