Posts Tagged ‘feathers’

Stepping Through ZAM: Day 8, Children’s Zoo Module

by | January 5th, 2012

Franette Armstrong is taking us through her Zoo Ambassador Training as she prepares to become a Zoo Docent.

I don’t know about you, but I have never given much thought to animals’ teeth. Turns out you can tell what an animal ate while it was living by looking at its jaw later. Today we studied some “biofacts” (physical specimens) to learn the ins and outs of how animals eat.

Herbivores have lots of molars—back, flat teeth for grinding branches, grasses and seeds.  Since their food doesn’t try to escape, they use their front teeth like pruning sheers to clip leaves and stems.

Herbivores don’t need sharp front teeth to catch prey.

 

 

 

 

Carnivore teeth on the other hand, are sharp and scissor-like. Their front teeth bite and hold on while their long canine teeth tear into prey. Their molars are used for slicing rather than chewing because they mainly swallow their food in whole chunks.

The canines on one of our new Tiger sisters are not what you would want to see on a dark path at night—and she was just playing around. Photo Credit: Steve Goodall

 

Omnivores, such as otters and bears, eat both plants and meat, so not surprisingly, they have a combination of sharp front teeth and grinding molars. Humans are set up with teeth like this, whether we eat meat or not, so look in your own mouth to see an example of omnivore teeth.

Insectivores, such as rodents and some bats, have sharp molars that can tear through the shells of insects.

The jaw of a hedgehog shows the sharp molars and lack of incisors of insectivores.

 

 

 

 

 

 

 

 

Moving Onto Birds…and Australia

You might wonder why it has taken so long to get to birds when they form such a huge part of our ecosystem. Reason is, we only have one species of bird in the Children’s Zoo: the Emus in our Australia exhibit. Nonetheless, understanding them requires understanding Bird taxonomy.

If you were ever into dinosaurs as a kid, the first fact we learned won’t shock you: Birds are members of the Class Reptilia. Yes, indeed…birds are Reptiles right along with crocodiles, snakes, lizards and something called Tuataras.

Tuataras are the oldest species of reptile living today and are found only in New Zealand.

Birds are defined as an animal with feathers and a beak that lays eggs. Flying is not a requirement, so Emus, Ostriches and Kiwis, who long ago lost their ability to fly, still count as birds. Emus are the second largest birds in the world (Ostriches take first place) and give us a chance to learn about feathers.

We looked at many types of feathers to see what allows birds to fly. One of the reasons Emus can’t, besides the fact that their wings are tiny remnants of what their ancestors had, is that their feathers are soft and downy, each actually two separate feathers connected at the stem. Their main purpose is to give these land-loving birds extra warmth.

Emu feathers are a radical departure from the single-quilled types on flying birds.

 

 

 

Emus are fascinating for another reason: the males take complete responsibility for nest-building, egg-incubating and child-rearing while the liberated lady Emus go off to lay eggs for some other lucky male.

This baby emu is just coming out of his dark-green shell.

The devoted daddy Emus sit on the dark green eggs, which look like large avocados, for about 8 weeks without leaving the nest to eat or drink. They can lose a third of their body weight during this period so they prepare by pigging out for months ahead of time. Once the babies are hatched, Dad shepherds them around until they are old enough to have and care for their own eggs.  He will even take in orphan babies if they are smaller than his own.

 

Marsupial Moms are Busy

Interesting reproductive abilities are a theme today as we moved on to Wallaroos and their baby-having rituals.

Now you already know that Kangaroos, Wallaroos, Wallabies and Opossums all raise their babies in pouches. That’s what Marsupials do. You might not know this, though: A mother Wallaroo can have three babies at once: one in the uterus, one in the pouch, and a Joey “at foot” who can hop in and out of the pouch for a quick milkshake whenever he wants. You can watch a great video of that here.

The Joeys keep this up until they are 14 months old and then go off and start having kids of their own. Here’s a great video about two of our Joeys.

Our baby Joeys move in and out of their mother's pouch whenever they are hungry or scared.

About to Get Buggy

We ended our class today with a brief lecture on Arthropods, which include all the inhabitants of the Bug House: ants, spiders, scorpions, millipedes, beetles and walking sticks. These are the only invertebrates in our Zoo.

As you will remember from Day One, Arthropods don’t have backbones…their skeletons are on the outside of their bodies in the form of shells or scales, and they all have jointed legs, so worms don’t fit into this Class.  Wednesday night we’ll go up close and personal with all of them. Yikes!

Enjoy your weekend,

 

 

To read about previous Zoo Ambassador training classes please visit:

www.oaklandzoo.org/blog/category/volunteering/