It's dog eat dog on the canine social ladder

Date:  July 2, 2019

Source:  University of Exeter

Climbing the social ladder is a ruff business for dogs, new research shows.

Top dogs in a pack are known to assert their dominance, but scientists studied a group of free-roaming mongrels and found high levels of aggression in the middle of the dominance hierarchy.

Most theories predict more aggression higher up the ladder. However, the researchers say the difficulty of working out the pecking order in the crowded middle leads to aggression.

The research was carried out by the University of Exeter (UK) and by the Veterinary Service of the Local Health Unit Rome 3 (Italy).

"Our results reveal the unavoidable costs of climbing a dominance hierarchy," said Dr Matthew Silk, of the Environment and Sustainability Institute on the University of Exeter's Penryn Campus in Cornwall.

"In the middle of the hierarchy -- where it's harder to predict which animal should be dominant -- we see lots of aggression."

Professor Robbie McDonald said: "Fighting over food and mates uses energy and time and can lead to injuries, so hierarchies play an important role because animals know their place without needing to fight."

The year-long study examined a pack of 27 mongrel dogs that roamed freely in the suburbs of Rome.

The dogs did not live with humans, although they relied on humans for food.

Their hierarchy was based on age and sex, with adults dominant over younger dogs and males dominant over females of the same age group.

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Wolves lead, dogs follow -- and both cooperate with humans

Date:  March 14, 2019

Source:  University of Veterinary Medicine -- Vienna

Human social life would be unthinkable without cooperation. The frequency and complexity with which humans cooperate with each other are extraordinary, if not unique. To better understand the evolution of this outstanding human skill, researchers have proposed dogs (Canis familiaris) as a good model of human cooperation.

The wolf inside dogs makes the difference

A recent study by Vetmeduni Vienna, published in the journal Scientific Reports, shows that the ability to work with people lies not so much within dogs themselves but in the "wolf within the dog" -- that is to say, in very specific behavioural characteristics that dogs share with wolves. The study tested the extent to which dogs and grey wolves collaborate with humans in order to solve certain tasks. The findings show that both dogs and wolves cooperate intensively with humans and are equally successful, although the animals attain their goals in different ways.

Wolves show more initiative

Especially in one point the two closely related animals show significantly different forms of behaviour. In their cooperation with human partners, dogs follow the behaviour of the humans while wolves lead the interaction: they are more independent. Study director Friederike Range from the Konrad Lorenz Institute at Vetmeduni Vienna says, "The detailed analysis of the cooperative interactions revealed interesting differences between wolves and dogs. It shows that, while wolves tend to initiate behaviour and take the lead, dogs are more likely to wait and see what the human partner does and follow that behaviour."

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Dogs' becoming major threat' to wildlife

By Navin Singh KhadkaEnvironment correspondent, BBC World Service

12 February 2019

They may be our "best friends" but dogs have also emerged as a major threat to wildlife.

Scientists say they have contributed to the extinction of nearly one dozen wild bird and animal species.

As such, they have become the third worst human-introduced predators after cats and rats.

Now dogs are said to threaten nearly 200 species worldwide, some of which are critically endangered, studies suggest.

And yet, feral and free-ranging dogs have received surprisingly little attention, conservationists say.

In a recent study carried out on dogs in Chile, the authors said: "Conservationists in Chile and elsewhere see urgency in controlling the impact of free-ranging dogs on wildlife."

It found dog owners were not concerned about the issue and many allowed their pets to move freely in the wild.

"Predation and harassment by dogs has been documented for the majority of larger terrestrial mammals that inhabit Chile, including the three species of canids (mammals from the dog family) and three species of deer," Eduardo Silva-Rodriguez, one of the authors of the study, told the BBC.

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A long walk: New insight into history of dogs and humans

By Helen Briggs BBC News

17 October 2018

Dogs were part of a key moment in human history - when our ancestors began trying their hand at farming.

As the first farmers moved out of the Middle East, herding animals such as sheep and goats, dogs tagged along too, say scientists.

The DNA evidence fills in some of the gaps in the story of how wolves became the dogs of all shapes and sizes that we know today.

Farming began in what is known as the Fertile Crescent of the Middle East.

This includes parts of modern-day Iraq, Syria, Lebanon, Jordan, Israel and Egypt.

Humans who were living as hunter-gatherers settled down and started growing wild varieties of crops like wheat, barley, peas and lentils.

They also domesticated animals from wild sheep, cows and pigs. About 9,000 years ago, they moved into Europe and Asia, taking their animals and farming know-how with them.

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First dogs in the Americas arrived from Siberia, disappeared after European contact

Date:  July 5, 2018

Source:  University of Illinois at Urbana-Champaign

A study reported in the journal Science offers an enhanced view of the origins and ultimate fate of the first dogs in the Americas. The dogs were not domesticated North American wolves, as some have speculated, but likely followed their human counterparts over a land bridge that once connected North Asia and the Americas, the study found.

This is the first comprehensive genomic study of ancient dogs in the Americas to analyze nuclear DNA, which is inherited from both parents, along with mitochondrial DNA, which is passed down only from mothers to their offspring. By comparing genomic signatures from 71 mitochondrial and seven nuclear genomes of ancient North American and Siberian dogs spanning a period of 9,000 years, the research team was able to gain a clearer picture of the history of the first canine inhabitants of the Americas.

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Extinct Doggos' Bone-Crushing Diet Preserved in Fossil Poop

By Mindy Weisberger, Senior Writer | May 25, 2018 10:25am ET

Long-extinct relatives of today's dogs and wolves may have used their powerful jaws to crush bones, and the proof is in the animals' fossilized poop.

Domestic dogs are known to enjoy chewing large bones, but they lack the jaw strength to pulverize them. In fact, in today's ecosystems, the only large predators with skulls and jaws powerful enough to splinter bones are hyenas. But that wasn't the case millions of years ago, researchers reported in a new study.

Scientists had known from years of analyzing fossils of a wolf-size species of wild dog called Borophagus parvus — which lived from about 16 million to 2 million years ago — that its skull and powerful jawbone shared many features with those of bone-crunching spotted hyenas (Crocuta crocuta), according to the study. While this suggested the canid also could crush bones, scientists still couldn't be sure that was true, study co-author Jack Tseng, a functional anatomist at the University at Buffalo, told Live Science in an email. [10 Extinct Giants That Once Roamed North America]

"You could say we were scientifically constipated," Tseng said.

However, the floodgates were opened with the discovery of a cache of coprolites — 14 pieces of fossilized poop — at a site in California's Mehrten Formation. The location dates to the late Miocene epoch, about 5.3 million to 6.4 million years ago, and is known for being rich in Borophagus fossils; the coprolites, which are much rarer than bones, are thought to be about 2 million years old, the study authors reported.

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Dogs could be more similar to humans than we thought

April 18, 2018, BioMed Central

Dog and human gut microbiomes have more similar genes and responses to diet than we previously thought, according to a study published in the open access journal, Microbiome.

Dr Luis Pedro Coelho and colleagues from the European Molecular Biology Laboratory, in collaboration with Nestlé Research, evaluated the gut microbiome of two dog breeds and found that the gene content of the dogs microbiome showed many similarities to the human gut microbiome, and was more similar to humans than the microbiome of pigs or mice.

Dr Luis Pedro Coelho, corresponding author of the study, commented:

"We found many similarities between the gene content of the human and dog gut microbiomes. The results of this comparison suggest that we are more similar to man's best friend than we originally thought."

The researchers found that changes in the amount of protein and carbohydrates in the diet had a similar effect on the microbiota of dogs and humans, independent of the dog's breed or sex. The microbiomes of overweight or obese dogs were found to be more responsive to a high protein diet compared to microbiomes of lean dogs; this is consistent with the idea that healthy microbiomes are more resilient.

Dr Luis Pedro Coelho, commented:

"These findings suggest that dogs could be a better model for nutrition studies than pigs or mice and we could potentially use data from dogs to study the impact of diet on gut microbiota in humans, and humans could be a good model to study the nutrition of dogs.

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First evidence of live-traded dogs for Maya ceremonies

Date:  March 19, 2018

Source:  Smithsonian Tropical Research Institute

Police detectives analyze isotopes in human hair to find out where a murder victim was born and grew up. Ashley Sharpe, an archaeologist at the Smithsonian Tropical Research Institute in Panama, and colleagues combined clues from carbon, nitrogen, oxygen and strontium isotope analysis discovering the earliest evidence that the Maya raised and traded dogs and other animals, probably for ceremonial use.

Their results are published in the Proceedings of the National Academy of Sciences during the week of March 19.

"In Asia, Africa and Europe, animal management went hand-in-hand with the development of cities," said Sharpe. "But in the Americas people may have raised animals for ceremonial purposes. The growth of cities doesn't seem to be directly tied to animal husbandry."

Sharpe found that animal trade and management began in the Preclassic Period some 2,500 years ago and intensified during the Classic Period, making it likely that organized ceremonies involving animal and human sacrifice and raising animals for food played important roles in the development of Maya civilization.

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Humans Cared for Sick Puppies Long Ago, Ancient Burial Shows

By Laura Geggel, Senior Writer | February 9, 2018 05:06pm ET

Ancient people likely cared for a sick, domesticated pup for weeks on end before it died about 14,000 years ago during the Paleolithic era, a new study finds.

After it died, the dog was buried with the remains of another dog and an adult man and woman — making it not only the oldest burial of a domestic dog on record, but also the oldest known grave to contain both dogs and people, the researchers said.

This discovery suggests that even though the dog was young, sick and likely untrained as a result, ancient people still had an emotional bond with it, the researchers wrote in the study. This may explain why the people buried the animal with two of their own, the researchers said. [10 Things You Didn't Know About Dogs]

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Doggone: Your Best Friend Is Red-Green Colorblind

By Laura Geggel, Senior Writer | November 8, 2017 06:06am ET

If you're ever deciding between throwing a red ball or a green ball for your dog to fetch, know this: It doesn't matter to Fido because dogs are red-green colorblind, a new small study suggests.

Researchers in Italy tested 16 dogs on their color vision and found the canids had red-green colorblindness, a condition known as deuteranopia that affects about 8 percent of men and 0.5 percent of women with Northern European ancestry, according to the National Eye Institute.

The finding suggests that, "if you are planning to train your dog to fetch a ball that fell on the green grass of your garden, think of using a blue, and not red, ball," said study lead researcher Marcello Siniscalchi, a professor in the Department of Veterinary Medicine at the University of Bari, in Italy. [10 Things You Didn't Know About Dogs]

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'Big, bad wolf' image flawed - scientists

By Helen BriggsBBC News

16 October 2017 

New research casts doubt on the idea that dogs are naturally more tolerant and friendly than wolves.

In tests of cooperation skills, wolves outperformed their domesticated relatives.

Scientists say the findings challenge assumptions about how dogs were tamed from wolves and came to live alongside humans.

Previous evidence has suggested that the domestication process may have given dogs a more tolerant temperament.

"We still have very much this idea of the big, bad wolf and the cuddly pooch on your sofa," Dr Sarah Marshall-Pescini, who led the research, told BBC News.

"But, I think the simplest message is that the story is not quite as clear as that."

Social bonds

Wolves are highly social animals. They live in close-knit family groups, raise puppies together and hunt in groups.

This sort of behaviour is not seen in modern dogs, despite the idea that domestication selected for dogs that were more tolerant and friendly, both of each other, and humans.

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Wolves understand cause and effect better than dogs

Date:  September 15, 2017

Source:  University of Veterinary Medicine -- Vienna

Summary:

A rattle will only make noise if you shake it. Animals like the wolf also understand such connections and are better at this than their domesticated descendants. Researchers say that wolves have a better causal understanding than dogs and that they follow human-given communicative cues equally well. The study provides insight that the process of domestication can also affect an animal's causal understanding.

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STSR tests confirm that dogs have self-awareness

September 6, 2017

A new study carried out by the Department of Psychology at Barnard College in the U.S. used a sniff test to evaluate the ability of dogs to recognize themselves. The results have been published in the journal Behavioural Processes.

The experiment confirms the hypothesis of dog self-cognition proposed last year by Prof. Roberto Cazzolla Gatti of the Biological Institute of the Tomsk State University, Russia. Dr. Alexandra Horowitz, the lead researcher, wrote, "While domestic dogs, Canis familiaris, have been found to be skillful at social cognitive tasks and even some meta-cognitive tasks, they have not passed the test of mirror self-recognition (MSR)."

Prof. Horowitz borrowed the "Sniff test of self-recognition (STSR)" proposed by Prof. Cazzolla Gatti in 2016 to shed light on methods of testing for self-recognition, and applied it to 36 domestic dogs accompanied by their owners.

This study confirmed the previous evidence proposed with the STSR by Dr. Cazzolla Gatti showing that "dogs distinguish between the olfactory 'image' of themselves when modified: Investigating their own odour for longer when it had an additional odour accompanying it than when it did not. Such behaviour implies a recognition of the odour as being of or from 'themselves.'"

Prof. Cazzolla Gatti firstly suggested the hypothesis of self-cognition in dogs in a 2016 pioneering paper entitled after the novel by Lewis Carroll "Self-consciousness: beyond the looking-glass and what dogs found there."

As the Associate Professor of the Tomsk State University anticipated: "this sniff-test could change the way some experiments on animal behaviour are validated." Soon, the study of Dr. Horowitz followed.

"I believe that dogs and other animals, being much less sensitive to visual stimuli than humans and many apes, cannot pass the mirror test because of the sensory modality chosen by the investigator to test self-awareness. This in not necessarily due to the absence of this cognitive ability in some animal species," says Cazzolla Gatti.

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Who's a Blue Boy? Indian Dogs Tinted by Polluted River

By Sara G. Miller, Staff Writer | August 16, 2017 01:43pm ET

Dogs of a different color have been spotted roaming the streets of Navi Mumbai in India, according to news reports.

At least five bright blue dogs have been seen in the industrial area of the city, and a polluted river may be to blame, the Hindustan Times reported on Aug. 12.

Stray dogs often wade into the Kasadi River in search of food, but thanks to the industrial waste that's been released into the water, the dogs emerged with a Smurf-like dye job in addition to any scraps they could fish out. 

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Modern domestic dog has a single geographic origin

August 7, 2017

By analyzing the DNA of two prehistoric dogs from Germany, an international research team led by Krishna R. Veeramah, Ph.D., of Stony Brook University in the USA has determined that their genomes were the probable ancestors of modern European dogs. The study also suggests that all contemporary dogs have a common origin and emerged through a single domestication process of wolves 20,000 to 40,000 years ago. Researchers at Johannes Gutenberg University Mainz (JGU) also participated in the study, the results of which recently have been published in Nature Communications.

Dogs were the first animals to be domesticated by humans. The oldest remains of dogs that can be clearly distinguished from those of wolves originate from what is now Germany and are about 15,000 years old. Unfortunately, the archaeological record is ambiguous, with claims of ancient domesticated dog bones from the most varied locations as far away as Siberia.

Only last year were researchers able to sequence the genome of a 5,000-year-old dog from Ireland using the latest paleogenomic techniques. The results of the study led the research team at the University of Oxford to suggest dogs were domesticated not once but twice. In addition, the research team also hypothesized that an indigenous dog population domesticated in Europe was replaced by incoming migrants independently domesticated in East Asia during the Neolithic period.

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Why dogs are friendly - it's written in their genes

By Helen BriggsBBC News

20 July 2017

Being friendly is in dogs' nature and could be key to how they came to share our lives, say US scientists.

Dogs evolved from wolves tens of thousands of years ago.

During this time, certain genes that make dogs particularly gregarious have been selected for, according to research.

This may give dogs their distinctive personalities, including a craving for human company.

"Our finding of genetic variation in both dogs and wolves provides a possible insight into animal personality, and may even suggest similar genes may have roles in other domestic species (maybe cats even)," said Dr Bridgett vonHoldt of Princeton University.

The researchers studied the behaviour of domestic dogs, and grey wolves living in captivity. They carried out a number of tests of the animals' skills at problem-solving and sociability.

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Dogs could sniff out Parkinson’s disease years before symptoms appear

Sarah Knapton, Science Editor

9 July 2017 • 1:34pm

Dogs could soon be used to sniff out Parkinson’s disease years before symptoms start to show.

Scientists are trying to discover which odour molecules are linked to the disease so that dogs can be trained to spot the illness.

Researchers at Manchester University first began to believe Parkinson’s might have a discernible odour when a woman in Perth, Scotland,  with a highly sensitive sense of smell claimed she detected a change in the odour of her husband six years before he was diagnosed with the condition.

Joy Milne claimed her husband’s smell changed subtly years before any difficulty with movement started to emerge.   

When researchers conducted tests with Mrs Milne they found she was able to identify people living with Parkinson’s from people without the condition by smelling skin swabs taken from both groups.

In one case, Mrs Milne identified an individual who had Parkinson’s but at the time had not been diagnosed with the condition, because they had no symptoms.

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Sensitivity to inequity is in wolves' and dogs' blood

Date: June 8, 2017

Source: University of Veterinary Medicine -- Vienna

Not only dogs but also wolves react to inequity -- similar to humans or primates. This has been confirmed in a new study by comparative psychologists of the Messerli Research Institute of the University of Veterinary Medicine, Vienna. Wolves and dogs refused to cooperate in an experiment when only the partner got a treat or they themselves received a lower quality reward. Since this behaviour is equally strong in wolves and dogs, this sensitivity to inequity is not likely to be an effect of domestication, as has been assumed so far. It is rather a behaviour inherited from a common ancestor. The results were published in Current Biology.

Recognising inequity is an important social skill in humans. This is particularly important when we cooperate with others. Different species of primates show this sensitivity to inequity, too. It has hardly been investigated if other species also realise inequity and react to it. Several studies with dogs were at least indicative of some form of inequity aversion, for example when the dogs themselves did not get food, but their partners did for the same action. So far, this skill in dogs has been attributed to their adaption to humans -- domestication.

Their closest relatives, wolves, however, exhibit the same inequity aversion. This has been confirmed in a new study by the Messerli Research Institute and the Wolf Science Center of the University of Veterinary Medicine, Vienna. When the animals pressed a buzzer after the trainer had asked them to do so, and received nothing or a lower quality reward compared to their partners for the same action, they refused to participate in the experiment earlier. The behaviour was similar in equally raised wolves and dogs that had, therefore, the same life experience. This indicates a skill inherited from a common ancestor. Thus, domestication is not the only reason why dogs react to inequity.

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