Category: Reptiles

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Tracking Wildlife in Winter

Jumping Mouse Tracks
Photo Courtesy & Copyright 2011
Mark Larese-Casanova

Moose Tracks in Snow
Photo Courtesy & Copyright 2011
Mark Larese-Casanova

Cottontail Rabbit Browse & Scat
Photo Courtesy & Copyright 2011
Mark Larese-Casanova

Hi, this is Mark Larese-Casanova from the Utah Master Naturalist Program at Utah State University Extension.

The cold depth of winter is a time when many animals are hiding- either hibernating until the thaw of spring, or finding shelter and warmth in burrows, under logs, or in the tangled branches of evergreen trees.

However, snow falls in much of Utah, and even a dusting can reveal the stories of wildlife in winter. It’s a bit like solving a mystery. By reading the clues of animal tracks, we can know not only the type of animal that made them, but also where they were going and what they were doing.

The most obvious clue is the size of a track. Smaller animals make smaller tracks, and also sets of tracks that are generally closer together.

The shape of an animal track is also very revealing. Members of the canine family, including domestic dogs, coyotes, and fox, show four toes in front, each with a visible claw. Felines, including bobcats and mountain lions, also show four toes, but no claws. Tracks from members of the weasel family, such as mink, ermine, and skunks, show five toes, each with a claw. Raccoon, squirrel, and mouse tracks almost look like they were made by tiny human hands. The long tails of some animals, including deer mice, jumping mice, and weasels, often leave a characteristic line through the center of a set of tracks.

Combining the size and shape of tracks reveals further details about wildlife. The three inch long cloven hoof print of a mule deer is easily recognizable. An elk track looks almost identical, but is about four inches long. A similar moose track is even larger at six inches long.

Figuring out which animal made a track is only half of the story. If we follow tracks, we’ll surely find clues about an animal’s daily life. Wildlife often gather around sources of water that aren’t frozen, which are critical to winter survival. Perhaps rabbit tracks lead under a spruce tree where browsed branches and droppings indicate a frequent feeding spot. Maybe mouse tracks lead from tree to rock to log as it avoids owls and hawks.

While we are much more likely to see wildlife during the warmer months, winter gives us a chance to unravel the story of daily survival during the most difficult time of the year in Utah.

For Wild About Utah, I’m Mark Larese-Casanova.

Credits:
Images: Courtesy and Copyright Mark Larese-Casanova
Text:     Mark Larese-Casanova

Additional Reading:

Canadian Wildlife Federation: Tracking Down Winter Wildlife. https://www.cwf-fcf.org/en/action/how-to/outside/tracking-down-winter-wildlife.html

Murie, O. J. (1982). Animal Tracks. Peterson Field Guides. New York, NY: Houghton Mifflin. https://www.amazon.com/Peterson-Field-Guide-Animal-Tracks/dp/061851743X

Vermont Nature and Outdoors: Tracking Winter Wildlife. https://www.ruralvermont.com/vermontweathervane/issues/winter/97012/vins97012_tracking.shtml

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Blind Snakes

Click for a larger view of Western Blind Snake in a bucket, Leptotyphlops humilis. Courtesy and Copyright 2006 John S. Ascher, Photographer, https://www.discoverlife.org/mp/20p?see=I_JSA1964&res=640
Western Blind Snake
Leptotyphlops humilis
Courtesy & Copyright 2006
John S. Ascher, Photographer

If you’re unfamiliar with blindsnakes, don’t worry; most people haven’t heard of them. The 400 species of these seriously strange serpents are mostly tropical. Two species do occur in the southwestern United States, including western Washington County in Utah. They are small, many no larger than a shoelace, and have smooth scales and small eyes.

Blindsnakes typically live underground in loose, moist soil, so you are most likely to find one when gardening. If you do, don’t be alarmed – these tiny snakes are harmless and beneficial. Look closely, or you might mistake one for a worm due to its pinkish color. A black light can be used to tell the difference, as Utah blindsnakes glow fluorescent like scorpions. Blindsnakes eat ants, termites, centipedes and spiders. They can help control populations of these invertebrate pests around your home.

Their jaw architecture is unique. The jaws work like tiny scoops to shovel the larvae and pupae of ants and termites into their mouths. Unlike most snakes, who only eat once every few weeks, blindsnakes consume huge numbers of prey items very quickly. One Australian Blackish Blindsnake was seen to ingest over 1,400 ant larvae without pause!

Biologist in Texas report that screech owls sometimes carry live blindsnakes to their nests. Up to fifteen live among the chicks. Nests with blindsnakes have fewer mites, insects and spiders. Owlets in these nests survived and grew faster than owlets from nests without blindsnakes. This amazing mutualism may have evolved long ago. At over 100 million years old, blindsnakes are the oldest living group of snakes. Although considered primitive, blindsnakes are incredibly successful, if secretive, members of our modern serpent fauna.

Today’s program was written by Andrew Durso of Utah State University’s biology department.

Our theme music was composed by Don Anderson and is performed by Leaping Lulu.

Credits:

Images: Courtesy & Copyright 2006 John S. Ascher, Photographer

Text: Andrew Durso, https://www.biology.usu.edu/htm/our-people/graduate-students?memberID=6753

Additional Reading:

Screech Owls and Blindsnakes: An Unlikely Mutualism, Life is Short, But Snakes are Long, A blog about snake natural history and herpetology research, Andrew Durso, February 28, 2013, https://snakesarelong.blogspot.com/2013_02_01_archive.html

Western Blind Snake (Leptotyphlops humilis), Red Cliffs Desert Reserve, Washington County HCP Administration, https://www.redcliffsdesertreserve.com/western-blind-snake

Feeding Mechanisms of Blindsnakes, Mandibular raking in Leptotyphlopidae, Video Clips, The Kley Lab, Department of Anatomical Sciences, Stony Brook University, The State University of New York, https://renaissance.stonybrookmedicine.edu/anatomy/people/facultypage/kley/videos

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Til Death Do Us Part

Audio:  mp3 Listen to WildAboutUtah

Tundra Swan Pair
Cygnus columbianus
Courtesy US FWS
Tim Bowman, Photographer

Hi, I’m Holly Strand.

Each year we celebrate Valentine’s Day by expressing our love and devotion to a significant other. While humans are the only species that actually celebrate it, we aren’t the only animals who bond together as couples. Monogamy–or long term pair bonding as animal behaviorists call it–is practiced by over 90 % of birds. Along with a modest number of mammals, including wolves, beavers, voles and gibbons. Even a few fish pair up.

Monogamy may have evolved for different reasons among different groups of animals. For some, female dispersal may have played a role. If females are few and far between–as is the case with white tail ptarmigans–there is a tendency to pair up. Perhaps additional potential mates are too far away too bother. For males, monogamy can save a lot of time and energy. Monogamous males don’t have to fight over females or bother with first time courtship rituals. And by closely guarding a single female , males can protect their genetic investment.

There are advantages for females too. With a mate, you can get a little assistance around the nest or den. Male partners can help incubate eggs, guard against predators and help feed the kids. The fact that male and females are equally suited to care for chicks may explain why monogamy is so much more common among birds. The male improves his chances for reproductive success by investing in just one female’s little ones. The situation is different in mammals. Mammal males just can’t step in and help as much with gestation and lactation. So perhaps that’s why only 3% of mammal species form pair bonds.

The offspring of monogamous pairs tend to be pretty helpless at birth. Having two caregivers means that the you can take more time to mature. This long, slow development leads to larger brain sizes. Humans demonstrate this phenomenon very well as we parent our children longer than any other species on earth!

The tundra swan is Utah’s best example of monogamy in the wild. Young tundra swans date around a bit when they are young, but they eventually settle down with a single mate for life. They build and defend a nest together and raise the kids. But then they stick together the rest of the year as well. Greetings and courtship rituals such as head bobbing and dipping and ritual bathing strengthen their commitment toward each other.

You can see these beautiful swans in massive numbers twice a year when they migrate through Utah. Tens of thousands of them stop by the Great Salt Lake on their way to either the Arctic tundra or to central California.

For sources, pictures, and archives of past programs, go to www.wildaboututah.org

For Wild About Utah, I’m Holly Strand.

Credits:

Image: Courtesy US FWS, images.fws.gov
Text: Holly Strand

Sources & Additional Reading

Limpert, R. J. and S. L. Earnst. 1994. Tundra Swan (Cygnus columbianus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: https://bna.birds.cornell.edu/bna/species/089

Mocka, Douglas, and Masahiro Fujiokab. 1990. “Monogamy and long-term pair bonding in vertebrates” Trends in Ecology & Evolution. Volume 5, Issue 2, February 1990, Pages 39–43

Reichard, Ulrich and Christoph Boesch. 2003. Monogramy: mating Strategies and Partnerships in Birds, Humans and Other Mammals. Cambridge University Press.

Schultz, Susanne and Robin I.M. Dunbar. 2010. “Bondedness and sociality”
Behaviour, Volume 147, Number 7, 2010 , pp. 775-803(29).

Schultz, Susanne and Robin I.M. Dunbar. 2010. Social bonds in birds are associated with brain size and contingent on the correlated evolution of life-history and increased parental investment. Biological Journal of the Linnean Society. Volume 100, Issue 1, pages 111–123, May 2010.

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Hearts

Hearts abound this time of year – gracing cards, storefronts, and of course, chocolates. And while the heart symbol bears little resemblance to the organ itself, their abundance of late has caused me to consider my own heart, beating away largely unacknowledged all these years.

In its simplest form, the heart is a pump. Its sole function is to keep the blood in your body on the move, partnering with your lungs to deliver life-giving oxygen to each and every hard-working cell, from the top of your head to the tip of your pinky toe. Most hearts have two distinct features – an atrium where blood collects on its way into the heart and a ventricle which pumps the blood back out.

But even with these shared components, not all hearts are alike. Throughout the animal kingdom, hearts take on a variety of forms. Fish, for example, have a two-chambered heart: one atrium that collects blood and one ventricle that pumps it back out. Blood journeys from the heart to the gills, where it picks up oxygen and then continues on its way, delivering its cargo to the body before making its way back.

Amphibians and reptiles, with the exception of the crocodile, have a three-chambered heart consisting of two atria and one ventricle. One atrium is designated for the oxygen-poor blood that is headed towards the lungs while the other is reserved for oxygen-rich blood coming back from the lungs and headed out into the rest of the body. In the shared ventricle, blood from both atria mix slightly, resulting in a somewhat inefficient system that nonetheless seems to meet the needs of the animals it serves.

Mammals and birds have taken the heart one evolutionary step further with the development of a four chambered heart that fully separates oxygenated and deoxygenated blood. Blood flowing in from the lungs enters the left atria and is pumped out to the body by the left ventricle, while blood returning from the body enters the right atria and is pumped to the lungs via the right ventricle. Because of this total separation, the blood leaving a mammal’s heart contains more oxygen than a reptile’s – a huge metabolic advantage that helps support our warm-blooded fast-paced lifestyle.

Two-, three- and four-chambered hearts are considered closed circulatory systems, meaning the fluid, or blood, is fully enclosed within blood vessels. Insects, on the other hand, have an open circulatory system which means that they don’t have blood vessels at all. Instead their bodies are simply full of fluid that is continually circulated with the help of multiple simple hearts that pass liquid through as they contract and relax.

Lastly, there are some organisms that don’t need hearts at all! These creatures absorb oxygen through their skin and are small or thin enough that oxygen easily diffuses to all parts of the body. Some jellyfish, for example, have a body wall only two cells thick that separates their internal body space from the water around them.

Without our comparatively complex hearts, we probably wouldn’t be able to do what we do as humans and mammals. So take a moment during this Valentine’s season to acknowledge your amazing heart. Throughout the course of your lifetime it will beat upwards of 2 billion times and will pump as much as 100 million gallons of blood through its chambers. A pretty amazing feat for something we only celebrate once a year.

For the Stokes Nature Center and Wild About Utah, this is Andrea Liberatore.

Credits:
Text:     Andrea Liberatore, Stokes Nature Center in Logan Canyon.

Additional Reading:

Campbell, N.A. (1996) Biology, Fourth Edition. Benjamin/Cummings Publishing Company, Menlo Park CA

Bailey, Regina (2013) Circulatory System: Types of Circulatory Systems. https://biology.about.com/od/organsystems/a/circulatorysystem.htm

Meyer, J.R. (2005) Insect Physiology: Circulatory System. North Carolina State University. https://www.cals.ncsu.edu/course/ent425/tutorial/circulatory.html