Mark Larese-Casanova, Author at Wild About Utah

September 26, 2013March 1, 2018

Owls: Silent Hunters

Barn owl sleeping in a tree, Photo Copyright 2010 Mike Fish — Barn Owl Sleeping in a Tree
Copyright © 2010 Mike Fish

Great Horned Owl
Photographer: Ronald Laubenstein
US FWS Digital Library

Western Screech Owl
Copyright © 2007 Lu Giddings

Tethered Snowy Owl in Alaska
*Bubo scandiacus*
Courtesy US FWS
Ronald Laubenstein, Photographer
Snowy Owl in Alaska
*Bubo scandiacus*
Courtesy Wikimedia
Floyd Davidson, Photographer
Licensed under the
Creative Commons: GNU Free Documentation License
Snowy Owl with Chick
*Bubo scandiacus*
Courtesy Wikimedia
Tony Hisgett, Photographer
Licensed under the
Creative Commons: Attribution 2.0 Generic License
Snowy Owl in Flight
*Bubo scandiacus*
Courtesy Wikimedia
Bert de Tilly, Photographer
Licensed under the
Creative Commons: Attribution-Share Alike 3.0 Unported License

Great Horned Owl Photographer: Ronald Laubenstein US FWS Digital Library — Barn Owl Sleeping in a Tree
Copyright © 2010 Mike Fish

Great Horned Owl
Photographer: Ronald Laubenstein
US FWS Digital Library

Western Screech Owl
Copyright © 2007 Lu Giddings

Tethered Snowy Owl in Alaska
*Bubo scandiacus*
Courtesy US FWS
Ronald Laubenstein, Photographer
Snowy Owl in Alaska
*Bubo scandiacus*
Courtesy Wikimedia
Floyd Davidson, Photographer
Licensed under the
Creative Commons: GNU Free Documentation License
Snowy Owl with Chick
*Bubo scandiacus*
Courtesy Wikimedia
Tony Hisgett, Photographer
Licensed under the
Creative Commons: Attribution 2.0 Generic License
Snowy Owl in Flight
*Bubo scandiacus*
Courtesy Wikimedia
Bert de Tilly, Photographer
Licensed under the
Creative Commons: Attribution-Share Alike 3.0 Unported License

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

Walking across the yard late at night, the crescent moon was casting little light. A dark, phantom shape soared past our heads. It was silent, not making a single noise. It could only be one thing out here in the night- an owl, drifting off into the darkness.

Even though they hunt at night, owls use their vision to find prey. Owl eyes are proportionately large compared to those of other birds, and also have large corneas and pupils to allow more light into the eye. The retina, where an image is formed at the back of the eye, is so large that an owl’s eye is shaped more like a rounded cone or tube rather than a ball. Because the back of an owl’s eye is wider than the front, owls cannot move their eyes within the socket like other animals. To make up for this, owls are able to turn their heads three-quarters of a full rotation!

To supplement its acute vision, owl’s ears are particularly well adapted for hearing prey. In fact, some owls hear so well that they can catch prey in complete darkness. The feathers of the facial disk- the round, flat areas around the eyes- help direct sound toward their large ear openings. In addition, an owl’s ear openings are set relatively far apart on its skull, and at different orientations on each side. One is high and more forward on the skull, and the other is lower and to the rear. This allows owls to locate noises, such as the rustling of a mouse, by triangulation with remarkable precision.

Excellent sight and hearing are helpful to owls, but very quiet feathers help them sneak up on prey. Relatively large wings covered with feathers that have a velvety soft upper surface and a serrated edge reduce noise during flight. Owls even have feathers on their legs to help keep quiet!

Most birds sleep soundly in their roosts at night. But, it’s not uncommon for us to see an owl gliding through the darkness in search of its prey. Just don’t expect to hear them…

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

Credits:
Images: Courtesy US FWS images.fws.gov
Courtesy and Copyright Mike Fish
Courtesy and Copyright Lu Giddings
Courtesy Wikimedia & licensed through CCL
Text: Mark Larese-Casanova, Utah Master Naturalist Program
at Utah State University Extension.

Additional Reading:

Berger, C. (2005). Owls. Mechanicsburg, PA: Stackpole Books.

Lynch, W. (2007). Owls of the United States and Canada. Baltimore, MD: Johns Hopkins University Press.

Owl Feathers and Flight. (2012). In The Owl Pages. Retrieved September 20, 2013, from https://www.owlpages.com/articles.php?section=owl+physiology&title=Feathers

Owl Eyes and Vision. (2012). In The Owl Pages. Retrieved September 20, 2013, from https://www.owlpages.com/articles.php?section=owl+physiology&title=Vision

August 26, 2013March 1, 2018

Nutcrackers and Squirrels, Farmers of the Forests

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

Throughout Utah’s forests, many plants and animals take advantage of other organisms to survive. Whether it is a caterpillar eating a tree leaf, mistletoe growing on a juniper branch, or an owl catching a mouse to eat, one organism being consumed by another is almost inevitable. However, some organisms may inadvertently help others not only survive, but also increase their range.

Many conifer trees, including pines, spruces, and firs, depend on fungi that live in and around their roots. The fine fibers of the fungi act as root hairs, helping trees better absorb water and nutrients from the soil. Some fungi also have symbiotic relationships with bacteria that are able to take Nitrogen from the air and turn it into ammonia, which is one of the forms of nitrogen that helps plants grow. Conifer trees reproduce via seeds from their cones, and fungi produce mushrooms to release spores. Squirrels happen to find conifer seeds and mushrooms particularly tasty, and will readily eat them. As squirrels are known to do, extra food is cached away for winter, and some seeds and mushrooms are inevitably forgotten. This helps disperse seeds and spores, aiding in population growth. So, the fungus helps the tree grow, the tree and fungus provide food for the squirrel, and the squirrel helps the tree and fungus spread to new areas.

The Clark’s nutcracker, a bird closely related to the crow and raven, is also particularly important in aiding in the spread of pine trees. Living at higher elevations, nutcrackers must store food for the long winters on Utah’s mountains. A nutcracker’s stout beak is used to crack open pine cones to retrieve the seeds inside. It stores seeds in a pouch under its tongue, and flies away to cache the seeds for winter. Each Clark’s nutcracker stores tens of thousands of seeds every year. While many seed caches are found and eaten, some are forgotten and germinate into young saplings.

So, while squirrels and nutcrackers are ultimately just looking for a good meal, both play a crucial role in establishing and maintaining healthy forest ecosystems in Utah’s mountains. For Wild About Utah, I’m Mark Larese-Casanova.

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

Credits:
Images: Courtesy US FWS images.fws.gov
Text: Mark Larese-Casanova, Utah Master Naturalist Program
at Utah State University Extension.

Additional Reading:

Cornell Lab of Ornithology. Clark’s nutcracker. https://www.allaboutbirds.org/guide/Clarks_Nutcracker/id

Larese-Casanova, M. Utah Master Naturalist Mountains Wildlife Field Guide. Utah State University Extension. 2012.

Maser, C., and Z. Maser. 1988. Interactions among squirrels, micorrhizal fungi, and coniferous forests in Oregon. The Great Basin Naturalist 48(3):358-369.

US Forest Service. Clark’s Nutcracker. https://www.fs.fed.us/database/feis/animals/bird/nuco/all.html#FOOD%20HABITS

Washington Department of Fish and Wildlife. Living with Wildlife: tree squirrels. https://wdfw.wa.gov/living/tree_squirrels.html

July 25, 2013July 18, 2022

Oolites

Click to view larger image of the Utah's Oolitic Sand, Photo Courtesy and Copyright Mark Larese-Casanova — Utah’s Oolitic Sand, Photo Courtesy and Copyright Mark Larese-Casanova

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

Imagine if prehistoric brine shrimp were responsible for one of the finest examples of architecture in Salt Lake City today.

Okay, so it may be a bit of a stretch, but let me explain. In a previous episode of Wild About Utah, I discussed the life cycle of brine shrimp and the important role that they play in the Great Salt Lake Ecosystem. Well, as the billions of brine shrimp feed on bacteria in Great Salt Lake, they excrete waste in the form of tiny fecal pellets. These pellets, along with sand grains and other bits of debris, eventually settle to the bottom of Great Salt Lake.

In shallow areas of the lake, where wind and waves routinely mix the water, these small particles gradually accumulate layers of calcium carbonate, forming an oolite (spelled o-o-l-i-t-e). This is very similar to how a pearl, also layers of calcium carbonate around a small particle, is formed within the shell of an oyster or mussel. The main difference, aside from a pearl being much larger, is that oolites are typically oblong, rather than round. The beaches on the west side of Antelope Island are a great place to find oolitic sand, which will look and feel as though you have a handful of tiny pearls.

Click to view larger image of the Utah's Oolitic Sandstone, Photo Courtesy and Copyright Mark Larese-Casanova — Utah’s Oolitic Sandstone
Photo Courtesy & Copyright
Mark Larese-Casanova

Around 50 million years ago, large fresh- and salt-water lakes covered parts of Utah, and in these areas, vast amounts of sediments, including oolites, were deposited. Over time, these oolites were compressed and cemented together into limestone.

A quarry near Ephraim in Sanpete County supplied oolitic limestone for the construction of the Governor’s Mansion in 1902 and the original Salt Lake City Public Library in 1905. The Library building, located at 15 South State Street, eventually housed the Hansen Planetarium and is now home to the O.C. Tanner flagship store. The building underwent an extensive restoration just a couple of years ago, and now serves as a shining example of neoclassical architecture in our capitol city.

The truth is, there are tens of millions of years separating oolitic limestone from our modern-day brine shrimp. So, we can’t exactly say that prehistoric brine shrimp were responsible for the existence of the O.C. Tanner building. But, it’s fun to imagine precious gems from around the world housed in a beautiful building constructed from the ‘pearls’ of Great Salt Lake.

Click to view larger image of the historic OC Tanner building made from oolitic sandstone (This building formerly housed the Salt Lake Library and Hansen Planetarium), Photo Courtesy and Copyright Mark Larese-Casanova — Historic OC Tanner Building
(formerly the Salt Lake Library
and later the Hansen Planetarium)
Photo Courtesy & Copyright
Mark Larese-Casanova

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

Images: Courtesy and copyright Mark Larese-Casanova

Text: Mark Larese-Casanova, Utah Master Naturalist Program at Utah State University Extension.
Additional Reading:

Utah Geological Survey https://geology.utah.gov/utahgeo/rockmineral/collecting/oolitic.htm

Utah Division of Wildlife Resources, Great Salt Lake Ecosystem Program
https://wildlife.utah.gov/gsl/facts/oolitic_sand.php

Salt Lake Brine Shrimp, https://saltlakebrineshrimp.com/harvest/

June 27, 2013May 17, 2019

Aquatic Insects, Harbingers of Health

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

As we officially enter summer, it’s easy to notice nature at its peak. Wildflowers are in bloom, birds are feeding their young, and insects fill the air. Life is especially robust near our wetlands, lakes, and streams.

Our aquatic, or wet, ecosystems provide habitat to abundant plants and animals. Only 1% of Utah is wet, but over 80% of all wildlife in Utah depend on aquatic ecosystems for at least part of their life cycle. However, the quality of Utah’s aquatic habitats is often affected by chemical pollution or excessive nutrients and sediment.

Some organisms, including many aquatic insects, only live in the healthiest of aquatic habitats. Many of the insects we see in summer live in the water when young, during the larval or nymph stage, before becoming adults. Three insects in particular- mayflies, stoneflies, and caddisflies- require especially clean, cold streams low in nutrients and high in dissolved oxygen to survive.

Mayflies are aquatic as nymphs and emerge from the water to live as adults for just a day. The external feather-like gills of the nymphs can be seen fluttering along the sides of their abdomen. They feed by scraping algae from rocks.

Stonefly nymphs are well adapted to living among the rocks of swift-moving streams. Their hooked legs grasp the slick rocks as they shred apart plant litter that falls into the stream.

Caddisfly larvae spin a sort of spider silk to glue rocks or sticks together to form a case in which they live. They will also build webs underwater to collect small particles of food that drift by.

The quality of a stream habitat can be assessed by counting the number of different species, or types, of mayflies, stoneflies, and caddisflies. A greater number of species generally means that habitat and water quality are higher. Dramatic decreases in insect diversity from season to season or year to year can signal a decline in stream health. Monitoring aquatic insects over time gives us an accurate picture of the long-term health of our stream ecosystems.

For more information about monitoring water quality and aquatic insects, visit Utah State University Water Quality Extension’s website. Once there, you’ll find a wealth of information about monitoring Utah’s aquatic ecosystems, including Utah Water Watch, a statewide volunteer citizen science program.

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

Credits:
Images: Northern caddisfly larvae, Howard Ensign Evans,
Colorado State University
Creative Commons Attribution 3.0 License.
Stonefly Nymph, © Robert Newell, displayed on Troutnut.com
Mayfly nymph, © Leo Kenney Vernal Pool Association
Text: Mark Larese-Casanova, Utah Master Naturalist Program
at Utah State University Extension.

Additional Reading:

Larese-Casanova, M. Utah Master Naturalist Watersheds Wildlife Field Guide. Utah State University Extension. 2012. https://extension.cart.usu.edu/Details.cfm?ProdID=41&category=0

USU Water Quality Extension. Utah Stream Team Manual. https://extension.usu.edu/waterquality/htm/citizen_monitoring/ust

Voshell, J. R. A Guide to Common Freshwater Invertebrates of North America. The McDonald and Woddward Publishing Company. 2002. https://www.amazon.com/Guide-Common-Freshwater-Invertebrates-America/dp/0939923874