DOI: 10.5061/dryad.34k42
title: Data from: Age-graded dominance hierarchies and social tolerance in packs of free-ranging dogs

description: It is believed that domestic dogs rarely form packs with age-graded
 hierarchical structures similar to those found in wolves. Dog-wolf
 comparisons in captivity suggest that human control has reduced dog
 dependency on cooperation with conspecifics, resulting in a more despotic
 dominance order. However, free-ranging dogs are under stronger natural
 selection than purebred dogs. They are dependent on companions’ social
 support but usually exhibit lower reproductive skew than wolves, possibly
 because access to easily available human-derived food may have relaxed
 within-group competition. We investigated social dominance in 5 packs of
 mongrel dogs living in a free-ranging or semifree-ranging state. We aimed
 at replicating the findings of the few studies that detected a dominance
 hierarchy in dogs using a larger sample of packs. Additionally, we
 provided behavioral measures of social tolerance. We found that a linear
 hierarchy existed in all packs studied and that the rank order was
 positively related to age in all packs but one. In 2 packs in which
 testing was possible, age was a better predictor of dominance than body
 size. Potentially injurious aggression was very rare. Hierarchy steepness
 in dogs was similar to that found in wolves and in tolerant primates.
 Submissive reversals were more common in dogs than in wolves. These
 results suggest that age-graded hierarchies in dogs are more common than
 previously thought, that rank is not usually acquired through fighting
 because subordinates rely on the guidance of elders, and contradict the
 view that domestication has increased despotism in dogs.
description: 1.Total_Number_of_Submissive_interactions_in_dog_packsThis file contains six tables. Each table is a squared matrix reporting the total number of submissive gestures exchanged among dogs belonging to the same pack. So, each table corresponds to a different dog pack. Performers of submissive gestures are reported on the vertical axis on the left side of each table, in which each individual dog is identified using a 2-3 letters code. Recipients of submissive gestures are reported on the upper horizontal axis of each table, and again each individual dog is identified using a 2-3 letter code. Note that the data reported for the Curva pack are not statistically independent from those reported for the Fused pack, since the latter originated from the fusion of the Curva pack with another one and the data collected before and after the fusion event were combined (see Bonanni et al. 2017, Behav Ecol, for additional explanations). In the original paper, the data reported in these tables were used to calculate the statistical parameters reported in Table 3, i.e. hierarchy linearity, directional consistency of submissive behaviour, hierarchy steepness, as well as percentage of unknown, 1-way, 2-ways, and tied dyadic relationships. Moreover, these data were also used to arrange pack members in the rank order that was most consistent with a linear hierachy.2.Gender_Age_DominanceRank_of_Individual_DogsThis file contains data concerning gender, age and dominance rank of all individual dogs studied. Note that “age” is reported as “age class”, i.e. individual dogs of each pack were assigned to age classes that were ranked from the youngest to the oldest one, based on their actual or estimated year of birth (which is also reported in the table). So, “age class” does not express the actual age of dogs in years. Note that empty cells refer to missing values, i.e. dogs whose ages could not be estimated relative to that of other dogs. Dominance rank was standardized by distributing ranks evenly between the highest (+1) and the lowest (-1), with the median rank being scored as 0, to allow comparison across packs. In the original paper these data were used to: 1) assess the correlation between dominance rank and age for each pack separately; 2) assess the effect of gender on dominance rank, as well as the effect of gender on age.3.Gender_DominanceRank_Age_Body_Size_of_Individual_DogsThis files contains data concerning gender, dominance rank, age and body size for some of the dogs studied. In particular, body measurements were collected for members of two dog packs, one studied during the period 2005-2006 (most behaviorual data analyses concerning this group were published by Cafazzo et al. 2010, Behav Ecol 21, 443-455), and another one studied during 2007-2008 (most behavioural data analyses concerning this one are included in Bonanni et al. 2017). As said above, the variable “age class” does not express the actual age of dogs in years, but rather it ranks pack members from the youngest (lowest rank) to the oldest one (highest rank). All body measurements are espressed in cm. Head size was obtained by summing up three distances: nose-occipital bone, temporal-temporal, mandible-forehead. Empty cells refer to missing values. In the original paper by Bonanni et al. (2017), these data were used to: 1) assess the correlation between standardized dominance rank and body measurements (separately for each pack); 2) assess the partial correlation between dominance rank and age, after controlling for body size (it was feasible only for the Corridoio pack); 3) assess the partial correlation between dominance rank and body measurements after controlling for age (it was feasible only for the Corridoio pack; 4) assess the effect of gender on the body measurements (all measured individuals taken together). Note that one female dog was a member of both packs at different times, and her body measurements were used in the statistical tests concerning both packs since she was already fully adult/grown during the study period 2005-2006.4.Total_Number_of_Affiliative_and_Agonistic_Submissive_interactions_in_dog_packsThis file contains ten tables. Each table is a squared matrix reporting the total number of affiliative or agonistic submissive gestures exchanged among dogs belonging to the same pack (see Bonanni et al. 2017, Behav Ecol, for a definition of both types of submission). So, there are two tables for each dog pack, one reporting the outcomes of affiliative submissive gestures and the other one reporting the outcomes of agonistic submissive gestures. Performers of affiliative/agonistic submissive gestures are reported on the vertical axis on the left side of each table, in which each individual dog is identified using a 2-3 letters code. Recipients of affiliative/agonistic submissive gestures are reported on the upper horizontal axis of each table, and again each individual dog is identified using a 2-3 letter code. Note that the data reported for the Curva pack are not statistically independent from those reported for the Fused pack, since the latter originated from the fusion of the Curva pack with another one and the data collected before and after the fusion event were combined (see Bonanni et al. 2017, Behav Ecol, for additional explanations). In the original paper, the data reported in these tables were used to calculate the directional consistency of affiliative and agonistic submissive gestures separately, and mostly to calculate the correlation between matrices of affiliative submissions and those of agonistic submissions for each pack separately.5.Measures_of_social_tolerance_in_dog_packsThis file contains a table reporting several measures of social tolerance (and other related variables) in domestic dog packs, comprising both the packs presented in the paper by Bonanni et al. (2017), and others for which data were published in other papers (data source is also reported). Measures of social tolerance comprised: directional consistency index of total submissive behaviour, hierarchy steepness (calculated from matrices reporting total submissive behavior, and based on Dij, i.e. dyadic dominance indexes corrected by chance), and proportion of bites in relation to the total number of agonistic interactions (obtained by summing up aggressive and dominance interactions). Related variables comprised: percentage of dyadic unknown relationships in matrices reporting total submissive behaviour, number of pack members, and proportion of pack members who were either spayed or castrated. In the original paper, these data were used to assess Spearman correlation between measures of social tolerance and related variables.6.Measures_of_social_tolerance_in_free-ranging_dogs_and_wolvesThis file contains a table reporting measures of social tolerance (and some related variables) in packs of free-ranging dogs and wolves. The latter comprises both packs presented in the paper by Bonanni et al. 2017, as well as packs studied in other papers (data source is also reported in the table). Measures of social tolerance comprised 1) directional consistency indexes of total submissive behaviour and 2) hierarchy steepness (calculated from matrices reporting total submissive behavior, and based on Dij, i.e. dyadic dominance indexes corrected by chance). The table also reports the number of pack members, and the percentage of unknown dyadic relationships in matrices reporting total submissive behaviour, i.e. the same matrices used to calculate measures of social tolerance. In the original paper, these data were used to compare the degree of social tolerance displayed by dogs with that displayed by wolves.7.Total_Number_of_Aggressive_interactions_in_dog_packsThis file contains six tables. Each table is a squared matrix reporting the total number of aggressive gestures exchanged among dogs belonging to the same pack. So, each table corresponds to a different dog pack. Performers of aggressive gestures are reported on the vertical axis on the left side of each table, in which each individual dog is identified using a 2-3 letters code. Recipients of aggressive gestures are reported on the upper horizontal axis of each table, and again each individual dog is identified using a 2-3 letter code. Note that the data reported for the Curva pack are not statistically independent from those reported for the Fused pack, since the latter originated from the fusion of the Curva pack with another one and the data collected before and after the fusion event were combined (see Bonanni et al. 2017, Behav Ecol, for additional explanations). In the original paper, the data reported in these tables were used to calculate the statistical parameters reported in Table S6, i.e. hierarchy linearity, directional consistency of aggressive behaviour, hierarchy steepness, as well as percentage of unknown, 1-way, 2-ways, and tied dyadic relationships.8.Total_Number_of_Dominance_interactions_in_dog_packsThis file contains six tables. Each table is a squared matrix reporting the total number of dominance displays exchanged among dogs belonging to the same pack. So, each table corresponds to a different dog pack. Performers of dominance displays are reported on the vertical axis on the left side of each table, in which each individual dog is identified using a 2-3 letters code. Recipients of dominance displays are reported on the upper horizontal axis of each table, and again each individual dog is identified using a 2-3 letter code. Note that the data reported for the Curva pack are not statistically independent from those reported for the Fused pack, since the latter originated from the fusion of the Curva pack with another one and the data collected before and after the fusion event were combined (see Bonanni et al. 2017, Behav Ecol, for additional explanations). Also, note that the data concerning the Caraffa pack are missing because they were lost. In the original paper, the data reported in these tables were used to calculate the statistical parameters reported in Table S6, i.e. hierarchy linearity, directional consistency of dominance behaviour, hierarchy steepness, as well as percentage of unknown, 1-way, 2-ways, and tied dyadic relationships.