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Wednesday, January 25, 2012

Wonderfully Wild Wednesday: Waxy frogs

Posted by: Rebecca Whitham, Communications

Introducing Wonderfully Wild Wednesday, where we’ll feature some fascinating wildlife adaptation each week. Let’s kick it off with one of the zoo’s newest residents—the waxy monkey frog.

I don’t need to tell you that the waxy monkey frog is awesome. You can see that for yourself…
But I will tell you that this frog—newly arrived to Woodland Park Zoo—is certainly unique among its amphibian brethren.

Most frogs have moist skin that is susceptible to drying out when exposed to direct sun for too long. But the South American waxy monkey frog is uniquely adapted to take in rays, allowing it to make a niche for itself in the hot, dry environment of its native habitat in Argentina, Brazil, Bolivia and Paraguay.
So how does the waxy monkey frog do it? It’s in the name (well, the waxy part of the name, not the monkey part. We’ll get to the monkey part later).

The waxy monkey frog comes complete with built-in sunblock, a waxy secretion that comes from its neck that it can then rub all over its body. The wax prevents it from drying out under the sun by sealing in its natural moisture.
At the zoo you’ll find these arboreal frogs spending much of their time perched on tree limbs in their exhibit. And that’s where the other part of their name comes in. The waxy monkey frog gets its monkey title from the way it moves around in the trees, walking rather than hopping like other frogs.
Look for the waxy monkey frogs hanging out on limbs, munching on insects in the zoo’s Day Exhibit where most of our amphibian and reptile species reside.

Photos by Ryan Hawk/Woodland Park Zoo.

Tuesday, January 24, 2012

Happy 1st birthday, Evita!

Posted by: Rebecca Whitham, Communications
How do you celebrate an ocelot’s 1st birthday? With a turkey cake and mouse candle, of course!

Our little Evita is not quite so little anymore. To celebrate her turning 1 year old last week, Evita’s keepers prepared a lovely birthday surprise including some wrapped presents (boomer balls generously bought for Evita from our animal enrichment wishlist), a papier mache ball with a mouse inside, and a heart-shaped frozen cake made from ground turkey, turkey breast and prepared feline diet with a “candle” that I hope to never see on any cake I eat—a mouse with its tail sticking up like a wick!

Evita was slow to investigate her treats until keepers added an unexpected twist—a fresh pile of snow picked from just outside the Tropical Rain Forest exhibit. Evita’s exhibit is near 80 degrees year round, so the snow brought out her curiosity. She rubbed her head in the snow and batted at it with her paws before moving on to the other treats.

The mouse candle was first to go—Evita plucked it right out of the cake to munch on. Then one by one she inspected and tore into her other treats like any birthday girl would.

In the wild, an ocelot kitten will begin to hunt on its own by around 18-24 months of age and by that time is ready to leave its mother’s side. As Evita is now reaching that age, we expect to find a new Association of Zoos & Aquariums accredited zoo home for her soon so she can establish her own territory away from her parents and find her own mate.

Photos by Ryan Hawk/Woodland Park Zoo.

Thursday, January 19, 2012

Snow day - Part II

Posted by: Rebecca Whitham, Communications

The zoo was closed to the public again today due to the snow and ice conditions. Here's a look at what was happening on grounds:

We'll post to www.zoo.org first thing in the morning tomorrow on whether we'll finally be able to open again. Until then, stay safe!

Photos by Ryan Hawk and Carol Roll/Woodland Park Zoo.

Wednesday, January 18, 2012

Snow day at the zoo

Posted by: Rebecca Whitham, Communications

The zoo may be closed today due to “Snowpocalypse,” but many of the animals are still out and about. Some animals retreat indoors or look for a warm spot to tuck themselves into to get out of the snow, while others—like our residents of the Northern Trail exhibit—are in their element.
The first animals you encounter in the Northern Trail are the pack of four sister wolves—Doba, Shila, Aponi and Kaya.
When we first approached the wolves this morning, they were beautiful to behold in their white fur coated in snow, an elk lounging in the background.
But it wasn’t long before one of the wolves interrupted the still, idyllic portrait with a piercing howl.
Then the wolves all began to vocalize together and play.
They chased.
And chased.
Then took a break to nibble at the snow.
We pulled ourselves away from the scene just long enough to see one of our grizzly bears shaking himself free of the snow piling onto his fur.
Then we were off to see the Steller’s sea eagles, whose bright orange beaks seemed so bright and bold against the white backdrop, and the elk who were fairly active.
While there wasn't as much action in other parts of the zoo, there were still a few other beautiful scenes worth sharing, including this emu...
...and these penguins.
We’re keeping an eye on weather conditions and our keepers are making sure all of the animals are warm, safe and comfortable. We hope to be able to open as usual tomorrow, and will post the latest status tomorrow morning to the homepage of www.zoo.org.

Be safe out there, everyone!

Photos: Grizzly bear photo by Kirsten Pisto/WPZ, all other photos by Ryan Hawk/WPZ.

Thursday, January 12, 2012

CONTEST: Guess the weight of our hippos!

Posted by: Gigi Allianic, Communications

Lupe practicing on the scale. Photo by Ric Brewer/WPZ.

Was losing weight your New Year's resolution? Well, for our hippos, it’s time to get on the scale!

Lily (left) and Lupe (right) in the African Savanna. Photo by Dennis Dow/WPZ.

We carefully monitor the weight of our animals and now that we have acquired a new scale to weigh our hippos, we’re holding a contest to see who can guess the combined weight of our graceful 33-year-old Water Lily and the lovely 12-year-old Guadalupe. The winner gets to go behind the scenes to meet the hippos up close!

Guadalupe with a snack. Photo by Dennis Dow/WPZ.
Beginning today, Washington state residents are invited to guess the COMBINED WEIGHT of both hippos by entering online at www.zoo.org/hippocontest through midnight, January 27, 2012. The winning entry will be the closest to the combined weight (if more than one person gets it right, we’ll draw one random winner from those finalists). Complete rules and entry form at the contest site.

What’s the prize?
  • Meet ‘n’ greet with the zoo’s hippos behind the scenes in the hippo barn
  • 4-gallon bucket of Zoo Doo
  • Six single-day passes to the zoo
  • ZooParent hippo adoption with a hippo plush toy.
A weight-monitoring program is important to help ensure the health of the animals at Woodland Park Zoo and is a part of the zoo’s exemplary animal care program. The new scale at our hippo barn will help us get an accurate weight on these giant pachyderms so we can modify their diets if necessary. Keepers have been working diligently to train the girls to step on the scale and hold still (the hard part!) to get a solid reading of their weight.

Water Lily. Photo by Ryan Hawk/WPZ
We’ll announce the winner in February and share photos of the girls getting their official weigh in.

Good luck!

Tuesday, January 10, 2012

Ultra awesome: Ultraviolet eyesight in animals

Posted by: Kirsten Pisto, Communications

Roses are red, violets are blue…unless you’re a tetrachromat, it’s true. Apologies for the obvious segue to a post about color, but I couldn’t resist!

A blue bellied roller and a brightly colored orchid show us examples of some of the beautiful colors here at Woodland Park Zoo. Photos by Ryan Hawk and Kirsten Pisto/WPZ.
Throughout the animal kingdom, there is enormous diversity in the structure and faculty of eyesight. Oftentimes, we relate our own human eyesight to the visual capabilities of animals, but most evidence points to the contrary: in fact, humans might be an underdog in visual perception.

A rainbow sits over the North Meadow. Red has the longest wavelength and blue has the shortest. Photo by Dennis Conner/WPZ. 

The human eye sees a wide range of what we call visual color, that is, measurable wavelengths in the range of about 390–700 nanometers. Our eyeballs have a ton of tiny little cones and rods in the retina, which are super sensitive photoreceptors. Cones determine which colors are perceived, rods determine light perception. Most people are trichromats, have three types of cone receptors; red, blue and green, and can see in what is referred to as 3-dimensional color.

So many colors can be found here at Woodland Park Zoo! All photos WPZ.
But guess what? Even humans can’t actually see all of the colors we perceive! Take magenta for example. Because magenta, or hot pink, is a mixture of multiple wavelengths, our eyes cannot actually distinguish it as a color; instead, our brain fills in the gaps with what we perceive to be the color magenta. Weird, huh? That’s a pretty cool trick, but a lot of animals have an even more extreme adaptation of their visual senses, much beyond the limits of human perception.

This color spectrum shows us visible light, that is, colors most humans can perceive. Ultraviolet light has shorter wavelengths. Via Science Blogs.
If you were to walk past violet on the color spectrum, you would get to ultraviolet rays in the range of 10 – 400 nm. As trichromats, (with red, blue and green cones) our eyes aren’t built to see this level of color, but animals with an ultraviolet cone receptor can!
So, which animals actually have UV vision? 

  • Monochromats (many undersea animals and nocturnal animals), have only one type of color receptor cone. In fact, many bats, nocturnal snakes and lizards have no cones at all, sacrificing the ability to distinguish color for increased absolute sensitivity. Some monochromats might see in ultraviolet, but it’s sort of an unknown. 
  • Some dichromats (animals that have only two types of color receptors), such as scorpions, can see UV color. Their cones are built to perceive ultraviolet and green/yellow colors, but they cannot see blue, green or red. Most mammals, however, are dichromats, with only red and green receptor cones.
  • As far as trichromats (humans and some other primates, marsupials, and honeybees) go, bees have the upper hand in UV vision. They have three receptor types, although unlike humans they are sensitive to ultraviolet light, with loss of sensitivity at the red end of the spectrum. Because color perception is a mixture of receptor types, this means that bees do not simply see additional UV colors, but will perceive even human-visible spectra in different hues to those which humans experience.

Tetrachromacy is suspected among some arachnids, fish, reptiles and amphibians. Photos by Ryan Hawk/WPZ.
  • Tetrachromats (animals with four types of cone receptors such as some birds, turtles and fish), can see UV wavelengths perfectly well because they have 4-dimensional color vision and the ability to see in ultraviolet. That means they can see all the colors we see (red, blue, green) plus an additional color, which of course is ultraviolet.
  • Pentachromats (butterflies and some birds), actually have five different color receptors and maybe more! Just imagine the colors we are missing out on!
It is well known that many bees and birds follow UV-reflecting nectar guides on flowers which lead them to the most nectar-rich part of the plant. These animals depend on UV colors to guide them to their food source, yet research done within the last few years has revealed that many animals use UV colors for much more than just finding the sweetest spot on a flower.

On the left is a daisy under a UV light lens. You can see the nectar pattern on the petals, although we still can’t actually see the correct UV color because, well, we are only human. On the right is what the flowers look like to us in visual color—no pattern! UV photo by Leonard Less, butterfly photo by Ryan Hawk/WPZ
For example, it is thought that desert iguanas might mark their paths with UV-absorbing urine, leaving behind territorial signals against the sand. Scorpions glow or appear yellow and green under UV illumination, keeping camouflaged to mammalian eyes, but standing out to each other.

Woodland Park Zoo hosts a wide variety of colored feathers, but just imagine if we could see these birds with ultraviolet vision! Photos by Dennis Dow/WPZ.
Many birds and butterflies have patterns in their plumage and wings that are invisible to human color vision but observable in ultraviolet. Recent research suggests that birds and butterflies might see about 10 billion colors, whereas humans can only see 10 million! This assists them in finding the correct mating species. The next time you look at a little brown bird such as the common sparrow and think, how drab, think again—to the bird world that little guy might have some majorly flamboyant feathers!

To us, this peacock resembles the painted pipes behind him, but would he stand out if we had ultraviolet vision? Photo by Ryan Hawk/ WPZ.
In May 2010, researchers at the University College London tested the electrical response of the retina of anaesthetized reindeer to UV light. What they found is that a reindeer’s retina responded to near UV, about 320 – 420 nm. That’s not up to par with a hummingbird or honeybee’s UV sight, but its pretty impressive for a mammal!

Could our arctic residents have an ultraviolet secret? Photo by Ryan Hawk/WPZ.
The research suggests that reindeer, an arctic animal that often experience white-out conditions, might use their UV eyesight to forage for food or even detect predators. UV rays are actually absorbed up by things like lichen, a plant which reindeer munch on, and the fur of a wolf’s coat, which reindeer would like very much to avoid. The UV rays appear darker to the reindeer, very helpful against a snowy landscape.

Researchers predict that other arctic mammals may also share this ultraviolet vision. One clue, arctic foxes, polar bears and seals are not known to suffer from snow blindness, pointing to their ability to see in extreme white out conditions. Of course, their sense of smell could be another reason these creatures outmaneuver people when it comes to blizzards. (Polar bears can smell their prey up to 20 miles away!). So, until more research is done on these individual species, it’s sort of an arctic mystery!

Imagine being able to see an entirely new color! What would our world look like if we had the ability to see in ultraviolet? Photo by Mat Hayward/WPZ.
Ultraviolet vision is still sort of a new science. Advances in access to tools such as the fiber-optic spectrophotometer allow researchers to measure ultraviolet color in different environments leading to a better understanding of how animals might use their UV vision. When you come to the zoo, you must use your imagination, because even though we can measure UV light, we still have no idea what it really looks like!