Explorative innovators and flexible use of social information in common ravens (Corvus corax) and carrion crows (Corvus corone).

Abstract

Innovation and social information use are influenced by individual characteristics, and are important for the creation and transmission of novel behavioral patterns. Here, we investigated which individual factors predict innovation rates and social transmission of information in a comparative study with identically reared common ravens (Corvus corax) and carrion crows (Corvus corone corone; Corvus corone cornix). In the innovation experiment (1), we presented the birds with a novel problem-solving task while alone, to determine which individuals would quickly solve ("innovators") or not solve ("noninnovators") this task. We then related these findings to sex, object exploration (frequency of novel item manipulation), object neophobia (latency to novel item interaction), and social rank position. We found that innovators were more explorative than noninnovators, although they did not differ significantly in social rank, object neophobia or sex. In the social information use experiments (2 & 3), subjects first observed a model (Exp. 2: conspecific, heterospecific; Exp. 3: conspecific innovator & noninnovator) demonstrate a specific color selection in a 2-choice cup task, before being allowed to make their own cup selection. Innovator and noninnovator observers did not significantly differ in their tendency to use social information, that is, to select the demonstrated cup first, from a conspecific or heterospecific model. Furthermore, observers did not preferentially use social information from an innovator over a noninnovator model. We discuss our findings in relation to the likely benefits of flexible information use, and the role of other model characteristics, such as relationships, on the use of social information. (PsycINFO Database Record

Eurasian jays do not copy the choices of conspecifics, but they do show evidence of stimulus enhancement

“…Two of seven jays (one male, one female) chose the same coloured cup (white) as the demonstrator (i.e., copied the demonstrator), while the other five jays (three females, two males) chose the non-demonstrated cup colour (black; Table 3). In comparison, Miller, Schwab & Bugnyar (in press) found that eight of eight crows (five females, three males) and eight of eight ravens (three females, five males) copied the conspecific demonstrator, which was significant (Binomial test: p  = 0.008 for each species). We additionally examined whether there was a difference in the latency to make the first choice between the birds that chose the demonstrated colour versus those that did not.…”

“…Homer touched both cups in session one and two, but passed criterion in session three. He was given four training sessions in total to ensure comparability with the number of demonstrator training sessions used for the carrion crows and ravens in Miller, Schwab & Bugnyar (in press). Homer chose the white cup 100% of the time during demonstrators for observers; therefore observers did not see any incorrect choices.…”

“…Evidence of social information use, specifically copying the choices of others, has been found in social corvid species, including pinyon jays ( Gymnorhinus cyanocephalus ; Templeton, Kamil & Balda, 1999), rooks (Dally, Clayton & Emery, 2008), jackdaws ( Corvus monedula ; (Schwab, Bugnyar & Kotrschal, 2008a), common ravens ( Corvus corax ; Fritz & Kotrschal, 1999; Schwab et al, 2008b), carrion crows ( Corvus corone corone , C. c. cornix ; Miller, Schwab & Bugnyar, in press) and New Caledonian crows (Logan et al, 2016a). Social species are predicted to be better at acquiring new skills in a social context than in a non-social context (Lefebvre & Giraldeau, 1996), because they may attend more to conspecifics than asocial species (Balda, Kamil & Bednekoff, 1996).…”

“…Unlike the object-dropping task, this is a fairly simple task and corvids, including Eurasian jays, have been shown to be capable of making colour discriminations (ravens: Range, Bugnyar & Kotrschal, 2008; Eurasian jays: Clayton & Krebs, 1994; G Davidson, R Miller, E Loissel, L Cheke & N Clayton, 2016, unpublished data). Furthermore, this test has explicitly been used previously to demonstrate use of social information in other corvids, namely common ravens and carrion crows, where all the individuals that were tested chose the demonstrated colour (Miller, Schwab & Bugnyar, in press). Ravens and crows are social species with high fission–fusion dynamics, being highly social in the non-breeding season, and territorial in the breeding season (Goodwin, 1986).…”

“…Ravens and crows are social species with high fission–fusion dynamics, being highly social in the non-breeding season, and territorial in the breeding season (Goodwin, 1986). We conducted the task in a comparable manner to Miller, Schwab & Bugnyar (in press) to allow for direct comparison between these two corvid studies. The inclusion of both tasks in the present study allowed us to compare jay performances with social corvid species that have been shown to use social information on the same tasks.…”