Abstract: Cuttlefish have a large repertoire of body patterns that are used for camouflage and interspecific signaling. Intraspecific signaling by male cuttlefish has been well documented but studies on signaling by females are lacking. We found that females displayed a newly described body pattern termed Splotch toward their mirror image and female conspecifics, but not to males, prey or inanimate objects. Female cuttlefish may use the Splotch body pattern as an intraspecific signal, possibly to reduce agonistic interactions. The ability of females to produce a consistent body pattern in response to conspecifics and mirrors suggests that they can recognize same-sex conspecifics using visual cues, despite the lack of sexual dimorphism visible to human observers.

Abstract: Gaze alternation (GA) is considered a hallmark of pointing in human infants, a sign of intentionality underlying the gesture. GA has occasionally been observed in great apes, and reported only anecdotally in a few monkeys. Three squirrel monkeys that had previously learned to reach toward out-of-reach food in the presence of a human partner were videotaped while the latter visually attended to the food, a distractor object, or the ceiling. Frame-by-frame video analysis revealed that, especially when reaching toward the food, the monkeys rapidly and repeatedly switched between looking at the partner's face and the food. This type of GA suggests that the monkeys were communicating with the partner. However, the monkeys' behavior was not influenced by changes in the partner's focus of attention.

Abstract: Most birds rely on imprinting and experience with conspecifics to learn species-specific recognition cues. Australian brush-turkeys (Alectura lathami) do not imprint and form no bonds with parents. They hatch asynchronously, disperse widely and meet juvenile conspecifics at an unpredictable age. Nevertheless, in captivity, hatchlings respond to other chicks. A recent study, which involved the use of robotic models, found that chicks prefer to approach robots that emit specific visual cues. Here, we evaluated their response to acoustic cues, which usually play an important role in avian social cognition. However, in simultaneous choice tests, neither 2-day-old nor 9-day-old chicks preferred the choice arm with playback of either chick or adult conspecific calls over the arm containing a silent loudspeaker. Chicks of both age classes, however, scanned their surroundings more during chick playback, and the response was thus consistent in younger and older chicks. We also presented the chicks with robotic models, either with or without playback of chick calls. They did not approach the calling robot more than they did the silent robot, indicating that the combination of visual and acoustic cues does not evoke a stronger response. These results will allow further comparison with species that face similar cognitive demands in the wild, such as brood parasites. Such a comparative approach, which is the focus of cognitive ecology, will enable us to further analyse the evolution and adaptive value of species recognition abilities.

Abstract: In 2001, Xitco et al. (Anim Cogn 4:115-123) described spontaneous behaviors in two bottlenose dolphins (Tursiops truncatus) that resembled pointing and gaze alternation. The dolphins' spontaneous behavior was influenced by the presence of a potential receiver, and the distance between the dolphin and the receiver. The present study adapted the technique of Call and Tomasello [(1994) J Comp Psychol 108:307-317], used with orangutans to test the effect of the receiver's orientation on pointing in these same dolphins. The dolphins directed more points and monitoring behavior at receivers whose orientation was consistent with attending to the dolphins. The results demonstrated that the dolphins' pointing and monitoring behavior, like that of apes and infants, was linked to the attentional behavior of the receiver.

Abstract: The ability of organisms to discriminate social signals, such as affective displays, using different sensory modalities is important for social communication. However, a major problem for understanding the evolution and integration of multimodal signals is determining how humans and animals attend to different sensory modalities, and these different modalities contribute to the perception and categorization of social signals. Using a matching-to-sample procedure, chimpanzees discriminated videos of conspecifics' facial expressions that contained only auditory or only visual cues by selecting one of two facial expression photographs that matched the expression category represented by the sample. Other videos were edited to contain incongruent sensory cues, i.e., visual features of one expression but auditory features of another. In these cases, subjects were free to select the expression that matched either the auditory or visual modality, whichever was more salient for that expression type. Results showed that chimpanzees were able to discriminate facial expressions using only auditory or visual cues, and when these modalities were mixed. However, in these latter trials, depending on the expression category, clear preferences for either the visual or auditory modality emerged. Pant-hoots and play faces were discriminated preferentially using the auditory modality, while screams were discriminated preferentially using the visual modality. Therefore, depending on the type of expressive display, the auditory and visual modalities were differentially salient in ways that appear consistent with the ethological importance of that display's social function.