Nicole R. Dorey

What did domestication do to dogs? A new account of dogs' sensitivity to human actions

Over the last two decades increasing evidence for an acute sensitivity to human gestures and attentional states in domestic dogs has led to a burgeoning of research into the social cognition of this highly familiar yet previously under‐studied animal. Dogs (Canis lupus familiaris) have been shown to be more successful than their closest relative (and wild progenitor) the wolf, and than mans closest relative, the chimpanzee, on tests of sensitivity to human social cues, such as following points to a container holding hidden food. The “Domestication Hypothesis” asserts that during domestication dogs evolved an inherent sensitivity to human gestures that their non‐domesticated counterparts do not share. According to this view, sensitivity to human cues is present in dogs at an early age and shows little evidence of acquisition during ontogeny. A closer look at the findings of research on canine domestication, socialization, and conditioning, brings the assumptions of this hypothesis into question. We propose the Two Stage Hypothesis, according to which the sensitivity of an individual animal to human actions depends on acceptance of humans as social companions, and conditioning to follow human limbs. This offers a more parsimonious explanation for the domestic dogs sensitivity to human gestures, without requiring the use of additional mechanisms. We outline how tests of this new hypothesis open directions for future study that offer promise of a deeper understanding of mankinds oldest companion.

Can your dog read your mind? Understanding the causes of canine perspective taking

Prior studies have documented the domestic dog’s (Canis lupus familiaris) sensitivity to human attentional state, including a tendency to preferentially beg for food from attentive individuals and an ability to selectively perform forbidden behaviors when humans are not looking. Due to the success of dogs on perspective-taking tasks, some have hypothesized that domestic dogs may have theory of mind, or the ability to infer what other individuals know. Here we provide the first evidence that nondomesticated canids, grey wolves (Canis lupus), are also sensitive to human attentional state under some conditions. We also demonstrate that dogs do not display an undifferentiated sensitivity to all visual cues of attentional state. Rather, dogs are more sensitive to stimuli encountered in their home environment. Some dogs perform poorly on perspective-taking tasks. These findings have important implications for the interpretation of research designed to understand complex social cognition across species.

Breed differences in dogs sensitivity to human points: A meta-analysis

The last decade has seen a substantial increase in research on the behavioral and cognitive abilities of pet dogs, Canis familiaris. The most commonly used experimental paradigm is the object-choice task in which a dog is given a choice of two containers and guided to the reinforced object by human pointing gestures. We review here studies of this type and attempt a meta-analysis of the available data. In the meta-analysis breeds of dogs were grouped into the eight categories of the American Kennel Club, and into four clusters identified by Parker and Ostrander [Parker, H.G., Ostrander, E.A., 2005. Canine genomics and genetics: running with the pack. PLoS Genet. 1, 507-513] on the basis of a genetic analysis. No differences in performance between breeds categorized in either fashion were identified. Rather, all dog breeds appear to be similarly and highly successful in following human points to locate desired food. We suggest this result could be due to the paucity of data available in published studies, and the restricted range of breeds tested.

FUNCTIONAL ANALYSIS AND TREATMENT OF SELF‐INJURY IN A CAPTIVE OLIVE BABOON

Self-injurious behavior (SIB), such as self-biting and head banging, has been reported to occur in approximately 10% of captive, individually housed nonhuman primates. Accounts of the etiology of SIB in primates range from ecological to physiological. However, to date, no research has examined the possible influence of social consequences delivered by handlers and keepers in the maintenance of SIB in this population. The current study investigated the effects of social contact as a potentially reinforcing consequence for the SIB displayed by an olive baboon (Papio hamadryas anubis). Results indicated that the behavior was maintained by attention from humans. As treatment, reinforcement was arranged for an appropriate alternative response, resulting in increases in the appropriate alternative behavior and decreases in SIB.

A two-choice preference assessment with five cotton-top tamarins (Saguinus oedipus).

A study selected 5 cotton-top tamarins (Saguinus oedipus) located at the Frank Buck Zoo in Gainesville, Texas, for a food preference assessment. The study used a paired-choice procedure across 7 different food items for all 5 tamarins. Preferences for the food items across all the tamarins varied, although general trends were noted as well. This article discusses the benefits of using paired-choice preference assessments in zoo settings.

Megachiropteran bats (Pteropus) utilize human referential stimuli to locate hidden food.

Spontaneous point-following behavior has been considered an indicator of advanced social cognition unique to humans. Recently, it has been suggested that a close evolutionary relationship with humans could result in similar social skills in domesticated species. An alternative view is that the mechanism is not genetic domestication alone but instead a combination of phylogenetic and ontogenetic variables. Here we test the necessity of phylogenetic domestication by investigating the point-following behavior of a captive population of nondomesticated megachiropteran bats (Pteropus pumilus, Pteropus rodricensis, Pteropus conspicillatus, Pteropus vampyrus). Three of five subjects were highly successful in following an unfamiliar humans point to a target location, providing the first empirical evidence of cross-species social referencing in bats. The three successful bats were all born in captivity and socialized to humans early in life, whereas unsuccessful bats were wild-born individuals. This study provides evidence that referential point following is not restricted to domesticated animals and indicates that early experience may be important. Megachiropteran bats may prove to be a useful model for studying social behaviors.

Is preference a predictor of enrichment efficacy in Galapagos tortoises (Chelonoidis nigra)

It is widely acknowledged that environmental enrichment plays an important role in promoting the welfare of captive animals. However, a topic of debate is whether an animals preference for an enrichment strategy is any indicator of its efficacy. In addition, relatively few studies have evaluated environmental enrichment strategies for non-mammalian species. In the present study, we compared the results of an observational evaluation of enrichment efficacy with the results of a paired-stimulus preference assessment for three Galapagos tortoises. In the observational study, object enrichment (boomer balls and a free-flowing sprinkler) and keeper interactions (shell scrubbing and neck rubbing) were evaluated systematically for their effects on locomotion, species-typical behavior, aggressive and non-aggressive conspecific interactions, and enclosure. Preference assessments were subsequently conducted in which subjects could choose the enrichment strategy to be implemented. All subjects preferred keeper interactions consistently over object enrichment. Our results suggest that enrichment preference was a variable predictor of efficacy across enrichment species-typical behavior, activity levels, enclosure use, and aggressive and non-aggressive conspecific interactions strategies. Preference predicted efficacy for promoting species-typical behavior (1/3 subjects), activity levels (2/3 subjects), and enclosure use (2/3 subjects), but not conspecific interactions (0/3 subjects). The results suggest that preference may be an efficient predictor of enrichment efficacy when daily observational evaluations are not practical; however, the predictive utility of preference assessments may depend on the behavioral goal of the enrichment strategy. We discuss the need for future research examining the relationship between preference and enrichment efficacy-as well as other potential indicators of enrichment effectiveness-in captive animals.

Interspecific communication from people to horses (Equus ferus caballus) is influenced by different horsemanship training styles.

The ability of many domesticated animals to follow human pointing gestures to locate hidden food has led to scientific debate on the relative importance of domestication and individual experience on the origins and development of this capacity. To further explore this question, we examined the influence of different prior training histories/methods on the ability of horses (Equus ferus caballus) to follow a momentary distal point. Ten horses previously trained using one of two methods (Parelli™ natural horsemanship or traditional horse training) were tested using a standard object choice task. The results show that neither group of horses was initially able to follow the momentary distal point. However, after more experience with the point, horses previously trained using the Parelli natural horsemanship method learned to follow momentary distal points significantly faster than those previously trained with traditional methods. The poor initial performance of horses on distal pointing tasks, coupled with the finding that prior training history and experimental experience can lead to success on this task, fails to support the predictions of the domestication hypothesis and instead lends support to the two-stage hypothesis.

Applying behavior-analytic methodology to the science and practice of environmental enrichment in zoos and aquariums

Environmental enrichment in zoos and aquariums is often evaluated at two overlapping levels: published research and day-to-day institutional record keeping. Several authors have discussed ongoing challenges with small sample sizes in between-groups zoological research and have cautioned against the inappropriate use of inferential statistics (Shepherdson, , International Zoo Yearbook, 38, 118-124; Shepherdson, Lewis, Carlstead, Bauman, & Perrin, Applied Animal Behaviour Science, 147, 298-277; Swaisgood, , Applied Animal Behaviour Science, 102, 139-162; Swaisgood & Shepherdson, , Zoo Biology, 24, 499-518). Multi-institutional studies are the typically-prescribed solution, but these are expensive and difficult to carry out. Kuhar ( Zoo Biology, 25, 339-352) provided a reminder that inferential statistics are only necessary when one wishes to draw general conclusions at the population level. Because welfare is assessed at the level of the individual animal, we argue that evaluations of enrichment efficacy are often instances in which inferential statistics may be neither necessary nor appropriate. In recent years, there have been calls for the application of behavior-analytic techniques to zoo animal behavior management, including environmental enrichment (e.g., Bloomsmith, Marr, & Maple, , Applied Animal Behaviour Science, 102, 205-222; Tarou & Bashaw, , Applied Animal Behaviour Science, 102, 189-204). Single-subject (also called single-case, or small-n) designs provide a means of designing evaluations of enrichment efficacy based on an individuals behavior. We discuss how these designs might apply to research and practice goals at zoos and aquariums, contrast them with standard practices in the field, and give examples of how each could be successfully applied in a zoo or aquarium setting.

A method to assess relative preference for training and environmental enrichment in captive wolves (Canis lupus and Canis lupus arctos)

It is currently debated as to whether or not positive reinforcement training is enriching to captive animals. Although both husbandry training and environmental enrichment (EE) have been found to benefit animal welfare in captivity, to date, no systematic investigation has compared an animals preference for performing a trained behavior to engaging freely with a stimuli provided as EE. In the current paper, we used four captive wolves to (1) test the efficacy of a paired-stimulus preference assessment to determine preference for engaging in a trained behavior as a choice; and to (2) use a paired-stimulus preference assessment to determine whether or not individuals prefer to engage in a previously trained behavior versus a previously encountered EE stimuli. Of the four subjects tested, visual inspection of the graphs revealed that two of the subjects preferred trained behavior stimuli and two of the subjects preferred EE stimuli; only one of the wolves had a statically higher preference for an EE stimulus over a trained behavior. We believe that letting the animals choose between these two events is the first step in answering the question of whether or not is training enriching, however more research needs to be done and suggestions for future research is discussed.