Nocturnal Animals

Nocturnal Animals

What does nocturnal mean?

oThis refers to animals that sleep during the daytime and are awake during the nighttime.

oThey can be mammals or reptiles.

The Eyes Have it!oNocturnal animals have special pupils that help them see well at night.

oTheir pupils can sometimes seem to “glow” when light shines on them.

The Pupils!oTheir pupils come in different shapes.

oSome pupil shapes are better than others at closing in bright light.

http://www.pbs.org/wgbh/nova/kalahari/nightvision.html

A video on Nocturnal Cats

World's Best: Series: Wild Cats. BBC. 2001.unitedstreaming. 17 September 2006<http://www.unitedstreaming.com/>

Look at these eyes and see if you can guess the

nocturnal animal they belong to.

Can you guess who I am?


A Cuttlefish


The cuttlefish is a cephalopod that buries itself in sediment by day and becomes active at night. The pupil of its highly sensitive eye, which sees as well as a human eye, is protected with a flap-like appendage that can close completely in bright light.



A F

ruit

Bat


Fruit bats are far from blind. In fact, they rely primarily on their eyes for navigation -- unlike most bats, who navigate by echolocation.



A Flying Gecko


Geckos have eyesight comparable to a cat, giving them the best eyesight of all lizards. The flying gecko has an unusual scalloped pupil. When fully contracted, the pupil can close completely -- except for a few tiny pinholes where the scalloped edges do not quite meet.



Pit vipers use two senses to better locate prey at night: sight and a heat-detecting ability. Deep pits, which lie on each side of the snake's face between the nostril and the eye, are capable of sensing the warmth given off by a human hand held a foot away. Heat and visual data are sent to the pit-viper's brain, where the two types of data are transposed into a single image of the prey.



A S

cree

ch O

wl


So extraordinary is an owl's night vision, it can spot a mouse creeping through the underbrush more than a football field away on a moonless night.



A T

arsi

er


The tarsier of Southeast Asia has the largest eyes relative to body size of any living creature. The eyes are so enormous that they cannot be moved in their sockets. To compensate, tarsiers can swivel their necks 180 degrees in either direction. Though most nocturnal primates eat insects, the tarsier likes meat and has the vision, speed and reflexes to catch small prey in pitch darkness.

Nocturnal animals are fascinating!

Works Citedo All pictures and information

obtained from…NOVA Onlinehttp://www.pbs.org/wgbh/nova/kalahari/nightvision.html



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Nocturnal Animals