[dinosaur] Reptile intelligence

Ben Creisler
[email protected]

Some recent papers about reptile intelligence...

Posted earlier on the DML in preprint form, now in final form with a free
pdf:


E. Font, R. García-Roa, D. Pincheira-Donoso & P. Carazo (2019)
Rethinking the Effects of Body Size on the Study of Brain Size Evolution.
Brain, Behavior, and Evolution 93: 182–195
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1159_000501161&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=CQY8cn-Uyg5WnKeHWa18Hq2QwXe2Ds0Mtpj2Am8-vvo&s=s87ahPpOMQwajPy_PHcvFgMQwSx4x6qZmFswR-KyOCo&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.karger.com_Article_FullText_501161&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=CQY8cn-Uyg5WnKeHWa18Hq2QwXe2Ds0Mtpj2Am8-vvo&s=jposJOtKsb34EQnHTKXrePWXWdgQyqSn2gqz5ciCLTQ&e= 

Free pdf:

https://urldefense.proofpoint.com/v2/url?u=https-3A__www.karger.com_Article_Pdf_501161&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=CQY8cn-Uyg5WnKeHWa18Hq2QwXe2Ds0Mtpj2Am8-vvo&s=nr3H7IvlQIAqQXlFge1gkuqTQZbf-rdwuifpn3SB53c&e= 

Body size correlates with most structural and functional components of an
organism’s phenotype -- brain size being a prime example of allometric
scaling with animal size. Therefore, comparative studies of brain evolution
in vertebrates rely on controlling for the scaling effects of body size
variation on brain size variation by calculating brain weight/body weight
ratios. Differences in the brain size-body size relationship between taxa
are usually interpreted as differences in selection acting on the brain or
its components, while selection pressures acting on body size, which are
among the most prevalent in nature, are rarely acknowledged, leading to
conflicting and confusing conclusions. We address these problems by
comparing brain-body relationships from across >1,000 species of birds and
non-avian reptiles. Relative brain size in birds is often assumed to be 10
times larger than in reptiles of similar body size. We examine how
differences in the specific gravity of body tissues and in body design
(e.g., presence/absence of a tail or a dense shell) between these two
groups can affect estimates of relative brain size. Using phylogenetic
comparative analyses, we show that the gap in relative brain size between
birds and reptiles has been grossly exaggerated. Our results highlight the
need to take into account differences between taxa arising from selection
pressures affecting body size and design, and call into question the
widespread misconception that reptile brains are small and incapable of
supporting sophisticated behavior and cognition.

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Tamar Gutnick, Anton Weissenbacher & Michael J. Kuba (2019)
The underestimated giants: operant conditioning, visual discrimination and
long-term memory in giant tortoises.
Animal Cognition (advance online publication)
doi: 10.1007/s10071-019-01326-6
https://urldefense.proofpoint.com/v2/url?u=https-3A__link.springer.com_article_10.1007-252Fs10071-2D019-2D01326-2D6&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=CQY8cn-Uyg5WnKeHWa18Hq2QwXe2Ds0Mtpj2Am8-vvo&s=MVnxRor5BRytoIfPyvUX_w90WgQ2z6lsjnITqKPcd4U&e= 


Relatively little is known about cognition in turtles, and most studies
have focused on aquatic animals. Almost nothing is known about the giant
land tortoises. These are visual animals that travel large distances in the
wild, interact with each other and with their environment, and live
extremely long lives. Here, we show that Galapagos and Seychelle tortoises,
housed in a zoo environment, readily underwent operant conditioning and we
provide evidence that they learned faster when trained in the presence of a
group rather than individually. The animals readily learned to distinguish
colors in a two-choice discrimination task. However, since each animal was
assigned its own individual colour for this task, the presence of the group
had no obvious effect on the speed of learning. When tested 95 days after
the initial training, all animals remembered the operant task. When tested
in the discrimination task, most animals relearned the task up to three
times faster than naïve animals. Remarkably, animals that were tested 9
years after the initial training still retained the operant conditioning.
As animals remembered the operant task, but needed to relearn the
discrimination task constitutes the first evidence for a differentiation
between implicit and explicit memory in tortoises. Our study is a first
step towards a wider appreciation of the cognitive abilities of these
unique animals.

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Adam E. Rosenblatt & Alyssa Johnson (2019)
An experimental test of crocodilian stick-displaying behavior.
Ethology Ecology & Evolution (advance online publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1080_03949370.2019.1691057&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=CQY8cn-Uyg5WnKeHWa18Hq2QwXe2Ds0Mtpj2Am8-vvo&s=2oz96NigmY1PUjOj6c0ykuHZBQVeeB1wJvvYbLUYLsc&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.tandfonline.com_doi_abs_10.1080_03949370.2019.1691057&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=CQY8cn-Uyg5WnKeHWa18Hq2QwXe2Ds0Mtpj2Am8-vvo&s=TAMxNRS_eIgvqSnQZxEzs1GzL9a6xQXubCEvEfGPX88&e= 


Tool use has been documented across a diverse array of animals; however,
this behavior has received little attention in reptiles. Recently,
researchers reported observations of two crocodilian species apparently
using sticks as lures to aid in the capture of nesting birds, but the
evidence for the behavior was anecdotal and correlative. To explore the
behavior in a more controlled situation we designed an experiment to
explicitly test the ability of crocodilians to tailor stick-displaying
behaviors to specific environmental contexts using four captive
pond-dwelling American alligator (Alligator mississippiensis) populations,
two of which reside near bird rookeries and two of which do not. During
bird nesting season we added sticks to each pond and observed the frequency
with which each population exhibited stick-displaying behaviors. We found
that in most comparisons the frequency of stick-displaying behavior did not
differ between rookery and no-rookery sites, while in one comparison the
alligators at a no-rookery site actually displayed the behavior more
frequently than a paired rookery site. Our results do not generally support
the hypothesis that crocodilians tailor stick-displaying behaviors to
specific environmental contexts, therefore the hypothesis that crocodilians
are true tool users is also called into question. Furthermore, our results
suggest that experiments on captive populations are not the ideal way to
study stick-displaying behavior because of issues like unrealistic
alligator densities and food provisioning.