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1999

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Articles 271 - 300 of 658

Full-Text Articles in Animal Sciences

Karyological Analysis And Body Proportion Of Catfish (Clariidae, Clarias Lazera, Valenciennes, 1840) In The Göksu Delta, Turkey, Serap Ergene Gözükara, Ender Portakal, Arzu Karahan Jan 1999

Karyological Analysis And Body Proportion Of Catfish (Clariidae, Clarias Lazera, Valenciennes, 1840) In The Göksu Delta, Turkey, Serap Ergene Gözükara, Ender Portakal, Arzu Karahan

Turkish Journal of Zoology

Chromosome analysis of Clarias lazera living in wet lands located in Göksu River (Göksu Delta) was accomplished by modified air-drying. Clarias lazera was found to have 18 metacentric, 26 submetacentric and 12 acrocentric chromosomes. Twenty-five systematically important meristic and morphometric characters of Clarias lazera in the Göksu Delta were examined for 49 specimens. In order to clarify the taxonomic status of Clarias lazera, which is not originally from this region, karyological analyses were carried out, and certain some morhometric characteristics were investigated.

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A Morphological Investigation On The Anuran Species Of The Reşadiye (Datça) Peninsula (Anura: Bufonidae, Hylidae, Ranidae), Cemal Varol Tok Jan 1999

A Morphological Investigation On The Anuran Species Of The Reşadiye (Datça) Peninsula (Anura: Bufonidae, Hylidae, Ranidae), Cemal Varol Tok

Turkish Journal of Zoology

In this survey the amphibian fauna of Reşadiye (Datça) Peninsula, which has not been studied in detail so far, is given. No urodelan species has been encountered during the present work; but the presence of four different species belonging to three anuran families is established. Bufo bufo, Bufo viridis, Hyla arborea and Rana ridibunda specimens were collected from two, five, three and six different localities respectively, establishing the status of the peninsula's anura fauna. A total of 125 adult and two juvenile specimens were studied morphologically. Some observations on the ecological and biological characteristics of the anurans are also given.

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Specimens Of Ophisops Elegans (Sauria:Lacertidae) Collected From Ihlara Valley (Aksaray), Kurtuluş Olgun, Cemal Varol Tok Jan 1999

Specimens Of Ophisops Elegans (Sauria:Lacertidae) Collected From Ihlara Valley (Aksaray), Kurtuluş Olgun, Cemal Varol Tok

Turkish Journal of Zoology

In this study, a total of 30 specimens (15 , 15 ) collected from Ihlara Valley were examined for their taxonomic characteristics. The Ihlara population was compared with two nearby populations (Kayseri and Karaman), which are included in the distribution range of Ophisops elegans centralanatoliae. When pholidosis, coloration and pattern features were taken into consideration it was concluded that the Ihlara population can be included in the species Ophisops elegans centralanatoliae.

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Fall 1998 Raptor Migrations Study In The Wellsville Mountains Of Northern Utah, United States Department Of Agriculture, Forest Service Jan 1999

Fall 1998 Raptor Migrations Study In The Wellsville Mountains Of Northern Utah, United States Department Of Agriculture, Forest Service

Elusive Documents

The Wellsville Mountains raptor migration study in northern Utah is an ongoing effort to monitor longterm trends in populations of raptors using this northern Rocky Mountain migratory flyway. Raptors feed atop food pyramids, inhabit most ecosystems, occupy large home ranges, and are sensitive to environmental contamination and other human disturbances. Therefore, they serve as important biological indicators of ecosystem health (Cade et al. 1988; Bednarz et al. 1990a; Bildstein and Zalles 1995). For example, long-term migration counts in the eastern United States documented declines in several raptor species and helped us understand the deleterious effects of organochlorine pesticides (Spofford 1969, …

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Utilization Of Turkey Waste Material In Beef Cattle Diets, Dale R. Zobell, Gary Anderson, Clell Bagley Jan 1999

Utilization Of Turkey Waste Material In Beef Cattle Diets, Dale R. Zobell, Gary Anderson, Clell Bagley

All Archived Publications

No abstract provided.

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Fish & Wildlife News: January 1999 (Special Edition: National Wildlife Refuge System Conference) Jan 1999

Fish & Wildlife News: January 1999 (Special Edition: National Wildlife Refuge System Conference)

Fish and Wildlife News

Contents:

High Altitude, High Spirits 2
Honoring a Congressman 5
Media Baron Speaks Up for Wildlife 6
“No More Roads,” Says Babbitt 6
Panelists Address Diversity Issues 9
Barry Describes the “State of the System” 13
Another Roosevelt Who Loves Refuges 15
Winning Managers Share Their Thoughts 17
Results of Breakout Sessions 22
Director Lauds a New Era 23
AD Dan Ashe Looks Back 26
Refuges Chief Coleman Looks Ahead 27

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Fish & Wildlife News: January/February 1999 Jan 1999

Fish & Wildlife News: January/February 1999

Fish and Wildlife News

Contents:

Anne Badgley in as Region 1 RD 2
Service Releases More Mexican Wolves 4
LE Busts Coral Smuggling Ring 5
Service Embraces Migratory Bird Initiatives 6
A New Concept in Beef 8
Interior Plans 150th Bashes Year-Round 9
Bringing the Hatchery to the Volunteers 10
Cranes Draw Crowds in New Mexico 11
Tribute to Region 1 Employees Killed on Duty 12
Team Implements Ecosystem Approach 15
Fighting Invasives in the Ohio River 16
Hollywood Comes to a Refuge 18
Rare Fish Makes a Comeback 23
Student Leaders Take D.C. by Storm 26

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Plant And Breeding Bird Communities Of Black-Tailed Prairie Dog Colonies And Non-Colonized Areas In Southwest Kansas And Southeast Colorado, Stephen L. Winter Jan 1999

Plant And Breeding Bird Communities Of Black-Tailed Prairie Dog Colonies And Non-Colonized Areas In Southwest Kansas And Southeast Colorado, Stephen L. Winter

School of Natural Resources: Dissertations, Theses, and Student Research

This research was initiated to determine if plant and bird communities on black-tailed prairie dog (Cynomys ludovicianus Ord) colonies in southwest Kansas and southeast Colorado differed from those found on associated non-colonized areas. Vegetation height and density, and the cover and frequency of numerous plant species differed between prairie dog colonies and non-colonized areas that were co-dominated by mid-height grasses and shortgrasses. A comparison of prairie dog colonies with non-colonized areas that were dominated solely by shortgrasses did not reveal a difference in vegetation height and density. The number of species that differed in cover or frequency between prairie dog …

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Changes In Ph Of Boar Semen Extenders, Mary Sue Newth, Donald G. Levis Jan 1999

Changes In Ph Of Boar Semen Extenders, Mary Sue Newth, Donald G. Levis

Nebraska Swine Reports

An experiment was conducted to examine the change in pH across time of five extenders (MR-A, VSP, BTS, Merck III and SpermAid). Type of extender and time of measurement affected (P < .01) the overall pH of liquid extender; however an interaction (P < .01) occurred between type of extender and time. BTS and MERCK III had a small increase in pH across time, MR-A and VSP had a linear increase in pH across time and SpermAid decreased in pH during the first 20 minutes before gradually increasing to a consistent level of pH at 50 minutes after preparation. Boar semen extenders do not have the same pattern of pH change across time. Semen should not be mixed with extender until a stable pH has been reached. In general, a liquid boar semen extender should be prepared 60 to 90 minutes prior to mixing with raw semen.

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Development And Use Of Pork Skin Fat Emulsion Gels In Low-Fat, High-Added-Water Bologna, Timothy D. Schnell, Roger W. Mandigo Jan 1999

Development And Use Of Pork Skin Fat Emulsion Gels In Low-Fat, High-Added-Water Bologna, Timothy D. Schnell, Roger W. Mandigo

Nebraska Swine Reports

Reduced-lean pork trimmings (~70 percent fat and 30 percent lean) have low economic value due to inherent high fat content. Mechanically modified pork skin was used to extend reduced- lean pork trimmings by making a fat emulsion gel, lowering fat content by dilution in an attempt to increase the value of reduced lean trimmings. The first objective was to extend reduced-lean pork trimmings by creating a pork skin fat emulsion gel (FG) and to characterize and optimize the functionality of FG from combinations of pork skin, reduced-lean trimmings and added water (AW). The next objective was to incorporate the best …

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Follicular Selection And Atresia In Gilts Selected For An Index Of High Ovulation Rate And High Prenatal Survival, Hui-Wen Yen, Rodger K. Johnson, Dwane R. Zimmerman Jan 1999

Follicular Selection And Atresia In Gilts Selected For An Index Of High Ovulation Rate And High Prenatal Survival, Hui-Wen Yen, Rodger K. Johnson, Dwane R. Zimmerman

Nebraska Swine Reports

Previously, we reported (See Yen et al., Nebraska Swine Report 1998) White Line gilts selected for an index of high ovulation rate and high prenatal survival (White Line-2, WL-2) maintained a larger pool of medium follicles (3 to 6.9 mm) during the early- to mid-follicular phase than randomly selected controls (White Line- 1, WL-1). The present study evaluated the health status of the medium follicles to determine whether WL-2 gilts maintain a healthier pool of medium follicles and are able to continue selection of ovulatory follicles later in the follicular phase to achieve their ovulation rate advantage (6.6 ova). Ovaries …

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Growth And Carcass Responses Of Barrows Fed A Corn-Soybean Meal Diet Or Low-Protein Amino Acid-Supplemented Diets At Two Feeding Levels, Sergio Gomez, Phillip S. Miller, Austin Lewis, Hsin-Yi Chen Jan 1999

Growth And Carcass Responses Of Barrows Fed A Corn-Soybean Meal Diet Or Low-Protein Amino Acid-Supplemented Diets At Two Feeding Levels, Sergio Gomez, Phillip S. Miller, Austin Lewis, Hsin-Yi Chen

Nebraska Swine Reports

An experiment, with 39 barrows with high lean gain potential, was conducted to evaluate the growth responses of pigs fed a corn-soybean meal diet (CONTROL) and low-crude protein diets supplemented with crystalline lysine, threonine, tryptophan and methionine either on an ideal protein basis (IDEAL) or to a pattern similar to the control diet (AACON). In both cases the amino acid patterns were on a true ileal digestible basis. The initial and final body weights were 72.0 and 125.8 pounds. The diets were offered on an ad libitum basis or by feeding 80 percent of the ad libitum intake. Pigs were …

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Zinc Oxide, With Or Without Carbadox, Stimulates Performance In Nursery Pigs, Hsin-Yi Chen, Austin J. Lewis, Phillip S. Miller Jan 1999

Zinc Oxide, With Or Without Carbadox, Stimulates Performance In Nursery Pigs, Hsin-Yi Chen, Austin J. Lewis, Phillip S. Miller

Nebraska Swine Reports

As part of a cooperative research study with several other Midwest universities, two experiments were conducted to evaluate the effects of high concentrations of zinc from zinc oxide in nursery diets. In the first experiment, the effects of adding various pharmacological concentrations of zinc as zinc oxide were tested. In the second experiment, the effects of both zinc and(or) carbadox additions to diets for weanling pigs were evaluated. Feeding pharmacological concentrations (2,000 to 3,000 mg/kg) of supplemental zinc from zinc oxide stimulated voluntary feed intake and weight gain of nursery pigs, but additive responses to carbadox (55 mg/kg) were not …

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Bioavailability Of Iron In Iron Proteinates, Austin Lewis, Phillip S. Miller, Hsin-Yi Chen Jan 1999

Bioavailability Of Iron In Iron Proteinates, Austin Lewis, Phillip S. Miller, Hsin-Yi Chen

Nebraska Swine Reports

The bioavailability of the iron in two different sources of iron proteinate was compared with that in feedgrade iron sulfate (FeSO4•H2O). Pigs, which were iron deficient and anemic at weaning, were given diets with no supplemental iron or supplements, of iron sulfate or iron proteinate. During the three-week study, weight gain and hemoglobin increased as the iron supplementation increased. When hemoglobin repletion was compared, there were no significant differences between iron sulfate and either of the iron proteinate sources. These results indicate the iron in iron sulfate and the two iron proteinate sources were similar in …

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Defining Swine Nutrient Requirements And Allowances—What Do The Numbers Mean?, Phillip S. Miller, Austin Lewis, Duane Reese, Mike Brumm Jan 1999

Defining Swine Nutrient Requirements And Allowances—What Do The Numbers Mean?, Phillip S. Miller, Austin Lewis, Duane Reese, Mike Brumm

Nebraska Swine Reports

Defining nutrient requirements or allowances is the first, and conceivably most important step, in developing a nutrition program for growing-finishing pigs. Understanding the terminology and underlying principles used to define nutrient requirements and allowances for pigs will help producers better evaluate their nutrition programs. This information will also enable producers to interface production outputs (e.g., growth rate and carcass data) to published nutrient requirement and allowance programs, such as The National Research Council, Nutrient Requirements of Swine, 1998. As these and other approaches describing nutrient requirements for pigs develop, producers need a better and more complete understanding of growth biology …

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The Effects Of Dietary Feather Meal Concentration On Performance And Carcass Characteristics Of Barrows, Kuo-Wei Ssu, Mike Brumm, Phillip S. Miller, Jill M. Heemstra Jan 1999

The Effects Of Dietary Feather Meal Concentration On Performance And Carcass Characteristics Of Barrows, Kuo-Wei Ssu, Mike Brumm, Phillip S. Miller, Jill M. Heemstra

Nebraska Swine Reports

An experiment was conducted to determine the effect of dietary feather meal level, as well as whether or not start weight influenced feather meal effects in growth performance and carcass traits of barrows. Dietary feather meal additions tended to decrease the final body weight variation of barrows. Barrows fed diets containing 20 percent feather meal from 80 pounds to slaughter had decreased average daily gain, average daily feed intake, digestible lysine intake, energy intake, daily lean gain and backfat depth. Barrows fed diets containing 10 percent feather meal from 190 pounds to slaughter had decreased average daily gain, average daily …

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Block And Bridle Annual, 1999 Jan 1999

Block And Bridle Annual, 1999

Block and Bridle Annual (1933–2021)

Table of Contents:

Emblem and Purpose
Treasurer’s Report
Historian’s Welcome
Members
Fall & Spring Initiates
Officers and Advisors
Faculty & Graduate Students
Jr. & Sr. Meats Judging Teams
Horse & Sr. Livestock Judging Teams
MAEC & Jr. Livestock Judging Teams
Calendar of Events
Fall & Spring Kids’ Days
Big Red Beef Pit & Christmas Luncheon
Little Ak-Sar-Ben
Little MAEC Contest – Market & Breeding
Little MAEC Contest – Meats
National Convention
Big Red Beef Show
AQHA Horse Show
State Agricultural Education Contest
1998 Honoree
Block & Bridle Awards
Animal Science Awards & Scholarships
Advertisements
Index of Advertisers
Closing

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In Situ Neutral Detergent Insoluble Nitrogen As A Method For Measuring Forage Protein Degradability, R. Mass, G. P. Lardy, R. J. Grant, Terry Klopfenstein Jan 1999

In Situ Neutral Detergent Insoluble Nitrogen As A Method For Measuring Forage Protein Degradability, R. Mass, G. P. Lardy, R. J. Grant, Terry Klopfenstein

Department of Animal Science: Faculty Publications

A method of estimating the undegraded intake protein (UIP) concentration of forages was developed and validated with a series of in situ experiments. The hypothesis was that UIP calculated from in situ neutral detergent insoluble N (NDIN) is equal to total in situ N minus the microbial N that is estimated from purines (MN). The in situ disappearance rates of total in situ N (TN), MN, and NDIN were measured for six hay samples and two range masticate samples. Hypothetical rates of passage (2 or 5%/h) were used to calculate UIP (% of DM) for each N pool. Estimates of …

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Genetic Relationships Between Visual And Objective Measures Of Carcass Composition In Crossbred Lambs, H. E. Jones, G. Simm, W. S. Dingwall, R. M. Lewis Jan 1999

Genetic Relationships Between Visual And Objective Measures Of Carcass Composition In Crossbred Lambs, H. E. Jones, G. Simm, W. S. Dingwall, R. M. Lewis

Department of Animal Science: Faculty Publications

The aim of this study was to estimate genetic and phenotypic (coroariances between objective measures and carcass visual scores, as a test of the potential value afvisual scores in selection programmes to improve carcass composition in crossbred lambs. In each of 1986, 1987 and 1988, 22 Suffolk rams were chosen with either high or low scores on an index designed to increase lean growth rate. These rams were joined with 18 to20 crossbred ewes each and theirlambs were grov.J11 on grass to one of three target live weights (35·5, 41·5 and 47·0 kg) for slaughter. The carcasses of 1881 lambs …

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Implant Strategies On Performance And Carcass Characteristics Of Finishing Steers, Rob Cooper, Todd Milton, Frank Prouty Jan 1999

Implant Strategies On Performance And Carcass Characteristics Of Finishing Steers, Rob Cooper, Todd Milton, Frank Prouty

Nebraska Beef Cattle Reports

A 145-day finishing trial was conducted to evaluate implant strategies on performance and carcass characteristics of yearling steers. Implanting steers with Synovex® C initially and then reimplanting with Synovex® Plus 75 days prior to slaughter improved feed efficiency compared to a single implant of Synovex® Plus or a reimplant program using Synovex® S. Carcass quality, as measured by the percentage USDA Choice carcasses and marbling scores, was unaffected by implant strategy. However, implanting steers with Synovex® PlusTM as a single implant or in a reimplant program increased profitability because feed efficiency and carcass weight were increased without decreasing carcass …

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Pork Meat And Bone Meal Value Relative To Soybean Meal For Growing Calves, Casey Wilson, Galen E. Erickson, Ryan Mass, Terry J. Klopfenstein Jan 1999

Pork Meat And Bone Meal Value Relative To Soybean Meal For Growing Calves, Casey Wilson, Galen E. Erickson, Ryan Mass, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

Individually fed steer calves (n=90) were used to evaluate different rendering procedures of pork meat and bone meal on protein quality as compared to soybean meal. Treatment proteins included an urea control, soybean meal, high-ash pork meat and bone meal, pork meat and bone meal control and non-enzymatically browned (NEB) pork meat and bone meal. High-ash meat and bone meal protein efficiency was higher than other treatments. However, the escape values determined by the ammonia release procedure were higher for NEB meat and bone meal, suggesting efficiency should have been improved relative to the control and high-ash meat and bone …

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Diagnosis Of Ovulation Rate And Embriyonal, Foetal Development By Transrectalultrasonography In The White Goats, Di̇lek Arsoy Başaran Jan 1999

Diagnosis Of Ovulation Rate And Embriyonal, Foetal Development By Transrectalultrasonography In The White Goats, Di̇lek Arsoy Başaran

Turkish Journal of Veterinary & Animal Sciences

The aim of this study was to check the ovulation rate, early pregnancy diagnosis, and the number of embryos and foetuses, and embryonic and foetal development using either FGA with a low dose PMSG(250 I.U.) or FGA without of PMSG in 2.5- 5.5-year-old white goats (Saanen X Kilis).Transrectal ultrasonography with a 5-7.5 MHz linear probe was used 7, 26, 33, 40, 50 and 57 days after mating. The ovulation rate was determined by the counting of corpora lutea in both of the ovaries 7 days after mating. The ovulation rate at day 7 in the PMSG group was (SE±)10.833±0.79, and …

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A Review Of The Anticoagulant Pesticide Pindone, Laurie E. Twigg, Tim J. Lowe, Gary R. Martin, Garry S. Gray Jan 1999

A Review Of The Anticoagulant Pesticide Pindone, Laurie E. Twigg, Tim J. Lowe, Gary R. Martin, Garry S. Gray

Books & book chapters

A review of the use of pindone for rabbit control in Western Australia is timely due to increased public concern over the use of this toxin, and because non-target deaths of some native Australian animals have been known to occur following its use. Pindone is one of the first generation indandione anticoagulant rodenticides which were developed in the late 1940' s. The toxicity of anticoagulants arises from their inhibition of vitamin K-dependent clotting factors in the blood. Thus therapeutic administration of vitamin K provides a reliable antidote against anticoagulant poisoning. Pindone is slow acting and works best with repeated small …

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Finding Western Australia's Most Profitable Merino Flocks, David Windsor Jan 1999

Finding Western Australia's Most Profitable Merino Flocks, David Windsor

Journal of the Department of Agriculture, Western Australia, Series 4

Wether trials across Western Australia are showing significant differences in Merino flock productivity, which have important implications for whole-farm profitability. David Windsor reports on how wool growers in the 21 st century can maximise productivity by combining superior management skills with the best available genetic material.

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Profit From Pastures, Mark Callow, Martin Van Houtert Jan 1999

Profit From Pastures, Mark Callow, Martin Van Houtert

Journal of the Department of Agriculture, Western Australia, Series 4

The research program has made a major contribution to the improvement of pasture management techniques, which has, in turn, led to a gain in productivity for dairy farms in the south-west of Western Australia. Analysis has shown a 25 per cent improvement in pasture utilisation, an increase in the average number of cows milked from 155 to 192, an increase in average stocking rates from 0.9 to 1.2 cows per hectare, and increased income from milk sales by $600 per hectare. There are still areas for improvement in sustainability, productivity, and profitability, but the success to date is a credit …

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Eradicating Virulent Footrot From Western Australia, R K. Mitchell Jan 1999

Eradicating Virulent Footrot From Western Australia, R K. Mitchell

Journal of the Department of Agriculture, Western Australia, Series 4

Western Australia has a unique opportunity to eradicate virulent footrot from the State's sheep flock, with only 62 properties or 0.6 per cent of sheep properties currently in quarantine. The majority of Western Australian flocks are now free of virulent footrot, with targeted on-farm and abattoir surveillance used to detect the remaining properties affected by the disease. Bob Mitchell reports on how farmers, industry, and government are working together, with research playing an important part in the eradication campaign.

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The Effect Of Proximity On Landmark Use In Clark’S Nutcrackers, Kristy L. Gould-Beierle, Alan Kamil Jan 1999

The Effect Of Proximity On Landmark Use In Clark’S Nutcrackers, Kristy L. Gould-Beierle, Alan Kamil

Avian Cognition Papers

Clark’s nutcrackers, Nucifraga columbiana, store thousands of pine seeds during the autumn and retrieve them throughout the winter. It has been shown that these birds are able to use visual cues to relocate hidden food in the laboratory. In this set of experiments, we trained three groups of Clark’s nutcrackers to find a hidden food goal that was placed in the same spatial location relative to the testing room. During training, the location of two local cues in relation to the goal differed between the three groups. Group 1 learned the task with the cues closest to the goal, group …

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Patterns Of Movement And Orientation During Caching And Recovery By Clark’S Nutcrackers, Nucifraga Columbiana, Alan Kamil, Russell P. Balda, Sally Good Jan 1999

Patterns Of Movement And Orientation During Caching And Recovery By Clark’S Nutcrackers, Nucifraga Columbiana, Alan Kamil, Russell P. Balda, Sally Good

Avian Cognition Papers

Clark’s nutcrackers regularly store large numbers of pine seeds and remember the locations of the cached seeds. Although they are very accurate, they do make some errors during recovery. In an attempt to determine whether any behaviours during caching predicted the occurrence of errors during recovery, we videotaped Clark’s nutcrackers while they cached and recovered seeds under laboratory conditions. We used the videotapes to develop complete, quantitative descriptions of caching and recovery behaviour, with an emphasis on body orientation and directions of movement. During caching, the birds showed the greatest change in their orientation and direction following cache creation. During …

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How Do They, Indeed? A Reply To Biegler Et Al., Alan Kamil, Juli E. Jones Jan 1999

How Do They, Indeed? A Reply To Biegler Et Al., Alan Kamil, Juli E. Jones

Avian Cognition Papers

We trained Clark’s nutcrackers, Nucifraga columbiana, to search halfway between two landmarks while varying the distance between the landmarks (Kamil & Jones 1997). We found that the birds learned the problem readily and generalized to novel interlandmark distances within the range of distances used during training. Unlike some other studies in which responses to proportional distance were obtained (e.g. O’Keefe & Burgess 1996; Tommasi et al. 1997), the nutcrackers showed very precise search and maintained this precision during the transfer test. The distributions of digging locations around the central position were concentrated within ±1–2 cm of the central location …

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Under-Ice Diel Vertical Migrations Of Oncorhynchus Nerka And Their Zooplankton Prey, G. B. Steinhart, Wayne A. Wurtsbaugh Jan 1999

Under-Ice Diel Vertical Migrations Of Oncorhynchus Nerka And Their Zooplankton Prey, G. B. Steinhart, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

We used stationary hydroacoustics and measures of environmental conditions (water temperature, dissolved oxygen, light levels, and zooplankton) to determine what factors, foraging or predation risk, influenced diel vertical migrations of Oncorhynchus nerka during winter in three high-mountain lakes. The Sawtooth Valley lakes are deep, oligotrophic, glacial lakes located in central Idaho, U.S.A., and historically contained populations of anadromous O. nerka. In general, low light intensities limited foraging opportunities of O. nerka under ice, especially at night. In Stanley Lake, O. nerka underwent diel vertical migrations to exploit available light to feed. Oncorhynchus nerka occupied shallow water at night, where there …

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