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Wallin, L., Strandberg, E., & Philipsson, J. (2001). Phenotypic relationship between test results of Swedish Warmblood horses as 4-year-olds and longevity. Livestock Production Science, 68(2-3), 97–105.
Abstract: The relationship between longevity and different traits scored in the Swedish Riding Horse Quality Test (RHQT) was studied to evaluate their use as predictors of survival. Data comprised 1815 Warmblood horses born between 1969 and 1982 that had participated in the RHQT as 4-year-olds. Survival information was obtained via a questionnaire sent to owners of horses that had participated in the RHQT between 1973 and 1986. All phenotypic values of traits scored at 4 years of age were adjusted for the effect of place/year (event). Survival analysis was performed taking into account censoring. Traits having significant effects on longevity were: conformation, legs (included in conformation), orthopaedic status, jumping ability, and the horses' combined classification score for dressage and jumping talents, respectively. Orthopaedic health had the greatest influence on longevity, and demonstrated the importance of judging health traits in young sports horses. The results of this study confirmed that there is a significant phenotypic relationship between many of the RHQT traits and longevity, and thus the possibility of using them as predictors of survival.
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Wallace, D. G., Hamilton, D. A., & Whishaw, I. Q. (2006). Movement characteristics support a role for dead reckoning in organizing exploratory behavior. Anim. Cogn., 9(3), 219–228.
Abstract: Rat exploration is an organized series of trips. Each exploratory trip involves an outward tour from the refuge followed by a return to the refuge. A tour consists of a sequence of progressions with variable direction and speed concatenated by stops, whereas the return consists of a single direct progression. We have argued that processing self-movement information generated on the tour allows a rat to plot the return to the refuge. This claim has been supported by observing consistent differences between tour and return segments independent of ambient cue availability; however, this distinction was based on differences in movement characteristics derived from multiple progressions and stops on the tour and the single progression on the return. The present study examines movement characteristics of the tour and return progressions under novel-dark and light conditions. Three novel characteristics of progressions were identified: (1) linear speeds and path curvature of exploratory trips are negatively correlated, (2) tour progression maximum linear speed and temporal pacing varies as a function of travel distance, and (3) return progression movement characteristics are qualitatively different from tour progressions of comparable length. These observations support a role for dead reckoning in organizing exploratory behavior.
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Wall, D. L., Topliff, D. R., Freeman, D. W., Wagner, D. G., Breazile, J. W., & Stutz, W. A. (1992). Effect of dietary cation-anion balance on urinary mineral excretion in exercised horses. Journal of Equine Veterinary Science, 12(3), 168–171.
Abstract: Summary Four mares and four geldings of Quarter Horse and Thoroughbred breeding were used in two simultaneous 4x4 Latin square experiments to study the effects of dietary cation-anion balance (DCAB), defined as meq ((Na+K)-C1)/kg dry matter, on urinary pH and mineral excretion in exercised horses. Diets consisted of a pelleted concentrate of corn, soybean meal and cottonseed hulls fed with bermudagrass hay. Treatments with DCAB of +5 (Low, L), +107 (Medium Low, ML), +201 (Medium High, MH) and +327 (High, H), meq ((Na+K)-Cl)/kg dry matter were formed by supplementing diet L with calcium chloride and ammonium chloride, diet ML with calcium chloride and diet H with sodium bicarbonate and potassium citrate (Table 1). Diet MH was not supplemented and served as the control treatment. Horses were conditioned aerobically for 6 weeks using long, slow, distance (LSD) workouts. During the experimental periods, horses were subjected to a combined exercise regimen alternating LSD with an interval-training protocol 6 days/week. There was a significant (P<.01) treatment effect on urine pH; least squares means for L, ML, MH and H were 6.73, 7.17, 7.38, and 7.92. Horses consuming diet L excreted more calcium in the urine (P<.05) than those consuming MH or H. Least squares means for daily urine calcium excretion tended to be linear across treatments and ranged from 19.66 g/day for diet L to 9.12 g/day for diet H. Urinary chloride excretion was higher (P<.05) for L than for MH or H. Horses fed diet H excreted more sodium (P<.05) in urine than horses fed the other diets. Lowering DCAB, increases urinary calcium loss; depending on the level of calcium intake, this could lead to negative calcium balance in exercising horses.
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Walker, S. (1989). An introduction to animal cognition : By . Hillsdale, New Jersey: Lawrence Erlbaum (1988). Pp. viii + 328. Price [pound sign]8.95 paperback. Anim. Behav., 37(Part 3), 521–522.
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Walker, M. L., & Becklund, W. W. (1971). Occurrence of a cattle eyeworm, Thelazia gulosa (Nematoda: Thelaziidae), in an imported giraffe in California and T. lacrymalis in a native horse in Maryland. J Parasitol, 57(6), 1362–1363.
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Walker, E. P., & Nowak, R. M. (1999). Walker's Mammals of the World.
Abstract: Description
From reviews of previous editions: “Professional naturalists will find [these volumes] invaluable as a handy reference, and amateurs at least those citizens alive to their earthly environment should delight in finding so much fascinating information made so available and palatable. Audubon ”What an amazing lot mammals are, seen here in all of their diversity! . . . Walker has made available a mine of information, for the specialist as well as for the casually interested . . . If you want to find out about a mammal, then, here is the place to look.“New York Times ”Every mammalogist must have [these books], and those who profess a broad interest in the fauna of the world will want them.“Natural History From aardwolves and bandicoots to yapoks and zorillas, Ernest P. Walker's Mammals of the World is the most comprehensive the pre-eminent reference work on mammals. Now, completely revised and updated, this fascinating guide is better than ever. Providing a complete account of every genus of mammal in all historical time, the sixth edition is 25 percent longer than its predecessor. Of the previous generic accounts, 95 percent have been substantively modified, and there are 80 new ones among them, three remarkable, large ungulates recently discovered in the forests of Indochina. New also is a full account of the woolly mammoth, now known to have survived until less than 4,000 years ago. Each section of the book describes one genus and includes facts such as scientific and common names, the number and distribution of species, measurements and physical traits, habitat, locomotion, daily and seasonal activity, population dynamics, home range, social life, reproduction, and longevity. Textual summaries present accurate, well-documented descriptions of the physical characteristics and living habits of mammals in every part of the world. As in the last two editions, the names and distributions of every species of every genus are listed in systematic order. These lists have now been cross-checked to ensure coverage of all species in the comprehensive new Smithsonian guide, Mammal Species of the World. Facts on the biology of mammals have been brought together from more than 2,700 newly cited references, nearly all published in the last decade. Also new are the latest data on reproduction, longevity, fur harvests, numbers in the wild and in captivity, and conservation status. The sixth edition also records all official classifications of every mammal species and subspecies in the massive 1996 IUCN Red List of Threatened Animals. The illustrations more than 1,700 include virtually every genus of mammal. Among them are pictures by such noted wildlife photographers as Leonard Lee Rue III, Bernhard Grzimek, David Pye, and Warren T. Houck. Mammals pictured here for the first time include the just-discovered giant muntjac deer of Viet Nam, a rodent known only from the Solomon Islands, a large fruit bat whose male suckles the young, and an extremely rare web-footed tenrec of Madagascar. Since its publication in 1964, Walker's Mammals of the World has become a favorite guide to the natural world for general readers as well as an invaluable resource for professionals. This sixth edition represents more than half a century of scholarship? Ernest P. Walker himself devoted more than thirty years to the original project and remains true to Walker's vision, smoothly combining thorough scholarship with a popular, readable style to preserve and enhance what the Washington Post called ”a landmark of zoological literature."
Reviews
“"An absolute treasure trove--a 'must' for the working naturalist as well as for any person who has curiosity about the world's mammals.”Roger Tory Peterson."?
“Unlike many academic reference works, all editions [Walker's Mammals], the new one included, are as accessible to amateurs as to professionals . . . For wildlife enthusiasts, this two-volume set is an indispensable resource. The new edition not only updates taxonomic information generated in the last 10 years, it pushes back the historical record, including all mammals known to have existed in the past 5,000 years. Twenty-one new genera also appear, animals that have recently been discovered. Either volume is hefty enough to kill a small mammal if dropped there's a total of 2,160 pages . . . And despite almost a decade between editions the last edition appeared in 1991 the price has remained virtually the same, despite an increase in book size of more than 20 percent. After being exposed to this kind of thorough, detailed information saturation, many readers may find it hard to go back to a plain old encyclopedia for their animal questions.”Bloomsbury Review
“For anyone who needs an up-to-date, comprehensive guide to every known species of mammal, Walker's Mammals of the World is an essential purchase.”Nicholas Gould, International Zoo News
“A massive compilation ideal for readers who want to have at their fingertips information on every mammal species.”International Zoo News
Author Information
Ernest P. Walker (1891-1969) began work on Mammals of the World in the early 1930s, when he became assistant director of the National Zoo in Washington. His work reflected an unequaled store of knowledge about the world's mammals. Ronald M. Nowak was senior author of the fourth edition and author of the fifth edition of Walker's Mammals of the World. His other works on mammalogy include North American Quaternary Canis and several parts of the National Geographic Society's Wild Animals of North America, for which he also was editorial consultant. He received a Ph.D. in biology from the University of Kansas in 1973 and was staff mammalogist at the former Office of Endangered Species, U.S. Fish and Wildlife Service, from 1974 to 1987. He served as an Air Force officer for four years and is a private pilot.
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Waldern, N. M., Wiestner, T., Ramseier, L. C., Amport, C., & Weishaupt, M. A. (2013). Effects of shoeing on limb movement and ground reaction forces in Icelandic horses at walk, tölt and trot. Vet. J., 198, Supplement 1, e103–e108.
Abstract: Abstract Tölt is a symmetric four-beat gait with a speed range extending into that of trot and canter. Specific shoeing methods, such as unnaturally high and long hooves, are used to enforce individual gait predisposition. The aim of this study was to assess the consequences of this shoeing style on loading and movement of the limbs at walk, tölt and trot, and at different velocities. Simultaneous kinetic and kinematic gait analysis was carried out at walk (1.4 m/s) and at two tölting and trotting speeds (3.3 m/s and 3.9 m/s) on an instrumented treadmill. Thirteen sound Icelandic horses were first measured with high, long front hooves (SH) and, 1 week later, after trimming the hooves according to standard shoeing principles (SN). Comparing SH with SN, front hooves had 21 ± 5 mm longer dorsal hoof walls, and the shoeing material per hoof was 273 ± 50 g heavier. In all three gaits, gait quality, as it is currently judged, was improved with SH due to a lower stride rate, a longer stride length and a higher, but not wider, forelimb protraction arc, which were also positively associated with speed. Forelimb–hind limb balance remained unchanged, but limb impulses were higher. Apart from an increase of ⩽2.2% in the forelimbs at the faster speed of both tölt and trot, SH had little influence on vertical peak forces.
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Wakeling, E. (2002). Feral Horses of the West. Retrieved June 22, 2024, from http://web.archive.org/web/20050206074127/http://www.personal.psu.edu/users/e/n/enw107/
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Waite, T. A., & Field, K. L. (2000). Erroneous choice and foregone gains in hoarding gray jays (Perisoreus canadensis). Anim. Cogn., 3(3), 127–134.
Abstract: Under the conventional assumption that natural selection favors choice behavior that maximizes some fitness-related currency, a forager making repeated binary choices should consistently choose the more valuable option. Under the alternative assumption that natural selection favors choice behavior that minimizes costly errors, erroneous choice is not only expected but is expected to be common when the cost of errors is low. This cost depends on the potential rate of return: the higher this rate, the smaller the cost of choosing the less valuable option. When this rate is very high, a forager may err frequently and yet forego no appreciable fitness gain. Errors should thus be more common when interruptions to foraging are shorter. Our experimental results supported this prediction: gray jays chose the less valuable option more frequently when subjected to shorter interruptions (experimentally imposed delays to access to food rewards). This tendency is consistent with the idea that an adaptive decision-making process may routinely produce errors, not because errors are in some way adaptive but because their fitness cost is minimal, particularly when delays are short. From a proximate perspective, this tendency to commit errors more frequently following shorter delays may be due to constraints on the jays' information-processing capacity. In general, choice behavior should be viewed as the joint byproduct of adaptive decision making and cognitive constraints.
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Waite, T. A. (2002). Interruptions improve choice performance in gray jays: prolonged information processing versus minimization of costly errors. Anim. Cogn., 5(4), 209–214.
Abstract: Under the assumption that selection favors minimization of costly errors, erroneous choice may be common when its fitness cost is low. According to an adaptive-choice model, this cost depends on the rate at which an animal encounters the choice: the higher this rate, the smaller the cost of choosing a less valuable option. Errors should thus be more common when interruptions to foraging are shorter. A previous experiment supported this prediction: gray jays, Perisoreus canadensis, were more error prone when subjected to shorter delays to access to food rewards. This pattern, though, is also predicted by an attentional-constraints model. Because the subjects were able to inspect the rewards during delays, their improved performance when subjected to longer delays could have been a byproduct of the experimentally prolonged opportunity for information processing. To evaluate this possibility, a follow-up experiment manipulated both delay to access and whether rewards could be inspected during delays. Depriving jays of the opportunity to inspect rewards (using opaque lids) induced only a small, nonsignificant increase in error rate. This effect was independent of length of delay and so the jays' improved performance when subjected to longer delays was not simply a byproduct of prolonged information processing. More definitively, even when the jays were prevented from inspecting rewards during delays, their performance improved when subjected to longer delays. The findings are thus consistent with the adaptive-choice model.
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