Investigating Behavioral Responses to Mirrors and the Mark Test in Adult Male Zebra Finches and House Crows

Abstract

Earlier evidence suggests that besides humans, some species of mammals and birds demonstrate visual self-recognition, assessed by the controversial “mark” test. Whereas, there are high levels of inter-individual differences amongst a single species, some species such as macaques and pigeons which do not spontaneously demonstrate mirror self-recognition (MSR) can be trained to do so. We were surprised to discover that despite being widely used as a model system for avian research, the performance of zebra finches (Taenopygia guttata) on the mark test had not been studied earlier. Additionally, we studied the behavioral responses of another species of passerine songbirds (Indian house crows; Corvus splendens) to a mirror and the MSR mark test. Although a small number of adult male zebra finches appeared to display heightened responses toward the mark while observing their reflections, we could not rule out the possibility that these were a part of general grooming rather than specific to the mark. Furthermore, none of the house crows demonstrated mark-directed behavior or increased self-exploratory behaviors when facing mirrors. Our study suggests that self-directed behaviors need to be tested more rigorously in adult male zebra finches while facing their reflections and these findings need to be replicated in a larger population, given the high degree of variability in mirror-directed behaviors.

A comparative study of mirror self-recognition in three corvid species

“…Despite the exhibition of self-directed behaviors in the mirror condition by the ravens, neither the ravens nor the azure-winged magpies, as the carrion crows before them, exhibited any mark-directed behaviors during the mark test. This failure of the mark test is in line with the performances of many other corvid species (Soler et al 2014(Soler et al , 2020Clary and Kelly 2016;Brecht et al 2020;Clary et al 2020;Smirnova et al 2020;Vanhooland et al 2020;Wang et al 2020;Parishar et al 2021). Our results further replicate and confirm the previous findings of azure-winged magpies failing the mark test and not exhibiting mark-directed behaviors when the mark can only be seen by utilizing a mirror (Wang et al 2020).…”

“…In fact, two corvid species (i.e., the Eurasian magpie and the Indian house crow) are the only avian species to have, to date, passed the mark test (Prior et al 2008;Buniyaadi et al 2020). However, attempts to replicate these findings in the Eurasian magpies (Soler et al 2020) or the Indian house crow (Parishar et al 2021) as well as studies on other corvid species such as jackdaws (Soler et al 2014), Clark's nutcrackers (Clary and Kelly 2016), California scrub jays (Clary et al 2020), azure-winged magpies (Wang et al 2020), large-billed crows (Kusayama et al 2000), New Caledonian crows (Medina et al 2011), carrion crows (Brecht et al 2020;Vanhooland et al 2020), and hooded crows (Smirnova et al 2020) failed to render any conclusive evidence on these species' abilities of MSR. Thus, indicating that the pre-requisites defined to date (i.e., a high encephalization index, high social complexity, and advanced cognitive abilities) are not sufficient to predict MSR.…”

Hooded Crows (Corvus cornix) May Be Aware of Their Own Body Size

“…Data on their ability to recognize their reflection is contradictory. Along with the results indicating that some corvids (magpies, Prior et al, 2008 ; Clark nutcrackers, Clary and Kelly, 2016 ; Indian house crows, Buniyaadi et al, 2019 ) can recognize their reflection, negative results were also obtained ( Soler et al, 2014 , 2020 ; Smirnova et al, 2019 ; Vanhooland et al, 2019 ; Brecht et al, 2020 ; Clary et al, 2020 ; Parishar et al, 2021 ). The degree of development of understanding the physical properties of their bodies in corvids and other birds has not been previously studied.…”

The Status and Value of Replications in Animal Behavior Science

“…Recent developments make us hopeful, however. For example, the last two years have seen more than a half a dozen of papers reporting (successful and unsuccessful) attempts to replicate the influential mirror mark test in corvids (Brecht et al, 2020;Buniyaadi et al, 2020;Clary et al, 2020;Parishar et al, 2021;Soler et al, 2020;Vanhooland et al, 2020;Wang et al, 2020). Moreover, registered replications are becoming more common (for a recent example see Motes-Rodrigo et al, 2021).…”