scholarly journals Can Dogs Limbo? Dogs’ Perception of Affordances for Negotiating an Opening

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 620
Author(s):  
Alexandra Horowitz ◽  
Eloise West ◽  
Molly Ball ◽  
Blakeley Bagwell
Keyword(s):  
Body Size ◽  
Domestic Dogs ◽  
Changing Environment ◽  
Approach Behavior ◽  
Preliminary Results

Very little research has focused on canines’ understanding of their own size, and their ability to apply this understanding to their surroundings. The current study tests domestic dogs’ judgment of their body size in relation to a changing environment in two novel experimental situations: when encountering an opening of decreasing height (Study 1) and when negotiating an opening when carrying a stick in their mouth (Study 2). We hypothesized that if dogs understand their own body size, they will accurately judge when an opening is too small for their body to fit through, showing longer latencies to approach the smaller openings and adjusting their body appropriately to get through—although this judgment may not extend to when their body size is effectively increased. In line with these hypotheses, we found that the latency for subjects to reach an aperture they could easily fit through was significantly shorter than to one which was almost too small to fit through. We also found that the order of subjects’ adjustments to negotiate an aperture was invariant across individuals, indicating that dogs’ perception of affordances to fit through an aperture is action-scaled. Preliminary results suggest that dogs’ approach behavior is different when a horizontal appendage is introduced, but that dogs were able to alter their behavior with experience. These results are consistent with the hypothesis that dogs understand their own body size and the affordances of their changing environment.

scholarly journals Risk Factors for Development of Canine and Human Osteosarcoma: A Comparative Review

2019 ◽  
Vol 6 (2) ◽  
pp. 48 ◽  
Author(s):  
Kelly M. Makielski ◽  
Lauren J. Mills ◽  
Aaron L. Sarver ◽  
Michael S. Henson ◽  
Logan G. Spector ◽  
...  
Keyword(s):  
Risk Factors ◽  
Body Size ◽  
Bone Cancer ◽  
Domestic Dogs ◽  
Comparative Approach ◽  
Important Species ◽  
Human Osteosarcoma ◽  
Comparative Review ◽  
Cellular Replication ◽  
Species Specific

Osteosarcoma is the most common primary tumor of bone. Osteosarcomas are rare in humans, but occur more commonly in dogs. A comparative approach to studying osteosarcoma has highlighted many clinical and biologic aspects of the disease that are similar between dogs and humans; however, important species-specific differences are becoming increasingly recognized. In this review, we describe risk factors for the development of osteosarcoma in dogs and humans, including height and body size, genetics, and conditions that increase turnover of bone-forming cells, underscoring the concept that stochastic mutational events associated with cellular replication are likely to be the major molecular drivers of this disease. We also discuss adaptive, cancer-protective traits that have evolved in large, long-lived mammals, and how increasing size and longevity in the absence of natural selection can account for the elevated bone cancer risk in modern domestic dogs.

Tooth size and shape and their relevance to studies of hominid evolution

1981 ◽  
Vol 292 (1057) ◽  
pp. 65-76 ◽  
Keyword(s):  
Body Size ◽  
Hominid Evolution ◽  
Tooth Size ◽  
Taxonomic Significance ◽  
Early Hominid ◽  
Australopithecus Africanus ◽  
Preliminary Results ◽  
Rate Of Increase ◽  
Crown Shape ◽  
Morphological Differences

Teeth have the potential to provide evidence about both the patterns of diversity of fossil hominids and the functional adaptations of early hominid taxa. Comparative studies of dental function and the direct examination of wear patterns in fossil teeth are now providing data for testing hypotheses that major differences in dietary adaptations underlie lineage diversity in the early hominids. However, this review focuses on the contributions that dental evidence can make to hominid systematic studies. Attention is drawn to the value of tooth enamel as a morphological marker and the major contribution that teeth make to the hominid fossil sample. Systematic analysis of hominid remains must start with the identification of patterns of morphological variation. Only then can the taxonomic significance of the morphological differences be assessed and attempts made to link designated taxa in a phylogenetic scheme. The preliminary results of a detailed metrical survey of early hominid premolar and molar teeth are presented. As part of this study cusp areas of first mandibular molars were measured by planimetry. Analysis of these data, without any prior assumptions about taxonomic groups, has demonstrated that the major axis of variation separates the pooled sample into morphological subgroups. These methods provide a systematic and rigorous way of identifying patterns of tooth crown morphology and will allow a more objective assessment of the affinities of individual specimens. Fossil taxa are described in terms of both absolute and relative tooth size. If canine base area and molar crown area are considered there is considerable overlap between Australopithecus africanus and Australopithecus ( paranthropus) robustus whereas there is little or no overlap between the ranges of Australopithecus africanus and Australopithecus (Parnthopus) boisei . Differences in relative tooth size among fossil taxa are taken as an example of how to attack the problem of assessing the taxonomic significance of morphological differences. Analogues from modern primates are used to derive tooth-body size relations for three relative growth models. The results suggest that increases in body size are usually accompanied by a more rapid rate of increase in canine size than in molar size. This suggests that the relatively smaller canines of the ‘robust’ australopithecines are not the result of simple scaling, but represent the result of selection against an allometric trend. Preliminary results of a survey of the subocclusal morphology of fossil teeth are presented to indicate the potential of radiographic studies and to demonstrate that changes in root morphology can be correlated with crown shape and relative size.

scholarly journals Sexual Allometric Monomorphism in Araucan Pig from Colombia: Preliminary Results

Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1763
Author(s):  
Arcesio Salamanca-Carreño ◽  
Jordi Jordana-Vidal ◽  
René Alejandro Crosby-Granados ◽  
José Norberto Arias-Landazábal ◽  
Pere M. Parés-Casanova
Keyword(s):  
Body Size ◽  
Quantitative Traits ◽  
Growth Patterns ◽  
Environmental Adaptation ◽  
Sexual Differences ◽  
Multivariate Approach ◽  
Allometric Growth ◽  
Preliminary Results ◽  
Face Width ◽  
Males And Females

This study aimed to evaluate the allometric growth of the Araucan pig breed, a creole breed from Arauca, East Colombia, locally known as “Sabaneros”, in relation to different quantitative traits and considering genders separately. To do this, a total of 31 male and 27 female Araucan pigs, ranging from 4 to 48 months of age, were studied in order to evaluate their growth patterns, using a multivariate approach. Animals belonged to different farms (“fincas”) of the Department of Arauca, Colombia. From each individual, 10 quantitative traits were obtained: face width, croup height, croup length, croup width, tail base height, hock height, loin height, cannon length, and length and width of ear. Our results, which must be interpreted as preliminary, showed that the Araucan pig is allometrically monomorphic as sexual differences do not increase with body size. We suggest that although males and females have evidently different reproductive roles, during growth they shift the allocation of energy to structures linked to environmental adaptation rather than those linked to reproduction.

scholarly journals Friendship or Competition? Symmetry in Social Play within the Two Packs of German Shepherd Puppies

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1627
Author(s):  
Jana Kottferová ◽  
Lenka Skurková ◽  
Lýdia Mesarčová ◽  
Lenka Lešková ◽  
Alena Demeová ◽  
...  
Keyword(s):  
Body Size ◽  
Social Play ◽  
Domestic Dogs ◽  
Chest Circumference ◽  
Dyadic Interactions ◽  
German Shepherd ◽  
Play Interactions ◽  
Free Ranging ◽  
The Impact ◽  
Competition Symmetry

The symmetry of social play in Canids has been previously studied, especially in wolves, free-ranging dogs, and within mixed-aged groups, however our study focused on symmetry and asymmetry within play interactions in two litters (14 puppies) of German Shepherd dogs (GSDs). At the age of 7 weeks, we evaluated 1287 dyadic interactions (litter 1: n = 339 interactions, litter 2: n = 948 interactions), and at the age of 9 weeks we evaluated 1255 dyadic interactions (litter 1: n = 433 interactions, litter 2: n = 822 interactions). Dyadic interactions were observed and the winning indexes were calculated for 43 pairs (dyads). The groups of puppies studied were all the same age, therefore we focused on the aspects of sex and body size as primary variables. The weight and chest circumference of all puppies were measured. The distribution of interactions showed a slight inclination to mixed-sex dyads, but we did not obtain any statistically significant results concerning the impact of body size on play interactions. Symmetry in play was observed within litter 1 at the age of 7 weeks and at the age of 9 weeks, and within litter 2 at the age of 7 weeks. Since the number of puppies in this study was too small, these results should be interpreted regarding this limitation, and cannot be generalized to a larger population of domestic dogs nor the GSD breed. In further studies, it would be interesting to compare larger samples of different breeds, under different breeding conditions, and the effect of the environment on the style of social play.

scholarly journals Body size, inbreeding, and lifespan in domestic dogs

2019 ◽  
Vol 21 (1) ◽  
pp. 137-148 ◽  
Author(s):  
Jennifer Yordy ◽  
Cornelia Kraus ◽  
Jessica J. Hayward ◽  
Michelle E. White ◽  
Laura M. Shannon ◽  
...  
Keyword(s):  
Body Size ◽  
Domestic Dogs

Intraspecific attachment in adult domestic dogs (Canis familiaris): Preliminary results

2014 ◽  
Vol 152 ◽  
pp. 64-72 ◽  
Author(s):  
Chiara Mariti ◽  
Beatrice Carlone ◽  
Eva Ricci ◽  
Claudio Sighieri ◽  
Angelo Gazzano
Keyword(s):  
Canis Familiaris ◽  
Domestic Dogs ◽  
Preliminary Results

scholarly journals Cross Modal Perception of Body Size in Domestic Dogs (Canis familiaris)

PLoS ONE ◽  
2011 ◽  
Vol 6 (2) ◽  
pp. e17069 ◽  
Author(s):  
Anna M. Taylor ◽  
David Reby ◽  
Karen McComb
Keyword(s):  
Body Size ◽  
Canis Familiaris ◽  
Domestic Dogs
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