| Records |
| Author |
Lachmann M.; Bergstrom C.T. |
| Title |
Signalling among Relatives II. Beyond the Tower of Babel |
Type |
Journal Article |
| Year |
1998 |
Publication |
Theoretical Population Biology |
Abbreviated Journal |
Theor. Pop. Biol. |
| Volume |
54 |
Issue  |
2 |
Pages |
146-160 |
| Keywords |
|
| Abstract |
Models of costly signalling are commonly employed in evolutionary biology in order to explain how honest communication between individuals with conflicting interests can be stable. These models have focused primarily on a single type of honest signalling equilibrium, the separating equilibrium in which any two different signallers send distinct signals, thereby providing signal receivers with complete information. In this paper, we demonstrate that in signalling among relatives (modelled using the Sir Philip Sidney game), there is not one but a large number of possible signalling equilibria, most of which are pooling equilibria in which different types of signallers may share a common signal. We prove that in a general Sir Philip Sidney game, any partition of signallers into equi-signalling classes can have a stable signalling equilibrium if and only if it is a contiguous partition, and provide examples of such partitions. A similar (but slightly stricter) condition is shown to hold when signals are transmitted through a medium with signalling error. These results suggest a solution to a problem faced by previous signalling theory models: when we consider the separating equilibrium, signal cost is independent of the frequency of individuals sending that signal and, consequently, even very rare signaller types can drastically affect signal cost. Here, we show that by allowing these rare signallers to pool with more common signallers, signal cost can be greatly reduced. Copyright 1998 Academic Press. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
560 |
| Permanent link to this record |
| |
|
| |
| Author |
Dugatkin, L.A. |
| Title |
A comment on Lafleur et al.'s re-evaluation of mate-choice copying in guppies |
Type |
Journal Article |
| Year |
1998 |
Publication |
Animal Behaviour. |
Abbreviated Journal |
Anim. Behav. |
| Volume |
56 |
Issue |
2 |
Pages |
513-514 |
| Keywords |
|
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
|
Serial |
1812 |
| Permanent link to this record |
| |
|
| |
| Author |
Barwick, R.S.; Mohammed, H.O.; McDonough, P.L.; White, M.E. |
| Title |
Epidemiologic features of equine Leptospira interrogans of human significance |
Type |
Journal Article |
| Year |
1998 |
Publication |
Preventive Veterinary Medicine |
Abbreviated Journal |
Prev Vet Med |
| Volume |
36 |
Issue |
2 |
Pages |
153-165 |
| Keywords |
Animals; Horse Diseases/epidemiology/*microbiology; Horses/microbiology; Humans; *Leptospira interrogans; New York/epidemiology; Weil Disease/epidemiology/microbiology/*veterinary; Zoonoses/epidemiology/*microbiology |
| Abstract |
Leptospirosis is a zoonotic bacterial disease caused by Leptospira interrogans. There is a serologic evidence that horses are exposed to L. interrogans and, as a shedder of these organisms, can be a threat to humans. We examined risk factors associated with the risk of testing seropositive to three L. interrogans serovars (L. icterohaemorrhagiae, L. grippotyphosa, and L. canicola) in the horses of New York State, in order to understand the epidemiology of the disease and suggest strategies to control and prevent equine leptospirosis. To carry out this study, blood samples were collected from a random sample of 2551 horses and tested for the presence of antibodies to the above serovars using the microscopic agglutination test. Samples with a titer $100 were considered positive. Clinical and demographic data were collected on each horse, the farms' management practices and ecology. Logistic regression analysis was used to develop a multivariate indexing system and to identify factors significantly associated with the risk of leptospirosis. Four indices were developed based on the possible sources of exposure: rodent exposure index; wildlife exposure index; soil and water index; and management index. The soil and water index was significantly associated with the risk of exposure to all three serovars. Management was positively associated with L. icterohaemorrhagiae and L. canicola. Density of horses turned out together was positively associated with the risk of exposure to L. grippotyphosa. We concluded that indirect exposure of horses to L. interrogans through contaminated soil and water appears to be significantly associated with the risk of exposure to all three serovars. Management appears to play an important role in the exposure to L. interrogans. Modification of management practices might reduce the horses' risk of exposure and hopefully minimize the human hazards. |
| Address |
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0167-5877 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:9762736 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
2653 |
| Permanent link to this record |
| |
|
| |
| Author |
Westergaard, G.C.; Liv, C.; Chavanne, T.J.; Suomi, S.J. |
| Title |
Token-mediated tool-use by a tufted capuchin monkey (Cebus apella) |
Type |
Journal Article |
| Year |
1998 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
| Volume |
1 |
Issue |
2 |
Pages |
101-106 |
| Keywords |
|
| Abstract |
This research examined token-mediated tool-use in a tufted capuchin monkey (Cebus apella). We conducted five experiments. In experiment 1 we examined the use of plastic color-coded chips to request food, and in experiments 2-5 we examined the use of color-coded chips to request tools. Our subject learned to use chips to request tools following the same general pattern seen in great apes performing analogous tasks, that is, initial discrimination followed by an understanding of the relationship among tokens, tools, and their functions. Our findings are consistent with the view that parallel representational processes underlie the tool-related behavior of capuchins and great apes. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3152 |
| Permanent link to this record |
| |
|
| |
| Author |
Astié, A.A.; Kacelnik, A.; Reboreda, J.C. |
| Title |
Sexual differences in memory in shiny cowbirds |
Type |
Journal Article |
| Year |
1998 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
| Volume |
1 |
Issue |
2 |
Pages |
77-82 |
| Keywords |
|
| Abstract |
Avian brood parasites depend on other species, the hosts, to raise their offspring. During the breeding season, parasitic cowbirds (Molothrus sp.) search for potential host nests to which they return for laying a few days after first locating them. Parasitic cowbirds have a larger hippocampus/telencephalon volume than non-parasitic species; this volume is larger in the sex involved in nest searching (females) and it is also larger in the breeding than in the non-breeding season. In nature, female shiny cowbirds Molothrus bonariensis search for nests without the male's assistance. Here we test whether, in association with these neuroanatomical and behavioural differences, shiny cowbirds display sexual differences in a memory task in the laboratory. We used a task consisting of finding food whose location was indicated either by the appearance or the location of a covering disk. Females learnt to retrieve food faster than males when food was associated with appearance cues, but we found no sexual differences when food was associated with a specific location. Our results are consistent with the view that parasitism and its neuroanatomical correlates affect performance in memory tasks, but the effects we found were not in the expected direction, emphasising that the nature of avian hippocampal function and its sexual differences are not yet understood. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3158 |
| Permanent link to this record |
| |
|
| |
| Author |
Call, J.; Hare, B.A.; Tomasello, M. |
| Title |
Chimpanzee gaze following in an object-choice task |
Type |
Journal Article |
| Year |
1998 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
| Volume |
1 |
Issue |
2 |
Pages |
89-99 |
| Keywords |
|
| Abstract |
Many primate species reliably track and follow the visual gaze of conspecifics and humans, even to locations above and behind the subject. However, it is not clear whether primates follow a human's gaze to find hidden food under one of two containers in an object-choice task. In a series of experiments six adult female chimpanzees followed a human's gaze (head and eye direction) to a distal location in space above and behind them, and checked back to the human's face when they did not find anything interesting or unusual. This study also assessed whether these same subjects would also use the human's gaze in an object-choice task with three types of occluders: barriers, tubes, and bowls. Barriers and tubes permitted the experimenter to see their contents (i.e., food) whereas bowls did not. Chimpanzees used the human's gaze direction to choose the tube or barrier containing food but they did not use the human's gaze to decide between bowls. Our findings allowed us to discard both simple orientation and understanding seeing-knowing in others as the explanations for gaze following in chimpanzees. However, they did not allow us to conclusively choose between orientation combined with foraging tendencies and understanding seeing in others. One interesting possibility raised by these results is that studies in which the human cannot see the reward at the time of subject choice may potentially be underestimating chimpanzees' social knowledge. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3165 |
| Permanent link to this record |
| |
|
| |
| Author |
Fiorito, G.; Biederman, G.B.; Davey, V.A.; Gherardi, F. |
| Title |
The role of stimulus preexposure in problem solving by Octopus vulgaris |
Type |
Journal Article |
| Year |
1998 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
| Volume |
1 |
Issue |
2 |
Pages |
107-112 |
| Keywords |
|
| Abstract |
Octopus vulgaris is able to open transparent glass jars closed with plastic plugs and containing live crabs. The decrease in performance times for removing the plug and seizing the prey with increasing experience of the task has been taken to indicate learning. However, octopuses' attack behaviors are typically slow and variable in novel environmental situations. In this study the role of preexposure to selected features of the problem-solving context was investigated. Although octopuses failed to benefit from greater familiarity with the training context or with selected elements of the task of solving the jar problem, the methodological strategies used are instructive in potentially clarifying the role of complex problem-solving behaviors in this species including stimulus preexposure and social learning. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3198 |
| Permanent link to this record |
| |
|
| |
| Author |
Fagot, J.; Kruschke, J.K.; Dépy, D.; Vauclair, J. |
| Title |
Associative learning in baboons (Papio papio) and humans (Homo sapiens): species differences in learned attention to visual features |
Type |
Journal Article |
| Year |
1998 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
| Volume |
1 |
Issue |
2 |
Pages |
123-133 |
| Keywords |
|
| Abstract |
We examined attention shifting in baboons and humans during the learning of visual categories. Within a conditional matching-to-sample task, participants of the two species sequentially learned two two-feature categories which shared a common feature. Results showed that humans encoded both features of the initially learned category, but predominantly only the distinctive feature of the subsequently learned category. Although baboons initially encoded both features of the first category, they ultimately retained only the distinctive features of each category. Empirical data from the two species were analyzed with the 1996 ADIT connectionist model of Kruschke. ADIT fits the baboon data when the attentional shift rate is zero, and the human data when the attentional shift rate is not zero. These empirical and modeling results suggest species differences in learned attention to visual features. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3267 |
| Permanent link to this record |
| |
|
| |
| Author |
Miklósi, A.; Polgárdi, R.; Topál, J.; Csányi, V. |
| Title |
Use of experimenter-given cues in dogs |
Type |
Journal Article |
| Year |
1998 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
| Volume |
1 |
Issue |
2 |
Pages |
113-121 |
| Keywords |
|
| Abstract |
Since the observations of O. Pfungst the use of human-provided cues by animals has been well-known in the behavioural sciences (“Clever Hans effect”). It has recently been shown that rhesus monkeys (Macaca mulatta) are unable to use the direction of gazing by the experimenter as a cue for finding food, although after some training they learned to respond to pointing by hand. Direction of gaze is used by chimpanzees, however. Dogs (Canis familiaris) are believed to be sensitive to human gestural communication but their ability has never been formally tested. In three experiments we examined whether dogs can respond to cues given by humans. We found that dogs are able to utilize pointing, bowing, nodding, head-turning and glancing gestures of humans as cues for finding hidden food. Dogs were also able to generalize from one person (owner) to another familiar person (experimenter) in using the same gestures as cues. Baseline trials were run to test the possibility that odour cues alone could be responsible for the dogs' performance. During training individual performance showed limited variability, probably because some dogs already “knew” some of the cues from their earlier experiences with humans. We suggest that the phenomenon of dogs responding to cues given by humans is better analysed as a case of interspecific communication than in terms of discrimination learning. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3378 |
| Permanent link to this record |
| |
|
| |
| Author |
Duncan, I.J.H.; Widowski, T.M.; Malleau, A.E.; Lindberg, A.C.; Petherick, J.C. |
| Title |
External factors and causation of dustbathing in domestic hens |
Type |
Journal Article |
| Year |
1998 |
Publication |
Behavioural Processes |
Abbreviated Journal |
Behav. Process. |
| Volume |
43 |
Issue |
2 |
Pages |
219-228 |
| Keywords |
Dustbathing; Illumination; Laying hens; Radiant heat; Social facilitation; Temperature |
| Abstract |
Dustbathing is known to be motivated by complex interactions between internal factors which build up over time and external factors, such as the sight of a dusty substrate. In this study, the effects of other external factors were investigated. Environmental temperature was shown to be important; frequencies of dustbathing were greater when hens were held at 22 than at 10[degree sign]C (P<0.01). In a second experiment, a radiant heat source or a radiant heat+light source, balanced to give the same radiant heat, resulted in more dustbathing behaviour during a 1-h stimulus period than during the same period with no stimulus (P<0.05). Components of dustbathing were increased more by the heat+light stimulus than by the heat stimulus alone (P<0.03). In a third experiment, the amount of dustbathing performed by individual hens in cages with dustbaths was increased by the presence of a group of hens dustbathing in an adjoining pen with a dustbath compared with the amount occurring when the hens were absent from the pen. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3607 |
| Permanent link to this record |
