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Full-Text Articles in Life Sciences

Environmental Enrichment And Prior Experience Of Live Prey Improve Foraging Behaviour In Hatchery-Reared Atlantic Salmon, C. Brown, T. Davidson, K. Laland Dec 2003

Environmental Enrichment And Prior Experience Of Live Prey Improve Foraging Behaviour In Hatchery-Reared Atlantic Salmon, C. Brown, T. Davidson, K. Laland

Aquaculture Collection

Atlantic salmon salmo salar L. parr were reared for 3 months under standard hatchery conditions or in a structurally enriched tank (containing plants, rocks and novel objects). Half of each of these fish had prior exposure to live prey in the form of live bloodworm while the other half were fed hatchery-pellets. After 12 days all fish were tested on a novel live prey item (brine shrimp). A significant interaction between the two factors (prior exposure to live prey and rearing condition) revealed that foraging performance was only enhanced in fish that had been reared in a complex environment and …


Habitat-Predator Association And Avoidance In Rainbowfish (Melanotaenia Spp.), Culum Brown Jun 2003

Habitat-Predator Association And Avoidance In Rainbowfish (Melanotaenia Spp.), Culum Brown

Sentience Collection

The ability to recall the location of a predator and later avoid it was tested in nine populations of rainbowfish (Melanotaenia spp.), representing three species from a variety of environments. Following the introduction of a model predator into a particular microhabitat, the model was removed, the arena rotated and the distribution of the fish recorded again. In this manner it could be determined what cues the fish relied on in order to recall the previous location of the predator model. Fish from all populations but one (Dirran Creek) were capable of avoiding the predator by remembering either the location and/or …


Reconstructing Cetacean Brain Evolution Using Computed Tomography, Lori Marino, Mark D. Uhen, Nicholas D. Pyenson, Bruno Frohlich May 2003

Reconstructing Cetacean Brain Evolution Using Computed Tomography, Lori Marino, Mark D. Uhen, Nicholas D. Pyenson, Bruno Frohlich

Veterinary Science and Medicine Collection

Until recently, there have been relatively few studies of brain mass and morphology in fossil cetaceans (dolphins, whales, and porpoises) because of difficulty accessing the matrix that fills the endocranial cavity of fossil cetacean skulls. As a result, our knowledge about cetacean brain evolution has been quite limited. By applying the noninvasive technique of computed tomography (CT) to visualize, measure, and reconstruct the endocranial morphology of fossil cetacean skulls, we can gain vastly more information at an unprecedented rate about cetacean brain evolution. Here, we discuss our method and demonstrate it with several examples from our fossil cetacean database. This …


Play And The Evolution Of Fairness: A Game Theory Model, Lee Alan Dugatkin, Marc Bekoff Jan 2003

Play And The Evolution Of Fairness: A Game Theory Model, Lee Alan Dugatkin, Marc Bekoff

Ethology Collection

Bekoff [J. Consci. Stud. 8 (2001) 81] argued that mammalian social play is a useful behavioral phenotype on which to concentrate in order to learn more about the evolution of fairness. Here, we build a game theoretical model designed to formalize some of the ideas laid out by Bekoff, and to examine whether ‘fair’ strategies can in fact be evolutionarily stable. The models we present examine fairness at two different developmental stages during an individual’s ontogeny, and hence we create four strategies--fair at time 1/fair at time 2, not fair at time 1/not fair at time 2, fair at time …


Wild Horses And Burros In The United States, Allen T. Rutberg Jan 2003

Wild Horses And Burros In The United States, Allen T. Rutberg

State of the Animals 2003

Treatment of wild horses and burros has improved remarkably over the last fifty years. In the mid-twentieth century, free-ranging horses and burros suffered horribly at the hands of “mustangers” who captured them at will and whim, sometimes using the most brutal of techniques, including aerial pursuit and shooting or crippling key herd members. The horses were packed into livestock trucks hurt, bleeding, and exhausted, and shipped to slaughter without stopping for rest or watering (Ryden 1999). Unprotected by law, only the good will of a few ranchers protected these abused animals. Public awareness of the plight of the wild horses …


The Science And Sociology Of Hunting: Shifting Practices And Perceptions In The United States And Great Britain, John W. Grandy, Elizabeth Stallman, David W. Macdonald Jan 2003

The Science And Sociology Of Hunting: Shifting Practices And Perceptions In The United States And Great Britain, John W. Grandy, Elizabeth Stallman, David W. Macdonald

State of the Animals 2003

Between the late nineteenth and early twenty-first centuries, both the rationale for and perception of hunting shifted in the United States, coinciding with demographic changes in the U.S. population (Duda 1993). Similar changes in attitude, though largely undocumented, probably occurred in the United Kingdom. (For example, foxhunting did not emerge as a substantial sport until the second half of the eighteenth century; before that, foxes were widely perceived as pests and killed whenever the opportunity arose [Marvin 2000]). Our purpose in this chapter is to compare these two countries in order to reveal some of the science and the sociology …


Nest Building In Captive Gorilla Gorilla Gorilla, Kristen E. Lukas, Tara S. Stoinski, Kyle Burks, Rebecca Snyder, Sarah Bexell, Terry L. Maple Jan 2003

Nest Building In Captive Gorilla Gorilla Gorilla, Kristen E. Lukas, Tara S. Stoinski, Kyle Burks, Rebecca Snyder, Sarah Bexell, Terry L. Maple

Sentience Collection

Although various aspects of gorilla nest building have been described in wild populations, nest-building behavior of captive gorillas has not been subject to much scientific review. We observed nest building in 17 gorillas during three periods: summer baseline, winter baseline, and winter treatment, in which the amount of available nesting material was doubled. We conducted observations exclusively in the indoor holding area in the hour following evening departure of animal care staff. During baseline, gorillas engaged in nest-building on 3.1% of scans and were on a constructed nest on 27.9% of scans. Overall, gorillas spent significantly more time on elevated …