Animal Social Network Analysis

Introduction Water buffaloes are group-living animals that perform several activities on pastures, including grazing, moving, standing, ruminating, and wallowing [1]. Various abiotic factors, such as temperature, humidity, wind, and rainfall may affect their grazing behavior and social structure within the herd [2,3]. Rainfall is particularly important for water buffaloes' welfare, as they rely on water to regulate their body temperature due to their poor thermoregulation system [4]. Previous studies have reported that animals may adjust their behavior during rainfall by reducing grazing, traveling longer distances in mild rainfall, and seeking shelter to protect themselves in windy rainstorms [5]. However, it is unclear whether rainfall affects the social structure of the herd during the activities that water buffaloes perform on pastures, and to our knowledge, there are no similar data available. Social Network Analysis (SNA) has recently emerged as a powerful tool for studying the social behavior of grazing livestock [6] such as cattle [7], sheep [8], bison [9], and water buffalo [1]. This method provides a variety of techniques for visualizing, constructing, and analyzing the complex interactions that occur within a network [10], using a range of global and local indices [11]. The aim of this study was to investigate the impact of rainfall on the social structure of water buffaloes during the activities they perform on pasture (grazing, moving, standing, ruminating, and wallowing) with the help of SNA. Our hypothesis was that the presence of rainfall would lead water buffaloes to display different patterns of social organization within the herd. 2. Materials and methods 2.1. Study area The research was conducted at Chrysochorafa (longitude 23°10′08.48″E, latitude 41°10′46.67″Ν), Northern Greece, from May 2015 to April 2016. The area is characterized by dry summers and wet winters. Mean air temperature during the study period ranged from 4.6 °C in the winter to 25.4 °C in the summer. Additionally, monthly precipitation ranged from 24.4 mm during summer to 72.3 mm during autumn. Autumn was the wettest season of the year and summer was the driest. Particularly, during

I use 10 years of data from a long-term study of lekmating long-tailed manakins to relate the social network among males to their spatial and genetic structure. Previously, I showed that the network connectivity of young males predicts their future success. Here, I ask whether kinship might shape the organization of this "young-boy network". Not surprisingly, males that were more socially distant (linked by longer network paths) were affiliated with perch zones (lek arenas) that were further apart. Relatedness (r) among males within the network decreased as social distance increased, as might be expected under kin selection. Nevertheless, any role for indirect inclusive fitness benefits is refuted by the slightly negative mean relatedness among males at all social distances within the network (overall mean r=−0.06). That is, relatedness ranged from slightly negative (−0.04) to more negative (−0.2). In contrast, relatedness in dyads for which at least one of the males was outside the social network (involving at least one blood-sampled male not documented to have interacted with other banded males) was slightly above the random expectation (mean r=0.05). The slight variations around r=0 among males of different categories likely reflect dispersal dynamics, rather than any influence of kinship on social organization. Relatedness did not covary with the age difference between males. These results, together with previous results for lack of relatedness between alpha and beta male partners, refute any role for kin selection in the evolution of cooperative display in this lek-mating system.

The monthly variation of Greek water buffaloes’ grazing behaviour was investigated at the Lake Kerkini National Park in Greece. Direct observations were carried out on six female buffaloes for two consecutive days every month for a one-year period, and the time spent (in minutes) on their grazing-related activities (feeding, moving, wallowing, standing, ruminating, drinking, and lying) was recorded. Moreover, social and aggressive interactions and self-grooming were recorded as number of events. Also, the daily distance travelled by buffaloes was recorded with a handheld GPS. Buffaloes travelled on average 6.9 km/day, and they walked their longest distance in June (10.7 km/day) and their shortest in September (2.9 km/day). They spent more time (P<0.05) on feeding (309.2 min/day) compared to moving (121.7 min/day), wallowing (27.9 min/day), standing (20.2 min/day), ruminating (15.4 min/day), drinking (4.7 min/day) and lying (4.2 min/day). Greek water buffaloes seem to be sociable ...

The advent of new technologies and statistical analyses has provided valuable insights into chondrichthyan social behavior. It has become apparent that sharks and rays lead more complex social lives than previously believed. Heterarchy combines hierarchy and social network theory and although it is not a new concept, it is rarely applied to animal social interactions. Here, we applied heterarchy to a case study involving smooth stingrays foraging for fish scraps at boat ramp in Jervis Bay, NSW Australia. We took advantage of their attraction to this site to examine their social behavior during agonistic interactions over the provisioned resource. We observed a stable, relatively linear but shallow dominance hierarchy that was highly transitive dominated by a single individual. Social network analysis revealed a non-random social network centered on the dominant individual. Contrary to previous research, size did not predict dominance, but it was correlated with network centrality. T...

Social structure is a fundamental aspect of animal populations. In order to understand the function and evolution of animal societies, it is important to quantify how individual attributes, such as age and sex, shape social relationships. Detecting these influences in wild populations under natural conditions can be challenging, especially when social interactions are difficult to observe and broad-scale measures of association are used as a proxy. In this study, we use unoccupied aerial systems to observe association, synchronous surfacing, and physical contact within a pod of southern resident killer whales (Orcinus orca). We show that interactions do not occur randomly between associated individuals, and that interaction types are not interchangeable. While age and sex did not detectably influence association network structure, both interaction networks showed significant social homophily by age and sex, and centrality within the contact network was higher among females and young individuals. These results suggest killer whales exhibit interesting parallels in social bond formation and social life histories with primates and other terrestrial social mammals, and demonstrate how important patterns can be missed when using associations as a proxy for interactions in animal social network studies.

Investigating local-scale interactions within a network makes it possible to test hypotheses about the mechanisms of global network connectivity and to ask whether there are general rules underlying network function across systems. Here we use motif analysis to determine whether the interactions within social insect colonies resemble the patterns exhibited by other animal associations or if they exhibit characteristics of biological regulatory systems. Colonies exhibit a predominance of feed-forward interaction motifs, in contrast to the densely interconnected clique patterns that characterize human interaction and animal social networks. The regulatory motif signature supports the hypothesis that social insect colonies are shaped by selection for network patterns that integrate colony functionality at the group rather than individual level, and demonstrates the utility of this approach for analysis of selection effects on complex systems across biological levels of organization.

The monthly variation of Greek water buffaloes' grazing behaviour was investigated at the Lake Kerkini National Park in Greece. Direct observations were carried out on six female buffaloes for two consecutive days every month for a one-year period, and the time spent (in minutes) on their grazing-related activities (feeding, moving, wallowing, standing, ruminating, drinking, and lying) was recorded. Moreover, social and aggressive interactions and selfgrooming were recorded as number of events. Also, the daily distance travelled by buffaloes was recorded with a handheld GPS. Buffaloes travelled on average 6.9 km/day, and they walked their longest distance in June (10.7 km/day) and their shortest in September (2.9 km/day). They spent more time (P<0.05) on feeding (309.2 min/day) compared to moving (121.7 min/day), wallowing (27.9 min/day), standing (20.2 min/day), ruminating (15.4 min/day), drinking (4.7 min/day) and lying (4.2 min/day). Greek water buffaloes seem to be sociable rather than aggressive animals as they devote to these activities on average 18.2 vs 0.5 events/day. We can conclude that the animals adjust their grazing behaviour to climatic conditions and the availability of forage resources. Izvleček Proučevali smo mesečno spreminjanje vedenja vodnih bivolov pri paši v narodnem parku Jezero Kerkini v severni Grčiji med novembrom leta 2011 in decembrom leta 2012. Neposredno smo opazovali šest samic vodnih bivolov dva zaporedna dneva vsak mesec v letu. Zabeležili smo, koliko časa v minutah porabijo za dejavnosti, povezane s pašo (hranjenje, premikanje, valjanje, stanje, prežvekovanje, pitje in ležanje). Dodatno smo kot število dogodkov zabeležili še druge aktivnosti: socialno in agresivno medsebojno delovanje, samonegovanje. Z GPS napravo smo beležili dnevne razdalje vodnih bivolov. Povprečno so prehodili 6,9 km na dan, najdaljšo razdaljo so naredili junija (10.7 km/dan) in najkrajšo septembra (2,9 km/dan). Bivoli so porabili (P<0,05) več časa za hranjenje (309,2 min/dan) kot za gibanje (121,7 min/dan), valjanje (27,9 min/dan), stanje (20,2 min/dan), prežvekovanje (15,4 min/dan), pitje (4,7 min/dan) in ležanje (4,2 min/dan). Grški vodni bivoli so bolj socialne kot agresivne živali, saj je socialnih aktivnosti več kot agresivnih (18,2 proti 0,5). Zaključimo lahko, da živali prilagodijo svoje vedenje, povezano s pašo, klimatskim razmeram in količini paše, ki je na voljo.

Behavioral Ecology our arsenal. Much social network analysis is essentially passive and aims to make predictions about the structure of a group based on a series of observations, where some analytical hypothesis-testing is possible through techniques such as knockouts of behavioral interactions (as detailed by Pinter-Wollman et al. 2013). We must not forget that if we do not conduct any experimental manipulations on the groups being observed, then we will be unable to expose any hypotheses we form about social structure to the scrutiny possible with a well-controlled experiment. Only when we are able to compare the structure of a series of experimentally manipulated groups with a series of valid controls can we truly embrace these techniques within the framework of behavioral ecology.

The chondrichthyan lineage diverged from the osteichthyan line around 440 million years ago, resulting in a vast evolutionary gulf between modern elasmobranchs and other vertebrates. Though this has supported the assumption that sharks are ancient, dangerous, and binary-minded, intelligent actions including social interactions have been noted in the field, while laboratory studies have confirmed a variety of cognitive capacities. Yet, due to fear of sharks and the difficulties of observing them in their aquatic environments, few ethological studies have been done, so their natural behaviour remains little known. On noting that Carcharhinus melanopterus displayed complex actions during incidental meetings, a long-term ethological study of the species was carried out on the north shore of Mo'orea Island, French Polynesia. During the 6.5 years of the study, new behaviours continued to present. The 35 context-specific actions identified as comprising the behavioural repertoire of C. melanopterus are described.