Mammals

79 Mind Blowing Animal Lifespans: How Long Animals Live (On Average)

This question is not as simple as it seems.

Two different ways of looking at it are: “How long can an individual animal live?” and “How long do members of a given species usually live?”

The first question really means how long can an individual animal live under ideal circumstances, i.e. no diseases or predators, plenty of food and the right living conditions.

For humans, as in all animals, this is a variable depending on the individual. Just as some people are bigger, stronger or smarter than others – so some live longer. Variation is one of the rules that govern all life. For a human being we can say that, at the moment, the limit is about 115 years – though very few of us actually last that long.

The scientifically accepted record is 122 for a French Woman, Jeanne Louise Calment, who died in 1997. For most of us the sort of lifespan we can expect – if everything works in our favor, such as good health – is between 80 and 90 years. Though centenarians are becoming less rare.

For other animals, the best estimates we have for this sort of measure of longevity is for animals born and bred in zoos – where they live a life free from predators and most diseases. The table at the end of this page is mostly composed of data from various zoos.

Normally speaking we expect very few individuals in a natural population to reach their maximum age.  So age estimates of wild-caught or killed animals are usually considered to be below the maximum. Biologists have a number of ways of aging animals. The techniques vary with different species and have lesser or greater degrees of accuracy.

However, recent data has suggested that human beings are not the oldest living mammals.

Animal With The Longest Lifespan? Whales!

Scientists have for some time known that some whales have potential lifespans as great as ours.

Research by Jeffrey Bada of the Scripps Institution of Oceanography in La Jolla, California suggests that Bowhead Whales may live to be more than 200 years old.

Out of a sample of 45 specimens, and using a method based on measuring the changes in levels of aspartic acid, an amino acid found in the lens of the eye (and other places). He found 5 really old males with ages registering as, 91, 135, 159, 172, and 211 years.

whale lifespan
The Bowhead whale, Balaena mysticetus, has the longest lifespan of any known mammal

The recent discovery (2007 and before) of harpoon heads more than a century old in harvested animals adds support to this research.

When considering how old a bowhead whale may grow (it’s longest potential lifespan), we need to consider that a random sample of 45 adult humans has very little chance of registering any centenarians. The discovery of a single 122 year old human is the result of a sample size of hundreds of millions of individuals not just 45.

News update.  However whales have recently been put into 2nd place by sharks.   In 2016, a group of scientist estimated the ages of a number of Greenland sharks using radiocarbon 14 dating.  They came to the astounding conclusion that the oldest specimen had probably lived for around 392 years (somewhere between 270 and 510 years) and was, therefore, born between 1504 and 1744.  This would make it without doubt the oldest known animal living in the world.  Greenland Sharks grow very slowly and scientists now think they do not reach sexual maturity until they are about 150 years of age.

The second question needs to be looked at more closely.

One measure is average lifespan. This is the mean of all recorded individuals and takes into account all those who die very young, as well as those that die after reaching maturity.

For wild animals, if we look at the average length of life, we would find that some species – particularly those who produce many young during their lives such as opossums – have a very short average life span.

In fact, most members of some species die before they reach sexual maturity, i.e. they die as juveniles, normally in the first year of life.

Calculating Reproductive Rate

A female opossum can give birth to more than 15 young in one litter and she can have several litters during her life.

Obviously if this happened all the time, the world would be inundated with opossums (and all the other creatures with this sort of life cycle).

At this rate of reproduction, one female opossum would be the great-great-great grandmother of nearly 6 million opossums in just 7 years.

Assuming each female lives to breed for 3 years in a row, that half the population are breeding females and that females breed the year after they are born, the math looks like this:

Reproductive rate in an imaginary Opossum

Year No. Dead No. Females No. Young No. Males Total No. Oppussums
Year 1 0 die 1 15 1 17
Year 2 0 die 8 120 8 136
Year 3 0 die 68 1020 68 1156
Year 4 2 die 577 8655 577 9811
Year 5 15 die 4898 73470 4898 83266
Year 6 121 die 41572 623580 41572 706725
Year 7 1,035 die 352845 5292675 352845 5998383

Actually, only 2 of the 12-15 young born in one litter need to survive long enough to reproduce themselves, in order to keep the population stable.

This tendency to produce as many young as possible – in the hope that some will survive – is a strategy used by quite a few animals. A species that uses this strategy is called an ‘r selected’ species, or an ‘r strategist’.

The opposite approach is to only produce a few young, but to put a lot more effort into keeping them alive to reach maturity. Animals that use this strategy are called ‘k selected’ or ‘k strategists’. In the animal world, long lived species tend to be ‘k strategists’ and short lived species ‘r strategists’

Potential Lifespan vs Average Lifespan

I hope this has helped you understand the difference between ‘potential life span‘, which is how long an animal can live under ideal conditions, and ‘average life span‘, which is the mathematical mean of all observed life spans.

Neither of these figures is very real.

Practically no animals in the wild survive long enough to fulfill their potential life span. Most animals die before they reach the mean lifespan for their species, but a few live way beyond this.

Here is a hypothetical example:

  • One year 35 opossums are born, 15 die before they are 3 months old, another 8 before they are 6 months old, 5 more die before they are 1 year old.

This means 28 of them have died before they reached sexual maturity. Seven live on to breed in the first year, 3 of these are females and they produce 10 young each, then 4 die. The next year, the last female produces another 8 young before her and the two remaining males die.

opossum lifespan
The lifespan of an opossum depends how we calculate it.

In this scene, the species is a success because the 35 opossums have left 38 others to replace them. Yet what is their average life span?

Rounding things up to the nearest quarter year, we get 15 X .25 years + 8 X .5 years + 5 X 1 year + 4 X 2 years + 3 X 3 years. Adding this up we get an average life span of 0.85 years.

So you can see that of our original 35 opossums, 15 + 8 = 23 (or 65.7%) died before they reached the average lifespan – while 3 individuals lived 3.5 times the average life span.

I hope this hasn’t confused you.

I only put it in here to show that, while you can work out both average and maximum potential lifespans, neither of them mean very much in terms of the animal’s actual lives.

This is why biologists construct life history tables which detail when most deaths occur for a species and what the cause of death was. Life history tables are very important in understanding the ecology of how an animal lives.

Why Do Some Animals Live Longer Than Others?

Scientists have been studying why some animals live longer than others.

Or to put it the other way round: why do some animals’ bodies wear out before others? They have come to realise that evolutionary adaptations can have priority.

With regard to length of life, this means that animals which haven’t evolved effective ways to protect themselves from parasites and predators have bodies which wear out quickly. Whereas animals which have evolved efficient defenses against parasites and predators, have bodies that take longer to wear out.

In other words, they age more slowly.

The reasoning behind this is that everything in life costs – and evolution only works with a reason.

galapagos tortoise
Galapagos tortoise (Chelonoidis nigra) can weigh upto 260kg and live more than 150 years.

An animal or plant won’t evolve a characteristic for which it has no use. If your chances of living to see your second birthday are so low as to be almost zero because of predator pressure, you are not likely to evolve the internal mechanisms which would allow you to live for ten years.

This would be like paying ten years’ rent on a house you were only going to live in for 2 years. Highly inefficient.

However, once a species has evolved sufficient protections against predators and so on (such that a fair percentage of the population are dying of old age, rather than from predation), then the reproductive output is likely to increase by having a body that ages more slowly, i.e., by living longer.

In this situation the metabolic activities that keep the body functioning are far more likely to evolve. Hence while small rodents have relatively short lives, bats of similar size (which suffer a much lower predator pressure) have potential lifespans which are 3 or 4 times as long.

Potential Lifespans Of Different Animals (Mammals)

Group Common Name Scientific Name Lifespan (Years)
Insectivores Short-tailed shrew Blovian brericauda 2.5
  Lesser Hedgehod-tenrec Echinops telfairi 16
  Greater White-toothed shrew Crocidura russula 4
Bats Indian Flying Fox Pteropus giganteus 30
  Vampire Bat Desmodus rotundus 12
  Daubentor’s Bat Myotis daubentonii 30
  Greater Horseshoe Bat Rhinolphus ferrumequinum 30
  Little Brown Bat Myotis lucifugus 32
Primates Chimpanzee Pan troglodytes 55+
  Orang-utan Pongo pygmaeus 55+
  Gorilla Gorilla gorilla 40+
  White-throated Capuchin Cebus capucinus 50+
  Lar Gibbon Hylobates lar 23+
  Vervet Cercopithecus aethiops 24
  Patas Monkey Erythrocebus patas 20
  Rhesus Monkey Macaca mulatta 29
  Yellow Baboon Papio cynocphalus 45
  Potto Perodicticus potto 15+
  Slow Loris Nyticebus coucang 10
  Lesser/Senegal Bush Baby Gulago senegalensis 14+
  Aye-Aye Daubentonia madagascariensis 7+
Rodents Sumatran Crested Porcupine Hystrix brachyura 27+
  African Porcupine Hystrix cristata 20+
  Grey Squirrel Sciuris carolinensis 14
  Malabar Squirrel Ratufa indica 16
  Alpine Marmot Marmota marmota 13
  American Beaver Castor canadensis 19
  Garden Dormouse Eliomys quercinus 5.5
  Deer Mouse Peromyscus maniculatus 5.5
  Harvest Mouse Micromys minutus 2.5
  African Giant Rat Cricetomys gambianus 4.5
  Lesser Egyptian Gerbil Gerbillus gerbillus 5
  Lesser Egyptian Jerboa Jaculus jaculus 6.5
  Springhaas Pedetes capensis 14+
  Mexican Agouti Dasyprocta mexicana 13
  Chinchilla sp Chinchilla lanigera 6.5
  Capybara Hydochaerus lychochoerus 8.5
Carnivores Lion Panthera leo 24
  Bobcat Lynx rufus 34
  Tiger Panthera tigris 20
  Leopard Panthera pardus 20
  Jaguar Panthera onca 20
  Puma Felis concolor 16
  Fossa Cryptoprocta ferox 17
  Coyote Canis latrans 18
  Grey Wolf Canis lupus 20
  Golden Jackal Canis aureus 20
  Grey Fox Vulpes cinereoargenteus 15
  Maned Wolf Chrysocyon brachyurus 15
  Dhole, Asian Wild dog Cuon alpinus 16
  Grizzly Bear Ursus arctos 47
  Polar Bear Ursus maritimus 21
Elephants Asiatic or Indian Elephant Elephas maximas 78
  African Elephant Loxodonta africana 60
Sirenia Dugon Dugon dugon 73
Marsupials Wombat Vombatus ursinus 26
  Eastern Grey Kangaroo Macropus giganteus 24
Monotremes Short-beaked Echidna Tachyglossus aculeatus 49
Pinnipedia Australian Sea Lion Neophoca cinerea 12
  Baikal Seal Phoca sibirica 56
  Caspian Seal Phoca caspica 50
  Grey Seal Halichoerus grypus 46
  Harbour Porpoise Phocaena phocaena 15
  Killer Whale Orcinus orca 40+
  Baird’s Beaked Whale Berardius bairdii 82
Cetacea Blue Whale Balaenoptera musculus 110
Cetacea Fin Whale Balaenoptera physalus 114
Cetacea Bowhead Whale Balaena mysticetus 200+
Antiodactyls Dorcas Gazelle Gazella dorcus 11.5
  Dama Gazelle Gazella dama 15.5
  Llama Lama glama 20
  Hippopotamus Hippopotamus amphibius 42
  American Bison Bison bison 22.5
  Defasser Waterbuck Kobus ellipsiprymnus defassa 16.5
  Wild Boar Sus scrofa 19.5
  Bactrian Camel Camelus bactrianus 25.5
Perissodactyls Burchill’s Zebra Equus burchelli 28
  Brazilian Tapir Tapirus terrestris 30.5
  Indian Rhinoceros Rhinocerus unicornis 47

What Next?

Well, I hope this has been useful in answering the somewhat complex question of how long animals live!

Perhaps now you’d like to learn about the mammal skeleton.

Gordon Ramel

Gordon is an ecologist with two degrees from Exeter University. He's also a teacher, a poet and the owner of 1,152 books. Oh - and he wrote this website.

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