Why do cats have vertical pupils? - Emma Bryce

Prevodilac: Milenka Okuka Lektor: Ivana Korom

Peering into the eyes of different animals,

Ako se zagledate u oči različitih životinja,

you’ll see some extraordinarily shaped pupils.

videćete zenice izuzetnih oblika.

But why?

Međutim, zašto?

It turns out that pupil shape is a powerful indicator

Ispostavlja se da je oblik zenica snažan nagoveštaj

of what role an animal plays in its ecosystem.

uloge koju životinja igra u ekosistemu.

Pupils mark the hollow opening in the iris,

Zenice označavaju šuplji otvor u dužici,

the eye’s band of pigmented muscle.

tj. sloju pigmentisanog mišića u oku.

They’re the portholes through which light enters the eye,

One su otvori kroz koje svetlost ulazi u oko,

where it then strikes the retina and activates light-sensitive cells,

gde potom pada na mrežnjaču i aktivira ćelije osetljive na svetlost,

setting the process of vision in motion.

pokrećući proces vida.

Pupils are black because most of the light that enters them is absorbed.

Zenice su crne jer se veći deo svetlosti koja uđe u njih apsorbuje.

Their size changes in response to brightness,

Veličina im se menja kao odgovor na jačinu svetlosti,

as well as certain drugs and emotional and mental states—

kao i na određene droge, emocionalna i mentalna stanja -

but their basic form varies greatly among species.

ali njihov osnovni oblik poprilično varira među vrstama.

House cats, for one, are twilight hunters with vertically elongated pupils.

Kućne mačke, pre svega, noćni su lovci sa vertikalno izduženim zenicama.

In the dark, these structures expand dramatically,

U mraku se ove strukture drastično šire,

taking in the available light.

upijajući dostupnu svetlost.

When it’s bright, they shrink into slits.

Pri jakoj svetlosti, skupljaju se u uske proreze.

In fact, cat pupils are so flexible that their maximum area is 135 times greater

Zapravo, mačje zenice su toliko elastične

da je njihova maksimalna površina 135 puta veća od minimalne -

than their minimum area—

whereas our pupils only shrink and expand 15-fold.

dok se naše zenice skupljaju i šire svega petnaestostruko.

And because of how the slit pupil takes in light,

A zbog toga kako skupljena zenica upija svetlost,

it creates sharp, vertical contours.

ona stvara oštre, vertikalne konture.

When the cat’s brain processes the visuals from each eye,

Kada mačji mozak obrađuje slike iz oba oka,

the small but sharp differences between them

sitne, ali oštre razlike među njima

help the cat judge the precise distance of its target.

pomažu mački da prosudi tačnu udaljenost svoje mete.

In fact, many other ambush hunters also have vertically elongated pupils—

Zapravo, mnogi drugi lovci iz zasede takođe imaju vertikalno izdužene zenice -

but mainly those whose eyes are located closer to the ground.

ali uglavnom su to oni čije se oči nalaze bliže tlu.

This may be because these pupils are especially useful in perceiving objects

Razlog tome je možda što su te zenice naročito korisne u zapažanju predmeta

at the relative short distances these animals tend to hunt.

na relativno kratkoj udaljenosti na kojoj ove životinje obično love.

The world looks very different from behind the horizontally elongated pupils

Svet izgleda veoma drugačije iza horizontalno izduženih zenica

of many grazing and browsing animals, like goats.

mnogih životinja koje pasu i brste, poput koza.

These pupils, situated on either side of the head,

Ove zenice, smeštene s obe strane glave,

let horizontal bands of light in that give the goat a near-360-degree view

propuštaju horizontalne snopove svetlosti

koji kozi omogućuju vid od skoro 360 stepeni

and provide it with sharp, horizontal images.

i daju oštre, horizontalne slike.

This helps goats detect any disruption to the horizon—

Ovo pomaže kozama da spaze bilo kakvo komešanje na horizontu -

alerting them to potential predators— while still enabling them to see ahead

upozoravajući ih na potencijalne predatore -

istovremeno omogućujući im da vide napred

and detect obstacles as they make their escape.

i da zapaze prepreke dok beže.

In fact, goats always keep their pupils aligned with the horizon,

Zapravo, koze uvek poravnavaju svoje zenice sa horizontom,

rotating their eyeballs in their sockets as they move their heads up and down.

rotirajući očne jabučice u očnim dupljama dok pomeraju glavu gore i dole.

Meanwhile, nocturnal geckos have pupils that shrink into slits

U međuvremenu, noćni tropski gušteri imaju zenice koje se skupljaju u proreze

studded with pinholes in higher light conditions.

oivičene rupicama u uslovima jače svetlosti.

Each pinhole projects a separate, sharp image onto the geckos retina.

Svaka rupica projektuje odvojenu, oštru sliku na gušterovoj mrežnjači.

Scientists think that comparing these different inputs

Naučnici smatraju da poređenje različitih informacija

might help the gecko judge distance without having to move.

možda pomaže gušteru da proceni udaljenost bez potrebe za pomeranjem.

And while they might have fooled you,

A, iako su vas možda obmanuli,

mantises and other insects and crustaceans have “pseudopupils.”

bogomoljke i drugi insekti, kao i ljuskari imaju „pseudozenice”.

These aren’t optical structures;

Ne radi se o optičkim strukturama;

they’re optical illusions experienced by the observer.

radi se o optičkim iluzijama koje doživljava posmatrač.

Mantises have compound eyes composed of thousands of light-sensing units.

Bogomoljke imaju složene oči

sastavljene od hiljada jedinica osetljivih na svetlost.

When some are aimed at you, they appear black

Kada se neke od njih upere u vas, čine se potpuno crnim

because they’re absorbing most wavelengths of incoming light—

jer apsorbuju veći deo talasnih dužina nadolazeće svetlosti -

but there’s no actual opening.

ali nema stvarnih otvora.

So, why do we have round pupils?

Dakle, zašto mi imamo okrugle zenice?

Elongated pupils help sharpen certain dimensions of an animal's vision.

Izdužene zenice izoštravaju određene dimenzije životinjskog vida.

But scientists think that, for animals like us with circular pupils,

Naučnici, pak, smatraju da je za životinje poput nas sa kružnim zenicama,

this is a lower priority.

ovo od manje važnosti.

Instead of seeing some elements of a scene in extreme focus,

Umesto sagledavanja nekih elemenata prizora u ekstremnom fokusu,

we see a larger picture in relative detail,

mi vidimo širu sliku sa što više detalja

which enables more general skills of observation.

što nam omogućuje opštiju veštinu opservacije.

This may be especially helpful for foragers looking for food,

Ovo je možda naročito od pomoći sakupljačima koji tragaju za hranom,

hunters eyeballing and chasing their prey,

lovcima koji nišane i jure svoju lovinu,

and social animals recognizing other faces.

kao i društvenim životinjama koje prepoznaju druga lica.

As we peer at different pupils, patterns emerge.

Kako zurimo u različite zenice, pojavljuju se obrasci.

And yet there are exceptions.

Pa ipak, imamo izuzetke.

For example, Pallas’s cats and mongooses are both small ambush predators,

Na primer, Palasova mačka i mungos su oboje mali predatori iz zasede,

but the Pallas’s cat has round pupils and mongooses have goat-like pupils.

ali Palasove mačke imaju okrugle zenice, dok mungosi imaju zenice slične kozjim.

And we’ve only explored a few pupil shapes.

Tek smo istražili nekoliko oblika zenica.

Other animals have crescent- or heart-shaped pupils.

Druge životinje imaju zenice u obliku srpa ili srca.

And the cuttlefish has perhaps some of the most bizarre:

A sipa ima možda jedne od najbizarnijih:

their pupils are circular in the dark, but W-shaped in the light.

njihove zenice su kružne u mraku, ali u obliku W na svetlosti.

So, what’s going on here?

Dakle, šta se ovde dešava?

Well, wouldn’t we all like to know?

Pa, zar svi mi ne bismo želeli da znamo?