Monday, August 30, 2010

Differences Between Tracking and Scent Lineups Are More Substantial Than Some Courts Recognize

A Texas court found that there is "little distinction between a scent lineup and a situation where a dog is required to track an individual’s scent over an area traversed by multiple persons.” Winston v. Texas, 78 S.W.3d 522 (Court of Appeals, 14th Dist., 2002). This supposed similarity, almost identity, of tracking and trailing to scent lineups, has been used by courts in applying the same foundational requirements to the admission of both types of evidence. There are, in fact, numerous differences between the two canine functions, and some are significant from a forensics perspective. The following list of differences is probably not exhaustive. Tracking and trailing descriptions are in Roman type, while scent lineup descriptions follow in italics.

1. Dogs trained to follow tracks or trails of targets usually on long, loose leads. Dogs trained in procedures designed to emphasize matching of scents correctly; dogs work either on lead or off lead in testing area.
2. Dogs may be trained in other police dog functions, or may be tracking specialists. Dogs may be trained in other police dog functions, but are generally specialists in European procedures and in the most reliable protocols.
3. Dog ideally scented to object touched by perpetrator but sometimes scented to area where perpetrator likely to have been present; dogs occasionally scented to pads. Dog scented to object likely to have scent of perpetrator or to scent pad created from object perpetrator may have touched.
4. Scent occasionally extracted and enhanced by scent transfer unit. Scent on scenting item and scents in stations of lineup frequently extracted and enhanced by scent transfer unit.
5. Dog more often following foot scent as individual human odor. Dog more often scented to objects touched by perpetrators’ hands but may be scented to item touched by another body part (e.g. elbow, face).
6. Scent source may have been touched by multiple individuals (“missing member” may be performed to eliminate non-suspects); track may have been crossed by multiple individuals. Scent source may have been touched by multiple individuals; lineup design generally precludes scents from individuals other than the suspect and foils in the lineup stations.
7. Dog must ignore cross tracks laid at different times generally by unknown individuals. Dog must choose between objects ideally scented at same time and by individuals of same gender, age, and ethnicity of suspect; objects are generally identical or alike.
8. Dog need not choose any individual but may lead to suspect. Dogs choose between a number of objects scented by target and decoys (in zero trials, no choice is correct).
9. Dogs may work in tandem or in groups. Dogs should always work alone; when trials involve using multiple dogs, equipment generally must be cleaned between each trial.
10. Object of work is to find path taken by perpetrator and find objects perpetrator may have left, and possibly find perpetrator. Object of trial is to determine if suspect was perpetrator.
11. Handler may have to know facts about perpetrator in case he encounters him or her while tracking (particularly if perpetrator may be armed and dangerous). Handler should be unaware of correct station and dog should not be able to see experimenter or other individual who knows correct station during trial.
12. Trail may be followed by more than one team at more than one time. Equipment must be cleaned between trials if dogs may have left saliva at scenting stations.
13. Trail cannot be followed after scent disappears. Test can be performed as long as scents are preserved.
14. Procedure may produce additional evidence (e.g., items dropped or abandoned by perpetrator, locations where perpetrator may have been). Procedure does not produce additional evidence.
15. Tracking occurs in diverse environments; dog may track to a building or vehicle, implicating privacy interests. Procedure generally conducted in police station or other facility.
16. Procedure rarely videotaped. Videotaping increasingly common and often required.
17. Tracking foundational requirements apply. Tracking foundational requirements require adaptation or ignoring (e.g. putting on track where perpetrator likely to have been; tracking continuously).
18. Cueing the dog generally only possible if suspect is encountered; dogs may sometimes be forced to follow a path against their inclination. Cueing the dog possible if the handler or other participant in the lineup visible to the dog knows the position of the suspect’s scent in the lineup.
19. Dog may have to be rescented if it loses trail or becomes distracted. In optimal protocols, dog will will not be rescented during trial.
20. Environment of tracking generally cannot be controlled beyond limiting interference of other investigators or bystanders. Environment should be highly controlled to avoid contamination and cueing.

I’ve discussed the distinctions between tracking and scent identification in a working paper posted on the Social Science Research Network (SSRN), Canine Tracking and Scent Identification: Factoring Science into the Threshold for Admissibility.

For a detailed discussion of the state of the law and research on scent lineups, see another working paper, Scent Identification in Criminal Investigations and Prosecutions: New Protocol Designs Improve Forensic Reliability, by Tadeusz Jezierski, Michael McCulloch, and me, also posted on SSRN.

The authors would appreciate comments on both of these papers. Please send comments on either paper to me at

Friday, August 27, 2010

Chasing the Bears Away: Yogi Doesn't Like the Barking but It Doesn't Keep Him Away for Long

When my wife and moved to Stone Ridge, New York, neighbors warned us that there were bears in the area, harmless and not very large black bears that could be pesky at times. We learned to put ammonia on our outdoor garbage can after a bear’s investigation of the can gave us a half hour of unpleasant yard work one morning. We were told that having a dog was good because bears are afraid of dogs. Perhaps once or twice Chloe’s barking in the night was at a bear and not a deer, but we’re not sure.

I recently came across a study on the effectiveness of dogs in deterring black bears (Ursus americanus) from coming into areas around Lake Tahoe where they could get into conflicts with humans. The six most common techniques for keeping bears away from humans, according to a survey of 33 state game departments, are (1) rubber buckshot, (2) rubber slugs, (3) pepper spray, (4) cracker shells, (5) dogs, and (6) loud noises. The Lake Tahoe researchers captured bears in culvert traps, tranquilized and immobilized them with Telazol-Xylazine, and fitted each with a mortality-sensing radio collar. Bears were then moved away from the capture sight and various deterrents were administered (i.e., the bears were shot or sprayed). Some bears were also chased by dogs, but some weren’t. The effectiveness of the discouraging techniques were then compared with and without the added factor of dogs, the location of each bear monitored relative to problem areas by the radio collars. In 92% of cases, bears returned to the places where they were captured, more than half in less than 30 days. Bears chased by dogs did return slightly later, though the difference wasn’t statistically significant. Jon P. Beckmann, Carl W. Lackey, and Joel Berger (2004). Evaluation of Deterrent Techniques and Dogs to Alter Behavior of “Nuisance” Black Bears. Wildlife Society Bulletin, 32(4), 1141-1146. I suppose the message is that if you want to keep the bears away, keep your dog outside as much as possible.

In British Columbia, some conservation groups are recommending that Karelian Bear Dogs be trained to chase nuisance bears away from areas, though the issue is controversial because chasing bears with dogs is considered harassment of wildlife. A program in Montana, the Wind River Karelian Bear Dog Program, teaches dogs to “speak to the bears,” i.e., to bark and chase bears on command from a handler.

On a related note, I wrote about dog fighting recently (Dog Fights and Serial Murderers…, August 15). I mentioned that fighting between dogs increased after dog fights with tethered bears and bulls were banned by the English Humane Act of 1835, which most states in the U.S. followed at some point. A reader has informed me that South Carolina remains an exception. The Humane Society of the United States is seeking to ban bear baying in South Carolina, a practice under which a defanged bear chained to a stake is attacked by dogs, apparently used to teach dogs to be aggressive towards bears during hunts. See the AP story by Meg Kinnard, “Group Wants SC Bear Hunters to Call off Their Dogs” (August 23, 2010).

Friday, August 20, 2010

Bomb Dog Fraud: Selling Ineffective Explosives Detection Dogs to the Feds Leads to Hard Time

Rollin Perkins, my criminal law professor at Hastings, often began classes with a “black letter” statement of the crime he would discuss that day. Perhaps this doesn’t qualify as black letter, but one of the first sentences in his lecture on fraud was a simple statement. “Where there’s a lot of money, there’s likely to be fraud.”

In a prior blog (July 17, IRS Affirms…), I mentioned a case on which I was consulted where a family with an autistic child paid around $20,000 for an autism service dog that had, as near as could be told, received little if any training. Families with autistic children are an obvious target for fraudsters. They are desperate for help but reputable service dog agencies have long waiting lists for autism service dogs. Some people jump when a breeder contacts them with a story about a service animal that just became available.

Another desperate situation where there was suddenly a lot of money for a time was the federal government in the wake of 9/11. Fears about terrorists bringing bombs into buildings, subways, or airplanes created enormous demand for explosives detection dogs. Among agencies seeking to fill this need were the State Department, the Federal Reserve, and the IRS. (The IRS expected to pay around $4 million annually for guard dog services for the National Office according to an undated "new contract opportunities" memo that listed contracts for 2007 and 2008.)  These agencies obtained dogs through intermediary suppliers, including Intercon Security Services, Inc. and Worldwide Security Services, Inc.

One person who sought to supply bomb dogs to the government was Russell Lee Ebersole, who had a business, Detector Dogs Against Drugs and Explosives, Inc., located in Virginia and Maryland. He sold canine teams to Intercon and Worldwide Security for about $700,000.

Eventually doubting the competence of the dogs and handlers supposedly trained by Ebersole (who were showing too much interest or making false alerts where there turned out to be no explosives, resulting in some costly bomb squad deployments), the State Department arranged odor recognition proficiency tests for the six dogs assigned to the Harry S. Truman Building, the State Department’s headquarters in Washington, D.C. The dogs were tested at the Canine Enforcement Training Academy of the Bureau of Alcohol, Firearms, and Tobacco in Front Royal, Virginia, and all failed. Three of Ebersole’s dogs that were working for the Federal Reserve were unable to alert to 50 pounds of trenchrite-5 dynamite, 50 pounds of TNT, or 15 pounds of C-4 placed in three separate unmarked vehicles. The large amounts of explosives may have been different from the levels the dogs were trained on, which sometimes does confuse animals, but the number of tests suggests the dogs were poorly trained.

The tests for all of Ebersole’s dogs are not described in detail, but the federal district court for the Eastern District of Virginia quotes from material concerning how the Treasury Department tests dogs. Dogs are to be tested on ten different explosives in ten different containers, with additional containers containing other substances or empty. Containers are spaced four feet apart. Sample containers must be in place for at least 15 minutes before testing. Dogs must alert correctly to all ten explosive odors, and a dog fails if it alerts more than twice to containers not holding explosives. Some of Ebersole’s teams missed every single explosive, but alerted to other substances.

On March 13, 2003, Ebersole was indicted for wire fraud and presenting false claims to the government under the federal criminal code,18 U.S.C. 1343 and 287. A former employee of Ebersole’s business testified about fabricating test results and certifications for dogs designated for the IRS assignment. Handlers hired by Ebersole testified that they had only trained for a fraction of the time that federal agencies believed they had been trained. On June 20, 2003, a jury convicted Ebersole. He was sentenced to 78 months in prison, which was eventually reduced to 63 months.

In one of Ebersole’s arguments for a retrial, he cites Justice Souter’s dissent in Illinois v. Caballes, 543 U.S. 405 (2005): “The infallible dog, however, is a creature of legal fiction.” This amounts to saying that the entire concept of explosives detection training is a fraud. The argument is doubly curious as one source advised me that Ebersole sometimes tried to teach dogs to have different alerts to different explosives, and also to have a separate alert for narcotics. This suggests that rather than doubting the skills of dogs, Ebersole may have overestimated what he could teach dogs and handlers to do. The court did not buy Ebersole’s excuse.

U.S. v. Ebersole, 411 F.3d 517, cert. denied, 126 S.Ct. 1142 (2006), on remand, 2007 WL 219969 (E.D. Va. 2007), aff’d, 189 Fed.Appx. 287 (4th Cir. 2006), motion to vacate denied, 2007 WL 750198 (E.D. Va. 2007).

The moral is that when the federal government can’t meet its own needs for police dogs, testing should be conducted before the bulk of a sizeable payment is made to a supplier.

Addendum. Failure to provide adequately trained explosives detection dogs was alleged as to a military contractor providing dogs for the entrance gates of the presidential compound in Kabul, Afghanistan. The contractor, DynCorp International, was hired by the State Department, whose Diplomatic Security Services Bureau had assumed responsibility for providing security for President Hamid Karzai. The suit, which was brought by a handler at the location who had determined the dogs being supplied were inadequate, was dismissed on procedural grounds. DynCorp's source for the dogs was not stated. U.S. ex rel. Cody v. Computer Sciences Corp., 246 F.R.D. 22 (D.C. D.C. 2007)

Second Addendum. In September 2010, the State Department's Inspector General released a report on deficiencies in testing bomb dogs deployed to Iraq and Afghanistan. The analysis was begun by the Middle East Regional Office (MERO) of the OIG, which had noticed a pattern of canine program deficiencies. About 200 dogs are used in these locations with a hefty price tag. The cost for the Baghdad Embassy Security Force alone amounts to $24 million a year.

State Department bomb dogs are expected to comply with the Department of Treasury's Odor Recognition Proficiency Standard for Explosives Detection Canines. (ATF announced the availability of the standard to law enforcement and government agencies in 1999. 64 Fed. Reg. 41487 (July 30, 1999))

The Inspector General found "systemic weaknesses in canine test procedures," including failure to test dogs on the six mandated explosive scents, use of old materials, failure to store test items separately, failure to keep documentation concerning testing materials and procedures, and other failures. State Department personnel did not understand bomb dog procedures and had to rely on the contractors, who were apparently not following Treasury's guidelines.

The State Department indicated it would try to improve compliance. A spokesman for RONCO Consulting Corp., one of the groups supplying the canine teams to the State Department, called the Inspector General's report inaccurate. U.S. Dept. of State, Office of Inspector General. Limited-Scope Review of the Bureau of Diplomatic Security's Oversight of Explosives Detection Canine Programs, MERO-I-10-14 (September 2010). See Richard Lardner, Associated Press Report: US Bomb-Sniffing Dogs Not Up to Snuff (October 13, 2010).

Sunday, August 15, 2010

Dog Fights and Serial Murderers: A Federal Judge Shines Light into the Dark World of Dog Fighting

Additional Note: The following blog was cited in a paper, History of Dog Fighting in the World, which appeared in 2015 the Journal of Animal Science Advances, 5(4), 1234-1237, by Dr. Orhan Yilmaz of Ardahan University, Turkey, Dr. Fusun Coskun of Ahi Evran University, Kirsehir, Turkey, and Dr. Mehmet Ertugrul of Ankara University, Ankara, Turkey. It was also cited in a paper, Human Factor in Dog Fighting, in the Journal of Veterinary Advances, also in 2015, by the same authors.     

A detailed and disturbing description of dog fighting has appeared in a sentencing memorandum filed by the district court for the Southern District of Illinois. The memorandum does not mention the actions of the defendants who were being sentenced, but describes dog fighting in the United States. U.S. v Berry, 2010 WL 1882057 (S.D. Ill., May 11, 2010).

The memorandum was written by Judge Michael J. Reagan of the Southern District of Illinois, a former police officer appointed to the federal bench by President Clinton. It must have been hard for him to write this memorandum as it is hard to read it, but dog lovers owe him a debt of thanks for putting this history into a judicial context and describing how much of a social cancer this dark sport is becoming.

Dog fighting came from England and existed in colonial America as early as 1750. Parliament passed the Humane Act of 1835 to ban bating sports in which dogs fought larger animals, such as bears and bulls tethered to a stake, but dog fighting remained legal. The sport was for a time endorsed by the United Kennel Club. Laws against dog fighting began to be passed by states in the 1860s, but enforcement was lax for decades. The sport began to go underground in the 1930s when the United Kennel Club and other organizations withdrew their support but it still had considerable appeal in certain places and two magazines, Dog Journal and Pit Dog Report, helped keep interest alive.

Although long illegal in the United Kingdom, the sport has been growing even there in recent years. It is popular in Latin America, Pakistan, parts of Europe, including Eastern Europe, and is estimated to bring in nearly $1 billion annually, about half of which goes to organized crime. The Taliban banned the sport in Afghanistan as un-Islamic, but it has come back with a vengeance in American controlled areas. (One would rather agree with one’s friends than one’s enemies but it is not always so.)

Dog fighting is legal in most of Russia and in parts of Japan, but in Japan dogs are taught to pin their opponents to the floor in a sort of canine version of Sumo wrestling.

Dog breeders that specialize in raising and training fighting dogs often keep upwards of 50 dogs and have a “keep journal” for each dog that describes the training, feeding, and drugs injected into the dog. Dog fights often draw participants from several states and notices are sent in code, which makes infiltration by law enforcement difficult. An article by Julie Bank and Stephen Zwistowski in an ASPCA journal estimated there were 40,000 professional dog fighters in the United States, but that this number has grown. There may be 100,000 gang members and street fighters participating in informal, sometimes spontaneous, fights occurring in poor neighborhoods, often in public view.

Breeds preferred by professionals include Fila Brasileiros, Dogo Argentinos, Presa Canarios, and pit bulls (American Pit Bull Terriers and the American Staffordshire Terriers). Mixes of these are also used. The increasingly common anti-pit bull legislation is in large part due to this culture, but is most unfortunate given that the dogs were once referred to as “nanny dogs” because of their gentle disposition and protectiveness of children in a household.

Judge Reagan describes the life of a fighting dog as follows:

"[F]ighting dogs spend the majority of their lives in filthy conditions, pinned in small cages or chained up with heavy chains across their neck. As the dog grows, owners will add weights to the chains in order to increase the dog's strength. Generally, the dogs are kept in close proximity to other fighting dogs in order to further antagonize and increase anxiety levels. The dogs are also beaten and goaded on a daily basis in order to raise the dog's tolerance towards pain and increase the 'fight' within the dog. At the professional level, fighting dogs receive better care in that they are at least fed on a daily basis and their exercise is monitored. However, these dogs are often injected with steroids, and various other legal and illegal drugs to increase the size, strength, and aggressiveness in the dog…. To increase aggression, these dogs may be starved, have lit cigarettes burned into their coats, or may be beaten with a variety of crude instruments including broken bottles, pipes, or even machetes."

Ears and tails are sometimes removed so that another dog cannot bite the appendages in a fight. Teeth may be filed to make them sharper and more dangerous. Leg strength may be developed by leashing the dog to a car and making it run alongside the vehicle at ever higher speeds. Dogs are often to attack “bait” animals, which may be rabbits, cats, and small dogs stolen from back yards.

In more formal fights, rules may be imposed, most commonly Cajun Rules, which were devised by a former Lafayette, Louisiana, police chief, G.A. Trahan, known as “Gaboon.” These rules are posted (“for historical purposes only”). The last rule reads: "Should the police interfere the referee to name the next meeting place." A curious rule to have been written by a police chief. When I signed onto the page, a pop-up screen offered pit bulls for sale with contact provided only through an untraceable email programmed into the website. So much for “historical purposes.”

Purses can go as high as $2 million. Fights last an hour or more. Losing dogs are usually killed or abandoned after a fight. The cost of medical care is considered too high given the dog’s poor performance. Also, wounded animals provide evidence of the horrors that have occurred. They also damage one’s reputation in the dog fighting world.

"[I]t is not uncommon for losing dogs to be drowned, hanged, electrocuted, burned alive, doused with corrosive chemicals or beaten to death with blunt objects.This list is not exhaustive, however, and animal rescuers are constantly surprised at how grisly these deaths are as handlers resort to more disturbing tactics to reassert their tough image. No matter the reason for disposing of the losing dog, the torture and ultimate death of the dog is almost always done in front of the crowd, who view this simply as part of the sport."

Torturing and killing a wounded and helpless animal means you're a real man in some places.

Law enforcement officers describe dog fights as convenience stores for criminals, with drugs, weapons, explosives, and prostitutes for sale along with the illegal gambling opportunities. For a list of 30 crimes often associated with dog fighting, see Hanna Gibson, Dog Fighting Detailed Discussion, Animal Legal and Historical Center (2005).

When dogs are abandoned, they sometimes survive and increase the feral dog populations of certain areas, including Los Angeles, Detroit, New Orleans, Cleveland, New York, Baltimore, Houston, Indianapolis, Santa Fe, and Pittsburgh. Abandoned fighting dogs are more dangerous than most other feral dogs and are known to attack livestock, pets, children, and even adults.

Various studies have found that exposing children to dog fighting has lasting consequences on what they become when they grow up. Some fathers think they are teaching their children to be tough, but they may be teaching them to be violent, and some association with serial killers has been argued. (Criminal Minds script writers, take note.) This is certainly more likely than their becoming professional football players, an unfortunate belief among some fans of this dark sport and of Michael Vick.

The defendants and their sentences were William Berry (one year and one day), Derrick Courtland (18 months), John Bacon (16 months), Julius Jackson (18 months), Joseph Addison (24 months), James H. Milburn III (one year and one day), and Ricky Stringfellow, Jr. (12 months). A small price for the souls they tortured but on the high side historically under sentencing rules given that dogs are personal property by the law, including the criminal law. Descriptions of other people indicted in this case have been posted on anti-animal abuse websites.

I'll be discussing some of the consequences of classifying our best friend as property with some other panelists at the Ford Hall Forum on September 16.

Additional sources:

Forsyth, C.J., and Evans, R.D. (1998). Dogmen: The Rationalization of Deviance. Society and Animals, 6(3), 203-208.

Twining, H., Arluke, A., and Patronek, G. (2000). Managing the Stigma of Outlaw Breeds: A Case Study of Pit Bull Owners. Society and Animals, 8(1).

Friday, August 13, 2010

Telling Tigers Apart: Scent Lineups Identify Individual Tigers from Scat

Dogs have been used to monitor the status of endangered species for some time, and a number of examples have been mentioned in prior blogs. (See Certification of Tortoise Detector dogs? May 20, 2009; Types of Detection Dogs—How Many Can You Name? March 5, 2010) In all cases I know of, however, the dogs were not trained to distinguish between individual bears, tortoises, ferrets, or whatever. Like drug dogs or cadaver dogs, they are trained to recognize any scent that belongs to the target category. An exception involves dogs that are being used to monitor the status of the Amur, or Siberian tiger (Panthera tigris altaica), found in the Russian far east. This involves training dogs under procedures similar to those used for scent lineups in criminal investigations where the dog is asked if there is a match to a scent from the crime in a lineup of scents from foils and a suspect in the crime.

Monitoring tigers has involved track size measurements, camera traps, and genetic analysis of hair and scat. Genetic analysis has been largely ineffective because of the low genetic variability of the remaining Amur tiger population. Camera traps often malfunction in cold temperatures, though winter may be the best time to survey these animals.

Two researchers from the Lazovsky State Nature Zapovednik (preserve) began training five dogs to develop the ability to distinguish tigers by scat. The training followed Dutch forensic practices, but the dogs were rewarded with food, not play. Dogs were selected at six to eight weeks based on observed play and food drive, and training began at four to six months of age. Dogs were trained to sniff the scat of one tiger, then alert to a match in a scent lineup of seven scat jars.

Dogs were first trained to smell jars by being presented with a row of 15 to 20 jars filled to the top with wadded paper on some of which was a small piece of hot dog. The dogs walked in front of the handler and were taught to smell each jar for the possible treat. After this was learned, treats were removed and jars were placed further apart and covered with scent boxes. A passive alert, a sit, was taught as the alert. The test jar, containing the scat the dog was supposed to match from the lineup, was placed on a 15 cm high stool. (See diagram.) Dogs were taught to smell the test jar first and received a reward from the handler on sitting at the matching jar. First this was done with a command but the command was soon removed so that the handler could remain blind to the correct target jar. Also, scat from different tigers was slowly introduced into every jar in the lineup but only one was a match.

When a dog chose the correct jar more than 70% of the time, more matching jars were introduced so that a dog might make one, two, or three matches in every trial (see diagram). Training was completed in two to four months, and performance usually continued to improve for four to six weeks after training was completed. Each trial took 10 to 15 minutes and dogs performed three to seven trials each day. Dogs that turned out to be unmotivated to work more than 10% of the time were retired.

Scat was obtained from tigers in zoos, circuses, and wild Amur tigers. Scats from known wild tigers (some of which were radio-collared) could be collected when there was a single set of tracks. The diet of wild tigers consists of red deer, wild boar, sika deer, and other animals, including dogs. Care had to be taken that collected scat did not grow mold, which could interfere with a dog’s ability to detect individual scent. Scats were aged about two days. Researchers found that dogs are attracted to some scats, as has been found by Adee Schoon and Tadeusz Jezierski with dogs used in forensic scent lineups. Of 58 scats, dogs were determined to be attracted to three for no apparent reason.

In 521 trails, dogs correctly chose one of seven scats with an average rate of 87% (individually varying from 79% correct up to 89% correct). When trials were repeated with different dogs, accuracy increased to 98%. Where two samples in the lineup matched the trial scent, dogs were accurate 84% of the time. Dogs were more accurate in identifying wild tigers than with captive tigers, perhaps reflecting the nearly identical diets of some of the captive tigers.

The researchers recommended that identifications be based on repeated tests of two or three dogs. They also recommended that scent identification be combined with other methods of following tigers.

Linda L. Kerley and Galina P. Salkina, Using Scent-Matching Dogs to Identify Individual Amur Tigers from Scats. Journal of Wildlife Management, 71(4), 1349-1356 (2007).  See also, Linda L. Kerley, Using Dogs for Tiger Conservation and Research.  Integrative Zoology, 5(4), 390-396.

Friday, August 6, 2010

Life is a High School for Puppies Too

When two dogs are playing competitively and a third joins in, the new individual may attack or bite one or the other. How does it choose which one to support and which one to attack? Three theories have been advanced:

1. Kin selection: interveners support relatives over nonrelatives, found in studies of primates, African wild dogs, and spotted hyenas. (Picture shows three African wild dog puppies at play. National Geographic Images. For the position of African wild dogs on the canid evolutionary tree, see Service and Therapy Dogs in American Society, p. 15.)
2. Reciprocity: an intervener supports the dog that has helped him or her in the past, found in primates, including human children.
3. Direct benefits: an intervener seeks to benefit from the interaction, generally by attacking the individual losing at the time of the intervention, also reported in primates and African wild dogs.

A human perspective might prefer the first or second approach be taken by our best friend, but one recent study at the University of Michigan concluded that the third theory fits the data best for puppies at play. Studies on interventions in competitive situations have largely focused on primates, though one study of wolves found that a subordinate male wolf successfully challenged his father because he received the assistance of two of his male siblings. (Jenks, S.M. (1988). Behavioral Regulation of Social Organization and Mating in a Captive Wolf Pack. Ph.D. thesis, University of Connecticut.)

The University of Michigan researchers noted that play fighting includes chasing, rough-and-tumble wrestling, genital sniffing, mounting (mimicking copulatory behavior), placing the chin over the other dog’s back, and inhibited biting. Aggressively standing over a submissive animal or side-to-side shaking of the head might also be involved, but the more serious actions will be intermixed with other cues that will help maintain the play atmosphere. (Bekoff, M. (1995). Play Signals as Punctuation: the Structure of Social Play in Canids. Behaviour, 132, 419-429.)

The researchers observed four litters, watching them extensively at the ages of 3 to 8 weeks, 10 to 11 weeks, and 27 to 40 weeks. Although the dogs may have gone to new homes, they were brought back to play with littermates for daytime sessions during the observation periods. Play was videotaped and the puppies had colored collars for easy identification. The researchers found that interveners targeted puppies in the losing role 69% of the time, but in 19.5% of the interventions the loser could not be identified. No support of preferred play partners was detected in the data, nor any tendency towards reciprocity. Interveners most commonly used biting in the first two periods, but preferred “jump ons” and mounting in the third period. Most of the dogs were neutered, but mounting occurs frequently in play. Both males and females used mounting.

The researchers suggest that puppies may target the loser when intervening in order to improve their own rank among littermates. In wolf packs, dogs losing at play may get less food, grow less, and be more likely to leave the pack. Competitive play may be part of the way dogs establish dominance hierarchies. It might also help dogs develop cooperative skills for group hunting and protecting lairs against intrusion by other packs.

Camille Ward, Rebecca Trisko, and Barbara B. Smuts (2009). Third-Party Interventions in Dyadic Play Between Littermates of Domestic Dogs, Canis lupus familiaris. Animal Behaviour, 78, 1153-1160.