Table 1.
Tasks and subjects included in the transfer effect analyses
| Article | Subjects, N=28 | Training | Basic watera | Large vs. small stones | Water vs. sand | Air vs. water | Sink vs. floatb | Baited vs. unbaited | U-Tube | Hollow vs. solid | Narrow vs. wide equal | Narrow vs. wide unequal | Uncovered U-Tube | Other tasksc |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Bird and Emery (2009b) | 4 captive rooks | Trained in Bird and Emery (2009a) | 3/3 (100)d | 3/3 (100) | 3/3 (100) | – | – | – | – | – | – | – | – | |
| Taylor et al. 2011 | 5 wild-caught New Caledonian crows | ✓ | 4/4 (100) | 4/4 (100) | 4/4 (100) | 4/4 (100) | 4/4 (100) | – | – | – | – | – | – | 2 Tube search tasks 2 tool-use tasks |
| Cheke et al. (2011) | 5 hand-raised Eurasian jays | ✓ | – | – | 2/4 (50) | 1/2 (50) | 2/2 (100) | 2/2 (100) | 0/3 (0)e | – | – | – | – | Arbitrary reward movement cues |
| Jelbert et al. (2014) | 6 wild-caught New Caledonian crows | ✓ | – | – | 6/6 (100) | – | 6/6 (100) | – | 0/4 (0) | 5/5 (100) | 0/5 (0) | 3/4 (75) | – | |
| Logan et al. (2014) | 8 wild-caught New Caledonian crows | ✓ | – | – | 3/5 (60) | – | 6/6 (100) | – | 1/5 (20) | 6/6 (100) | 4/6 (67) | 3/4 (75) | 0/5 (0) | Multistone platform |
| Totals 7/7(100) | 7/7 (100) | 18/22 (82) | 5/6 (83) | 18/18 (100) | 2/2 (100) | 1/12 (8)f | 11/11 (100) | 4/11 (36)f | 6/8 (75) | 0/5 (0)f |
The basic water task did not involve a binary choice and was thus not included in the transfer analyses
Sink vs. float is called heavy vs. light in Taylor et al. (2011)
The column lists additional tasks presented in each article that did not involve water (displacement), and were not included in the transfer analyses
x/n = number of Ss that the authors described as successful/number of Ss participating in the task. Percent of successful birds are in parentheses. Each task involved a binary choice and water (displacement) except basic water
Following the initial U-Tube task, two corvids completed a second U-Tube task in which the color and shape that denoted the functional tube was reversed. These additional data were included in the task transfer analyses in “Characterization of subjects’ transfer of learning between tasks”
The majority of corvids tested did not successfully complete the U-Tube, narrow vs. wide equal, and uncovered U-Tube tasks