scholarly journals Do Domestic Dogs (Canis lupus familiaris) Perceive Numerosity Illusions?

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2304
Author(s):  
Miina Lõoke ◽  
Lieta Marinelli ◽  
Carla Jade Eatherington ◽  
Christian Agrillo ◽  
Paolo Mongillo

Recent studies have showed that domestic dogs are only scantly susceptible to visual illusions, suggesting that the perceptual mechanisms might be different in humans and dogs. However, to date, none of these studies have utilized illusions that are linked to quantity discrimination. In the current study, we tested whether dogs are susceptible to a linear version of the Solitaire illusion, a robust numerosity illusion experienced by most humans. In the first experiment, we tested dogs’ ability to discriminate items in a 0.67 and 0.75 numerical ratio. The results showed that dogs’ quantity discrimination abilities fall in between these two ratios. In Experiment 2, we presented the dogs with the Solitaire illusion pattern using a spontaneous procedure. No evidence supporting any numerosity misperception was found. This conclusion was replicated in Experiment 3, where we manipulated dogs’ initial experience with the stimuli and their contrast with the background. The lack of dogs’ susceptibility to the Solitaire illusion suggests that numerical estimation of dogs is not influenced by the spatial arrangement of the items to be enumerated. In view of the existing evidence, the effect may be extended to dogs’ quantitative abilities at large.

2016 ◽  
Vol 20 (3) ◽  
pp. 427-434 ◽  
Author(s):  
Maria Elena Miletto Petrazzini ◽  
Angelo Bisazza ◽  
Christian Agrillo

2013 ◽  
Vol 25 (8) ◽  
pp. 1142 ◽  
Author(s):  
Insung Hwang ◽  
Yeon Woo Jeong ◽  
Joung Joo Kim ◽  
Hyo Jeong Lee ◽  
Mina Kang ◽  
...  

Interspecies somatic cell nuclear transfer (iSCNT) is an emerging assisted reproductive technology (ART) for preserving Nature’s diversity. The scarcity of oocytes from some species makes utilisation of readily available oocytes inevitable. In the present study, we describe the successful cloning of coyotes (Canis latrans) through iSCNT using oocytes from domestic dogs (Canis lupus familiaris or dingo). Transfer of 320 interspecies-reconstructed embryos into 22 domestic dog recipients resulted in six pregnancies, from which eight viable offspring were delivered. Fusion rate and cloning efficiency during iSCNT cloning of coyotes were not significantly different from those observed during intraspecies cloning of domestic dogs. Using neonatal fibroblasts as donor cells significantly improved the cloning efficiency compared with cloning using adult fibroblast donor cells (P < 0.05). The use of domestic dog oocytes in the cloning of coyotes in the present study holds promise for cloning other endangered species in the Canidae family using similar techniques. However, there are still limitations of the iSCNT technology, as demonstrated by births of morphologically abnormal coyotes and the clones’ inheritance of maternal domestic dog mitochondrial DNA.


2021 ◽  
Author(s):  
Gabriela Molina ◽  
Stefano De Luca ◽  
Fabiana Scarso

Scavenging of human remains by dogs can make the process of identification and analysis of perimortem trauma difficult. Numerous scientific studies have been published about the damage caused to osseous remains by dogs due to postmortem consumption orlethal attacks. However, few studies deal with the issue of the analysis of clothing associated with human remains. The purpose of this investigation was to identify patterns of damage caused by domestic dogs to commonly used, woven textiles. Forty-five cloth bags were used (20 × 30 cm each), made by hand with three different types of woven textile (15 of each textile): stretch(polyester with elastic), denim, and polyester, with a thickness of 40.84, 57.95, and 31.46 threads per cm², respectively. The canine sample consisted of 15 dogs, differing in size, age, and sex, coming from the “Fundación Chile Mestizo,” in Santiago, Chile. Through analysis of variance, researchers examined the relationship between the type of textile and presence of damage, and later, they calculated the frequency of damage according to type of textile. The statistical program Minitab 19 was used to do this. According to the results, four types of patterns were identified: puncture and mastication, present in 62% and 75% of the cases, respectively; perforation; and “hole and tear” damage in 91% of the analyzed cases. Regarding the relationship between textile type and frequency of damage, researchers found that the thickness and weight of the textile are directly connected to the type of damage. 


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