question: Why are most big felines that live in the savanna diurnal?
comment: Predators are active when their prey is most vulnerable. Somewhat counterintuitively, the various prey animals the big African cats hunt are harder to get while asleep. The herd packs in a lot tighter at night and singling out one individual to attack is difficult. When foraging the animals spread out more and can be separated from the herd more easily. Injury means death for a predator, and charging into a sleeping herd of zebras means you have to fight them all instead of just one. Sure you get the drop on one of them, but the racket will awake forty more.
passages: In Peru's Cocha Cashu Biological Station, radio-collared individuals rested during the day in dens below large trees or other sheltered sites on the ground. They started to be active earliest in the late afternoon and moved between 3.2 and 17 hours until latest dawn, when they returned to their dens. Their usual pace of walking was about per hour when hunting. They moved up to per hour when heading to a known kill site or patrolling their territory.
   Leopards are generally most active between sunset and sunrise, and kill more prey at this time. In Kruger National Park, male leopards and female leopards with cubs were more active at night than solitary females. The highest rates of daytime activity were recorded for leopards using thorn thickets during the wet season, when impala also used them.
   Section::::Ecology and behaviour.
  
  Sunda leopard cats photographed by camera-traps in Kalimantan between 2008 and 2018 were foremost nocturnal, overlapping with the activity pattern of flat-headed cats ("Prionailurus planiceps").
  
  Those recorded in an oil palm plantation in central Kalimantan were active from late afternoon to early morning and preyed foremost on ricefield rats and other rodents.
   Radio-collared clouded leopards were foremost active by night but also showed crepuscular activity peaks.
  
  Clouded leopards recorded in northeast India were most active in the late evening after sunset.
  
  Home ranges have only been estimated in Thailand:
  
  BULLET::::- Four individuals were radio-collared in Phu Khieo Wildlife Sanctuary from April 2000 to February 2003. Home ranges of two females were and , and of two males and .
   Selection pressures, such as high predatory activity or low food may require animals to change their behaviours to adapt. An animal changing the time of day at which it carries out significant tasks (e.g., mating and/or foraging) is recognized as one of these adaptive behaviours. For example, human activity, which is more predominant during daylight hours, has forced certain species (most often larger mammals) living in urban areas to shift their schedules to crepuscular ones. When observed in environments where there is little or no human activity, these same species often do not exhibit this temporal shift. It may be argued that if the goal is to avoid human activity, or any other diurnal predator's activity, a nocturnal schedule would be safer. However, many of these animals depend on sight, so a matutinal or crepuscular schedule is especially advantageous as it allows animals to both avoid predation, and have sufficient light to mate and forage.
   Leopards are active mainly from dusk till dawn and rest for most of the day and for some hours at night in thickets, among rocks or over tree branches. Leopards have been observed walking across their range at night; they may even wander up to if disturbed. In some regions, they are nocturnal. In western African forests, they have been observed to be largely diurnal and hunting during twilight, when their prey animals are active; activity patterns varies between seasons.
  
  Leopards can climb trees very skilfully, often rest on tree branches and descend from trees headfirst.
   Asian golden cats are territorial and solitary. Previous observations suggested that they are primarily nocturnal, but a field study on two radio-collared specimens revealed arrhythmic activity patterns dominated by crepuscular and diurnal activity peaks, with much less activity late at night. In the study, the male's territory was in size and increased by more than 15% during the rainy season. The female's territory was in size. Both cats traveled between only to more than in a day, and were more active in July than in March.
   Even small amounts of environmental light change have shown to have an effect on the activity of mammals. An observational study done on the activity of nocturnal owl monkeys in the Gran Chaco in South America showed that increased amounts of moonlight at night increased their activity levels through the night, which led to a decrease of daytime activity. Meaning that for this species, ambient moonlight is negatively correlated with diurnal activity. This is also connected with the foraging behaviours of the monkeys, as when there were nights of little to no moonlight, it affected the monkey’s ability to forage efficiently, so they were forced to be more active in the day to find food.
   Megabats are mostly nocturnal and crepuscular, though some have been observed flying during the day. A few island species and subspecies are diurnal, hypothesized as a response to a lack of predators.
  
  Diurnal taxa include "P. melanotus natalis", the Mauritian flying fox, the Caroline flying fox, "P. p. insularis", and the Seychelles fruit bat.
  
  Section::::Biology and ecology.:Behavior and social systems.:Roosting.
   In Morocco, a male sand cat travelled in 30 hours. A female sand cat moved in an area of during six days, and two males had home ranges of .
  
  Section::::Behaviour and ecology.:Hunting and diet.
   In the first series in 1996, the show followed first-time mother Kidogo and her two 12-week-old cubs. While most cheetahs hunt during the day, Kidogo hunted late in the day. In one of "Big Cat Diary"'s few episodes filmed at night, Kidogo and cubs come dangerously close to hunting lions. 
  
  Section::::The "Big Cat" stars.:Cheetahs in the hostile world.:Fundi.
  
  Fundi was also part of the first series. Fundi hunted regularly in thick acacia trees to keep her two adolescent cubs well-fed, unusual for cheetahs who usually hunt on open plains. Fundi means "craftsman" in Swahili. 
   Steenbok are active during the day and the night; however, during hotter periods, they rest under shade during the heat of the day. The time spent feeding at night increases in the dry season. While resting, they may be busy grooming, ruminating or taking brief spells of sleep.
  
  Section::::Behaviour.:Anti-predator.
   African golden cats are able to climb, but hunt primarily on the ground. They mainly feed on tree hyrax, rodents, but also hunt birds, small monkeys, duikers, young of giant forest hog, and small antelope. They have also been known to take domestic poultry and livestock.
  
  Section::::Ecology and behavior.:Reproduction.
   Still today, diurnality seems to be reappearing in many lineages of other animals, including small rodent mammals like the Nile grass rat and golden mantle squirrel and reptiles. More specifically, geckos, which have thought to be naturally nocturnal have shown many transitions to diurnality, with about 430 species of geckos now showing diurnal activity. With so many diurnal species recorded, comparative analysis studies using newer lineages of gecko species have been done to study the evolution of diurnality. With about 20 transitions counted for the gecko lineages, it shows the significance of diurnality. Strong environmental influences like climate change, predation risk, and competition for resources are all contributing factors. Using the example of geckos, it is thought that species like "Mediodactylus amictopholis" that live at higher altitudes have switched to diurnality to help gain more heat through the day, and therefore conserve more energy, especially when colder seasonal temperatures hit.
   Although the area included in a home range is relatively constant over time, the preferences in regard to what part of the range is most used shift with the seasons. From March until August, forest buffalo spend most of their time in the forest, while from September through February, they favor the savannas and marshes.
   In Uganda's Kibale National Park, an African golden cat was recorded in an old growth forest patch in 2008.
  
  In Gabon’s Moukalaba-Doudou National Park, it was recorded in forested areas during surveys in 2012.
  
  Section::::Ecology and behavior.
  
  Due to its extremely reclusive habits, little is known about the behavior of African golden cats. They are solitary animals, and are normally crepuscular or nocturnal, although they have also been observed hunting during the day, depending on the availability of local prey.
   The leopard depends mainly on its acute senses of hearing and vision for hunting. It primarily hunts at night in most areas. In western African forests and Tsavo National Park, leopards have been also observed hunting by day. Leopards usually hunt on the ground. In the Serengeti, leopards have been observed to ambush prey by jumping down on it from trees.
   Large home ranges can be associated with less-productive habitats; however, a larger area of open grassland has been observed to have a positive relationship with herd size. Home ranges remain remarkably constant and stable year after year. The only documentation of the actual home range boundaries of these animals is relatively recent, so only time will tell how these boundaries remain over large lengths of time; however, studies have shown almost no movement in range boundaries from one year to the next.
   Verreaux's sifakas forage for food with their troop, primarily in the morning and late afternoon, so they can rest during the hottest part of the day. They are herbivores; leaves, fruit, bark and flowers are typical components of the diet. However, they are mostly folivorous (leaves represent the majority of the diet over the year, especially in the dry season) and they seem to choose food items based on quality (lower tannin content) rather than on availability.
  
  Section::::Behaviour.
   What’s really special about Gorgonopsids is their patience and implacability. Once they have smelt blood they have a tendency to pursue their prey at all costs. In fact it was this keen sense of smell that originally tempted it into the cold present, lured by the smell of humans and waste from a supermarket. They then store their kills in trees like leopards.
   Social behaviour is influenced by the climate and geography; as such, the impala are territorial at certain times of the year and gregarious at other times, and the length of these periods can vary broadly among populations. For instance, populations in southern Africa display territorial behaviour only during the few months of the rut, whereas in eastern African populations, territoriality is relatively minimal despite a protracted mating season. Moreover, territorial males often tolerate bachelors, and may even alternate between bachelorhood and territoriality at different times of the year. A study of impala in the Serengeti National Park showed that in 94% of the males, territoriality was observed for less than four months.
   During a study in northeastern Spain, males have been found to be more active than females at night because of their greater size, which indicates that males have greater energy requirements to satisfy their physiological needs. Females typically weigh less, and they have been found to be less active overall. Females' home ranges are also smaller than those of males. Males had a mean annual home range of , and females of . While males have larger home ranges in all seasons, the differences between males' and females' territories are most significant during the winter. Their home ranges are slightly larger during the spring because they are more active, not only nocturnally, but in seeking a mate. Because of their increased activity, they require more energy and are more active to acquire the necessary sustenance.
   The black mamba is both terrestrial and arboreal. On the ground, it moves with its head and neck raised, and typically uses termite mounds, abandoned burrows, rock crevices and tree cracks as shelter. Black mambas are diurnal; in South Africa, they are recorded to bask between 7 and 10 am and again from 2 to 4 pm. They may return daily to the same basking site.
   Section::::Behavior.
  
  Outdoor cats are active both day and night, although they tend to be slightly more active at night. The timing of cats' activity is quite flexible and varied, which means house cats may be more active in the morning and evening, as a response to greater human activity at these times. Although they spend the majority of their time in the vicinity of their home, housecats can range many hundreds of meters from this central point, and are known to establish territories that vary considerably in size, in one study ranging from .
   Very little is known about ecology and behaviour of rusty-spotted cats in the wild. Captive ones are mostly nocturnal but also briefly active during the day. Most wild ones were also recorded after dark. At Horton Plain National Park in Sri Lanka, they were mostly recorded between sunset and sunrise, with limited daytime activity. Several individuals were observed hiding in trees and in caves.
  
raw_presuppositions: Hunting should be easier under the cover of night for big African cats.
raw_corrections: Herds pack in tight to sleep at night, but individuals are easier to separate from the herd when they forage during the day.