Beaver Tail Slap

Beaver Tail Slap: Beaver swimming Courtesy NPS,  J Schmidt, Photographer
Beaver swimming
Courtesy NPS,
J Schmidt, Photographer
When I first saw a beaver in Cache Valley I thought I’d seen an alligator. I was sitting in the front of a canoe when a large head shot past the bow followed by a black tail that flew into the air and came down on the water with a resounding slap

“What was that?” I asked
“I don’t know,” my friend answered
“I think it was an alligator,” I said
By then then creature had disappeared and we paddled on.

I found out later that tail slapping is a common beaver behavior. Its a warning shot before the beaver dives for cover.

Intrigued, I set out to learn more. It came as a surprise to me to find out that when a beaver builds a dam, it is actually building a home. Inside a sturdy wall of sticks, rocks and mud, the beavers build a living space above the water line. It’s dry – and its safe because it can only be entered by swimming through underwater tunnels. Not a problem for a beaver who can swim underwater for as long as 15 minutes.

When the surface of the pond freezes over, the females will give birth. Its an extended family life – an adult pair, the yearlings, and the new kits. When winter is long, and with so many mouths to feed, the beavers have perfected their food storage. Hauling their favorite food, aspen , back to the lodge, they jam it into the muddy bottom of the pond. There is stays, fresh and crisp like any refrigerated food, until its needed.

When fur trappers arrived in Northern Utah in the 1800’s, European hat makers had discovered that felted beaver wool made the very best hats. Bear Lake became a hot spot. The historical marker just north of Garden City tells us,

“Donald MacKenzie, Jim Bridger, and a host of famous beaver hunters operated here. Two major summer frolics and trade fairs brought plenty of excitement to Bear Lake in 1827 and 1828.”

Trappers were harvesting up to 500 lbs a year. But by 1840, the beavers had become almost extinct. European fashion in hats moved on to silk – a good thing for the hat makers as well because the mercury used in the felting of beaver wool caused all kinds of neurological disorders. Its no joke the Hatter in Alice in Wonderland is mad.

Back in northern Utah, the beaver population slowly rebuilt, but the human population also grew and conflicts arose. Recently a farmer in Benson became irate when beavers began to redirect the flow of water through his irrigation canals

Beaver Health Exam Courtesy & © Mary Heers, Becky Yeager, Photographer
Beaver Health Exam
Courtesy & © Mary Heers, Becky Yeager, Photographer
It’s the job of the Utah Division of Wildlife Resources to live trap and relocate these beavers. I was lucky to be allowed into the loop at this point.

When I picked up one of the smaller beavers, I could feel its heart going a mile a minute under my fingers. But it settled down as I sat in a chair holding it against my chest while it got a quick physical checkup.

Holding the beaver close, I had a good look at the nibble fingers on its front feet, the webbing on its back feet that can paddle along at 6mph, and the marvelous flat tail, a good rudder for swimming, a prop for standing on land, and perfect for slapping the water’s surface.

Take my word for it, once you’ve seen this slap up close, you won’t forget it.

I’m Mary Heers and I’m Wild About Utah.

Credits:
Photos: Courtesy US NPS, Yellowstone Collection, J. Schmidt, Photographer
Photos: Courtesy & Copyright © Mary Heers
Featured Audio: Courtesy Friend Weller, Utah Public Radio
Text & Voice: Mary Heers
Additional Reading: Lyle Bingham, Webmaster

Additional Reading

Leavitt, Shauna, Beaver in Utah’s Desert Rivers, Wild About Utah, July 6, 2020, https://wildaboututah.org/beaver-in-utahs-desert-rivers/

Leavitt, Shauna, Proposed Beaver Holding Facility in Millville, Utah, Wild About Utah, September 3, 2018, https://wildaboututah.org/proposed-beaver-holding-facility-in-millville-utah/

Goodwin, Jim, Riparian Zones and a Critter Quiz, Wild About Utah, January 22, 2015, June 15, 2015, https://wildaboututah.org/riparian-zones-and-a-critter-quiz/

Strand, Holly, Beavers: The Original Army Corps of Engineers, Wild About Utah, April 29, 20-10, August 16, 2012, https://wildaboututah.org/beavers-the-original-army-corps-of-engineers/

Kervin, Linda, Huddling for Warmth, Wild About Utah, February 3, 2011, https://wildaboututah.org/huddling-for-warmth/

Beaver Monitoring App, Utah Water Watch, Extension, Utah State University, https://extension.usu.edu/utahwaterwatch/citizenscience/beavermonitoringapp/

Pollock, M.M., G.M. Lewallen, K. Woodruff, C.E. Jordan and J.M. Castro (Editors) 2018. The Beaver Restoration Guidebook: Working with Beaver to Restore Streams, Wetlands, and Floodplains. Version 2.01. United States Fish and Wildlife Service, Portland, Oregon. 189 pp. Online at: https://www.fws.gov/oregonfwo/ToolsForLandowners/RiverScience/Beaver.asp
also https://restoration.usu.edu/pdf/2018BRGv.2.01.pdf

Macfarlane W.W., Wheaton J.M., and M.L. Jensen. 2014. The Utah Beaver Restoration Assessment Tool: A Decision Support and Planning Tool. Ecogeomorphology and Topographic Analysis Lab, Utah State University, Prepared for Utah Division of Wildlife Resources, Logan, Utah, 135 pp. Available at: https://etalweb.joewheaton.org.s3-us-west-2.amazonaws.com/Downloads/BRAT/UTAH_BRAT_FinalReport.pdf

Wheaton JM. 2013. Scoping Study and Recommendations for an Adaptive Beaver Management Plan. Prepared for Park City
Municipal Corporation. Logan, Utah, 30 pp. https://etalweb.joewheaton.org.s3-us-west-2.amazonaws.com/Reports/Beaver_Management_Plan_Recc_Park_City_%20Report_FINAL.pdf

Beaver Reintroduction Looks Positive for Stream Restoration
in Northern Utah, Utah Forest News, USU Forestry Extension, Utah State University, Volume 18, Number 3, 2014, https://forestry.usu.edu/files/utah-forest-newsletter/utah-forest-newsletter-2014-3.pdf

Muffoletto, Mary-Ann, Dam Good! Beavers May Restore Imperiled Streams, Fish Populations, Today, Utah State University, July 07, 2016, https://www.usu.edu/today/story/dam-good-beavers-may-restore-imperiled-streams-fish-populations

Restoring Degraded Waters, One Pest at a Time, Utah State Magazine, Utah State University, December 7, 2021, https://utahstatemagazine.usu.edu/environment/restoring-degraded-waters-one-nuisance-at-a-time/

Proposed Beaver Holding Facility in Millville, Utah

Beaver Holding Facility: Beaver, Castor canadensis, Courtesy FWS, Steve Hillebrand, photographer
Beaver, Castor canadensis, Courtesy FWS, Steve Hillebrand, photographer
Nuisance beavers, who in recent years were viewed as pests and quickly disposed of, are now in high demand.Proposed Beaver Holding Facility in Millville, Utah

A growing number of ranchers, and federal and state agencies are asking to have beavers translocated to their lands to act as affordable ecosystem engineers to restore riparian habitats, hold water on the dry arid lands, and restore creeks to their historic condition.

Currently the number of requests for live beavers outnumbers the amount of available animals.

Spawn Creek Beaver Dams Courtesy & Copyright Joe Wheaton, Photographer
Spawn Creek Beaver Dams
Courtesy & Copyright Joe Wheaton, Photographer
Nick Bouwes, Assistant Professor in Watershed Sciences at Utah State University said, “To assist in fulfilling this need, USU’s Department of Watershed Sciences and Department of Wildland Resources in the Quinney College of Natural Resources is working with Utah Division of Wildlife Resources (DWR) to build a beaver holding facility a few miles south of USU’s main campus.”

The architects are drafting blueprints, consultants are analyzing the needs of beavers in captivity, and scientists are seeking funding for the project.

According to Joseph Wheaton, Associate Professor in the Department of Watershed Sciences, “We plan to build a place where [beaver] that would typically be lethally removed, will be given a second chance by moving them to places where their engineering skills will be helpful in stream restoration and …where they won’t get into trouble.”

Beaver Cutting Courtesty & Copyright Joe Wheaton, Photographer
Beaver Cutting
Courtesty & Copyright Joe Wheaton, Photographer
Bouwes adds, “It’s…not as easy as simply catching and releasing a beaver. A lot goes on to increase their ability to survive and stay put after the release. They are social animals, so trapping a whole family unit is the best method. If a single beaver is released, they tend to take off and look for other beavers.”

Researchers hope the facility will expand to be an educational tool where they can hold workshops, study the beavers themselves, and educate the public with tours and visiting hours.


The project includes a design for a mobile trapping facility. This will allow the researchers to travel around the state trapping beavers that are currently in incompatible locations.

Bouwes explains, “It’s basically a trailer with kennels to keep the beavers cool. They are…sensitive to heat. If we go off location for any length of time, being able to keep the beavers cool and [safe]…will be very useful.”

When the trailer arrives back at the holding facility, scientists will move the beavers to kennels that have a slight slope and a divot at the end that serves as a small pond where the beavers can swim.

Nate Norman, consultant on the project from Balance Environmental, adds, “We are not looking for this to be a new home, we just want it to be safe and comfortable for the beavers until we can get them back into the wild.”

Researchers will quarantine the beavers for 72 hours to ensure they are free of disease and parasites, before managers move them to a new watershed.

Once the quarantine is complete, scientists will use the Beaver Assessment Tool to determine where the beaver family would most likely succeed.

Bouwes explains, “This [tool] looks at all the stream networks across Utah and identifies…the best place to re-introduce beaver. It evaluates the dam building capacity of a stream, and identifies places of potential conflict.”

The success of this project is dependent on its partners: DWR provides the expertise and oversight, USU supplies the land and research facilities, and ranchers allow access to streams for placing the beavers.

When the beaver holding facility is open, scientists and managers hope to be translocating 50-100 beavers a year.

Those interested in learning more about beavers and stream restoration are invited to attend a workshop at USU in October.

Look for details at restoration.usu.edu.

This is Shauna Leavitt and I’m Wild About Utah.

Credits:
Photos: Courtesy & Copyright © Mark McKinstry
Audio: Courtesy Western Soundscape Archive, University of Utah, Sound provided by Jeff Rice, licenesed under CCA-ND
Text: Shauna Leavitt, Utah Cooperative Fish and Wildlife Research Unit, Quinney College of Natural Resources, Utah State University

Sources & Additional Reading

Hellstern, Ron, Leave it to Beaver, Wild About Utah, July 30, 2018, https://wildaboututah.org/leave-it-to-beaver/

Leavitt, Shauna, Beaver–Helping Keep Water on Drying Lands, Wild About Utah, April 17, 2017, https://wildaboututah.org/the-beaver-helping-keep-water-on-drying-lands/

Strand, Holly, Beavers: The Original Army Corps of Engineers, Wild About Utah, August 16, 2012, https://wildaboututah.org/beavers-the-original-army-corps-of-engineers/

Beaver Monitoring App, Utah State University Extension, https://extension.usu.edu/utahwaterwatch/citizenscience/beavermonitoringapp/

Fluvial Habitats Center/Ecogeomorphology & Topographic Analysis Laboratory, Joe Wheaton et. al. https://etal.joewheaton.org/

Restoring Degraded Waters, One Pest at a Time, Utah State Magazine, Utah State University, December 7, 2021, https://utahstatemagazine.usu.edu/environment/restoring-degraded-waters-one-nuisance-at-a-time/

Goldfarb, Ben, Eager: The Surprising, Secret Life of Beavers and Why They Matter, Chelsea Green Publishing, March 8, 2019, https://www.amazon.com/Eager-Surprising-Secret-Beavers-Matter/dp/1603589082/ref=asc_df_1603589082/

Leave it to Beaver

Leave it to Beaver: Beaver Dam and Pond Courtesy and Copyright Bethany Neilson, Photographer
Beaver Dam and Pond
Courtesy and Copyright Bethany Neilson, Photographer
A few years ago the Utah Division of Wildlife Resources conducted a wonderful workshop for educators to provide them with materials to take to their classes to help students understand the many issues dealing with wildlife.

As an introductory activity, the Ranger asked each of us to name the animal we thought that had the greatest influence or impact on ecosystems. People mentioned Deer, Cougars, Moose, Wolves and so on until it was my turn. Without hesitation I said “Beavers”. One of the teachers laughed at me and mocked my answer trying to embarrass me. So I asked the Ranger to repeat the question: Which animal did we think had the greatest influence or impact on ecosystems.

Leave it to Beaver: Beaver Dam Releasing Water Courtesy and Copyright Bethany Neilson, Photographer
Beaver Dam Releasing Water
Courtesy and Copyright Bethany Neilson, Photographer
“Oh”, I said making certain I had now understood the question. “In that case I have no hesitation now in saying the Beaver.” The room grew quiet, but the Ranger agreed with my answer.

Leave it to Beaver: Below a Beaver Dam Courtesy and Copyright Bethany Neilson, Photographer
Below a Beaver Dam
Courtesy and Copyright Bethany Neilson, Photographer
There is no question that all animals impact ecosystems. Heavy grazing or browsing by deer or elk can change the structure of forests and meadows. Predators, or the lack of them, can definitely alter what happens to those species. But consider the beaver for a moment. There are positive and negative things they do, but they definitely impact ecosystems. So consider this love-hate relationship humans have with them.

Yes, they will take down some trees to build dams and lodges. Problems might include:
The potential flooding of homes, agricultural land, timber land or orchards;
Their abandoned dams can create floods as they collapse;
There is potential flooding of roads and blocking of culverts;
And the deterioration of stream banks can occur.

But in a natural setting, where they do not impact roads or developments, beavers can do amazing things.
On the positive side, they create ponds which:
Provide habitat for trout;
Provide drinking water for all the animals in the area, from birds to bears;
Provide a storage of water that could be critical in drought conditions;
Trap silt and control small floods;
Invigorate the sprouting of early riparian and wetland plants;
Can help combat the effects of continual rising temperatures and earlier Spring snowmelt by maintaining a water supply for ranching, wildlife and native vegetation;
And they are basically constructed and maintained at little or no cost to humans.

Utah State University, and the Division of Wildlife Resources, have been developing partnerships with landowners to help restore beavers in locations where they can succeed and provide benefits to the land, wildlife, and ranching efforts. In areas where there are few trees, they construct Beaver Dam Analogues by pounding fence posts across streams, weaving willow branches between them, and plugging the base with large rocks and mud. These are similar to natural beaver dams and give them a good start to build their own homes there.
If you are aware of any beavers in questionable areas, contact

USU Watershed Sciences or the DWR to help relocate them where they can impact ecosystems in positive ways.

This is Ron Hellstern, and I am Wild About Utah.
 
Credits:

Images: Courtesy and Copyright Bethany Neilson, Photographer https://uwrl.usu.edu/people/faculty/neilson-bethany
Audio: Courtesy Western Soundscape Archive, University of Utah, Sound provided by Jeff Rice, licensed under CCA-ND
Text: Ron Hellstern, Cache Valley Wildlife Association

Additional Reading

North American Beaver, Castor canadensis, Utah Division of Wildlife Resources, Wildlife Notebook Series No. 24,
https://digitallibrary.utah.gov/awweb/awarchive?type=download&item=56529

UTAH BEAVER MANAGEMENT PLAN 2010–2020, Developed with the Beaver Advisory Committee, DWR Publication 09-29, Utah Division of Wildlife Resources, 2010, https://wildlife.utah.gov/furbearer/pdf/beaver_plan_2010-2020.pdf

WATS 6860 – Partnering with Beaver in Restoration Design, University Catalog 2017-2018, Utah State University, https://catalog.usu.edu/preview_course_nopop.php?catoid=12&coid=93002

Beaver: Restoration liaison between riparian and upland systems. Joe Wheaton, Assistant Professor, Utah …, https://www.youtube.com/watch?v=62A3RqL7Xp8

WEBINAR: Cheap and Cheerful Stream Riparian Restoration with Beaver. Joe Wheaton …
https://www.youtube.com/watch?v=m1uysDrOI_w

Beaver Restoration Workshop, Partnering with Beaver in Restoration, https://beaver.joewheaton.org/

Webinar: Cheap & Cheerful Stream Restoration – With Beaver? https://beaver.joewheaton.org/beaver-news/webinar-cheap-cheerful-stream-restoration-with-beaver

Science Unwrapped Talk by Joe on Beaver
https://beaver.joewheaton.org/beaver-news/science-unwrapped-talk-by-joe-on-beaver

Videos & Movies
https://beaver.joewheaton.org/videos–movies.html

Joe Wheaton – Beaver: Restoration liaison between riparian and upland systems
https://beaver.joewheaton.org/

Dr. Joseph Michael Wheaton, Watershed Sciences, Associate Professor, https://qcnr.usu.edu/directory/wheaton_joseph
Utah Water Watch, Beaver Monitoring App, https://extension.usu.edu/utahwaterwatch/citizenscience/beavermonitoringapp/

Beaver Dam Mapping App Now Available for Citizen Scientists, https://www.exploreutahscience.org/science-topics/environment/item/148-citizen-scientists-can-now-use-an-app-to-help-map-beaver-dams-in-utah


ARKive Images of Life on Earth, Information Sheet on Castor Canadensis (including some outstanding videos) https://www.arkive.org/ – (BBC Natural History Unit)

  • American Beaver – Overview
  • American Beaver in the Lodge with Young
  • American beaver felling trees and storing food for the winter
  • American beaver scaring moose away from its lodge
  • American beaver returning to its lodge with food

  • Collen, P. and R.J. Gibson. 2001. The general ecology of beavers (Castor spp.), as related to their influence on stream ecosystems and riparian habitats, and the subsequent effects on fish – a review. Reviews in Fish Biology and Fisheries 10: 439–461, 2001. https://www.researchgate.net/publication/227028536_The_general_ecology_of_beavers_Castor_spp_as_related_to_their_influence_on_stream_ecosystems_and_riparian_habitats_and_the_subsequent_effects_on_fish_-_A_review [ Accessed May 1, 2010]

    Prettyman, B. 2009. Utah wildlife: Leave it to the beavers. Article in Salt Lake Tribune, October 16, 2009. https://www.sltrib.com/ci_13570110 [ Accessed April 29, 2010]

    Smithsonian Castor Canadensis Information Page https://www.mnh.si.edu/mna/image_info.cfm?species_id=32 [ Accessed April 29, 2010]

    Big Bend Habitat Restoration Project: A Natural Work of Heart, Open Spaces-A Talk on the Wild Side, US FWS, https://www.fws.gov/news/blog/index.cfm/2016/3/25/Big-Bend-Habitat-Restoration-Project-A-Natural-Work-of-Heart [Accessed March 31, 2016]

    Beaver Dams Strengthened by Humans Help Fish Rebound
    60-Second Science – July 25, 2016 – By Jason G. Goldman02:29 https://www.scientificamerican.com/podcast/episode/beaver-dams-strengthened-by-humans-help-fish-rebound/ Also available through the podcast https://itunes.apple.com/us/podcast/60-second-science/id189330872?mt=2

    Goldfarb, Ben, Eager: The Surprising, Secret Life of Beavers and Why They Matter, Chelsea Green Publishing, March 8, 2019, https://www.amazon.com/Eager-Surprising-Secret-Beavers-Matter/dp/1603589082/ref=asc_df_1603589082/

    Sixty In-stream Habitat Structures in Four Days: Demonstrating Creek Restoration Techniques

    In-stream Habitat Structures: Crews from multiple agencies gather in the encroaching pinyon-juniper forest to begin building the in-stream structures in Birch Creek, UT. Courtesy & Copyright Shauna Leavitt, Photographer
    Crews from multiple agencies gather in the encroaching pinyon-juniper forest to begin building the in-stream structures in Birch Creek, UT.
    Courtesy & Copyright Shauna Leavitt, Photographer
    The job of building 60 in-stream habitat structures in one week seems like a daunting task. But an energetic group of 16 natural resource managers, researchers and volunteers, finish all 60 in four days.

    The crew members come from numerous agencies including the Bureau of Land Management, Utah Division of Wildlife Resources, the National Forest Service, interagency firefighting hotshots, and Utah State University.
    The purpose of the project is to demonstrate how effective various in-stream structures are at improving habitat for Bonneville cutthroat trout and restoring riparian habitat on a two-mile stretch of Utah’s Birch Creek, located southeast of Beaver, Utah.

    In-stream Habitat Structures: Crews from multiple agencies building in-stream structures to restore Birch Creek. Courtesy & Copyright Shauna Leavitt, Photographer
    Crews from multiple agencies building in-stream structures to restore Birch Creek. Courtesy & Copyright Shauna Leavitt, Photographer
    At one time Birch Creek was rich with beaver, riparian vegetation and diverse in-stream habitat making it an ideal home for Bonneville Cutthroat trout and sage grouse.

    The beaver are now gone, and the once woody riparian vegetation has been largely replaced by an encroaching pinyon-juniper forest. The creek is one narrow ditch-like channel.

    According to Joseph Wheaton, Associate Professor in the Department of Watershed Sciences and Principal Investigator, “Without the help [of man-made structures or beaver dams] recovery from this type of degradation could take centuries.”

    The crews built a variety of simple structures, some designed to mimic beaver dams and others to imitate natural accumulations of wood and debris jams.

    In-stream Habitat Structures: An in-stream structure build from juniper branches, cobble, gravel and mud. Courtesy & Copyright Shauna Leavitt, Photographer
    An in-stream structure build from juniper branches, cobble, gravel and mud. Courtesy & Copyright Shauna Leavitt, Photographer
    The largest structures are built with an excavator. The machine pulls up large junipers and drops them in the stream so the water can run over, around and through the juniper and its root wads.
    Wheaton explains, ”By putting the [Juniper} in the channel we’re making habitat for fish and at the same time raising water tables, which support a whole range of riparian vegetation and wetland vegetation.”
    Another structure is the Beaver Dam Analogues (BDAs), which is a simple, cost-effective method of using posts and juniper branches then adding rocks and mud to partially plug up the deliberately leaky dams, designed to be passable to fish.

    In-stream Habitat Structures: A pool forming behind a newly build in-stream habitat structure. Courtesy & Copyright Shauna Leavitt, Photographer
    A pool forming behind a newly build in-stream habitat structure. Courtesy & Copyright Shauna Leavitt, Photographer
    Crews see immediate improvements after each structure is built. New pools form, old-channels that haven’t seen water for decades begin to flow parallel to the main channel, and formerly dry floodplains become wet sponges and wetlands.

    These wet sponges will release their water later in the season providing additional moisture in dryer times.
    Justin Jimenez, Fisheries Riparian Program Manager with Bureau of Land Management explains why these pools are essential, “We’re working to improve the habitat for native fish by increasing the pool frequency and depth. The depth provides thermal cover.” Which is cooler for summer rearing habitat, and warmer for winter survival.
    Before this project began, downstream water-rights holders were concerned about how these structures would impact water for irrigation.

    In response to their concerns, Gary O’Brien, a Geomorphologist in the Fluvial Habitat Center at USU installed a common measuring device called a V-notch weir at the top and bottom the of the two-mile stretch to measure the discharge of the stream.

    According to O’Brien, “once all the structures fill their pools and the system adjusts for infiltration, we expect the top and the bottom weirs to measure a relatively consistent discharge.”
    By the addition of a pressure transducer in the pool behind the weirs, O’Brien will have continuous flow of data at every stage.

    With these readings the ranchers can be kept up-to-date on the impact the structures are having on the water resources. The agencies have agreed to remove the structures if gaging shows the structures are negatively impacting downstream water users.

    Throughout the project, UDWR, BLM and the USFS will be monitoring cutthroat trout response, and USU will be monitoring how the habitat responds and changes through time.

    By monitoring the responses, managers and researchers will be able to make more informed decisions about which types and mix of structures can be most effectively used to restore similar streams cheaply across the state.

    This is Shauna Leavitt for Wild About Utah.

    Credits:
    Photos: Courtesy and Copyright Shauna Leavitt
    Text: Shauna Leavitt

    Sources & Additional Reading

    Streams & Rivers Restoration, Restoration Center, NOAA Habitat Conservation, National Marine Fisheries Service,
    https://habitat.noaa.gov/restoration/techniques/srrestoration.html

    White, Courtney, Thinking Like a Creek, originally published by The Carbon Pilgrim, March 6, 2014,
    https://resilience.org/stories/2014-03-06/thinking-like-a-creek/

    Stream Restoration, United States Department of Agriculture(USDA), Natural Resources Conservation Service(NRCS),
    https://nrcs.usda.gov/wps/portal/nrcs/main/national/water/manage/restoration/

    Rubenstein, Marcus, CPESC, Stream Restoration, Purpose Practice and Methods, Southeast Storm Water Association,
    https://seswa.org/assets/Services/Annual-Conference/2010/11%20-%20stream%20restoration%20%20methods%20purpose%20and%20practices%20rubenstein.pdf