How are scientists able to say that a random species is extinct? Did they have to look everywhere?

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How are scientists able to say that a random species is extinct? Did they have to look everywhere?

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Anonymous 0 Comments

They can refer to the species as “extinct” when no living members of the species are known to remain anywhere. That doesn’t mean the species actually and truly is extinct, it just means that there is no available evidence to provide that it is not. Sometimes that’s easy – for example, large land-based animals like rhinos are easy to spot and count – and sometimes that’s hard because the creature is small such as an insect, or widespread, or living in a still-very-wild area.

Sometimes species that were thought to be extinct are rediscovered later on. Probably the best known example is the coelacanth, a large fish from the time of the dinosaurs that we found in the fossil record. It was thought to have been wiped out when the dinosaurs left… until they caught one in the 1930’s. Crazy looking fish too.

Others have their last remaining members captured and moved to zoos. Tasmanian wolves are an example here, there’s black-and-white footage of the last known one in captivity before the species was lost.

Anonymous 0 Comments

Its more they check for long enough and find nothing.

The fact that we know about them in the first place, and can track declining numbers for some, makes their absence the basis for that decision.

That said, some species turn into hide and seek champions, showing up long after they are “presumed extinct”

Anonymous 0 Comments

To complement other answers, pandas have been declared extinct because no one found any for a century.

Anonymous 0 Comments

It’s not that complicated. It means we can’t find them anymore.

They know that certain animal lives in certain areas and when they are unable to find any after some time. They will declare them as extinct.

As you might imagine it’s easier to find some animals than others, which means we got it wrong from time to time.

Luckily it’s very easy to prove, when they were wrong. If you find any members of the species than they are not extinct.

Anonymous 0 Comments

Usually they get declared extinct after no one has seen one in a while.

For example the Bramble Cay mosaic-tailed rat was a small rodent only found on the small Bramble Cay island.

The island isn’t big and the last time anyone saw any of them was in 2009. since then people have gone looking for survivors several times over the years until in 2019 the Australian government and the ICUN in 2015 labeled them as ‘extinct’.

There is a chance that some of the small rodents might still live somewhere but unless on is found they are considered to be extinct.

Anonymous 0 Comments

They don’t have to look everywhere. They only have to look in the places you’d expect to find it. Dodos were only found on Mauritius so they didn’t have to look in Belgium to see if one turned up there.

Of course if the animal has a wide range it can be hard to tell. Usually they’ll wait a while before declaring it extinct.

Sometimes they’re wrong and it’s still around but that’s no big deal.

Anonymous 0 Comments

Nowadays, we tend to closely observe animals that are close to extinction. Scientists will tag and keep watch of them and generally have a good idea of how many remain. If and when one dies, they tend to know. If they’re aware of the total population and they’ve been observing for decades and watching them die off one by one, they can say with confidence that they are extinct.

For animals that aren’t as closely observed or perhaps live in a larger geographical range, if no animals of this species have been seen in the area for a certain amount of time, they’re classified as extinct.

But if they somehow, miraculously, reappear, they can be moved from extinct to not extinct.

Anonymous 0 Comments

The Okapi was once considered extinct (and I believe was used on the logo of a charity/organisation for extinct animals? May be remembering that wrong) but was later rediscovered.

The most famous example though is the coelacanth. So species absolutely can be declared extinct and slip under the radar.

Also there’s a lot of reports of some extinct species, like the Thylacine, being sighted from time to time.

Anonymous 0 Comments

All science is always “to the best of our knowledge”.

A species can be declared extinct when it isn’t found anywhere for a long enough time that, to the best of our knowledge, it appears to have died off entirely.

Sometimes we’re wrong and we find that species again later! But science is always able to be proven wrong; that’s how we learn.

Anonymous 0 Comments

They can’t

It’s literally speculation based on not having seen the said species in its known habitat

Of course, the species could have evolved super intelligence and is now living in an underwater city called Rapture far from human eyes

But most likely lack of sightings means they’re either gone or very few remaining