Quantity discrimination in jungle crows, Corvus macrorhynchos

Bogale, Bezawork Afework; Kamata, Naoki; Mioko, Katano; Sugita, Shoei

doi:10.1016/j.anbehav.2011.05.025

Cited by 65 publications

(48 citation statements)

References 36 publications

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“…Previous work by Bogale et al [19,34] and Ujfalussy et al [20] required relative numerosity judgements. These, however, do not require animals to know anything about the precise numerical value in order to make a correct choice [43].…”

Section: Introductionmentioning

confidence: 99%

“…Ever since Koehler and his co-workers explored the numerical capabilities of birds [31], corvids have been known to show some level of quantity discrimination [32], and they use quantity rules to direct behaviour [33]. Jungle crows have been trained on relative numerosity discriminations to always choose the larger of two sets of (3)(4)(5)(6)(7)(8) visual shapes [34]. Relative quantity judgements are also observable without training, as crows and jackdaws [20] spontaneously selected the larger of two food quantities as long as one of the sets contained fewer than five objects [19].…”

Section: Introductionmentioning

confidence: 99%

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Numerosity representations in crows obey the Weber–Fechner law

Ditz¹,

Nieder²

2016

Proc. R. Soc. B.

104

105

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The ability to estimate number is widespread throughout the animal kingdom. Based on the relative close phylogenetic relationship (and thus equivalent brain structures), non-verbal numerical representations in human and nonhuman primates show almost identical behavioural signatures that obey the Weber-Fechner law. However, whether numerosity discriminations of vertebrates with a very different endbrain organization show the same behavioural signatures remains unknown. Therefore, we tested the numerical discrimination performance of two carrion crows (Corvus corone) to a broad range of numerosities from 1 to 30 in a delayed match-to-sample task similar to the one used previously with primates. The crows' discrimination was based on an analogue number system and showed the Weber-fraction signature (i.e. the 'just noticeable difference' between numerosity pairs increased in proportion to the numerical magnitudes). The detailed analysis of the performance indicates that numerosity representations in crows are scaled on a logarithmically compressed 'number line'. Because the same psychophysical characteristics are found in primates, these findings suggest fundamentally similar number representations between primates and birds. This study helps to resolve a classical debate in psychophysics: the mental number line seems to be logarithmic rather than linear, and not just in primates, but across vertebrates.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Numerosity representations in crows obey the Weber–Fechner law

Ditz¹,

Nieder²

2016

Proc. R. Soc. B.

104

105

View full text Add to dashboard Cite

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“…Researchers in these fields have found that the ability to discriminate between different numbers of objects appears to be a foundational cognitive ability and have documented this ability in numerous species across the Animal Kingdom. For example, quantity discrimination has been demonstrated experimentally in several species of fish [5,11,[19][20][21], amphibians [8,22,23], birds [18,[24][25][26][27][28][29][30][31][32][33][34][35], mammals [9,[36][37][38][39][40][41], primates [42][43][44][45], human infants [46][47][48][49] and even some invertebrates [50][51][52]. The only study testing quantity discrimination in a reptile found that although ruin lizards (Podarcis sicula) do spontaneously select the larger quantity of food, they do not spontaneously select the option with a higher number of food items [53].…”

Section: Introductionmentioning

confidence: 99%

Numerical assessment in the wild: insights from social carnivores

Benson‐Amram

Gilfillan

McComb

2018

Phil. Trans. R. Soc. B

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SummaryPlayback experiments have proven to be a useful tool to investigate the extent to which wild animals understand numerical concepts and the factors that play into their decisions to respond to different numbers of vocalizing conspecifics. In particular, playback experiments have broadened our understanding of the cognitive abilities of historically understudied species that are challenging to test in the traditional laboratory, such as members of the Order Carnivora. Additionally, playback experiments allow us to assess the importance of numerical information versus other ecologically important variables when animals are making adaptive decisions in their natural habitats. Here, webegin by reviewing what we know about quantity discrimination in carnivores from studies conducted in captivity. We then review a series of playback experiments conducted with wild social carnivores, including African lions, spotted hyenas, and wolves, which demonstrate that these animals can assess the number of conspecifics calling and respond based on numerical advantage.We discuss how the wild studies compliment those conducted in captivity and allow us to gain insights into why wild animals may not always respond based solely on differences in quantity. We then consider the key role that individual discrimination and cross-modal recognition play in the 2 ability of animals to assess the number of conspecifics vocalizing nearby. Finally, we explore new directions for future research in this area, highlighting in particular the need for further work on the cognitive basis of numerical assessment skills and experimental paradigms that can be effective in both captive and wild settings.

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“…single-cell recordings | crow | nidopallium caudolaterale | quantity B irds show elaborate quantification skills (1)(2)(3) that are of adaptive value in naturalistic situations like nest parasitism (4), food caching (5), or communication (6). The neuronal correlates of numerosity representations have only been explored in humans (7)(8)(9) and primates (10)(11)(12)(13)(14)(15)(16)(17)(18), and they have been found to reside in the prefrontal and posterior parietal neocortices.…”

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confidence: 99%

Neurons selective to the number of visual items in the corvid songbird endbrain

Ditz

Nieder

2015

Proc. Natl. Acad. Sci. U.S.A.

155

187

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It is unknown whether anatomical specializations in the endbrains of different vertebrates determine the neuronal code to represent numerical quantity. Therefore, we recorded single-neuron activity from the endbrain of crows trained to judge the number of items in displays. Many neurons were tuned for numerosities irrespective of the physical appearance of the items, and their activity correlated with performance outcome. Comparison of both behavioral and neuronal representations of numerosity revealed that the data are best described by a logarithmically compressed scaling of numerical information, as postulated by the WeberFechner law. The behavioral and neuronal numerosity representations in the crow reflect surprisingly well those found in the primate association cortex. This finding suggests that distantly related vertebrates with independently developed endbrains adopted similar neuronal solutions to process quantity.single-cell recordings | crow | nidopallium caudolaterale | quantity B irds show elaborate quantification skills (1-3) that are of adaptive value in naturalistic situations like nest parasitism (4), food caching (5), or communication (6). The neuronal correlates of numerosity representations have only been explored in humans (7-9) and primates (10-18), and they have been found to reside in the prefrontal and posterior parietal neocortices. In contrast to primates, birds lack a six-layered neocortex. The birds' lineage diverged from mammals 300 Mya (19), at a time when the neocortex had not yet developed from the pallium of the endbrain. Instead, birds developed different pallial parts as dominant endbrain structures (20, 21) based on convergent evolution, with the nidopallium caudolaterale (NCL) as a highlevel association area (22-26). Where and how numerosity is encoded in vertebrates lacking a neocortex is unknown. Here, we show that neurons in the telencephalic NCL of corvid songbirds respond to numerosity and show a specific code for numerical information. ResultsCrows were trained in a delayed matching-to-sample task to match the number of (one to five) dots presented on touch-sensitive computer displays ( Fig. 1 A and B). Crows watched two displays (first sample, then test) separated by a 1-s delay. They were trained to peck at the displays on the screen if the test displays contained the same number of items as the sample. We varied the exact physical appearance of the displays by randomly placing dots in arbitrary locations, and by randomly choosing dot size.The crows performed the task proficiently (73.8 ± 0.4% and 77.5 ± 0.5% correct over all recording sessions for crow A and crow J, respectively; Fig. 1C). Average performance of both crows was significantly better than chance (50%) for all sample numerosities relative to the numerically most distant nonmatches (Binomial test, P < 0.01). Better performance for sample numerosities at the low (one) and high (five) numerosity range (Fig. 1D) are most likely due to "endeffects," because one and five items had to be discriminated only fro...

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Quantity discrimination in jungle crows, Corvus macrorhynchos

Cited by 65 publications

References 36 publications

Numerosity representations in crows obey the Weber–Fechner law

Numerosity representations in crows obey the Weber–Fechner law

Numerical assessment in the wild: insights from social carnivores

Neurons selective to the number of visual items in the corvid songbird endbrain

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