Free-ranging dogs in India, daily activity

Indian Pariah Dog, Central India 

Many countries, both developed and developing have large populations of free-ranging dogs, notably Mexico, Ecuador, Zambia, Zimbabwe Italy, India, Nepal and Japan. Free-ranging dogs are a ubiquitous part of the urban ecology in these counties and others. However, dogs in India have lived outside of human homes for centuries and been used for hunting. Dog figurines and remains have been unearthed in the Indus Valley Civilization and references to dogs can be found in ancient Indian texts like the Rg Veda, the Puranas, the Mahabharata, the Ramayana and the Manu Samhita. Dogs are also present in many folk tales from across the country. The Hindu culture considers dog outcasts, associated with death and evil. However householder’s that have dogs outside their house have the daily duty feeding the dogs and outcasts. While the European influence has introduced pedigreed dogs to the homes of the middle class and elite society, the Indian pariah dog has continued to live on the streets, depending on garbage and begging for food.

In a recent paper Majumder et al. (2014) study free-ranging dogs, noting very little is known about the ecoethology and most of what we know about dog behavior is based on studies of pets reared by humans. The free-ranging dogs lead a scavenging life, depending on human excesses for their survival, and rarely hunt. They are often considered a menace by many people, as dirty animals that bark, bite and spread rabies. These notions are often founded on personal biases and little scientific data exist to either support or refute such claims. As part of an extended study on the behavioral ecology of free-ranging dogs in India, they carried out random sampling of dog behavior through censuses in two cities and one township of India. Data from 1941 sightings provided the basis for a time activity budget of dogs during the part of the day when they share the streets with humans.

The analysis revealed that the dogs are inactive for over half of the day, either sleeping, lazing or just sitting. Sampling was done only during the time when dogs could actually be seen on the streets, and were not hiding in shelters, so the authors suggest this is actually an underestimate. Their results match the observations on free-ranging dogs in Berkeley, California, USA, in which repeated sampling were carried out in a 48 ha residential area for seven months. In this study, 1243 sightings were made on about 50 unique free-ranging dogs, which were found to be resting in 44.4% of the sightings. This study also reported that free-ranging dogs were most abundant in the early mornings and late afternoons, with the percentage of dogs found to be resting increasing with temperature, for an observed temperature range of 9–29⁰C. Though temperature was not recorded during this study, the temperature range during observations was 8–36⁰C, considering all the time periods and the three locations covered. When the dogs were not resting, they were most often seen to be walking. Since the sampling was based on random sightings, the purpose of walking was unknown. Dogs typically walk in search of food, and also for marking their territories. Interaction rates were quite low, and all recorded instances of interaction with humans were submissive. Thus, this analysis does not support the general notion of free-ranging dogs being aggressive, unfriendly animals that are a constant source of nuisance to people on the streets of India.

Dogs bark and howl, often producing a chorus reminiscent of their wolf ancestors, and this makes them an irritant with many humans. Many encounters between dogs are often interrupted by people who chase them away, often by throwing stones or dousing them with water. Dogs were sighted producing sound in only 65 cases, which was 3.34% of the total observations. Thus, the perception of dogs as noisy and aggressive creatures that present a threat to human well-being is quite biased.

However, it is true that many dogs in the Indian streets are rabid, and dog bites do occur, though these are not regular incidents as perceived by some. Dogs are efficient scavengers, and are responsible for removing of a large volume of garbage from the streets. While this preliminary study suggests that the general perception of these dogs as a nuisance is quite flawed. The authors argue that the solution to dog–human conflict is not culling, but efficient management of garbage and rabies in the country, and a positive attitude towards dogs.

Citation

Majumder SS, Chatterjee A, & Bhadra A. (2014). A dog’s day with humans–time activity budget of free-ranging dogs in India. Current Science, 106(6), 874.

Dogs Jealous?

Jealousy is usually thought of as being unique to humans, in part because of the complex cognitions often involved in this emotion. However, from a functional perspective, one might expect that an emotion that evolved to protect social bonds from interlopers might exist in other social species, particularly one as cognitively sophisticated as the dog.

Harris and Prouvost (2014) experimented using a paradigm from human infant studies to examine jealousy in domestic dogs. They found that dogs exhibited significantly more jealous behaviors (such as snapping, getting between the owner and object, pushing/touching the object/owner) when their owners displayed affectionate behaviors towards what appeared to be another dog as compared to nonsocial objects.

When their owners showed affection toward a stuffed dog, the real puppies in the study responded by snapping or pushing the stuffed dog aside. This jealous streak only surfaced when owners were attending to the stuffed dog and not when they were occupied with random objects. However, this was no ordinary stuffed dog: It was engineered to bark, whine and wag its tail convincingly.

Since jealously is generally believed to be an emotion that requires more complex thinking, the researchers suggested there could be a more basic form of jealousy specific to dogs and some other social animals that helps protect their bonds and ward off outsiders.

"Many people have assumed that jealousy is a social construction of human beings -- or that it's an emotion specifically tied to sexual and romantic relationships," study co-author Christine Harris, a psychology professor at UCSD, said in a university news release. "Our results challenge these ideas, showing that animals besides ourselves display strong distress whenever a rival usurps a loved one's affection."

As for whether the puppies in the study viewed the stuffed dog as an actual rival, the researchers pointed to this result as evidence that they did: 86 percent of the puppies sniffed the stuffed dog's rear end.

The study, published July 23 in the journal PLOS ONE, involved 36 puppies. Each dog was just 6 months old. All of the puppies were tested separately and videotaped.

During the test, owners were told to ignore their dog and turn their attention to three different objects. First, the owners attended to the realistic-looking stuffed dog. Then they focused on a pail. The third object in the test was a book.

In observing the dogs' behavior, the researchers looked for signs of aggression, attention-seeking and interest in their owner or the objects. The test was designed to help the researchers determine if the dogs felt an emotion similar to jealousy, or if they were just generally annoyed when they lost their owners' attention.

The dogs demonstrated more jealous behaviors when their owner focused on the stuffed dog than when their owner paid attention to the other objects, the study found. These behaviors included trying to come between their owner and the stuffed dog, pushing their owner and snapping when the owners displayed affection toward the stuffed dog.

The researchers concluded a form of primitive jealousy that exists in babies may also exist in at least one other social animal: dogs. This emotion, the study's authors suggested, may have evolved to help infants compete for resources from their parents, including food, attention, love and care.

Citation

Harris CR, Prouvost C (2014) Jealousy in Dogs. PLoS ONE 9(7): e94597. doi:10.1371/journal.pone.0094597

Dogs as vectors of rabies

While rabies is considered a relatively rare disease in developed countries, in much of the developing world it remains a serious health issue for humans. Two recent papers deal with dogs as vectors of rabies to humans.

Electron micrograph of the Rabies Virus. This electron 

micrograph shows the rabies virus - the small gray 

bodies, as well as Negri bodies, or cellular inclusions. 

CDC/Dr. Fred Murphy.

Aréchiga Ceballos et al. (2014) report that over 90% of human deaths from rabies worldwide are caused by dog bites. Mass vaccination, along with the effective control of dog populations, has been used successfully in industrialized countries to control this disease. However, a lower success rate in developing countries is due to a number of factors, including vaccination campaigns that do not cover a sufficient number of animals or reach all communities, and a wide biodiversity that increases the number of reservoirs of the rabies virus. Educational programs are needed, which focus on the commitment involved when acquiring a domestic animal, stating clearly what is required to provide it with a good quality of life. New technologies developed in the industrialized world will not always be successful in less developed countries. Approaches must be adapted to the particular conditions in each country, taking cultural and socio-economic issues into account. Authorities must promote research on dog population dynamics, the development of non-invasive methods to control dog populations and the most efficient, stable and low-cost options for vaccination. Under the One Health model, it is hoped that dog-transmitted human rabies will be accorded high priority as a zoonosis by human health authorities, international authorities and donor agencies to support ambitious eradication goals, particularly those being set in South-East Asia. Well-designed and adequately resourced vaccination programs, based on the World Organization for Animal Health (OIE) guidelines, will have significant animal welfare benefits, due to the availability of improved vaccines (in terms of efficacy, duration of immunity, ease of administration and lower cost), advances in dog population management and the more widespread implementation of the OIE Guidelines on stray Dog Control. Animal welfare benefits include not only the elimination of pain and suffering caused by the clinical disease itself, but also the avoidance of the indirect impact of inhumane culling when methods are used that have not been approved by the OIE.

In a second, recent paper on dogs and rabies Ajoke et al. (2014)  review the risk factors associated with dog trading and slaughtering dogs for food in the transmission of rabies in Nigeria. Emphasis on the potential role that the butchers play in rabies transmission and their susceptibility to rabies through contact with infectious meat samples and materials is also discussed. Dog meat has become a delicacy in many parts of Nigeria. It is eaten for various reasons including medicinal values, source of protein, and in rituals. Dogs are transported to the slaughter-houses for processing and they may have multiple origins. The rabies virus has been confirmed in apparently healthy dogs to be slaughtered showing that butchers are at risk, especially in Nigeria, where the butchers neither wear protective gear nor have they been vaccinated against rabies. The authors recommend regular vaccination for butchers and dogs. They conclude that dog trading, slaughtering and consumption probably play a major role in the epidemiology of rabies from dogs to humans in Nigeria.

Citation
Ajoke E., Solomon A, and Ikhide E. 2014. The role of dog trading and slaughter for meat in rabies epidemiology with special reference to Nigeria - a review. Journal of Experimental Biology and Agricultural Sciences, 2:130-136.

Aréchiga Ceballos N, Karunaratna D, Aguilar Setién 2014. Control of canine rabies in developing countries: key features and animal welfare implications. A Revue Scientifique et Technique (International Office of Epizootics)  33:311-321

The Donggyeong, a poorly known dog from Korea

Native dogs of Korea

The Cultural Heritage Administration (Korea) registered the Donggyeong breed on its list of natural monuments in 2012. This is a state-designated heritage classification for animals, plants and biological and geological features carrying exceptional historical, cultural, scientific, aesthetic or academic value. The Jindo and the Sapsal dogs had been previously given this designation (see photos to the left).

The oldest reference to the Donggyeong is in The Chronicles of the Three Kingdoms, a book about Korea’s Three Kingdoms era, a period between the fourth and seventh centuries, and written during the Goryeo period (918-1392). One of the chapters of the book, “Assorted Information on the Donggyeong,” is dedicated to the dog. The Donggyeong was also a model for dogs appearing on earthenware made by during the Silla Dynasty (B.C. 57-935). 

At first glance, the Donggyeong looks very similar to the Jindo. However, the key distinction is in the tail: While the Jindo’s tail is long and curved, the Donggyeong has  a bobtail or completely lacks a tail.

In 2007 locals initiated a project to preserve the breed, forming an organization called the Korea Preservation Association for Gyeongju Dog Donggyeong and started breeding the dog in Gyeongju. Today, there are some 306 Donggyeong dogs which are officially recognized by the CHA.

In a forthcoming paper in the Journal of Veterinary Medical Science (Japan) Gil-jae Cho and colleagues analyze 10 microsatellite markers in the Donggyeong dog and compare it to 12 other dog breeds (369 individual dogs). The number of alleles per locus varied from 5 to 10 with a mean value of 7.6 in the Donggyeong dog. This study found specific alleles in the Donggyeong dog when compared with other dog breeds. Also, the results showed two Korean native dogs cluster together while other dog breeds form a distinctly different cluster. The closest distance (0.1184) was observed between the Donggyeong and Jindo suggesting a common ancestor.

Citations

Lee, E. W., Choi, S. K., & Cho, G. J. (in press, 2014). Molecular Genetic Diversity of the Gyeongju Donggyeong Dog in Korea. The Journal of veterinary medical science/the Japanese Society of Veterinary Science.

Dog of Silla royalty gets heritage designation. Korea JoogAng Daily. April 9, 2012.

Detection dogs and big cats

Greg Davidson and detection dog Chevy searching for cougar scat.

Detection dogs can be trained to locate explosives, illegal drugs, wildlife scat, or human remains. They have even been trained to locate illicit mobile phones in prisons. But, they have become extremely valuable for wildlife biologists and have been used to collect data on invasive species as well as endangered species.

In a forthcoming study in the Journal of Wildlife Management, Greg Davidson and colleagues from Find it Detection Dogs, used detection dogs to estimate the population size of cougars in northeast Oregon. Cougars are solitary, elusive, and have large home ranges. The researchers surveyed a 220 km² area using conservation detection dogs trained to locate cougar scat. Two hundred and seventy-two scat samples were collected, and 249 were analyzed for individual identification using DNA.  From 73 samples, 21 cougars (9 males and 12 females) could be recognized. The authors evaluated four models to estimate cougar densities: Huggins closed population capture–recapture (Huggins), CAPWIRE, multiple detections with Poisson (MDP), and spatially explicit capture–recapture (SECR). Their population estimates for the study area were 26 (9 males and 17 females) from Huggins models, 24 (9 males and 15 females) from CAPWIRE, and 27 (9 males and 18 females) from the MDP model.

This study demonstrates the efficacy of using detection dogs to collect cougar scat. The results suggest the probability of a dog finding a cougar’s scat on the landscape (given scat was available) in any of the 4 surveys was 0.99 for males and 0.68 for females. As a result, the authors were able to collected scat from all 4 GPS-collared cougars known to occupy a portion of the study area. The reported capture probabilities of this study were the largest observed for any previous study conducted with wild felids, which highlight the benefits of using scat detecting dogs to estimate cougar densities. Determining the age of the cougars captured was not possible because of the use of scat; so, their estimates included adults, subadults, and juveniles old enough to leave den sites.

Citation

Davidson, G. A., Clark, D. A., Johnson, B. K., Waits, L. P., & Adams, J. R. (in press, 2014). Estimating cougar densities in northeast Oregon using conservation detection dogs. The Journal of Wildlife Management. DOI: 10.1002/jwmg.758

The advantages of being a scavenger, and the evolution of dogs

Dogs are scavnegers. JCM

 One night in the tropics I had to stop to change a tire. My companion was looking along the roadside for snakes while I set up the jack, removed the tire from the trunk and jacked-up the car. It was just about this time when I heard him vomiting. He returned to the car muttering – “oh that was horrible.” At first I thought he was talking about dinner.  After inquiring about his health he said, he was ok, but had seen something vile –telling me not to look. Needless to say I did look and found the remains of a goat, which had been tied along the road and hit by a vehicle. Actually when I say remains - the only remains of the goat was a seething mass of maggots in the perfect outline of the goat. Decomposition repels humans- the odor, the bloat, the liquefaction – horrible stuff but it eventually happens to all of us when the ecosystem recycles our molecules.

Animals die from a variety of causes other than predation. Accidents and disease take their toll and when they die the carcass is a valuable source of calories, proteins, and nutrients for any animal that can scavenge the remains. In the tropics scavengers are in a race with the decomposers (bacteria and fungi) to obtain those nutrients, but at high latitudes where cooler temperatures prevail decomposition is much slower. Large animal carcasses may stay around for months or even years if it is in an area of permafrost, because temperatures do not favor bacterial or fungal growth.

Virtually any vertebrate predator can be a scavenger, even predators that are dedicated predator may eat carrion on occasion.

DeVault et al. (2002) note, “The costs and benefits associated with carrion use influences the evolution of scavenging behavior in vertebrates, resulting in a continuum of facultative scavengers that use carrion to varying degrees. The realized usage of carrion by a vertebrate species is influenced by the speed and efficiency with which it forages, its visual and olfactory abilities, and its capacity for detoxifying products of decomposition. A deeper understanding of carrion use by facultative scavengers will improve our knowledge of community and ecosystem processes, especially the flow of energy through food webs.”

Making a living scavenging carrion has its advantages: the animal is dead so there is no chance the prey will injure the predator as it is killed and there is little effort involved in actually getting to the meal, but, there may be completion from other scavengers.

To be sure wolves do act as scavengers, but when they kill prey they also provide food for other scavengers in the community.

So, under what conditions might a population of wolves be selected to be scavengers instead of predators? The possible answers to this question will provide clues as to how a population of wolves evolved into dogs sometime between 135,000 and 40,000 YBP (years before present).

Citation

DeVault TL, Rhodes OE Jr, and Shivik JA 2003. Scavenging by vertebrates: behavioral, ecological, and evolutionary perspectives on an important energy transfer pathway in terrestrial ecosystems. USDA National Wildlife Research Center – Staff Publications Paper 269.

How long ago did the dog and wolf separate from their ancestor?

Dates for the most recent common ancestor (MRCA) for dogs and wolves are remarkable recent. When Stan Olsen (1983) wrote his classic work on domestic dog fossils (1983) he noted the oldest known remains were from Palegawra Cave in northeastern Iraq with an estimated age of 12 thousand years before present (YBP).

But subsequent evidence suggests that dogs split from wolves much latter than those fossils would imply. Deep in Chauvet cave, in France, Garcia (2005) found a track of footprints from a large canid associated with one of a child. Torch wipes made by this child were dated at about 26,000 YBP. Based on the short length of medial fingers in the footprints the canid track was interpreted as being made by a large dog.

Genetic data also suggests that the dogs originated prior to the often cited 15,000 YBP. Ostrander and Wayne (2005) report that mitochondrial DNA (mtDNA) sequence analysis shed some light on the location of dog domestication as well as the number of founding matralines. They found dog sequences in at least four distinct clades, suggesting a single origin event and at least three other origination or interbreeding events. They also found nucleotide diversity high, implying an origin date of 135 to 40 thousand YBP. And Ostrander and Wayne (2005) suggests dogs may have had a long prehistory when they were not phenotypically distinct from wolf progenitors. Therefore early dogs may not have been recognized as domesticated in the archaeological record prior to 15,000 YBP because of their physical similarity to gray wolves.

However, a group of morphologically distinct canids hypothesized to be early domesticated dogs have been identified by Germonpré et al., (2009, 2012). Seven complete large canid skulls and 26 skull fragments from the Gravettian Předmostí site in the Czech Republic were examined, three skulls were identified as European Palaeolithic dogs, characterized by short skulls, short snouts, wide palates and braincases, and even-sized carnassials. The presence of dogs at Předmostí supports the hypothesis that domestication of dogs began long before the Late Glacial. One of the skulls was identified as a Pleistocene wolf, three other skulls could not be assigned to a group. Furthermore, at Předmostí, several human modifications of the skulls and canines hint at a specific relationship between humans and large canids.

While this has been controversial (see Crockford and Kuzmin, 2012), the evidence continues to mount supporting a much older origin of dogs. Druzhkova et al. (2013) provide molecular evidence that the 33,000-year old Pleistocene dog from Altai has a unique haplotype and the Altai dog is more closely related to modern dogs and prehistoric New World canids than it is to extant wolves.

In a forthcoming article in Quaternary International Pat Shipman of Pennsylvania State University asks the question, how do you kill 86 mammoths. The author examines a series of Eurasian archaeological sites formed between about 40 and 15 thousand years ago that feature unusually large numbers of mammoth remains with abundant artifacts and, often, mammoth bone dwellings. 

Since the late 19th century, archaeological sites dominated by mammoth remains have been a focus for research. How the bones of large numbers of mammoths, ranging from a minimum number of five individuals to hundreds of individuals, were deposited in one place remains an un-answered question. And, despite previous investigation, the cause of death of mammoths in these sites has remained controversial.

Two predominate hypotheses have been used to explain these megasites (a reference to the large number of mammoth remains): (1) the mammoths died natural deaths which were subsequently scavenged by humans; (2) or that specialized human hunting resulted in the deaths of the mammoths. Questions about collection and excavation techniques pose challenges for synthesizing the information, but the wealth of material has produced numerous published zooarchaeological analyses of the sites, including number of non-mammoth species represented, minimum numbers of mammoths at each site, mammoth age at death, and mammoth age profiles from individual sites.

All of these mammoth megasites are dated after the appearance of modern humans in Eurasia. These unusual sites are of interest given the obvious successes of the humans that made them. But, also because of the large number of individual mammoths and the scarcity of carnivore tooth marks and gnawing.  The evidence suggest the mammoth hunters had invented a new ability to retain and control the mammoth carcasses – protecting all of that valuable protein from scavengers.

Age profiles of mammoths at the megasites differ statistically at the p < 0.01 level from age profiles of African elephant populations that died of either attritional or catastrophic causes. However, age profiles from some mammoth sites exhibit a chain of linked resemblances with each other through time and space, again suggesting hunter behavioral and technological innovation.

The megasites Shipman analyzed are spread across most of the Eurasian continent and over a substantial time span. The introduction and spread of complex projectile weaponry by modern humans was probably important in producing the abrupt changes in assemblages associated with hominins that started about 45,000 YBP. Previous authors observed that reduced weight projectile weapons are a “niche-broadening technology” because they are easily carried, retain energy longer in flight, and they reduce the risk of injury when hunting dangerous animals or in combat when fighting other people. Thus early modern humans may have broaden their ecological niche. The reduced weight projectile weapons transforms the hunters from ambush predators (as Neanderthals were) to being long-distance hunters. Shipman also suggests a second advance which occurred during MIS 3 (marine isotope stage 3, which started 57,000 YBP) may have enhanced the advantages of reduced weight projectile weapon technology - a quasi-domesticated large canids willing to work cooperatively with humans.

Shipman (2014) hypothesize that this innovation may have been facilitated by an early attempt to domesticate dogs, as indicated by a group of genetically and morphologically distinct large canids which first appear in archaeological sites at about 32,000 YBP.

Thus at the moment it would appear that the MRCA of dogs and wolves is indeed much older than 15,000 YBP. It also appears that dogs, were co-operating with humans at least 32,000 YPB. But did humans domesticate the dog, or did dogs evolve from wolves all on their own?

Citations

Crockford, S. J., & Kuzmin, Y. V. (2012). Comments on Germonpré et al., Journal of Archaeological Science 36, 2009 “Fossil dogs and wolves from Palaeolithic sites in Belgium, the Ukraine and Russia: osteometry, ancient DNA and stable isotopes”, and Germonpré, Lázkičková-Galetová, and Sablin, Journal of Archaeological Science 39, 2012 “Palaeolithic dog skulls at the Gravettian Předmostí site, the Czech Republic”. Journal of Archaeological Science, 39(8), 2797-2801.

Druzhkova AS, Thalmann O, Trifonov VA, Leonard JA, Vorobieva NV, et al. (2013) Ancient DNA Analysis Affirms the Canid from Altai as a Primitive Dog. PLoS ONE 8(3): e57754. doi:10.1371/journal.pone.0057754.

Garcia, M.A., 2005. Ichnologie ge’ne’ rale de la grotte Chauvet. Bulletin de la Socie’ te’ pre’ historique francaise 102, 103–108.

Germonpré, M., Sablin, M. V., Stevens, R. E., Hedges, R. E., Hofreiter, M., Stiller, M., & Després, V. R. (2009). Fossil dogs and wolves from Palaeolithic sites in Belgium, the Ukraine and Russia: osteometry, ancient DNA and stable isotopes. Journal of Archaeological Science, 36: 473-490.

Germonpré, M., Lázničková-Galetová, M., & Sablin, M. V. (2012). Palaeolithic dog skulls at the Gravettian Předmostí site, the Czech Republic. Journal of Archaeological Science, 39(1), 184-202.

Kolosov, P. N. (2014). Primitive Mammoth Hunters and the Earliest Breed of Dog. Natural Resources, 2014.

Olsen, S. J. (1985). Origins of the domestic dog: the fossil record. University of Arizona Press, Tucson. 117 pp.

Ostrander, E. A., & Wayne, R. K. (2005). The canine genome. Genome research, 15(12), 1706-1716.

Shipman, P. (in press, 2014). How do you kill 86 mammoths? Taphonomic investigations of mammoth megasites. Quaternary International.

H3N8 structure determined – canine influenza originated in horses

Canine influenza is a highly contagious respiratory infection of dogs caused by a novel influenza virus (H3N8) that was first discovered in 2004. Like influenza in other species, the canine influenza virus causes a cough, sneezing and nasal discharge. A fever may also occur, but it is usually transient and rarely noticed by dog owners. H3N8 cannot be distinguish from other respiratory infections without diagnostic tests.

All dogs exposed to H3N8 become infected; about 80% become ill, the other 20% show no symptoms. Recovery time is about two weeks but some dogs progress to pneumonia, which is usually due to secondary bacterial infections. While the mortality rate for canine influenza is very low, the secondary pneumonia can be life-threatening in some cases. Canine influenza is an emergent disease in dogs.

Collins et al. (2014) recently used x-ray crystallography to determine the structure of the H3 hemagglutinins (HAs) in two different equine viruses and the canine virus. They found all three are very similar in structure with the majority of amino acid sequence differences between the two equine HAs located on the virus membrane. HAs of canine viruses are distinct in containing the amino acid substitution Trp-222→Leu in the receptor binding site that influences specificity for the receptor. In the canine and recent equine virus HAs a unique difference is observed by comparison with all other HAs examined to date. Analyses of site-specific mutant HAs indicate that a single amino acid substitution, Thr-30→Ser, influences interactions between N-terminal and C-terminal regions of the subdomain that are important in the structural changes required for membrane fusion activity. Both structural modifications may have facilitated the transmission of H3N8 influenza from horses to dogs.

The authors summarized the situation as follows. Equine influenza viruses of the H3N8 subtype were first isolated in 1963 from race horses in Miami. Since then they have caused numerous outbreaks of infection in horses around the world with serious disease and economic consequences. In 2004, again in Florida, an H3N8 virus was isolated from an outbreak of canine influenza and similar viruses have since been isolated from dogs in the United States and in Europe. Genetic comparisons indicate that the canine viruses are closely related to equine viruses that were in circulation in horses around 2000. In studies of differences in equine viruses isolated since 1963 and between equine and canine viruses, the sequences of genes for the hemagglutinin membrane glycoprotein (HA) have been compared. Sequence data for equine virus HAs indicate the evolution of four distinct lineages. The first was associated with antigenic drift, between 1963 and 1980, and following this three separate branches formed a “Eurasian” lineage, an “American” lineage, and a divided lineage containing two clades, “Florida” clade 1 and Florida clade 2. The HAs of the canine viruses are most similar to those of Florida clade 1 equines. The majority of amino acid sequence changes revealed from the analyses are in the HA1 component of HA, some in regions known to be antigenically important in H3 HAs, and several near the receptor binding site.

The pdf is available on-line.

Citation

Collins, P. J.,  et al. (2014). Recent evolution of equine influenza and the origin of canine influenza. Proceedings of the National Academy of Sciences, 201406606.

Dogs are scavengers first

Much of what has been written about dogs is undoubtedly nonsense. And, we will leave the critique of popular TV dog shows for the future. While dogs and wolves undoubtedly shared a common ancestor, it seems improbable that dogs were originally modified from wolves by artificial selection by humans. After all, abandoned dogs do not revert to being wolves, they become just feral dogs. Have humans selected dogs for various traits (color, body size, temperament, etc.) in recent times – undoubtedly they have. But, humans probably had little to do with getting a population of wolves to evolve into the dog. The animal that is generally considered the oldest domesticated species.

A free-ranging dog scavenging leatherback sea turtle nests

on Grande Riviere Beach on the north coast of Trinidad. Note

the large number of black vultures also present. JCM

In chapter 10 of the recently published book, Domestic Dog Cognition and Behavior, titled “A Dog’s-Eye View of Canine Cognition” by Udell, Lord, Feuerbacher and Wynne the authors suggest the following.

Most dogs are scavengers and live on the periphery of human society. These dogs are more likely to avoid human contact than seek it. While pet dogs have been a major focus of recent research is unlikely that the human-dog bond is a special adaptation that is the result of co-evolution, but rather the bond is the expression of basic processes such as conditioning, socialization and biological traits that are shared by domestic and wild canids. Individual dogs that have been socialized to humans and become dependent on them have high levels of sensitivity to human actions. Udell and colleagues argue that the fundamental differences between dog and wolf behavior lie at more basic levels: in the processes of socialization, foraging, and reproduction. Small but crucial intertwined changes in the ancestral dog population led dogs to (1) become more promiscuous than any other canid, (2) be able to reproduce more rapidly than wolves, (3) be a much less effective hunter but (4) dogs are more efficient scavenger than other canids. The authors view the indirect consequences of these changes as producing dogs, and suggest that while “…it may be a little less flattering to the human species, we believe this perspective on dogs is at least as fascinating and closer to the historical truth than the story that humans created dogs.”

Citation

Udell, M. A., Lord, K., Feuerbacher, E. N., & Wynne, C. D. (2014). A Dog’s-Eye View of Canine Cognition. In Domestic Dog Cognition and Behavior (pp. 221-240). Springer Berlin Heidelberg. A pdf of this chapter can be found on-line.

Some of my early experiences with dogs

In the early 1980’s during a reptile survey on Trinidad I was watching a lizard, an Amieva or as the Trinidadians call them, a zandolie, forage for insects at the edge of a dump. My binoculars were focused on the lizard’s movements and it was several minutes before I realized Turkey Vultures had gathered on the waste pile. The birds had surrounded a severely emaciated puppy with its ribs clearly visible through its severely ulcerated skin. The dog’s death was imminent.  The birds moved closer and soon my view of the dog disappeared amid a flurry black feathers.

Biology tells us that all organisms produce far more offspring that can be expected to survive. This was one of Charles Darwin’s founding principles for natural selection and an idea he may have gleaned from Thomas Malthus’ Essay on Population. Over production of offspring allows the environment to select the individuals best adapted to local condition to survive and reproduce, while those individuals least fit for the environment are eaten by predators, or they become diseased, and unable to find shelter – they become victims of the climate and food for scavengers and decomposers. Despite my understanding of this basic principle my gut told me I should save the dog while my brain told me the vultures need food, the dog was too far gone to be rescued, and this is the way ecosystems process matter and energy.  I had observed predation and scavenging numerous times involving many species but never remember feeling the way I did at that dump. Before that point in time I had never owned a dog and the observation increased my curiosity about dogs, humans and myself.

Dogs generate a strong emotional and empathetic response in most of us, perhaps because we identify with them, or perhaps because we know that as humans we are responsible for their plight. Dogs, after all, are human commensals. Rats, cats, cockroaches and, of course dogs, owe their biological success to humans. Humans have created environments where these species thrive by increasing their food supply, habitat, and social environment. But, aside from cats, dogs are the only commensal we have an emotional bond with. The emotion I felt at the Trinidadian dump and the bonds I have formed over the years with several different family dogs are responsible for the title of this blog. There is something quite unique at the core of dog-human relationships and it is the central focus of this blog. Why should a human feel an emotional bond with a dog?  Particularly, if that human had never had extended contact with a dog.

Twenty-five years after the observation in Trinidad I was studying aquatic snakes in Thailand and dogs were often present. Well cared for dogs were the exception, in villages and on the edges of large cities feral dogs are a serious problem. One hotel I stayed at just north of Bangkok was next to a canal with roads paralleling the water on each side. One side of the canal was lined with homes and stores; the other side was abandoned rice paddies. It made an excellent jogging trail for early morning exercise. At this time of day local fishers were throwing cast nets into the canal, and factory workers were on their way to work on an armada of motor bikes. Dogs, lots of dogs, were sleeping on the street and along the dirt road. Most were small, 15 to 25 pounds and often uniform tan in color or with blotches of white or black. Most had skin infections, were severely malnourished, and sometimes followed me for short distances as I walked and jogged along the path. These feral animals resembled my family dogs only in form and they made me nervous – rabies was a potential result of being bitten by one of these animals.

My family’s first dog was purchased in a pet shop. Sara’s fifth birthday was approaching and the only thing she had ever asked for was a dog. Kathie and I had resisted. While I was busy looking at an anaconda for sale in the pet shop, Kathie and Sara were visiting the dogs. One of the employees removed a keeshond puppy from a cage, and it immediately took to following Sara. One pet shop customer, impressed with the dog’s interest in Sara, approached Kathie and said something like, “This is a Kodak moment. You are going to buy her that dog, aren’t you?” We left the pet shop without the dog, had dinner, and returned to buy or rescue the puppy. Sara loved Star Wars, and the dog’s appearance was reminiscent of the Ewok creatures in fur density and coloration, we named him Wicket.

Yes, I know I was not supposed to buy a pet shop dog, it was probably produced in a puppy mill, but I also knew that the dog would have a much better life with us than someone else. Parents of many species go to extremes for their offspring. Biologists call this kin selection and it’s an idea that plays a major role in understanding relationships between dogs and people as well as between members within each species.

Wicket was soon a member of the family. Our fenced-in-yard on a busy street assured him a secure place to play, but there were stairs involved in getting into the yard and the dog was too small to navigate the steps. I spent a considerable amount of time transporting Wicket to the yard during that winter in an attempt to housebreak him.

It was sometime in late winter when I arrived home from school; Kathie and Sara were already there. As I walked in the door Wicket raced back and forth between me and the back door. I followed him to the steps that lead into the yard. What followed is something that animal behavior courses do not prepare you for. The dog was accustomed to me carrying him into the yard. As I opened the door, Wicket raced down the stairs by himself and returned to the top of the stairs, and again raced to the bottom of the stairs and back up. The damn dog was showing me that he could now navigate the stairs by himself and no longer needed my help. Wicket taught me much about behavior and dogs. Another moment of learning came when I walked Sara and the dog to a nearby park. Sara played on the swings and was having a good time and she did not want to leave. While she rarely argued with me, this day she did. I said, “Ok, Wicket and I are going home.” As I walked away from Sara, the dog sat down and I had to pull him down the street in the sitting position. He was not going to leave Sara willingly. This kind of loyalty was not present in the village dogs that followed me along that dirt road in Bangkok. The village dogs had not been socialized.

Wicket lived a good life, despite the fact that he developed epilepsy and need to be treated with drugs for much of his life. After a grand mall seizure he would frequently be confused for hours. After a particularly severe seizure I remember him standing with his head in the corner of a room not knowing how to get out.  After eight or nine years he reached a point beyond which we could care for him, and like many family dogs he had to be euthanized.

I had been thinking about dogs more frequently and it occurred to me that having two may be better for them and increase what I could learn about them. Sara was now in high school and I had found a kennel that bred Samoyeds. During a visit to the kennel the breeder had an 18 month old female that she was interested in selling on a breeding contract. After considerable thought, we agreed. We would buy Taiga and breed her once. Our intention was to keep one of the puppies. Again, I would not recommend this kind of arrangement to people just wanting a dog or two, but I was curious and interested in learning what I could from the experience.

Taiga was large, she weighed about 80 pounds and her wolf-like appearance on the street made many people nervous. While she was exceptionally friendly, she was not at all loyal. She would go off with just about anyone. Shortly after she started living with us there was a snow storm, I had closed the side door to the garage and opened the main door to shovel the driveway. The blowing snow reduced visibility and the wind had popped the side door open. I soon gave up on shoveling and returned to the house only to find the dog gone. Looking for a white dog in a snow storm is like, well you know, like trying to find the proverbial needle. I drove around the neighborhood looking for her without success. We had to be at school and Kathie and I asked everyone if they had seen the dog, one student said he had seen a large white dog getting into a police car not too far from our house. A call to the station confirmed the village police had picked her up after she walked into a neighbor’s house and joined the family for breakfast. The homeowner was retrieving his newspaper and as he entered the house Taiga followed.

Taiga went into estrus and was mated to a male from her home kennel, 60 days later she went into labor. It was early in the morning when the first pup was born and I had already gone to school. Kathie called and insisted I return because she did not want to play midwife. Taiga was having strong contractions but more puppies were not coming through the birth canal. Kathie and Sara went school, leaving me with the dog. Steve was a good friend and a vet and I soon had him on the phone. His first advice was, wait another 10 minutes for the next puppy. I waited 15 minutes and there was no puppy. Another phone call to Steve, and he asked how many puppies were expected? The x-rays had shown nine. Steve’s advice was to wait another 10 minutes. While waiting I called my office and got someone to cover my first class. Ten minutes passed and still no puppy. The third call to Steve, and the advice was the same wait 10 more minutes. I had predicted the response on the fourth call to Steve― get the dog to the local vet. At the vet’s office an injection of oxytocin, a pituitary hormone, stimulated the muscles in the uterus and birth canal to contract and push the puppies out of Taiga. By early evening I picked up the dogs and brought them home.

Taiga delivered nine pups; two had not survived the trip through the birth canal. The surviving pups were housed in a whelping box, and Taiga proved an attentive mother, frequently cleaning and feeding her offspring and, as they became more mobile she kept them from wandering out of box. Despite the fact she had a warm room in the house to maintain her puppies she would often return to the den hole she had started to dig under the house in the backyard.  We had provided a dog door in the wall of the hallway so she could exit the house onto the deck and have access to the backyard. Soon the puppies were following her outside. Once they had reached eight weeks of age the breeder took six of them, we kept two and gave one to some close friends. We kept Rossi, the first puppy born at the house, and the largest male in the litter. Taiga trained Rossi to use the backyard, he required no housebreaking from us and he grew quickly, eventually weighing 100 pounds.

Rossi was highly intelligent and much more loyal than his mother. He would often report his mother’s mischievous deeds to us. Taiga was a consummate counter-surfer; anything edible left on a counter would be found and consumed. One day she found a five-pound bag of M&M candy on the counter, took it to the backyard, and consumed much of it. Contrary to popular belief, chocolate is not always toxic to dogs. Rossi found the wrapper and brought it to Kathie. Taiga also gained a reputation with the cable company for chewing up remotes. You know you have a problem when you see power buttons sticking out of dog poop in the backyard.

Rossi

The ability to mimic behavior is often consider a sign of intelligence and Rossi would mimic emergency vehicle sirens and would even include the sound changes that resulted from the Doppler effect as the emergency vehicles approached and then pass the house. But one day he mimicked me in a quite unexpected way. Rossi was completely house broken; he never had an accident in the house. One day I was mopping the hardwood floors with a sponge mop and a bottle of cleaner. I would squirt some the cleaner onto the floor and then mop the area. Rossi watched me intently. A stream of cleaner would come out of the bottle and I would push it around with the mop. Standing in front of the mop, Rossi released a stream of urine on the floor, directly in front of the mop. I am sure he thought he was helping by mimicking my behavior with the bottle of cleaner. 

Why dogs look like they do - domestication syndrome

A free-ranging dog living at a Trinidad dump. JCM

More than 140 years ago, Charles Darwin noticed something peculiar about domesticated mammals. Compared to their wild ancestors, domestic species are more tame, and they also tend to display a suite of other characteristic features, including floppier ears, patches of white fur, and more juvenile faces with smaller jaws. Since Darwin's observations, the explanation for this pattern has proved elusive, but now, in a Perspectives article published in the journal Genetics, a new hypothesis has been proposed that could explain why breeding for tameness causes changes in such diverse traits.

The underlying link between these features could be the group of embryonic stem cells called the neural crest, suggest the authors. Although this proposal has not yet been tested, it is the first unified hypothesis that connects several components of the "domestication syndrome." It not only applies to mammals like dogs, foxes, pigs, horses, sheep and rabbits, but it may even explain similar changes in domesticated birds and fish.

"Because Darwin made his observations just as the science of genetics was beginning, the domestication syndrome is one of the oldest problems in the field. So it was tremendously exciting when we realized that the neural crest hypothesis neatly ties together this hodge-podge of traits," says Adam Wilkins, from the Humboldt University of Berlin. Wilkins is an editor at Genetics and one of the paper's authors.

Neural crest cells are formed near the developing spinal cord of early vertebrate embryos. As the embryo matures, the cells migrate to different parts of the body and give rise to many tissue types. These tissues include pigment cells and parts of the skull, jaws, teeth, and ears -- as well as the adrenal glands, which are the center of the "fight-or-flight" response. Neural crest cells also indirectly affect brain development.

In the hypothesis proposed by Wilkins and co-authors Richard Wrangham of Harvard University and Tecumseh Fitch of the University of Vienna, domesticated mammals may show impaired development or migration of neural crest cells compared to their wild ancestors.

"When humans bred these animals for tameness, they may have inadvertently selected those with mild neural crest deficits, resulting in smaller or slow-maturing adrenal glands," Wilkins says. "So, these animals were less fearful."

But the neural crest influences more than adrenal glands. Among other effects, neural crest deficits can cause de-pigmentation in some areas of skin (e.g. white patches), malformed ear cartilage, tooth anomalies, and jaw development changes, all of which are seen in the domestication syndrome. The authors also suggest that the reduced forebrain size of most domestic mammals could be an indirect effect of neural crest changes, because a chemical signal sent by these cells is critical for proper brain development.

"This interesting idea based in developmental biology brings us closer to solving a riddle that's been with us a long time. It provides a unifying hypothesis to test and brings valuable insight into the biology of domestication," says Mark Johnston, Editor-in-Chief of Genetics.

Tests of the neural crest hypothesis may not be far off, as other scientists are rapidly mapping the genes that have been altered by domestication in the rat, fox, and dog. The hypothesis predicts that some of these genes will influence neural crest cell biology.

If so, we will have a much deeper understanding of the biology underlying a significant evolutionary event, Wilkins says. "Animal domestication was a crucial step in the development of human civilizations. Without these animals, it's hard to imagine that human societies would have thrived in the way they have."

The full article is available on-line.

Citation
A. S. Wilkins, R. W. Wrangham, W. T. Fitch. The "Domestication Syndrome" in Mammals: A Unified Explanation Based on Neural Crest Cell Behavior and Genetics. Genetics, 2014; 197 (3): 795 DOI: 10.1534/genetics.114.165423