Back to more normal fare for me, some cool papers!
The first, by Martinho III, is about 'beakedness' in New Caledonian crows, and has Alex Kacelnik as an author on the paper. The second, by Alpin, is about culture and it's spread in great tits (work similar to some of Alex Thornton's early stuff on meerkats) and has some big hitters on the author list: Ben Sheldon, Andrew Cockburn and Alex Thornton.
Martinho III et al (2014) Monocular Tool Control, Eye Dominance, and Laterality in New Caledonian Crows. Current Biology, DOI: http://dx.doi.org/10.1016/j.cub.2014.10.035
Tool use, though rare, is taxonomically widespread, but morphological adaptations for tool use are virtually unknown [ 1 ]. We focus on the New Caledonian crow (NCC, Corvus moneduloides), which displays some of the most innovative tool-related behavior among nonhumans [ 2–6 ]. One of their major food sources is larvae extracted from burrows with sticks held diagonally [ 7 ] in the bill, oriented with individual, but not species-wide, laterality [ 8, 9 ]. Among possible behavioral [ 10 ] and anatomical adaptations for tool use [ 5, 11–15 ], NCCs possess unusually wide binocular visual fields (up to 60°), suggesting that extreme binocular vision may facilitate tool use [ 5 ]. Here, we establish that during natural extractions, tool tips can only be viewed by the contralateral eye. Thus, maintaining binocular view of tool tips is unlikely to have selected for wide binocular fields; the selective factor is more likely to have been to allow each eye to see far enough across the midsagittal line to view the tool’s tip monocularly [ 5, 16 ]. Consequently, we tested the hypothesis that tool side preference follows eye preference and found that eye dominance does predict tool laterality across individuals. This contrasts with humans’ species-wide motor laterality and uncorrelated motor-visual laterality [ 17 ], possibly because bill-held tools are viewed monocularly and move in concert with eyes, whereas hand-held tools are visible to both eyes and allow independent combinations of eye preference and handedness. This difference may affect other models of coordination between vision and mechanical control, not necessarily involving tools.
http://www.cell.com/current-biology/abstract/S0960-9822(14)01344-X
Alpin et al (2014) Experimentally induced innovations lead to persistent culture via conformity in wild birds. Nature, DOI: 10.1038/nature13998
In human societies, cultural norms arise when behaviours are transmitted through social networks via high-fidelity social learning1. However, a paucity of experimental studies has meant that there is no comparable understanding of the process by which socially transmitted behaviours might spread and persist in animal populations2, 3. Here we show experimental evidence of the establishment of foraging traditions in a wild bird population. We introduced alternative novel foraging techniques into replicated wild sub-populations of great tits (Parus major) and used automated tracking to map the diffusion, establishment and long-term persistence of the seeded innovations. Furthermore, we used social network analysis to examine the social factors that influenced diffusion dynamics. From only two trained birds in each sub-population, the information spread rapidly through social network ties, to reach an average of 75% of individuals, with a total of 414 knowledgeable individuals performing 57,909 solutions over all replicates. The sub-populations were heavily biased towards using the technique that was originally introduced, resulting in established local traditions that were stable over two generations, despite a high population turnover. Finally, we demonstrate a strong effect of social conformity, with individuals disproportionately adopting the most frequent local variant when first acquiring an innovation, and continuing to favour social information over personal information. Cultural conformity is thought to be a key factor in the evolution of complex culture in humans4, 5, 6, 7. In providing the first experimental demonstration of conformity in a wild non-primate, and of cultural norms in foraging techniques in any wild animal, our results suggest a much broader taxonomic occurrence of such an apparently complex cultural behaviour.
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13998.html
The first, by Martinho III, is about 'beakedness' in New Caledonian crows, and has Alex Kacelnik as an author on the paper. The second, by Alpin, is about culture and it's spread in great tits (work similar to some of Alex Thornton's early stuff on meerkats) and has some big hitters on the author list: Ben Sheldon, Andrew Cockburn and Alex Thornton.
Martinho III et al (2014) Monocular Tool Control, Eye Dominance, and Laterality in New Caledonian Crows. Current Biology, DOI: http://dx.doi.org/10.1016/j.cub.2014.10.035
Tool use, though rare, is taxonomically widespread, but morphological adaptations for tool use are virtually unknown [ 1 ]. We focus on the New Caledonian crow (NCC, Corvus moneduloides), which displays some of the most innovative tool-related behavior among nonhumans [ 2–6 ]. One of their major food sources is larvae extracted from burrows with sticks held diagonally [ 7 ] in the bill, oriented with individual, but not species-wide, laterality [ 8, 9 ]. Among possible behavioral [ 10 ] and anatomical adaptations for tool use [ 5, 11–15 ], NCCs possess unusually wide binocular visual fields (up to 60°), suggesting that extreme binocular vision may facilitate tool use [ 5 ]. Here, we establish that during natural extractions, tool tips can only be viewed by the contralateral eye. Thus, maintaining binocular view of tool tips is unlikely to have selected for wide binocular fields; the selective factor is more likely to have been to allow each eye to see far enough across the midsagittal line to view the tool’s tip monocularly [ 5, 16 ]. Consequently, we tested the hypothesis that tool side preference follows eye preference and found that eye dominance does predict tool laterality across individuals. This contrasts with humans’ species-wide motor laterality and uncorrelated motor-visual laterality [ 17 ], possibly because bill-held tools are viewed monocularly and move in concert with eyes, whereas hand-held tools are visible to both eyes and allow independent combinations of eye preference and handedness. This difference may affect other models of coordination between vision and mechanical control, not necessarily involving tools.
http://www.cell.com/current-biology/abstract/S0960-9822(14)01344-X
Alpin et al (2014) Experimentally induced innovations lead to persistent culture via conformity in wild birds. Nature, DOI: 10.1038/nature13998
In human societies, cultural norms arise when behaviours are transmitted through social networks via high-fidelity social learning1. However, a paucity of experimental studies has meant that there is no comparable understanding of the process by which socially transmitted behaviours might spread and persist in animal populations2, 3. Here we show experimental evidence of the establishment of foraging traditions in a wild bird population. We introduced alternative novel foraging techniques into replicated wild sub-populations of great tits (Parus major) and used automated tracking to map the diffusion, establishment and long-term persistence of the seeded innovations. Furthermore, we used social network analysis to examine the social factors that influenced diffusion dynamics. From only two trained birds in each sub-population, the information spread rapidly through social network ties, to reach an average of 75% of individuals, with a total of 414 knowledgeable individuals performing 57,909 solutions over all replicates. The sub-populations were heavily biased towards using the technique that was originally introduced, resulting in established local traditions that were stable over two generations, despite a high population turnover. Finally, we demonstrate a strong effect of social conformity, with individuals disproportionately adopting the most frequent local variant when first acquiring an innovation, and continuing to favour social information over personal information. Cultural conformity is thought to be a key factor in the evolution of complex culture in humans4, 5, 6, 7. In providing the first experimental demonstration of conformity in a wild non-primate, and of cultural norms in foraging techniques in any wild animal, our results suggest a much broader taxonomic occurrence of such an apparently complex cultural behaviour.
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13998.html
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