ArticlePloS one2017
Inactivity/sleep in two wild free-roaming African elephant matriarchs - Does large body size make elephants the shortest mammalian sleepers?
Article in PloS one, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 48 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
48 citing papers in PubMed, 126 citations in OpenAlex.
- Monitoring Zoo Elephant Rumble Activity Using Combined Seismic and Acoustic Data.Ecology and evolution · 2026Article
- Trunk Tip Wear in Wild African Savanna Elephants.Integrative and comparative biology · 2025Article
- Local versus global sleep organization and the quest to determine sleep function.Neurobiology of sleep and circadian rhythms · 2025Article
- Bridging the gap between lab and field sleep studies: a proof-of-concept for studying wild rats in semi-captive environments.Sleep advances : a journal of the Sleep Research Society · 2025Article
- The Disputable Costs of Sleeping.Biology · 2025Review
- Metabolic skinflint or spendthrift? Insights into ground sloth integument and thermophysiology revealed by biophysical modeling and clumped isotope paleothermometry.Journal of mammalian evolution · 2025Article
- A valuation based theory of learning's origin and development.Frontiers in systems neuroscience · 2025Article
- An electrophysiological correlate of sleep in a shark.Journal of experimental zoology. Part A, Ecological and integrative physiology · 2024Article
- Sleep in the East African root rat, Tachyoryctes splendens.Journal of experimental zoology. Part A, Ecological and integrative physiology · 2024Article
- The new science of sleep: From cells to large-scale societies.PLoS biology · 2024Article
- Divergent evolution of sleep in Drosophila species.Nature communications · 2024Article
- A 108-h total sleep deprivation did not impair fur seal performance in delayed matching to sample task.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2024Article
- Sleep in the wild: the importance of individual effects and environmental conditions on sleep behaviour in wild boar.Proceedings. Biological sciences · 2024Article
- Individual sleep need is flexible and dynamically related to cognitive function.Nature human behaviour · 2024Review
- CT reconstruction based 3D model of the digital cushion's blood supply in the hind foot of an African savanna elephant (Frontiers in veterinary science · 2024Article
- Nocturnal behavioral patterns of African ungulates in zoos.Ecology and evolution · 2023Article
- Worse sleep and increased energy expenditure yet no movement changes in sub-urban wild boar experiencing an influx of human visitors (anthropulse) during the COVID-19 pandemic.The Science of the total environment · 2023Article
- From left to right all through the night: Characteristics of lying rest in zoo elephants.Zoo biology · 2023Article
- Sleep deprivation, sleep fragmentation, and social jet lag increase temperature preference inFrontiers in neuroscience · 2023Article
- Sleep function: an evolutionary perspective.The Lancet. Neurology · 2022Review
Corrections and comments
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Authors and funding
8 authors at 3 institutions in 2 countries.
Funding
Abstract
The current study provides details of sleep (or inactivity) in two wild, free-roaming African elephant matriarchs studied in their natural habitat with remote monitoring using an actiwatch subcutaneously implanted in the trunk, a standard elephant collar equipped with a GPS system and gyroscope, and a portable weather station. We found that these two elephants were polyphasic sleepers, had an average daily total sleep time of 2 h, mostly between 02:00 and 06:00, and displayed the shortest daily sleep time of any mammal recorded to date. Moreover, these two elephants exhibited both standing and recumbent sleep, but only exhibited recumbent sleep every third or fourth day, potentially limiting their ability to enter REM sleep on a daily basis. In addition, we observed on five occasions that the elephants went without sleep for up to 46 h and traversed around 30 km in 10 h, possibly due to disturbances such as potential predation or poaching events, or a bull elephant in musth. They exhibited no form of sleep rebound following a night without sleep. Environmental conditions, especially ambient air temperature and relative humidity, analysed as wet-bulb globe temperature, reliably predict sleep onset and offset times. The elephants selected novel sleep sites each night and the amount of activity between sleep periods did not affect the amount of sleep. A number of similarities and differences to studies of elephant sleep in captivity are noted, and specific factors shaping sleep architecture in elephants, on various temporal scales, are discussed.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.