Can fear conditioning repel California sea lions from fishing activities?

Z.S. was supported by a NSF predoctoral fellowship and by a grant from the LaKretz Center for California Conservation Science. D.T.B. was supported by the NSF during manuscript preparation.Marine mammal interactions with fisheries create conflicts that can threaten human safety, economic interests and marine mammal survival. A deterrent that capitalizes on learning mechanisms, like fear conditioning, may enhance success while simultaneously balancing welfare concerns and reduce noise pollution. During fear conditioning, individuals learn the cues that precede the dangerous stimuli, and respond by avoiding the painful situations. We tested the efficacy of fear conditioning using acoustic stimuli for reducing California sea lion Zalophus californianus interactions from two fishing contexts in California, USA; bait barges and recreational fishing vessels. We performed conditioning trials on 24 individual sea lions interacting with bait barges. We tested for acquisition of conditioned fear by pairing a neutral tone with a startle stimulus. Avoidance was strongest in response to the startle stimulus alone, but low when paired with a neutral tone. From actively fishing vessels, we tested for fear conditioning by exposing sea lions to a neutral tone followed by a startle pulse, a startle pulse alone or a no sound control. We conducted playbacks from 146 (including 48 no sound control) stops over two summer fishing seasons (2013, 2014). The startle stimulus decreased surfacing frequency, reduced bait foraging and increased surfacing distance from the vessel while the conditioned stimulus only caused a mild reduction in surfacing frequency with no other behavioral change. Exposing animals to a pair of a conditioned stimulus with a startle pulse did not achieve the intended management outcome. Rather, it generated evidence (in two study contexts) of immediate learning that led to the reduction of the unconditioned response. Taken together, our results suggest that for fear conditioning to be applied as a non-lethal deterrent, careful consideration has to be given to individual behavior, the unconditioned/conditioned responses and the overall management goals.PostprintPeer reviewe

Harnessing learning biases is essential for applying social learning in conservation

Social learning can influence how animals respond to anthropogenic changes in the environment, determining whether animals survive novel threats and exploit novel resources or produce maladaptive behaviour and contribute to human-wildlife conflict. Predicting where social learning will occur and manipulating its use are, therefore, important in conservation, but doing so is not straightforward. Learning is an inherently biased process that has been shaped by natural selection to prioritize important information and facilitate its efficient uptake. In this regard, social learning is no different from other learning processes because it too is shaped by perceptual filters, attentional biases and learning constraints that can differ between habitats, species, individuals and contexts. The biases that constrain social learning are not understood well enough to accurately predict whether or not social learning will occur in many situations, which limits the effective use of social learning in conservation practice. Nevertheless, we argue that by tapping into the biases that guide the social transmission of information, the conservation applications of social learning could be improved. We explore the conservation areas where social learning is highly relevant and link them to biases in the cues and contexts that shape social information use. The resulting synthesis highlights many promising areas for collaboration between the fields and stresses the importance of systematic reviews of the evidence surrounding social learning practices.BBSRC David Phillips Fellowship (BB/H021817/1

Subliminal Pictorial Stimuli, Color, and Conscious Perception

Does man have the capacity to process environmental. stimulation of such weak magnitude or rapid duration that he is not aware of it? If so, can such minimal stimuli affect man\u27s subsequent behavior? Dixon (1971) and Gordon (l967) presented en overview of early scholarly thought on these questions. Democritus, in 400 B.c., may have been the first to have recorded man\u27s contemplation of subliminal information processing. He stated that much is perceptible which is not perceived by us (cited in Dixon, 1971, P.6)..

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Individual foraging information for California Sea lions at Bonnevill

Data from: Social associations between California sea lions influence the use of a novel foraging ground

Social relationships define an individual's position in its social network, which can influence the acquisition and spread of information and behavioural variants through the population. Thus, when nuisance behaviours spread through wildlife populations, identifying central individuals may provide valuable insights for problem-species management. We studied the effects of network position on California sea lion (Zalophus californianus) discovery and foraging success at a novel foraging ground—the salmonids that aggregate at the Bonneville Dam tail-race, 235 km up the Columbia River. We found that an individual's centrality in their social network influenced discovery of the Bonneville Dam and whether they returned the next year. Foraging success once at the dam was independent of network position. Extensive lethal and non-lethal removal efforts have been implemented at Bonneville Dam and focused on reducing the number of individual sea lions at the dam. Since social relationships forged at the opening of the Columbia River influence both the discovery and return to the Bonneville Dam, efforts to increase salmon recovery may be enhanced by breaking apart social networks at the opening of the river

SUBLIMINAL PICTORIAL STIMULI, COLOR, AND CONSCIOUS PERCEPTION

Research into the nature of subliminal stimulation has indicated its influence upon perception, memory, drive level, thinking, and perhaps consumer buying behavior. Studies assessing the connotations of color have generally found red to be an exciting, affect-arousing hue. The present study assessed the impact of subliminal pictorial modifications (happy or angry), chromatic background (red or white), and their interactions upon impressions of a neutral human face. A complete factorial design allowed the investigation of every combination of these variables. It was hypothesized that the subliminal facial modifications would influence conscious perception of the neutral supraliminal face in the desired direction, and that color (red) would enhance the impact of the subliminal modifications. A series of researchers have found subliminal suggestion (pictorial, semantic, or figural) to affect conscious perceptual impression. The color red has been associated with both verbal reports and physiological indices of heightened emotion. Few studies, however, have systematically explored the influence of subliminal stimulation in interaction with color. One study demonstrated that a subliminal aggressive stimulus, projected upon a red background, diminished analytic performance; another study found subliminal sexual stimuli, when presented upon a red background, to be associated with an exaggerated affective response. In order to investigate subliminal stimulation, color, and their interaction, 52 volunteer college students were randomly assigned to one of six treatment conditions, providing 8, 9, or 10 subjects per group. All subjects were screened for defective color vision. The luminance of the red and white stimuli were equated through heterochromatic flicker photometry. The stimulus presentations utilized a computer-programmed multiple slide projector format. Subjects viewed a supraliminal neutral face with or without subliminal/chromatic modifications and rated their impressions on a simplified, 13-item, bipolar-adjective scale, representing the dimension of pleasantness/unpleasantness. All groups received the same basic experimental procedure: color vision screening, random assignment to seating, ascending method of limits to calibrate subliminal levels of illumination, priming of relaxed cognitive set, stimulus presentation, rating of impressions, discrimination task, disclosure of subliminal stimulus, and discussion. The data regarding the pleasantness/unpleasantness of impression of the human face were subjected to a 3 x 2 Analysis of Variance-Fixed Effects Model. The null hypothesis was not rejected in regard to group differences due to the main effects (subliminal modification and chromatic background) or their interactions. The subliminal modifications were at a level of illumination which was below the level of awareness, in all four subliminal groups. The internal consistency of the items on the dependent measure (Impressions Sheet) yielded an Alpha Reliability Coefficient of .95. Thus, neither the chromatic background, nor subliminal pictorial modification significantly altered impressions of a clearly visible, but briefly exposed, neutral face in this study. The results were explained in relation to factors which may attenuate the impact of the subtle and complex subliminal phenomenon

Applying principles of animal behavior to issues involving California sea lions interacting with Southern California fisheries and predation of endangered salmonids.

The United States Marine Mammal Protection Act (MMPA 1972) resulted in federal protection and enhanced the recovery of California sea lion (CSL--Zalophus californianus) populations in the United States. As an unintended consequence of their protection, sea lion populations have expanded their range, negatively interacting with every commercial fishery on the west coast of the United States, predating endangered Pacific salmonids at upriver dams, and damaging docks/fishing vessels. Conservation and management problems with California sea lions can benefit from mechanistic insights into how individuals respond to stimuli and learn about biologically important events. This dissertation provides an in depth examination into how animal learning theory can be applied to conservation issues. I apply learning mechanisms to enhance management of two conservation issues involving sea lions; depredation (removal of fish from fishing lines) and predation of endangered salmonids at the fish ladders below the Bonneville Dam. This dissertation is structured into two reviews, an empirical test of learning on deterrents on California sea lions (Zalophus californianus) interacting with fisheries, an analysis of social transmission and the impact of culling of California sea lions foraging at the Bonneville Dam. Chapter two unpacks the behavioral mechanisms involved in non-lethal deterrents and reviews their application for depredating marine mammals. This review makes the argument that Pavlovian fear conditioning can applied to deterrents to enhance success in cases of human wildlife conflict and reduce management concerns over non-target animals. Chapter three presents a field experiment on Pavlovian fear conditioning for deterrents on wild California sea lions which examines whether conditioned individuals exhibit greater avoidance compared to control animals. Chapter four reviews how learning can be applied to solve conservation problems. Social learning, for instance, functions as a multiplier, rapidly spreading undesirable wildlife behaviors through populations, suggesting that target lethal or non-lethal management strategies may be necessary. Chapter five uses social network based diffusion analysis to show that social transmission is driving foraging of endangered salmonids by California sea lions. Social transmission has implications for management measures, and we used epidemiological models of behavioral transmission to assess current and potential lethal removal strategies