Paola Valsecchi

Is your choice my choice? The owners’ effect on pet dogs’ (Canis lupus familiaris) performance in a food choice task

This study investigates the influence of owners on their dogs’ performance in a food choice task using either different or equal quantities of food. Fifty-four pet dogs were tested in three different conditions. In Condition 1 we evaluated their ability to choose between a large and small amount of food (quantity discrimination task). In Condition 2 dogs were again presented with a choice between the large and small food quantity, but only after having witnessed their owner favouring the small quantity. In Condition 3 dogs were given a choice between two equally small quantities of food having witnessed their owner favouring either one or the other. A strong effect of the owner on the dogs’ performance was observed. In Condition 1 dogs as a group chose significantly more often the large food quantity, thus showing their ability to solve the quantity discrimination task. After observing their owner expressing a preference for the small food quantity they chose the large quantity of food significantly less than in the independent choice situation. The tendency to conform to the owner’s choice was higher when the dogs had to choose between equally small quantities of food (Condition 3) rather than between a large and a small one (Condition 2). These results provide evidence that dogs can be influenced by their owners even when their indications are clearly in contrast with direct perceptual information, thus leading dogs to ultimately make counterproductive choices.

The bond that never developed: adoption and relinquishment of dogs in a rescue shelter.

This study carried out a survey in an Italian shelter to analyze adoptions resulting in the rejection of the newly adopted dog. The results of this study show that the number of dogs adopted and returned was stable during the study, that more females than males were adopted, and that males were more likely to be returned. Almost all the dogs were returned because of behavioral problems, and most were more than 6 months of age. Some dogs were returned more than once, with 20% of the people who adopted the same dog at different times reporting the same behavioral problem. Having a house with a yard, a garden, or a terrace appeared to be important for better management of the dog and influenced the length of adoption. Half of the adopters had previous experience as caregiver for a dog; compared to adopters who had no previous experience, however, they returned their companion animal after a shorter period and because of behavioral reasons. Understanding why adopters return their dogs to shelters is an important step toward attempting to minimize relinquishments and, thus, optimize adoptions.

Free-ranging dogs assess the quantity of opponents in intergroup conflicts

In conflicts between social groups, the decision of competitors whether to attack/retreat should be based on the assessment of the quantity of individuals in their own and the opposing group. Experimental studies on numerical cognition in animals suggest that they may represent both large and small numbers as noisy mental magnitudes subject to scalar variability, and small numbers (≤4) also as discrete object-files. Consequently, discriminating between large quantities, but not between smaller ones, should become easier as the asymmetry between quantities increases. Here, we tested these hypotheses by recording naturally occurring conflicts in a population of free-ranging dogs, Canis lupus familiaris, living in a suburban environment. The overall probability of at least one pack member approaching opponents aggressively increased with a decreasing ratio of the number of rivals to that of companions. Moreover, the probability that more than half of the pack members withdrew from a conflict increased when this ratio increased. The skill of dogs in correctly assessing relative group size appeared to improve with increasing the asymmetry in size when at least one pack comprised more than four individuals, and appeared affected to a lesser extent by group size asymmetries when dogs had to compare only small numbers. These results provide the first indications that a representation of quantity based on noisy mental magnitudes may be involved in the assessment of opponents in intergroup conflicts and leave open the possibility that an additional, more precise mechanism may operate with small numbers.

Kinship and familiarity as factors affecting social transfer of food preferences in adult Mongolian gerbils (Meriones unguiculatus).

Experiments were carried out with Mongolian gerbils (Meriones unguiculatus) to assess whether a socially mediated acquisition of diet selection exists in this species. Results showed that a gerbil was influenced in its diet choices by information extracted during a brief period of interaction with a familiar conspecific that had recently eaten a novel food. Data revealed that the acquisition of a food preference from a conspecific depends on the existence of a social bond between the interacting gerbils. Either genetic relatedness (being brother or sister raised in different litters) or familiarity (being bred in the same litter or being member of a reproductive pair) is necessary for the transfer of information. Unfamiliar and unrelated observer gerbils did not selectively choose their demonstrators food.

Behavioral and physiological responses of guide dogs to a situation of emotional distress.

The aim of this study was to analyze the behavioral and physiological reactions of guide dogs in a distressing situation which promotes attachment behaviors towards their blind owners, and to compare such reactions with those of untrained or trainee dogs. The subjects were 57 adult Labrador and Golden retriever dogs (14 males, 43 females) belonging to four different groups: 19 Custody dogs, 13 Apprentice dogs, 10 Guide dogs and 15 Pet dogs. Dogs were tested using the Strange Situation Test, consisting in seven 3-minute episodes in which the dogs were placed in an unfamiliar environment, introduced to an unfamiliar woman and subjected to separation from their human companion. Tests were video-recorded and behaviors were scored using a 5-second point sampling method. Polar Vantage telemetric system was used to record cardiac activity. ANOVAs for repeated measures with groups and breeds as independent variables, showed a more anxious reaction in pet dogs, which revealed a high degree of proximity seeking behavior. Cardiac activity increased during episodes characterized by the exclusive presence of the stranger, but this increase was more conspicuous in guide dogs than in custody and apprentice dogs. Golden retrievers showed more behaviors suggesting distress compared to Labrador retrievers. This study showed that guide dogs, when separated from their blind owner, reveal a controlled behavioral reaction that is however accompanied by a stronger cardiac activation.

Estrogenic involvement in social learning, social recognition and pathogen avoidance

Sociality comes with specific cognitive skills that allow the proper processing of information about others (social recognition), as well as of information originating from others (social learning). Because sociality and social interactions can also facilitate the spread of infection among individuals the ability to recognize and avoid pathogen threat is also essential. We review here various studies primarily from the rodent literature supporting estrogenic involvement in the regulation of social recognition, social learning (socially acquired food preferences and mate choice copying) and the recognition and avoidance of infected and potentially infected individuals. We consider both genomic and rapid estrogenic effects involving estrogen receptors α and β, and G-protein coupled estrogen receptor 1, along with their interactions with neuropeptide systems in the processing of social stimuli and the regulation and expression of these various socially relevant behaviors.

Social eavesdropping in the domestic dog

Eavesdropping on third-party interactions has been observed in a number of species and is considered an important source of information in decision-making processes relating to fighting and mate choice. Human beings, however, use publicly available information flexibly in many different contexts including assessing others’ altruistic tendencies, which may in turn inform their choice of the most appropriate cooperative partner. We assessed whether dogs, Canis familiaris, were capable of discerning a generous versus selfish food-sharing interaction between humans, and investigated which communicative cues (voice versus gestures) may be more salient for them. Importantly a control condition was included to ascertain whether it was in fact the interaction between individuals as opposed to the direct actions of the actors that the dogs evaluated. We found that the dogs were capable of eavesdropping on human food-sharing interactions, and vocal communication was particularly important to convey the human’s cooperative versus noncooperative intent.

Hormonal regulation of agonistic and affiliative behavior in female mongolian gerbils (Meriones unguiculatus).

Ovarian steroids and oxytocin (OT) have been implicated in the regulation of social behaviors. The purpose of the present study was to examine hormonal substrates of aggression and affiliation in the female Mongolian gerbil (Meriones unguiculatus), a highly social, monogamous rodent. Sexually naive adult females were paired with sexually experienced males for 48 h and their interactions videotaped. Females were gonadally intact and tested during vaginal estrus (INT) or ovariectomized and observed after the following treatments, administered by means of sc injections: EBEB (7 days of estradiol-benzoate); EBP (2 days of EB followed by progesterone), SALEB (saline, days 1-5 then 2 days of EB), OTEB (OT for days 1-5 then 2 days of EB); OTOIL (OT for days 1-5 then 2 days of OIL); or SALOIL (saline days 1-5 then 2 days of OIL). During the first hour of pairing INT females displayed higher levels of affiliation and lower levels of sniffing and agonistic behavior than SALOIL females. All hormonal treatments reduced agonistic behaviors when compared to SALOIL, although none of the hormonal treatments restored affiliation to INT levels. During the 48-h test overt aggression varied by treatment with INT, EBEB, EBP, and OTEB females displaying lower levels than SALOIL, while all groups displayed similar levels of affiliation. The results indicate that OT and E play a significant role in regulating male-directed aggressive behavior in females and that the presence of ovarian hormones as well as OT can increase affiliation during initial contact. Over a sustained period of cohabitation social cues appear to be more important in regulating affiliation than gonadal hormones.

The effect of demonstrator age and number on duration of socially-induced food preferences in house mouse (Mus domesticus)

Present research was undertaken to investigate whether the transfer of food preference from a demonstrator mouse to an observer can be influenced by their relative age. In experiment 1 an adult female mouse, the observer, was allowed to interact with a recently-fed demonstrator which was a pup of her litter or an adult female mouse. The observer was then tested to assess whether it acquired a preference for the demonstrators diet. The results showed that a pup demonstrators influence on an adults food preference is shorter-lasting than an adult demonstrators influence. Experiment 2 was aimed to investigate whether many demonstrators have an additive effect in influencing their observers choice. The results indicated that multiple pup demonstrations do not increase longevity of food preferences induced by pup demonstrators. Moreover, the longevity of an adult observers preference for its demonstrators food is reduced by the exposure to multiple adult demonstrators. Results are discussed in terms of demonstrators reliability and of social constraints that could affect social transfer of food information in the house mouse.

Familiarity and relatedness: Effects on social learning about foods by Norway rats and Mongolian gerbils

In recent experiments in which the social influences on feeding in Mongolian gerbils were investigated, observer gerbils acquired food preferences from conspecific demonstrators only if the demonstrators and observers were either related or familiar. Even then, the effects of demonstrator gerbils on observers’ food choices lasted less than 24 h. In similar experiments with Norway rats, the familiarity/relatedness of demonstrators and observers had little effect on social learning, and the demonstrators’ influence on observers’ food choices lasted many days. We examined the causes of these differences and found that, after observer gerbils interacted with either unfamiliar or familiar conspecific demonstrators that had been fed using procedures typically used to feed demonstrator rats, they showed long-lasting social learning about foods, whereas observer rats interacting with conspecific demonstrators that had been fed as demonstrator gerbils normally are fed showed effects of familiarity/relatedness to demonstrators on their social learning about foods. Procedural differences, rather than species differences, seem to be responsible for reported inconsistencies in social learning about foods by rats and gerbils.