Intentional Presentation of Objects in Cooperatively Breeding Arabian Babblers (Turdoides squamiceps)

The emergence of intentional communication and the intentional presentation of objects have been highlighted as important steps in the ontogeny of cooperative communication in humans. Furthermore, intentional object presentation has been suggested as an extremely rare form of communication evolutionarily. Research on comparable means of communication in non-human species may therefore shed light on the selection pressures that acted upon components of human communication. However, the functions and cognitive mechanisms that underlie object presentation in animals are poorly understood. Here, we addressed these issues by investigating object presentations in wild, cooperative breeding Arabian babblers (Aves: Turdoides squamiceps). Our results showed that individuals presented objects to specific recipients. The recipients most often responded by approaching the signaler and the dyad then moveed jointly to copulate at a hidden location. We provide evidence that object presentations by Arabian babblers (i) do not represent a costly signal, as objects were not costly to acquire; (ii) were not used to trade food for sex, as the presentation of food was not more likely to result in copulation; and (iii) possessed hallmarks of first-order intentionality. These results show that intentional presentation of objects is not restricted to the primate linage and may suggest that the need to engage in cooperative interactions facilitates elaborate socio-cognitive performances

Nest-site competition between invasive and native cavity nesting birds and its implication for conservation

Nesting cavities are often a limited resource that multiple species use. There is an ongoing discussion on whether invasive cavity nesting birds restrict the availability of this key limited resource. While the answer to this question has important conservation implications, little experimental work has been done to examine it. Here, we aimed to experimentally test whether alien cavity nesting birds affect the occupancy of cavities and the resulting breeding success of native cavity breeders in a large urban park located in Tel Aviv, Israel. Over three breeding seasons, we manipulated the entry size of nest boxes and compared the occupancy and breeding success of birds in nest boxes of two treatments. These included nest boxes with large-entrance and small-entrance holes. The large-entrance holes allowed access for both the native and invasive birds (the two main aliens in the park are the common mynas and rose-ringed parakeets). The smaller-entrance boxes, on the other hand, allowed only the smaller sized native cavity breeders (great tits and house sparrows) to enter the boxes but prevented the alien species from entering. We found that the large-entrance nest boxes were occupied by five different bird species, comprising three natives (great tit, house sparrow, Scops owl) and two invasive species (common myna, rose-ringed parakeet) while the small-entrance boxes were only occupied by the two native species. The alien common mynas and rose-ringed parakeets occupied 77.5% of the large-entrance nest boxes whereas native species, mainly great tits, occupied less than 9% of the large-entrance boxes and 36.5% of the small-entrance boxes. When examining the occupancy of those cavities that were not occupied by the aliens, natives occupied both the small and large-entrance nest boxes equally. Three quarters (78%) of the great tits breeding in the large-entrance boxes were usurped by common mynas during the breeding season and as a result breeding success was significantly lower for great tits breeding in the large-entrance boxes compared with the small-entrance boxes. The results of this study suggests that the invasive alien species can reduce the breeding potential of native cavity breeders both by exploiting the limited breeding resource (nest cavities) and by directly usurping cavities already occupied by the native species. Since the majority of large-entrance nest boxes were occupied by the larger alien birds, less native species bred in the limited number of unoccupied large-entrance nest boxes because of exploitation competition. We propose that for management purposes, nest-box programs that alter the entrance size of available natural cavities may be a practical approach, reducing the competition between native cavity breeders and alien invasive birds, and especially benefiting the smaller native cavity breeders

Social cognition and social behaviour in cooperatively breeding Arabian babblers (Turdoides squamiceps) and humans (Homo sapiens) : a case of convergent evolution?

In this Ph.D. thesis I investigate the role that cooperative breeding, monopolisation of mating and an “ape-like cognitive system” may have played in the evolution of human social traits. To this end, I have studied two specific socio-cognitive skills (intentional communication, joint attention) and a social behaviour (concealed sex) in a cooperative breeding bird species: the Arabian babbler (Turdoides squamiceps). In the following, I outline the main results of my dissertation.In article one, “Intentional presentation of objects in cooperatively breeding Arabian babblers (Turdoides squamiceps)”, I test whether Arabian babblers are capable of first-order intentional communication, a socio-cognitive skill that is fundamental to human communication. The results show that: (i) Arabian babblers invite each other for copulation by presenting an object; (ii) object presentation is not a costly signal, as objects are not costly to acquire; (iii) birds do not trade food for sex, as presenting edible items is not more likely to result in copulation; and (iv) object presentation by Arabian babblers possesses characteristics that are used to infer first-order intentional communication in pre-linguistic children.In article two, “Joint attention skills in wild Arabian babblers (Turdoides squamiceps): A consequence of cooperative breeding?”, I test the hypothesis that the evolution of joint attention skills requires an ape-like cognitive system and systematic reliance on alloparental care. I present evidence that travel coordination among Arabian babblers fulfils key hallmarks that are used to infer joint attention-based communication in pre-linguistic children: (i) intentional communication, (ii) co-orientation of attention, and (iii) establishment of common ground between interlocutors. The finding of intentional communication and joint attention - two socio-cognitive skills that are considered uniquely human by some scholars – in a cooperatively breeding bird species questions the necessity of an ape-like cognitive system for the evolution of these skills. At the same time, these results support the hypothesis that cooperative breeding facilitates socio-cognitive performances.In article three, “Why hide? Concealed sex in dominant Arabian babblers (Turdoides squamiceps) in the wild”, I show that dominant Arabian babblers use tactical deception to conceal their copulations from the view of their group members. I present evidence that dominant Arabian babblers do not conceal sex, either to avoid predation, as a dominance signal or to avoid social interference. I suggest that concealment of copulations by dominant animals and concealment of socially legitimate sex by humans raise the same question: why do individuals, whose sexual activity is not expected to be interrupted, conceal sex from the sensory perception of conspecifics? I present the "Cooperation-Maintenance" hypothesis, which postulates that concealed sex is a behavioural strategy prevent sexual arousal in observers (proximate explanation), thereby to maintain sexual monopolisation of one’s partner/s and cooperation with other group members (ultimate explanations).In article four, “Why do humans and nonhuman animals conceal sex? The Cooperation-Maintenance Hypothesis”, I analyse zoological and cultural data to (i) provide the first systematic evidence that the preference to conceal sex is widespread across human cultures; (ii) show that current hypotheses about the function of concealed sex in humans are not supported by ethnographic data, nor by comparative data from nonhuman great apes; and (iii) present an integrative framework for studying concealed sex across species and cultures.In article five, “Why do we hide legitimate sex? The relationship between concealed sex and sexual exclusivity in humans”, I present preliminary analyses of the largest ethnographic database exists – the eHRAF - showing that the extent of sexual exclusivity between human pairs is associated with the extent of sex concealment across cultures. These results provide first empirical support for the cooperation-maintenance hypothesis. The findings that a cooperative breeding bird species demonstrates cognitive skills and a complex social behaviour that were long considered human prerogatives, lead to two conclusions: First, the need to balance intensive cooperative versus competitive motives within the social group (e.g., heavy reliance on alloparental care versus monopolisation of all/specific sexual partners) may have had a synergetic effect on the evolution of social traits in Arabian babblers, humans and other species that live in comparable social systems. Second, the presented similarities between humans and a phylogenetically distant species emphasise the need to expand comparative research in evolutionary anthropology to species that experience similar social pressures to humans. In particular, the comparison between humans and cooperative breeding species that live in groups with skewed mating ratio, may shed important light on the evolution of sophisticated social traits.publishe

Why do human and non-human species conceal mating? The cooperation maintenance hypothesis

Despite considerable cultural differences, a striking uniformity is argued to exist in human preferences for concealing sexual intercourse from the sensory perception of conspecifics. However, no systematic accounts support this claim, with only limited attempts to understand the selective pressures acting on the evolution of this preference. Here, I combine cross-cultural and cross-species comparative approaches to investigate these topics. First, an analysis of more than 4572 ethnographies from 249 cultures presents systematic evidence that the preference to conceal mating is widespread across cultures. Second, I argue that current anthropological hypotheses do not sufficiently explain why habitual concealment of mating evolved in humans but is only seldom exhibited by other social species. Third, I introduce the cooperation maintenance hypothesis, which postulates that humans, and a specific category of non-human species, conceal matings to prevent sexual arousal in witnesses (proximate explanation). This allows them to simultaneously maintain mating control over their partner(s) and cooperation with group members who are prevented from mating (ultimate explanations). I conclude by presenting a comparative framework and predictions to be tested across species and human cultures

Intentional communication: solving methodological issues to assigning first‐order intentional signalling

Intentional signalling plays a fundamental role in human communication. Mapping the taxonomic distribution of comparable capacities may thus shed light on the selective pressures that enabled the evolution of human communication. Nonetheless, severe methodological issues undermine comparisons among studies, species and communicative modalities. Here, we discuss three main obstacles that hinder comparative research of ‘first‐order’ intentional signalling (i.e. voluntary signalling in pursuit of a cognitively represented goal): (i) inconsistency in how behavioural hallmarks are defined and operationalised, (ii) testing of behavioural hallmarks without statistical comparison to control conditions, and (iii) bias against the publication of negative results. To address these obstacles, we present a four‐step scheme with 20 statistical operational criteria to distinguish between non‐intentional and first‐order intentional signalling. Our unified scheme applies to visual and audible signals, thereby validating comparison across communicative modalities and species. This, in turn, promotes the generation and testing of hypotheses about the evolution of intentional communication

Discussing rights and wrongs: Three suggestions for moving forward with the migrant health rights debate

Gottlieb ND, Ben Mocha Y. Discussing rights and wrongs: Three suggestions for moving forward with the migrant health rights debate. Bioethics. 2018;32(6):353-359

BW use of gaze alternation

Babbler walk: use of gaze alternatio

OP use of gaze alternation

Object presentation: use of gaze alternatio

Data from: Joint attention skills in wild Arabian babblers (Turdoides squamiceps): a consequence of cooperative breeding?

Human cooperation strongly relies on the ability of interlocutors to coordinate each other’s attentional state: joint attention. One predominant hypothesis postulates that this hallmark of the unique cognitive system of humans evolved due to the combination of an ape-like cognitive system and the prosocial motives that facilitate cooperative breeding. Here, we tested this hypothesis by investigating the communicative interactions of a cooperatively breeding bird species, the Arabian babbler (Turdoides squamiceps). The behaviour of twelve wild social groups was observed focusing on two distinct communicative behaviours, OBJECT PRESENTATION and BABBLER WALK. The results showed that both behaviours fulfilled the criteria for first-order intentional communication and involved co-orientation of the recipients' attention. In turn, recipients responded with cooperative and communicative acts that resulted in coordinated joint travel between interlocutors. These findings provide the first evidence that another animal species shows several key criteria traditionally used to infer joint attention in prelinguistic human infants. Furthermore, they emphasize the effect of cooperative breeding on sophisticated socio-cognitive performances, while questioning the necessity of an ape-like cognitive system underlying joint attentional behaviour

Proto-tool use for food processing in wild Arabian babblers : matching processing methods, substrates and prey types

Cognition is a powerful adaptation, enabling animals to utilise resources that are unavailable without manipulation. Tool use and food processing are examples of using cognition to overcome the protective mechanisms of food resources. Here, we describe and examine the flexibility of proto-tool use (defined as the alteration of an object through object-substrate manipulation) for food processing in a cooperatively breeding bird, the Arabian babbler (Argya squamiceps). Field observations demonstrate that the birds transport different caterpillar species to different substrate types depending on the processing method needed to prepare the caterpillar for eating. Species with toxic setae (e.g. Casama innotata) are transported to be rubbed on rough substrates (e.g. sand) before consumption, while other species (e.g. Hyles livornica) are transported to be pounded against hard substrates until their inner organs are removed and only their external body part is consumed. These results are among the few to describe flexible proto-tool use for food processing in wild animals. They thereby contribute to the taxonomic mapping of proto-tool use and food processing in non-human species, which is a fundamental step to advance comparative studies on the evolution of these behaviours and their underlying cognitive mechanisms.publishe