| food, audience and sex effects on pinyon jay (gymnorhinus cyanocephalus) communication. | pinyon jays (gymnorhinus cyanocephalus) have a complex social system that may require a complex communication system. they need to interact with multiple flock members, and they form life-long pair-bonds. we researched whether pinyon jays would selectively vocalize depending on the presence or absence of food and certain flock members. we recorded the vocalizations of nine pinyon jays (four pair-bonds and one single male) in response to different audience types. the calls of the test bird were r ... | 2005 | 15639383 |
| cognitive representation in transitive inference: a comparison of four corvid species. | during operant transitive inference experiments, subjects are trained on adjacent stimulus pairs in an implicit linear hierarchy in which responses to higher ranked stimuli are rewarded. two contrasting forms of cognitive representation are often used to explain resulting choice behavior. associative representation is based on memory for the reward history of each stimulus. relational representation depends on memory for the context in which stimuli have been presented. natural history character ... | 2010 | 20708664 |
| serial reversal learning and the evolution of behavioral flexibility in three species of north american corvids (gymnorhinus cyanocephalus, nucifraga columbiana, aphelocoma californica). | in serial reversal learning, subjects learn to respond differentially to 2 stimuli. when the task is fully acquired, reward contingencies are reversed, requiring the subject to relearn the altered associations. this alternation of acquisition and reversal can be repeated many times, and the ability of a species to adapt to this regimen has been considered as an indication of behavioral flexibility. serial reversal learning of 2-choice discriminations was contrasted in 3 related species of north ... | 2007 | 18085920 |
| a comparison of four corvid species in a working and reference memory task using a radial maze. | birds were tested in an open-room radial maze with learned spatial locations that varied from trial to trial (working memory) and locations that remained spatially stable (reference memory). three of the species, the clark's nutcracker (nucifraga columbiana), pinyon jay (gymnorhinus cyanocephalus), and western scrub jay (aphelocoma coerulescens) store food to varying degrees. the other species, the eurasian jackdaw (corvus monedula) does not. pinyon jays and scrub jays performed better than the ... | 2000 | 11149538 |
| differences in hippocampal volume among food storing corvids. | the hippocampal complex (hippocampus and parahippocampalis) is known to play a role in spatial memory in birds and is known to be larger in food-storing versus non-storing birds. in the present study, we investigated the relative volume of the hippocampal complex in four food-storing corvids: gray-breasted jays (aphelocoma ultramarina), scrub jays (aphelocoma coerulescens), pinyon jays (gymnorhinus cyanocephalus), and clark's nutcrackers (nucifraga columbiana). the results show that clark's nutc ... | 1996 | 8680849 |
| performance of four seed-caching corvid species in the radial-arm maze analog. | four seed-caching corvid species were tested in an open-room analog of the radial-arm maze. during experiment 1, the species more dependent on stored food. clark's nutcrackers (nucifraga columbiana) and pinyon jays (gymnorhinus cyanocephalus), acquired the task more quickly and to higher accuracy levels than either scrub jays (aphelocoma coerulescens) or mexican jays (a. ultramarina). during experiment 2, performance after retention intervals was tested. when intervals of 30-210 min were tested ... | 1994 | 7813195 |
| differences in relative hippocampus volume and number of hippocampus neurons among five corvid species. | the relative size of the avian hippocampus (hp) has been shown to be related to spatial memory and food storing in two avian families, the parids and corvids. basil et al. [brain behav evol 1996;47:156-164] examined north american food-storing birds in the corvid family and found that clark's nutcrackers had a larger relative hp than pinyon jays and western scrub jays. these results correlated with the nutcracker's better performance on most spatial memory tasks and their strong reliance on stor ... | 2013 | 23364270 |
| the fine-grained spatial abilities of three seed-caching corvids. | we used a psychophysical method to examine the ability of three corvid species to discern fine-grained spatial information. nutcrackers, pinyon jays, and scrub-jays were required to discriminate the distance between two landmarks on a computer screen in an operant chamber. all three species were able to discriminate between arrays that differed by 20 mm; the discrimination gradients for scrub-jays and pinyon jays were sharper than those for nutcrackers, however. the results suggest that differen ... | 2005 | 15971493 |
| the domain specificity of intertemporal choice in pinyon jays. | when choosing between a piece of cake now versus a slimmer waistline in the future, many of us have difficulty with self-control. food-caching species, however, regularly hide food for later recovery, sometimes waiting months before retrieving their caches. it remains unclear whether these long-term choices generalize outside of the caching domain. we hypothesized that the ability to save for the future is a general tendency that cuts across different situations. to test this hypothesis, we meas ... | 2016 | 26620957 |
| direct and relational representation during transitive list linking in pinyon jays (gymnorhinus cyanocephalus). | the authors used the list-linking procedure (treichler & van tilburg, 1996) to explore the processes by which animals assemble cognitive structures from fragmentary and often contradictory data. pinyon jays (gymnorhinus cyanocephalus) were trained to a high level of accuracy on 2 implicit transitive lists, a > b > c > d > e and 1 > 2 > 3 > 4 > 5. they were then given linkage training on e > 1, the single pair that linked the 2 lists into a composite, 10-item hierarchy. following linkage training ... | 2014 | 24188622 |
| pinyon jays use transitive inference to predict social dominance. | living in large, stable social groups is often considered to favour the evolution of enhanced cognitive abilities, such as recognizing group members, tracking their social status and inferring relationships among them. an individual's place in the social order can be learned through direct interactions with others, but conflicts can be time-consuming and even injurious. because the number of possible pairwise interactions increases rapidly with group size, members of large social groups will ben ... | 2004 | 15306809 |
| sociality and social learning in two species of corvids: the pinyon jay (gymnorhinus cyanocephalus) and the clark's nutcracker (nucifraga columbiana). | the hypothesis that social learning is an adaptive specialization for social living predicts that social species should learn better socially than they do individually, but that nonsocial species should not exhibit a similar enhancement of performance under social learning conditions. the authors compared individual and social learning abilities in 2 corvid species: the highly social pinyon jay (gymnorhinus cyanocephalus) and the less social clark's nutcracker (nucifraga columbiana). the birds w ... | 1999 | 10608569 |
| individual exploratory responses are not repeatable across time or context for four species of food-storing corvid. | exploration is among one of the most studied of animal personality traits (i.e., individual-level behavioural responses repeatable across time and contexts). however, not all species show clear evidence of this personality trait, and this is particularly so for members of the corvidae family. we assessed the exploratory behaviour of four food-caching corvid species: pinyon jays (gymnorhinus cyanocephalus), clark's nutcrackers (nucifraga columbiana), california scrub jays (aphelocoma californica) ... | 2020 | 31941921 |
| the genus brueelia (phthiraptera: ischnocera: philopteridae) of north american jays and allies (aves: passeriformes: corvidae), with descriptions of five new species. | five new species of chewing lice in the genus brueelia kéler, 1936 , are described from north american jays and allies. they are brueelia mexicana n. sp. from aphelocoma woodhouseii cyanotis ridgway, 1887 ; brueelia bonnevillensis n. sp. from aphelocoma woodhouseii nevadae pitelka, 1945 ; brueelia diblasiae n. sp. from cyanocitta stelleri frontalis ( ridgway, 1873 ); brueelia tempestwilliamsae n. sp. from gymnorhinus cyanocephala wied-neuwied, 1841 ; brueelia mcnewae n. sp. from nucifraga columb ... | 2019 | 31805246 |
| mesotocin influences pinyon jay prosociality. | many species exhibit prosocial behaviour, in which one individual's actions benefit another individual, often without an immediate benefit to itself. the neuropeptide oxytocin is an important hormonal mechanism influencing prosociality in mammals, but it is unclear whether the avian homologue mesotocin plays a similar functional role in birds. here, we experimentally tested prosociality in pinyon jays (gymnorhinus cyanocephalus), a highly social corvid species that spontaneously shares food with ... | 2018 | 29643220 |