Censuses and Surveys

Wolf with Radio Collar watches biologists FWS Digital Library, Photo by William Campbell
Wolf with Radio Collar
Photographer: William Campbell

Hi, I’m Holly Strand from Stokes Nature Center in beautiful Logan Canyon.

This year’s Census is the 23rd national headcount in United States history.

Census results affect the allocation of all kinds of government financial and program resources. The Census also determines the distribution of seats in
the state and federal House of Representatives.

It is also important to know the number and whereabouts of different wildlife species. This information is used for a number of management purposes– for instance, monitoring the status of endangered species or determining hunting or fishing quotas.

Mountain Lion with Radio Collar
Photographer: Claire Dobert
Courtesy US FWS

Counting wildlife isn’t as easy as counting people. You can’t mail
animals a survey with a self-addressed stamped envelope and you don’t necessarily know where to find them at any given point in time.

True censuses of animals are rare for in most cases a complete count is either too expensive or too difficult to undertake. Only animals conveniently and visibly grouped in a particular location can be censused– such as fish in a fish hatchery, or large animals along a certain migration route.

Setting a waterfowl capture net
Courtesy US FWS

Instead, biologists define an area of interest, then sample at random locations within that area. Samples usually consist of a number of transects or randomly selected quadrants. Counts from these samples are then extrapolated to an entire habitat or study area.

Along with selecting a sampling method, you have to figure out how you are going to effectively count an individual occurrence. This can be extremely tricky. Especially if your animal is reclusive or nocturnal. According to Dr. Eric Gese, a specialist in predator ecology at Utah State University, biologists use tracks, scats, scratches, burrows, hair samples –even roadkill counts as proxies for individual animals.

FWS Biologist Tracking a Black Bear
Photo by John & Karen Hollingsworth,
Courtesy US FWS

Capturing, marking and recapturing animals is one of the most reliable–albeit expensive– ways to do a direct count of animals. Captured animals are marked with ear tags, radio collars, dyes or even radioactive isotopes. In a future program I’ll describe an example of how one scientist tracks and counts large and elusive predators in the wild.

Thanks to Utah State University’s College of Natural Resources for supporting the development of this Wild About Utah topic.

For Wild About Utah and Stokes Nature Center, I’m Holly Strand.
Images: Courtesy US FWS Digital Library
Text:     Holly Strand, Stokes Nature Center

Sources & Additional Reading:

Gese, E. M. 2001. Monitoring of terrestrial carnivore populations. Pages 372–396 in J. L. Gittleman, S. M. Funk, D. Macdonald, and R. K. Wayne, editors., Carnivore conservation. Cambridge University, Cambridge, United Kingdom.

Video: Biologists track hibernating bears for research, KSL Broadcasting Salt Lake City UT, 27 March 2010, http://www.ksl.com/index.php?nid=647&sid=10166167

American Black Bear, Utah Division of Wildlife Resources, wildlife.utah.gov/publications/pdf/bearnew.pdf

(tracking) Black-footed Ferrets, Wildlife Review Utah Division of Wildlife Resources, wildlife.utah.gov/wr/0804ferrets/0804ferrets.pdf


Utah’s Conifer Trees

Juniper Leaves & Cones
Juniper Leaves & Cones
Copyright © 2009 Linda Kervin

Two-needle Pinion PineTwo-needle Pinion Pine
Copyright © 2009 Linda Kervin

Norway Spruce ConesNorway Spruce Cones
Copyright © 2009 Linda Kervin

True Fir NeedlesTrue Fir Needles
Copyright © 2009 Linda Kervin

Douglas Fir Cones
Copyright © 2009 Linda Kervin

Now that the leaves have fallen from the deciduous trees, we can fully appreciate Utah’s evergreen trees. Conifers are trees that bear their seeds in cones instead of producing flowers and fruits. Utah has five kinds of conifers; all with stiff, needle-like leaves that remain green throughout the winter. Traits of their needles and cones allow you to distinguish between our different types of conifers. Cones can be found still attached or scattered on the ground.

I will start with the junipers. These conifers have scaly, slightly fleshly leaves. Juniper seeds are embedded in a cone that resembles a green berry. The cones are round and densely fleshy. Junipers are widely adaptable here, from arid foothills to rocky alpine slopes.

Our pines collectively span this same elevation range. They are the only conifers that have cylindrical needles bundled in clusters of 2 to 5. The one exception to this is Single Leaf Pinon, which as you might guess has single, round needles. The count of pine needles is often diagnostic of their species. Pinons mix with junipers at low elevations; their oily, wingless seeds are the edible pinon nut. Bristlecone pines, found in southern Utah, can live for over 1000 years.

Spruces are conifers that many recognize from their own yards. The spruce needle leaves a peg on the stem when it drops, which gives their twigs a rough, nubbly surface. Spruces grow in a classic pyramidal shape.

Another montane group is the true firs. Their flat needle attaches smoothly to the twig. True firs have uniquely upright cones that gradually disintegrate without dropping to the ground. Crushed fir needles are wonderfully fragrant, redolent of tangerines or grapefruit. Perhaps that is why true firs are a favorite Christmas tree.

Douglas fir, despite its common name, is in a different genus than the true firs. Its cones are distinctive; having long, three-pointed, papery bracts that project out from amid the cone’s scales. Douglas fir is one of the west’s most valuable timber tress. Like the spruces and firs, it is a montane species.

Conifer trees are a great resource for Utah wildlife, providing food and shelter, especially in the icy cold of winter.

This is Linda Kervin for Bridgerland Audubon Society.

Pictures: Copyright © 2009 Linda Kervin
Text: Linda Kervin and Jim Cane

Additional Reading:

Sibley, David Allen. 2009. The Sibley Guide to Trees. New York: Alfred A. Knopf.

Johnson, Carl M. 1991. Common Native Trees of Utah. Utah State University Extension Service. Logan, UT. 109 p

Kuhns, Michael R., Utah Forest Facts, Conifers for Utah, http://extension.usu.edu/forestry/Reading/Assets/PDFDocs/NR_FF/NRFF015.pdf, USU Extension

Spruces in the Urban Landscape

Colorado Blue Spruce
Courtesy Linda Kervin

A spruce tree was felled in my neighborhood recently. I have no quarrels with its removal, especially since it was leaning over my roof. But some wild neighbors were not so upbeat about the incident. A Red Squirrel scolded anyone within earshot. It had lost its secure pathway between the front and backyards. Now it must run on the ground before once again climbing into the safety of loftier pathways.

Spruce trees have much to offer the non-human inhabitants of our urban landscapes. The noisy Red Squirrel may also have been complaining about the loss of a nest. Both squirrels and birds like to nest in spruce trees.
The dim interior of the spruce is a good place to look for owls roosting during daylight.

Spruce trees shelter animals during storms, their dense branches providing a dry, calm haven from wind, rain and snow.

Spruces offer a high perch from which every bird, house finch to crow to robin, can declare their territory by song sung lustily from the topmost branches.
When the Sharp-shinned Hawk swoops the birdfeeder for a feathery meal, the juncos and chickadees scatter to hide themselves in the spruce’s embrace.

Last winter, flocks of White-winged Crossbills descended upon Utah. Their bill crosses at the tip, which makes it perfect for prying open spruce cones to get to the tasty and nutritious seeds. These birds wander the Northern Hemisphere in search of abundant cone crops of spruce and other conifers.

The noble, lofty spruce is more than a decorative landscape tree. It offers food, home, safety and shelter to our wild neighbors.

Our theme music was written by Don Anderson and is performed by Leaping Lulu from their CD High Road, Low Road. Our bird music is provided by Kevin Colver.

Text: Linda Kervin, Bridgerland Audubon Society

Additional Reading:


Tales of the Packrat The Legacy of Early Grazing on Utah’s Rangelands

Tales of the Packrat: Pack Rat Midden,  Photo Courtesy and Copyright 2009 Ken Cole - All Rights Reserved
Pack Rat Midden
Copyright © 2009 Ken Cole

Reaching for a Pack Rat Midden, Click to Zoom, Photo Courtesy and Copyright 2009 Ken Cole - All Rights Reserved Reaching for a Pack Rat Midden
Copyright © 2009 Ken Cole

One of the best storytellers in Utah’s national parks is not a ranger, but the lowly packrat.Tales of the Packrat
Their stories of past plant communities are written in their middens. The midden is a heap of leaves, twigs, seeds and fruits the packrat discards outside its nest. Protected in a desert cave or rock crevice and preserved by a rat’s own urine, this heap is a detailed and accurate time capsule of the past local flora.

Ken Cole with the US Geological Survey is a fluent translator of the packrat’s stories. Ken and colleagues sampled old packrat nests around Glen Canyon National Recreation Area and Capitol Reef National Park. By carbon-14 dating, the nest ages are known to span the last 10,000 years. As controls, they also collected nests from mesa tops inaccessible to livestock. Ken and colleagues then carefully translated these packrats’ stories by identifying and counting the plant fragments in these fossil nests.

At both Capitol Reef and Glen Canyon, old packrat nests revealed pre-settlement plant communities that were rich in diverse grasses, wildflowers and shrubs. Then these floras changed. Beginning 150 years ago, vast herds of sheep and cattle tromped and chewed their way across the unfenced rangelands of Utah in numbers unimaginable today. We know that palatable plant species and those susceptible to trampling suffered declines, because they are absent from middens from that time period. Unpalatable shrubs multiplied. Despite curtailed grazing in subsequent decades at Capitol Reef and Glen Canyon, packrats show us that the flora still has not recovered. Like Aesop’s fables, this cautionary lesson of the packrat’s ecological tale remains clear and relevant today. We should all listen.

This is Linda Kervin for Bridgerland Audubon Society.
Tales of the Packrat
Photos: Courtesy and Copyright Ken Cole
Text: Julio Betancourt USGS and Jim Cane, Bridgerland Audubon
Additional Reading:

Betancourt, Julio L., Thomas R. Van Devender, and Paul S. Martin, eds. Packrat Middens: The Last 40,000 Years of Biotic Change, University of Arizona Press, 1990 https://www.uapress.arizona.edu/books/BID40.htm

Pack Rat Middens, Colorado Plateau in Land Use History of North America, Ken Cole, USGS/Northern Arizona University, https://cpluhna.nau.edu/Tools/packrat_middens.htm

Introduction [to Carbon 14 Dating], Tom Higham, Radiocarbon Laboratory, University of Waikato, New Zealand https://www.c14dating.com/int.html [Sep 24, 2009]