Amiyaal Ilany

Tel Aviv University | TAU · School of Zoology

High population density should drive individuals to more frequently share space and interact, producing better-connected spatial and social networks. Despite this widely-held assumption, it remains unconfirmed how local density generally drives individuals' positions within wild animal networks. We analysed 34 datasets of simultaneous spatial and s...

The impact of human-driven hunting on large carnivores has been an important factor in altering recent and sub-recent ecosystems. However, comprehending this vital interaction in ancient times is compromised by the scarcity of carnivore remains in archaeological records. To address this, we examined historical human carnivore hunting dynamics in th...

The Arabian leopard (Panthera pardus nimr) has experienced dramatic range and population contractions over the last century. Conservation efforts for this felid focused on captive breeding and identification of suitable conditions for reintroductions. With this study, we unravelled historical collaring and direct observations data to understand the...

Social structure can have significant effects on selection, affecting both individual fitness traits and population-level processes. As such, research into its dynamics and evolution has spiked in the last decade, where theoretical and computational advances in social network analysis have increased our understanding of its ecological and inheritan...

Group movement leadership is associated with higher risks for those in the front. Leaders are the first to explore new areas and may be exposed to predation. Individual differences in risk-taking behavior may be related to hormonal differences. In challenging circumstances, such as risk-taking leadership that may pose a cost to the leader, cortisol...

Network structure is a key driver of animal fitness, pathogen transmission, information spread, and population demographics in the wild. Although a considerable body of research applied network analysis to animal societies, only little effort has been devoted to separate daytime and nighttime sociality and explicitly test working hypotheses on soci...

Here, we present a protocol for collecting data on multiple interaction types in small, stable groups of Arabian babblers (Argya squamiceps). We describe the procedure of habituation, the recording of social interactions, and how to classify the interaction types. Additionally, we provide code for testing, comparing, and visualizing data. The high-...

Competition in group-living animals often results in a dominance hierarchy. The sex that is larger (usually the males) generally dominates the one that is smaller (the females). In certain species, however, despite being smaller, the females dominate several males. Female dominance over males may here arise from the self-reinforcing effects of winn...

Spotted hyenas are an exception in the animal kingdom not only due to female dominance over males, but also because of the strict female linear hierarchy which determines priority of access to resources and produces considerable female reproductive skew. This special social system raises a question: what would become of a beneficial mutation if it...

Rhythmic stability (nonrandom temporal structure) is required for many neural and physiological functions, whereas rhythmic irregularities can indicate genetic or developmental deficiencies. Therefore, rhythmic courtship or contest signals are widespread in nature as honest advertisement displays. Examination of bird songs revealed the pervasivenes...

Social and non-social animals can aggregate at a specific site for various reasons such as reproduction, feeding, or other synchronized patterns of movements. While shark aggregations are well documented, mixed-species aggregations are less studied and therefore poorly understood. To overcome this, a combination of acoustic telemetry and social net...

Network structure is a key driver of animal survival, reproductive success, pathogen transmission, and information spread in animal societies. Yet our knowledge of animal social structure is mostly limited to species’ main activity periods. Here, we investigated the role of nocturnal sociality in a wild herbivore population, the rock hyrax (Procavi...

In many mammalian species, both sexes may take leadership role, but different traits may play a role in determining variation within species. Here we examine the effect of sex on leadership. We present three complementary datasets derived from a well-studied population of wild rock hyrax (Procavia capensis). The findings demonstrated that male and...

The social environment of individuals affects various evolutionary and ecological processes. Their social environment is affected by individual and environmental traits. We assessed the effects of these traits on nodes and dyads in six layers of networks of Arabian babblers, representing different interaction types. Additionally, we tested how trai...

Mother knows best Inheritance of social status, and its associated costs and benefits, is well demonstrated in humans. Whether such an intergenerational system occurs in other species is harder to demonstrate. Ilany et al. looked at nearly 30 years of social interaction data in spotted hyenas, a female-dominated system with a highly structured soci...

Information complexity in animals is an indicator of advanced communication and an intricate socio‐ecology. Zipf's Law of least effort has been used to assess the potential information content of animal repertoires, including whether or not a particular animal communication could be ‘language‐like’. As all human languages follow Zipf's law, with a...

Living in a group creates a complex and dynamic environment in which behavior of individuals is influenced by and affects the behavior of others. Although social interaction and group living are fundamental adaptations exhibited by many organisms, little is known about how prior social experience, internal states, and group composition shape behavi...

Acoustic and rhythmic temporal patterns may have important roles both in animal vocalizations and in human music. Male rock hyraxes, Procavia capensis, advertise their quality and emotional state by singing a long complex song, comprising repetitive elements. Research has revealed that the temporal structure of hyrax songs is similar to a musical c...

The structure of animal social networks influences survival and reproductive success, as well as pathogen and information transmission. However, the general mechanisms determining social structure remain unclear. Using data on 73,767 social interactions among wild spotted hyenas over 27 years, we show that a process of social inheritance determines...

Living in a group creates a complex and dynamic environment in which the behavior of the individual is influenced by and affects the behavior of others. Although social interactions and group living are fundamental adaptations exhibited by many organisms, relatively little is known about how prior social experience, internal states and group compos...

Adriana A. Maldonado-Chaparro and Damien R. Farine, Demographic processes in animal networks are a question of time Amiyaal Ilany, Complex societies, simple processes Orr Spiegel and Noa Pinter-Wollman, Placing the effects of demography on networks in ecological context Ipek G. Kulahci, Individual differences can affect how networks respond to demo...

The efficiency of informational transfer is one of the key aspects of any communication system. The informational coding economy of human languages is often demonstrated by their almost universal fit to Zipf's “Law of Brevity,” expressing negative relationship between word length and its usage frequency. Animal vocal systems, however, provided mixe...

Although males and females share traits, their motivations and needs may be different, due to life-history disparities that lead to divergent selection pressures. Proximate mechanisms underlying differences between the sexes include hormones that mediate the development and activation of suites of traits. Testosterone is associated with morphologic...

Testosterone affects physical and motivational states, both of which may strongly influence vocalization structure and acoustics. The loud complex calls (i.e., songs) of male rock hyraxes (Procavia capensis) are used as honest signals for advertising physical and social states. The snort, a low frequency, noisy element of the song, encodes informat...

The ontogeny of quality-based signals has been studied in numerous animal systems but the degradation of vocal signals with age has received much less attention. Investigating age-related changes in quality- based acoustic signals and the associated social processes (e.g. rank changes, competition intensity) can expand our understanding of the info...

The source-filter theory proposes that information on caller properties is communicated through acoustic qualities, as physical state and performance ability are reflected in the voice. Vocal stability, manifested through harshness, is especially intriguing and has rarely been explored although harsh sounds are prevalent in nature. Male rock hyraxe...

The study of animal vocal signals can either focus on the properties of distinct vocal elements or address the signal as a whole. Although some attention has been given to the continuous progression patterns of bird songs, such patterns in mammalian vocalisations have been largely overlooked. We examined temporal changes in structural and acoustic...

Animals are embedded in dynamically changing networks of relationships with conspecifics. These dynamic networks are fundamental aspects of their environment, creating selection on behaviours and other traits. However, most social network‐based approaches in ecology are constrained to considering networks as static, despite several calls for such a...

Maynard-Smith’s game-theoretical framework suggests that conflicts should be resolved through an exchange of agonistic displays which can be as effective as physical attack in securing contested resources. Hence, participants use signaling tactics that are governed by game-theoretical competition rules to maximize their benefit from the interaction...

Social network analysis has produced important insights regarding the causes and consequences of animal social structure. Social structure has been shown to impact longevity, reproductive success, transmission of pathogens and information, and also play important role in the evolution of cooperation. Studies of the determinants of social structure...

In polygynandrous mating systems, the factors that mediate copulation success and the use of alternative mating tactics, such as mate guarding, are still poorly understood. In the rock hyrax (Procavia capensis), both sexes mate annually with multiple partners during a single month. In order to examine the factors that drive copulation success, we u...

The social network structure of animal populations has major implications for survival, reproductive success, sexual selection, and pathogen transmission of individuals. But as of yet, no general theory of social network structure exists that can explain the diversity of social networks observed in nature, and serve as a null model for detecting sp...

Social structure influences ecological processes such as dispersal and invasion, and affects survival and reproductive success. Recent studies have used static snapshots of social networks, thus neglecting their temporal dynamics, and focused primarily on a limited number of variables that might be affecting social structure. Here, instead we model...

The social network structure of animal populations has major implications to survival, reproductive success, sexual selection, and pathogen transmission. Recent studies showed in various species that the structure of social networks and individuals’ positions in it are influenced by individual traits such as sex, age, and social rank, and can be he...

Animal acoustic communication often takes the form of complex sequences, made up of multiple distinct acoustic units. Apart from the well-known example of birdsong, other animals such as insects, amphibians, and mammals (including bats, rodents, primates, and cetaceans) also generate complex acoustic sequences. Occasionally, such as with birdsong,...

The goal of vocal communication is the efficient delivery of signals to a target audience. Long and complex vocalizations are especially challenging because they are subject to environmental interference and may incur significant costs for the signaler. One of the various ways of increasing the efficiency of signal delivery is enhancement of commun...

Recent studies of animal social networks have significantly increased our understanding of animal behavior, social interactions, and many important ecological and epidemiological processes. However, most of the studies are at low temporal and spatial resolution due to the difficulty in recording accurate contact information. Domestic animals such a...

Contact patterns among hosts are considered as one of the most critical factors contributing to unequal pathogen transmission. Consequently, networks have been widely applied in infectious disease modeling. However most studies assume static network structure due to lack of accurate observation and appropriate analytic tools. In this study we used...

The social structure of a population is based on individual social associations, which can be described using network patterns (motifs). Our understanding of the forces stabilizing specific social structures in animals is limited. Structural balance theory was proposed for exploring social alliances and suggested that some network motifs are more s...

In many species individuals advertise their quality via vocal communication. Although sound production requires energy, it is still unclear to what extent vocalizing increases metabolic rate. A substantial energetic cost of vocalization may suggest that it serves as a handicap. In this study, we evaluated the energetic cost of vocalization in the c...

We used a recent passerine phylogeny and comparative method to evaluate the macroevolution of body and egg mass, incubation and fledging periods, time to independence and time with parents of the main passerine lineages. We hypothesised that passerine reproductive traits are affected by adaptation to both past and present environmental factors and...

Few mammalian species produce vocalizations that are as richly structured as bird songs, and this greatly restricts the capacity for information transfer. Syntactically complex mammalian vocalizations have been previously studied only in primates, cetaceans and bats. We provide evidence of complex syntactic vocalizations in a small social mammal: t...

Signal detection theory predicts that signals directed at distant or busy receivers in noisy backgrounds will begin with an alert component, in order to draw attention. Instead of an alert component, however, animals could get the same effect by using an external stimulus. Here we combined observations of free-living rock hyraxes (Procavia capensis...

Examples of two social networks for David (a) 2008 and Arugot 2009 (b) populations. Social groups, following community detection results (see methods section), are delimited by dotted lines. Males and females are represented by empty and full circles, respectively. Line width between nodes is proportional to the association index values, representi...

Summary results of the Barker model analysis of survival and recapture rates for the Arugot population between 2000 and 2009 in Ein Gedi, Israel. Models highlighted in bold are the best-supported models in the candidate set. Additional parameters were previously modeled and kept constant: r(.)R(06- ./.)R′(06- ./.)F(g = 1, m-.)F′(g-., m = 0). See Ta...

(DOC)

parameter combinations modeled with Barker models. Notation: t = time dependent, . = constant, 2a = 2 age classes, di, dj = group names, g = group, m = males. (DOC)

Summary results of the Barker model analysis of survival and recapture rates for the David population between 2002 and 2009 in Ein Gedi, Israel. Models highlighted in bold are the best-supported models in the candidate set. Additional parameters were previously modeled and kept constant: r(t) R(06- ./.)R′(06- ./.)F(g-., m-.)F′(.). Group names: di =...

In communal mammals the levels of social interaction among group members vary considerably. In recent years, biologists have realized that within-group interactions may affect survival of the group members. Several recent studies have demonstrated that the social integration of adult females is positively associated with infant survival, and female...

At least four hypotheses have been suggested to explain the formation and maintenance of song dialects among birds: historic processes (epiphenomenon), genetic or local adaptation, acoustic adaptation, and social adaptation. We studied spatial and temporal distribution of dialect in the orange-tufted sunbird (Nectarinia osea), a small nectarivorous...

Abstract

Raptor–prey encounters were studied to evaluate the strategies and success rate of both predator attack and prey defense. We compared the success of barn owls in catching stationary simulated prey (food item) with that of moving prey (food item that was pulled in various directions). We also tracked real encounters between barn owls and spiny mice...