Crepuscular Animals

Curve Billed Thrasher at Twilight

I love new, interesting words, don't you? When reading about snakes found in Arizona, the word  "crepuscular" appeared in the text, which of course triggered my overactive wonder muscle. I  had never heard this delightful adjective, used to describe creatures who are active primarily during the most glorious time of day... twilight...gentle, soothing twilight. Not quite nocturnal or diurnal, the animals who prefer this time are unique.

Twilight is a golden package of fleeting moments, found like book ends on each side of the day.  In the morning, it seems to embody the beauty and hope of a new fresh day, and in the evening, it gently wraps the day in a quiet, ethereal light, spilled alongside deep shadows across the landscape.  It is a time for seeing and hearing animals in a way unlike any other. Many photographers prefer the soothing, natural light that descends in the hour near twilight, a time when our cameras seem to do their best work.

One notable crepuscular desert dweller is the Javelina, or Collard Peccary.  I have only seen them during twilight hours. Unless sick, javelinas will travel in bands of 6 - 12 animals led by a dominant male. They have many incredible design features, such as their ability to eat prickly pear, spines and all. Javelinas derive most of their water from the plants they eat, so juicy prickly pear are among their favorite.  Watch for prickly pear plants that look like they have been torn versus cut or barrel cacti that have been overturned with the flesh scooped about like a tunnel into the underside.

 Javelinas are not considered dangerous if left alone, but an entire band can be aggressive and unpredictable, and if provoked, may attack when there are young or wounded among their members. They also have terrible eyesight, and use their sense of smell to communicate, so you will usually smell the musky scent of a javelina before you see one. They have several scent glands, which are located below each eye and on their back/rump. The glands release a strong odor when marking territory, members of their group, or when they become alarmed or excited.

The hour leading up to evening twilight is my favorite time to trek in the desert.  The harsh mid-day sunlight softens into a warm glow, and as the air cools, a playful breeze carries the sound of owl hoots and cricket songs. Bats and Nighthawks dance overhead, cotton tailed rabbits and other small mammals disappear into the shadows like children heading inside after a long day of play. Although seen other times of the day, Bobcats, Black Tailed Rabbits, as well as some snakes and birds are also considered crepuscular.  Many snakes are nocturnal during the hot summer, crepuscular in the spring and fall.

As you trek at twilight, watch for interesting crepuscular creatures, but remember that it is their feeding time, so try not to disturb them.  In the dim light, gaze with wonder at the unique happenings found only at twilight.

References and Resources
Earth Sky - What Exactly is Twilight?
Animal Sake
Desert USA - Collared Peccary
A-Z Animals - Collard Peccary
National Park Service - Javelina

Images: Sharon Pegany

Cultivate Wonder... Discover Design

Jack Rabbit Ears

Black Tailed Jack Rabbit

This morning was cool and windy.  I took off before sunrise to see if I could spot any interesting creatures starting their day or finishing their night hunts.  As the sun began to spread its light and warmth across the landscape, all was still except for the early morning bird calls. As I turned to start for home, a Black Tailed Jack Rabbit burst from behind a boulder and bounded off through the brush.

In our area, we see oodles of cotton tailed rabbits, but spotting the large muscular hare known as a Jack Rabbit is a little more unusual. Jack rabbits are actually not rabbits, but hares, and the two are completely different species. Jack Rabbits are fun to observe.   Jacks can jump up to 10 feet and run at 40 miles per hour! It is comical to see them bouncing over the landscape like a Loony Tunes character.

Jack rabbits do tend to hang out in large open areas.  I have noticed that if I see one in an area, there are probably more and the abundance of rabbit droppings seems to confirm my theory. There are five species of jack rabbit found in the desert. Two of the most common are the Black Tailed and the Antelope.  Antelope Jacks are slightly larger and have ears edged in white, whereas the Black Tailed Jack has ears tipped in black as well as black on the tail, hence the name.

Jacks are known for their huge ears, which not only give them excellent hearing, but serve to help cool the jack by releasing heat from the large surface. The skin on their ears is very thin and full of blood vessels. During the hot part of the day, a jack rabbit will retreat to the shade where the slightly cooler air will cause blood vessels in their ears to widen, allowing more blood to flow to their ears. Some of the resulting heat in the ears will move into the cooler air, ultimately cooling the hot rabbit too.  Interestingly, rabbits don't pant and sweat as much as some other animals do, which helps to preserve precious internal fluid. The jack rabbit's cooling system design is perfect for a desert dweller.

This week, watch for small mammals in open areas and washes. Let their hippity, hoppity, scrambling ways cause you to wonder.

References and Resources

Desert USA
Animalia
animals.mom.me - What Adaptations Help Jackrabbits Stay Cool?
Wonderopolis - What is the Difference Between and Rabbit and a Hare?
Biomimicry Institute asknature.com - Large Ears Used to Cool Off

Images: Sharon Pegany

Fox Sighting

The Sonoran Desert is enjoying a cool spell, providing gorgeous weather for an afternoon trek in the McDowell Sonoran Preserve.  Three of us met up to trek out to Balanced Rock and marvel at the towering saguaros on the way.  On our return, we stopped to enjoy the noisy chatter of two ground squirrels, when a sharp-eyed trekker spotted large mammal movement below the trail.

At first, we thought it was a juvenile coyote, but there was something different about it... more delicate and angular, with enormous ears. Turns out it was a beautiful little gray fox.

Foxes are nocturnal, so it is not easy to see them. However, the gray fox also can be seen out and about during the morning and early evening hours searching for a wide variety of things to eat from small mammals and reptiles to berries, beans and cactus fruit.

Gray foxes are known for their unique ability to climb trees using their sharp, thick and slightly curved claws.  Their tree climbing ability enables them to escape many predators such as coyotes and dogs trailing them.

The untouched boulder-strewn terrain found of the area is the perfect place for a gray fox pair to create a den for their young, usually born in the spring. On this particular day, this gray fox seemed to be enjoying the cool, sunny afternoon as he ignored the scolding squirrels. After a couple of minutes, he turned on his paws and trotted off, quickly camouflaged against the backdrop of granite and creosote. Wonder in the desert is often fleeting, so enjoy the moment.

Points to Ponder for Young Trackers

• When you trek in wild places, pay attention to the birds and animals.  Sometimes a flitting bird or chattering squirrel is a warning. Stop and survey the terrain to see if you can spot a potential predator.
• Learn about animal tracks.  It is sometimes hard to see tracks in the dry dusty soil of the desert. Check areas where water collects. 
• Scat, fur and other animal remains can give us clues about what animals frequent the area. 
• Look for areas with steady food and water sources.  Berries, nuts, seeds and lush foliage attract insects, birds and smaller animals, and where there is an abundance of prey, larger predators are sure to appear.
• Always, track with caution.  Wild animals are fun to see, but need to be enjoyed at a safe distance. Animals who are sick, accompanying young or and/feel threatened can be dangerous.

References and Resources

Fox World - Kit Fox
Tucson.com - How to Read the Footprints of Desert Critters
Nature Tracking 
McDowell Mountain Preserve Flora and Fauna
Desert Wildlife Services


Cultivate Wonder... Discover Design

Poop Tales

It all began with an afternoon walk in the desert.  For some reason, I kept noticing animal poop. Rabbit poop, coyote poop, bird poop and even insect poop. All different in shape, size, color and even content. As much as I tried to resist it, I could feel the unmistakable stream of wonder begin to trickle through my mind. Sometimes, controlling wonder is a tricky proposition.

As I trekked through an area with lots of wild rabbits, I noticed two kinds of droppings, one light and one dark. It seems that rabbits do indeed excrete two varieties of droppings. The lighter colored one is simply waste, but the darker dropping is actually a nutrition-packed pellet that rabbits eat to remain healthy.  In fact, both wild and domesticated rabbits deprived of them will suffer from malnutrition.

Many of the granite boulders in the area  have the white-stained streaks of bird droppings, triggering another wonder response... why is bird poop typically white and not dark like most animals?  Birds do not urinate.  Instead, their bodies go through a similar process of gathering waste, but when it comes time to get rid of it, the waste is released from just one place instead of two.  This all-purpose passageway is also where eggs exit the bird's body. Like mammals, bird's kidneys filter blood to extract waste. Since birds do not urinate, the extracted uric acid waste combines with solid waste, dissolving much of the solid mass and turning it white. The final "product" is one white blob with specks of darker solids here and there. This no frills design may help birds retain water, as well as keep their bodies lighter for flight.

The orb web spider, Cyclosa Ginnaga actually builds a spot in their web that resembles a splat of bird poop.  The spider itself sits in the center to add to the illusion. This ingenious trick helps protect the spider from would-be predators, such as wasps, who are not much interested in a bird poop lunch.

Animal scat or droppings are not fun to look at, but if you can get passed the gross-out factor, scat can tell us a story about who is in the area, how healthy they are and what they are eating, among other things. Trackers look for bird droppings on rocks and cliffs to find perches and nesting sites. Small mammal scat can tell us about predator/prey relationships. Large mammal scat from bear and cougar can serve as a warning.

When you are trekking and tracking wonder, be aware of animal scat and see if you can "read" the tales it tells. Help children develop a healthy curiosity about all aspects of nature. Learning to understand every process, no matter how unpleasant it may be, is just part of cultivating wonder and discovering design.

Questions for Young Trackers:

• Who does this scat belong to? Bird, Mammal, Retile, Insect? How can you tell?
• Did the scat come from an herbivore, carnivore or omnivore? How do you know?
• Do you see evidence of bird perches in the area?
• How many different kinds of scat can you find?
• What can you learn about an animal by studying its droppings?

References and Resources
mentalfloss.com- Why is Bird Poop White?
The Mystery of Rabbit Poop
peta.com - Living in Harmony with Wild Rabbits
thedodo.com - 9 Quirky Animals with Very Special Ways of Pooping
nbcnews.com - Spiders Pose as Bird Poop to Evade Predators

Images: Sharon Pegany

Cultivate Wonder... Discover Design