Trout vs. Chub

Trout vs. Chub: Graduate student Lisa Winters holds a mature tiger trout. Trout grow quickly when they are on a Utah chub diet.
Graduate student Lisa Winters holds a mature tiger trout. Trout grow quickly when they are on a Utah chub diet.
Scofield Reservoir (a 2,815-acre, man-made lake), has, “Historically [been] the most important trout fishery in Utah’s southeastern region…” says Dr. Phaedra Budy, Unit Leader for the U.S. Geological Survey Cooperative Fish & Wildlife Research Unit at USU.

The trout (tiger, cutthroat and rainbow) now share the reservoir with high densities of Utah chub. The reservoir is thick with chub – a carp-like fish that matures quickly and is extremely prolific. At times chub have outnumbered trout in Scofield Reservoir nine to one.

Trout vs. Chub: The competitors: trout vs Utah chub in Scofield Reservoir
The competitors: trout vs Utah chub in Scofield Reservoir
The Utah Chub is native to the state, as indicated by its name, but it wasn’t observed in the lake until 2005.

The main concern for fisheries managers is whether or not the growing population of chub will compete with sport fish for food and/or space, as has been observed elsewhere, or whether chub can be effectively controlled by trout populations.

Trout vs. Chub: Undergraduate student Konrad Hafen holds a mature Tiger trout which preys on the Utah chub.
Undergraduate student Konrad Hafen holds a mature Tiger trout which preys on the Utah chub.
In an effort to answer these questions, Utah Division of Wildlife Resources (UDWR) commissioned a multi-year research project with Dr. Phaedra Budy’s Fish Ecology Lab in the Department of Watershed Sciences, Quinney College of Natural Resources to determine the predator and forage relationships between the trout and chub.

Fishing on Scofield Reservoir
Fishing on Scofield Reservoir
Based on this USU research, one observed benefit of chub is the impact it has on the growth of trout that eat it. After stocked tiger and cutthroat trout reach a certain size (usually a year after being stocked) they switch to a diet of fish and begin eating the chub.

According to Gary Thiede, fishery biologist in the Department of Watershed Sciences, once the trout begin eating chub they grow rapidly. Tiger trout in particular grow to very large sizes eating a diet of 100% chub.

Sunset on Scofield Reservoir
Sunset on Scofield Reservoir
The chub may, therefore, be beneficial to the reservoir’s ecosystem if the numbers are controlled.

DWR has used three trout species to control the population of chub and also enforced a catch and release rule for larger cutthroat trout so the biggest predators would remain in the reservoir. But since chub can live up to 30 years, some of the adults have reached a size where they are too big for trout to eat.

Graduate student Lisa Winters holds a tiger trout likely stocked earlier that spring. It takes at least a year before the stocked fish grow big enough to begin preying on the chub.
Graduate student Lisa Winters holds a tiger trout likely stocked earlier that spring. It takes at least a year before the stocked fish grow big enough to begin preying on the chub.
In 2016, it became obvious the public would no longer tolerate waiting for the trouts’ appetite to decrease the chub population.

After an extensive public input process, of gathering over 2500 public angler surveys, a committee was formed comprising of Scofield residents, sportsmen organizations, and wildlife agencies to develop a management plan, which would provide DWR recommendations to control the Utah chub population and create a sustainable, high-quality fishery at Scofield.

Research technicians pull in a net full of Utah chub.
Research technicians pull in a net full of Utah chub.
The plan was reviewed and approved by the Central and Southeast Regional Advisory Councils.

The first step in the plan will be DWR introducing three new fish to Scofield: wiper (a hybrid of white and striped bass), tiger muskie and triploid walleye.

According to Chris Wood, the southeastern regional supervisor, “All three grow quickly and have an appetite for the Utah chub.”

Justin Hart, the DWR’s aquatics manager in southeastern Utah said, we don’t want to completely eliminate [the chub], but we do need to get their biomass down. We plan to use the chub to grow some big fish.

Once the chub population has dropped, DWR will resume stocking the rainbow trout – a favorite among the state anglers.

If the plan is successful, the chub population will remain at a sustainable level and be a benefit, instead of a burden to the Scofield Reservoir trout populations.

This is Shauna Leavitt for Wild About Utah.

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

Sources & Additional Reading

Leavitt, Shauna, Trout vs. chub, Dueling it out in Scofield Reservoir, https://wildlife.utah.gov/blog/2014/trout-vs-chub/

Bird Brains

CT image of a Bird Brain Golden Woodpecker, Melanerpes aurifrons https://www.nsf.gov/news/mmg/mmg_disp.jsp?med_id=79726
CT image of a Bird Brain
Golden Woodpecker
Melanerpes aurifrons
https://www.nsf.gov/news/mmg/mmg_disp.jsp?med_id=79726
When I was a young lad being called “bird brain” was an indication that one was lacking in mental capacity.
Over the years I’ve come to question this connotation, and might even consider it a compliment. I suggest that quantity of this gray matter might be outweighed by quality.

Consider the hummingbird brain. Slightly larger than a bibi, it is very capable of feats beyond our imagining. Think unerring migration over hundreds of miles, efficient pollination while suspended in air, extraordinary flight capability, adjusting to extreme environmental challenges of cold, heat, predation, nourishment; exquisite nest design and construction, and so on.

Clark's Nutcracker Courtesy US Fish & Wildlife Service Dave Menke, Photographer
Clark’s Nutcracker
Courtesy US Fish & Wildlife Service
Dave Menke, Photographer
Regarding memory, nothing has been found to match the recall ability of the Clark’s nutcracker, which can bury thousands of pine nuts in rugged mountain terrain, finding them with uncanny ability following months of absence. Of course they hoard far more than needed, allowing many to germinate into seedlings- an amazing keystone species responsible for planting millions of trees from Mexico to Canada – this “squirrel bird” of the Rockies.

I’ve watched crows dropping nuts on roadways so they can be crushed open by passing vehicles, then flying down to eat the contents between oncoming traffic. And gulls dropping rocks on our pets to shoo them away from food dishes so they can have their turn at the table.

An ice fisherman was puzzled by a thief who was stealing his fish by pulling the line out of the ice hole and removing the fish. The culprit was finally observed- a raven- who used its beak and feet to gradually pull up the line with fish attached- an easy catch!

How about those mimics- parrots, corvids, starlings, gray catbirds, and the masterful mocking bird who can expand their repertoire of mimics to nearly 100 imitations without a pause.

And let us consider the remarkable Peregrine falcon. How is it possible that this lovely bird can strike a fast moving, highly maneuverable target as it drops from the heavens at a speed approaching 200 mph? Eyes, muscles, and nerves woven in such a manner that allow it to perform this feat is beyond comprehension.

I’ll conclude with perhaps my favorite bird attribute- their vocalizations. The more scientists learn, the richer their communications appear, possessing qualities once ascribed solely to the human language. Recent research has revealed that birds use syntax, which is altering the sequence of notes for variable meanings. Call order matters to them, much like word order does to us. The sound of birds calling isn’t just pretty. It’s full of meaning. I dare you to call me bird brain!

This is Jack Greene writing and reading for Wild About Utah

Credits:

Pictures: Courtesy US National Science Foundation & Courtesy US Fish & Wildlife Service, Dave Menke, Photographer
Text: Jack Greene, Bridgerland Audubon Society

Additional Reading:

Bird IQ Tests: 8 Ways Researchers Test Bird Intelligence, National Audubon, Alexandra Ossola, 9 Dec 2015, http://www.audubon.org/news/bird-iq-tests-8-ways-researchers-test-bird-intelligence

Bird Intelligence: Using Tools, Speech, Memory, Interactive Toys, and Emotional Displays
Veterinary & Aquatic Services Department, Drs. Foster & Smith, PetEducation.com, Petco Wellness LLC, http://www.peteducation.com/article.cfm?c=15+1795&aid=3342

Here’s Why ‘Birdbrain’ Should Be a Compliment, Simon Worrall, National Geographic, 15 May 2016, http://news.nationalgeographic.com/2016/05/160515-genius-birds-animal-intelligence-ackerman-ngbooktalk/

Bear Lake Sculpin – Cottus extensus

Bear Lake Sculpin - Cottus extensus: Hayley Glassic with a Bear Lake Cutthroat Courtesy & Copyright Jeremy Jensen
Hayley Glassic with a Bear Lake Cutthroat
Courtesy & Copyright Jeremy Jensen
In Bear Lake, there lives a small, bright blue eyed, bottom-dwelling fish species that may appear insignificant as it moves among the lake’s cobble areas.

The fish grows up to three inches in length and is endemic to Utah’s northern most lake, hence its name – the Bear Lake sculpin.

The sculpin is a scale-free, tadpole-like fish with a broad flat head, a slender body and eyes placed high on its head. It has elaborate pectoral fins that stretch out like decorative fans from both sides of its body and two dorsal fins along its back that sometimes connect at the base.

Bear Lake Sculpin - Cottus extensus: Sculpin Courtesy & Copyright Jereme Gaeta
Sculpin
Courtesy & Copyright Jereme Gaeta
Although the sculpin is small, its worth is significant. One of the main sportfish of Bear Lake, the Bonneville Cutthroat trout, rely heavily on the sculpin to be a source of food as its main forage fish, the sculpin makes up more than 70% of the diet for juvenile trout.

Interestingly, Bear Lake is the only place the sculpin is natively found and it is one of only two sculpins in the West that live in deep-water lake habitats.

It stays exclusively in the lake. While other fish in Bear Lake migrate up the tributaries to spawn, the sculpin seek out the lakes cobble areas where it can find cavities under and between the rocks to lay its eggs.

The best cobble habitat in Bear Lake is along the eastern shore at Cisco Beach where the shallow water covers the rounded rocks that range from 2-12 inches in size. Only 0.1% of Bear Lake is cobble habitat.

Bear Lake Sculpin - Cottus extensus: Bear Lake Sckulpin Courtesy & Copyright Jeremy Jensen
Bear Lake Sculpin
Courtesy & Copyright Jeremy Jensen
The shallow location of the cobble is important for the successful nest since the wave turbulence begins the hatching process. Waves and currents also help with the dispersal of the sculpin embryos throughout the 282 square kilometer lake.

Once hatched the young-of-the year have a feeding ritual quite different from their juvenile and adult counterparts. While the older sculpin stay on the bottom of the lake foraging for food, the young float up during the day to where the sun easily penetrates the water. The sunlight makes it easier for the young sculpin to find their food and it warms their bodies so they can digest their food more rapidly– which stimulates growth. The young sculpin can feed up to nine times faster during the day than they would at night. Once they have grown, it is difficult for sculpin to rise up the water column because they do not have swim bladders as trout do.

An essential component to have a large population of new sculpin each year is to ensure there is sufficient cobble habitat in Bear Lake.

When drought years hit, large portions of the cobble are exposed due to both that drought and human use. While the lake has never dropped to the level where all cobble habitat is exposed, a USU research team has documented more than 96% of cobble reductions during extreme multi-year drought events. This raises major concerns and questions about how a decrease in cobble would impact the sculpin population.

To investigate this question, Utah Division of Wildlife Resources awarded a research grant to Jereme Gaeta, assistant professor in the Department of Watershed Sciences and the Ecology Center in the Quinney College of Natural Resources to improve our understanding of the potential effects of drought on cobble habitats and fish communities.

Bear Lake Sculpin - Cottus extensus: Sculpin in Haley Glassic's hand Courtesy & Copyright Jeremy Jensen
Sculpin in Haley Glassic’s hand
Courtesy & Copyright Jeremy Jensen
Hayley Glassic, a graduate student in Gaeta’s lab has worked on this project since 2015. In the coming months their findings will be published and made available to the public.

This may be important reading for any agency or person making decisions about the Bear Lake water levels, which would impact the cobble habitat of the Bear Lake sculpin.

According to Glassic, “Sculpin appear to be one of the essential parts of the entire (Bear Lake) ecosystem.” Ensuring their cobble habitat is preserved during drought years is necessary for the overall health of the lake’s ecosystem.

This is Shauna Leavitt for Wild About Utah.

Credits:
Photos: Courtesy and Copyright Jeremy Jensen
Photos: Courtesy and Copyright Jereme Gaeta
Text: Shauna Leavitt

Sources & Additional Reading

Bear Lake Sculpin – Cottus extensus, USGS, https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=503

Bear Lake Sculpin – Cottus extensus, Fishbase Consortium, http://fishbase.org/summary/Cottus-extensus.html

Bear Lake Sculpin – Cottus extensus, Utah Division of Wildlife Resources, https://dwrcdc.nr.utah.gov/rsgis2/Search/Display.asp?FlNm=cottexte

Bear Lake Blue Ribbon Fishery, Utah Division of Wildlife Resources, https://wildlife.utah.gov/hotspots/brwaterbody.php?id=41

Bear Lake Sculpin – Cottus extensus, Idaho Fish & Game, https://idfg.idaho.gov/ifwis/cwcs/pdf/Bear%20Lake%20Sculpin.pdf

Orphaned Bear Cub Rehabilitation

Orphaned Cub: Bear Cubs in an Enclosure One of the facility’s natural climbing structures, and some of the conspecific interactions that took place in the pens. myers.patrick.rehab.bear.cubs.250x224
Bear Cubs in an Enclosure One of the facility’s natural climbing structures, and some of the conspecific interactions that took place in the pens.

New research reveals that orphaned cubs will likely avoid humans if properly rehabilitated.

Sadly each year, there are orphaned bear cubs in Utah. Some lose their mothers to forest fires, while others are orphaned by vehicle-bear collisions or other human-related conflicts.

If the orphaned cubs are too young to survive on their own and the Utah Division of Wildlife Resources (DWR) finds them before they perish they can be rehabilitated and have a good chance of surviving.

With the help of USU’s Dr. Julie Young a U.S. Department of Agriculture wildlife biologist and associate professor in the Quinney College of Natural Resources, who has expertise in managing carnivores in captivity, DWR was able to help build appropriate enclosures for the rehabilitation of the cubs.

Young helped built these temporary homes at the USDA National Wildlife Research Center’s Predator Research Facility in Millville, Utah.

To ensure the enclosures met the basic needs of cubs the researchers contacted approximately a dozen rehab facilities around the US and Canada to find out “HOW” to rehab bears.
Interestingly, there were large differences in responses.

According to Young, “A few consistent traits did emerge. Bears get easily bored, they like to play and investigate everything. So, we made sure the pens had lots of enrichment items and activities and everything was extremely sturdy since bears are very strong even as babies!

“Because they were being released back into the wild, we wanted to do as much as we could to give them natural surroundings – like logs, twigs, etc.

We scattered nuts and berries around so the cubs could learn to forage.”
One fun thing about bears – is they love water! The cubs spent a lot of time in their huge tubs or playing in the water fountain meant for drinking.

Dr. Young’s graduate student, Patrick Myers, recently completed a study of the orphaned cub rehabilitation which contributed to DWR’s Bear Management Plan to “maintain a healthy bear population…while considering human safety.”
Myers began his work in the summer of 2014 when DWR brought six orphaned cubs to the Millville bear rehabilitation site.
Throughout the rehabilitation, there was very little human contact to ensure the bears did not become familiar with humans. This was tough since cubs are cute and people wanted to see them. However, they remained firm and did not allow visiting hours. They removed as many human sights, sounds and odors as possible by keeping noise to a minimum, and since bears have extremely good noses they eliminated as many human smells as possible no perfumes or scented lotions were allowed.

At feeding time they fed the cubs from behind a blind, or put them in one pen while they cleaned and left food in the other. The researchers never went in the same pen as the cubs.

Loading two immobilized and recently collared cubs into their enclosures for transport to their release locations. myers.patrick.release.team.250x166
Loading two immobilized and recently collared cubs into their enclosures for transport to their release locations.

Myer’s research was unique. In addition to the regular food and development regiments, the cubs went through numerous behavioral tests to determine if they were bold, shy or somewhere in between when introduced to novel stimulus.

Consistent test results were the key in determining what type of animal personalities the cubs had.
One test included placing the cubs in a new enclosure with the same layout as their previous one. The shy cubs responded by hugging the walls and cautiously moving around while the bold cubs began exploring immediately with little signs of fear.

Once Myers classified the bears, and the cubs were old enough, the research team released the young bears to remote locations throughout Utah.

Patrick Myers has immobilized and extracted one of the bears from her den in early spring of 2016 to assess her health and the fit of her collar; this was in the Lake Canyon area, southwest of Duchesne. myers.patrick.den.check.250x188
Patrick Myers has immobilized and extracted one of the bears from her den in early spring of 2016 to assess her health and the fit of her collar; this was in the Lake Canyon area, southwest of Duchesne.

Myers monitored the bears throughout 2015 until they emerged from their dens in the spring of 2016.
“The bears were fitted with expandable GPS collars so they would grow when the cubs did and so Myers could watch their movement from a computer. Myers went to check out dens once they left them, to be sure their habitat choices were appropriate based on bear biology.

Young explains, “We went with UDWR and checked on the two females their second denning season in the wild –and they looked great!”

Myers and Young were pleased to see that even though the cubs had been in close proximity to the smell of humans for many months; neither the bold nor the shy bears sought humans once they released them. They all had healthy responses to their natural habitat and behaved much like young bears not orphaned. They searched for dens almost immediately, and remained in the remote locations.

Although this is a small study, the initial results show that orphaned cubs, whether shy or bold, will likely avoid humans and retain their natural instincts if property rehabilitated.

This may be a useful management practice for restoring bears where populations are dwindling and habitat is ideal.

This is Shauna Leavitt for Wild About Utah.

Credits:
Photo: Courtesy Utah Division of Wildlife Resources
Text: Shauna Leavitt

Sources & Additional Reading

USDA APHIS National Wildlife Research Center, https://www.aphis.usda.gov/aphis/ourfocus/wildlifedamage/programs/nwrc

Bear denning in the south Book Cliffs, Utah Division of Wildlife Resources, https://wildlife.utah.gov/blog/2013/bear-denning-in-the-south-book-cliffs/

“Can you help me? There’s a bear on my boat.”, Utah Division of Wildlife Resources, https://wildlife.utah.gov/blog/2013/can-you-help-me-theres-a-bear-on-my-boat/