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Nelson, D. M., Gardner, I. A., Chiles, R. F., Balasuriya, U. B., Eldridge, B. F., Scott, T. W., et al. (2004). Prevalence of antibodies against Saint Louis encephalitis and Jamestown Canyon viruses in California horses. Comp Immunol Microbiol Infect Dis, 27(3), 209–215.
Abstract: Jamestown Canyon (JC) and Saint Louis encephalitis (SLE) viruses are mosquito-transmitted viruses that have long been present in California. The objective of this study was to determine the seroprevalence of these two viruses in horses prior to the introduction of West Nile (WN) virus. Approximately 15% of serum samples collected in 1998 from 425 horses on 44 equine operations horses throughout California had serum antibodies to JC virus, whereas antibodies were not detected to SLE virus. The results indicate that horses in California were commonly infected prior to 1998 with mosquito-transmitted Bunyaviruses that are identical or closely related to JC virus, but not with SLE virus. The different seroprevalence of SLE and JC viruses in horses likely reflects the unique ecology of each virus, and it is predicted that WN virus will have a wider distribution in California than closely related SLE virus.
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Nakagawa, S., & Waas, J. R. (2004). 'O sibling, where art thou?' – A review of avian sibling recognition with respect to the mammalian literature. Biological Reviews of the Cambridge Philosophical Society, 79(1), 101–119.
Abstract: Avian literature on sibling recognition is rare compared to that developed by mammalian researchers. We compare avian and mammalian research on sibling recognition to identify why avian work is rare, how approaches differ and what avian and mammalian researchers can learn from each other. Three factors: (1) biological differences between birds and mammals, (2) conceptual biases and (3) practical constraints, appear to influence our current understanding. Avian research focuses on colonial species because sibling recognition is considered adaptive where 'mixing potential' of dependent young is high; research on a wider range of species, breeding systems and ecological conditions is now needed. Studies of acoustic recognition cues dominate avian literature; other types of cues (e.g. visual, olfactory) deserve further attention. The effect of gender on avian sibling recognition has yet to be investigated; mammalian work shows that gender can have important influences. Most importantly, many researchers assume that birds recognise siblings through 'direct familiarisation' (commonly known as associative learning or familiarity); future experiments should also incorporate tests for 'indirect familiarisation' (commonly known as phenotype matching). If direct familiarisation proves crucial, avian research should investigate how periods of separation influence sibling discrimination. Mammalian researchers typically interpret sibling recognition in broad functional terms (nepotism, optimal outbreeding); some avian researchers more successfully identify specific and testable adaptive explanations, with greater relevance to natural contexts. We end by reporting exciting discoveries from recent studies of avian sibling recognition that inspire further interest in this topic.
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Nakagawa, S. (2004). A farewell to Bonferroni: the problems of low statistical power and publication bias. Behav Ecol, 15.
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Nakagawa, S. (2004). A farewell to Bonferroni: the problems of low statistical power and publication bias. beheco, 15(6), 1044–1045.
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Naguib, M., Amrhein, V., & Kunc, H. P. (2004). Effects of territorial intrusions on eavesdropping neighbors: communication networks in nightingales. Behav. Ecol., 15(6), 1011–1015.
Abstract: Animal communication often occurs in communication networks in which multiple signalers and receivers are within signaling range of each other. In such networks, individuals can obtain information on the quality and motivation of territorial neighbors by eavesdropping on their signaling interactions. In songbirds, extracting information from interactions involving neighbors is thought to be an important factor in the evolution of strategies of territory defense. In a playback experiment with radio-tagged nightingales Luscinia megarhynchos we here demonstrate that territorial males use their familiar neighbors' performance in a vocal interaction with an unfamiliar intruder as a standard for their own response. Males were attracted by a vocal interaction between their neighbor and a simulated stranger and intruded into the neighbor's territory. The more intensely the neighbor had interacted with playback, the earlier the intrusions were made, indicating that males eavesdropped on the vocal contest involving a neighbor. However, males never intruded when we had simulated by a second playback that the intruder had retreated and sang outside the neighbor's territory. These results suggest that territorial males use their neighbors' singing behavior as an early warning system when territorial integrity is threatened. Simultaneous responses by neighboring males towards unfamiliar rivals are likely to be beneficial to the individuals in maintaining territorial integrity.
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Murray, J. K., Singer, E. R., Morgan, K. L., Proudman, C. J., & French, N. P. (2004). Memory decay and performance-related information bias in the reporting of scores by event riders. Preventive Veterinary Medicine, 63(3-4), 173–182.
Abstract: We used data from a case-control study investigating risk factors for horse falls in the cross-country phase of eventing in Great Britain (GB) to examine evidence for memory decay and information bias. Responses to two questions obtained by telephone for 173 cases and 521 controls were examined for evidence of differential reporting according to the respondent's case-control status and performance in the dressage and cross-country phases of competitions. Information bias was found in the accuracy of reporting dressage penalty scores when analysed as a function of performance level (good/poor). Poor dressage performers were less likely to report accurate dressage scores than good performers. The accuracy of reporting dressage scores decreased as the time between the event and questionnaire completion increased, with no case-control interaction. Competitors who incurred cross-country jumping penalties at the event preceding the selected event reported their cross-country scores with less accuracy when compared with competitors who incurred no penalties. No information bias was found when the reporting of dressage and cross-country scores were analysed as a function of respondent category (case/control).
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Murphy, J., Waldmann, T., & Arkins, S. (2004). Sex differences in equine learning skills and visuo-spatial ability. Appl. Anim. Behav. Sci., 87(1-2), 119–130.
Abstract: There is evidence of superior visuo-spatial ability in males compared to females in most species investigated to-date. However, no known studies have addressed this issue in the equine. Equine visuo-spatial ability was investigated using a novel test apparatus with a sample of 62 horses (males=34 and females=28) during a series of six tests, where the horses were required to access a food source. The test apparatus consisted of a series of four adjacent stalls, each of which had a feed bin and a moveable barrier. The test apparatus was designed such that the breastplate barriers controlled and limited access by the horses to feed bins in all but one stall during each test. Male horses performed such that there were significant differences (P<0.05) in the ability of the subjects to complete all six tests in a mean time of 30 s or less per test. There were significant differences in mean completion times for male subjects between test 1 and test 2 (P<0.05), test 1 and test 3 (P<0.001), test 1 and test 4 (P<0.05) and test 1 and test 5 (P<0.05). There were no significant differences in mean completion times between any of the six tests for female subjects. Males had a lower mean total number of errors during all tests. Male horses also successfully completed significantly more tests than females (P<0.05). These results provide the first behavioural demonstration of superior visuo-spatial ability in male horses, similar to that reported in other species.
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Murai, C., Tomonaga, M., Kamegai, K., Terazawa, N., & Yamaguchi, M. K. (2004). Do infant Japanese macaques ( Macaca fuscata) categorize objects without specific training? Primates, 45(1), 1–6.
Abstract: In the present study, we examined whether infant Japanese macaques categorize objects without any training, using a similar technique also used with human infants (the paired-preference method). During the familiarization phase, subjects were presented twice with two pairs of different objects from one global-level category. During the test phase, they were presented twice with a pair consisting of a novel familiar-category object and a novel global-level category object. The subjects were tested with three global-level categories (animal, furniture, and vehicle). It was found that they showed significant novelty preferences as a whole, indicating that they processed similarities between familiarization objects and novel familiar-category objects. These results suggest that subjects responded distinctively to objects without training, indicating the possibility that infant macaques possess the capacity for categorization.
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Monfort, S. (2004). Przewalski’s Horse (Equus przewalskii) Species Survival Plan. In PROCEEDINGS OF THE EAZA EQUID TAG MEETING FROM 5TH TO 9TH MAY 2004 AT HORTOBÁGY NATIONAL PARK, HUNGARY.
Abstract: A Master Planning meeting for the Asian wild horse, or Przewalski’s horse, was held 14th –15th April 2004 at the National Zoological Park’s Conservation and Research Center (CRC) in Front Royal, Virginia. The overall objectives of the meeting were to 1) develop a strategy to maximize genetic diversity and improve demographics, 2) make specific breeding recommendations, 3) establish ex situ research priorities, and 4) discuss strategies for ensuring that the North American herd contributes to the global managed population, as well as ongoing in situ conservation programs. Of particular importance were discussions focused on whether to continue managing the North American herd as two separate bloodlines — the A- and B-lines — or to manage the entire population using an M-line, or mixed-line strategy, designed to maximize founder representation and genetic diversity. The Equid Taxon Advisory Group has currently designated a target population of 150 specimens for this species. The current SSP population is 154 individuals distributed among 18 institutions (15 AZA, 3 non-AZA), of which San Diego Zoo, the Wilds, Minnesota Zoo, Calgary Zoo, the Wildlife Conservation Society/Bronx Zoo and the National Zoological Park were represented at the Master Planning meeting.
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Milo, R., Itzkovitz, S., Kashtan, N., Levitt, R., Shen-Orr, S., Ayzenshtat, I., et al. (2004). Superfamilies of Evolved and Designed Networks. Science, 303(5663), 1538–1542.
Abstract: Complex biological, technological, and sociological networks can be of very different sizes and connectivities, making it difficult to compare their structures. Here we present an approach to systematically study similarity in the local structure of networks, based on the significance profile (SP) of small subgraphs in the network compared to randomized networks. We find several superfamilies of previously unrelated networks with very similar SPs. One superfamily, including transcription networks of microorganisms, represents “rate-limited” information-processing networks strongly constrained by the response time of their components. A distinct superfamily includes protein signaling, developmental genetic networks, and neuronal wiring. Additional superfamilies include power grids, protein-structure networks and geometric networks, World Wide Web links and social networks, and word-adjacency networks from different languages.
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