Performance during testing in the L-shaped arena.

<p>The proportion of choices (mean and standard error of the mean) made to each of the corners in the L-shaped environment across all testing trials.</p

Training Environment.

<p>A) Schematic representation of the virtual training environment. Participants in Group AC were trained to choose either of the response boxes (indicated by the filled squares) located at the geometrically identical corners A and C whereas participants in Group BD were trained to choose either of the responses boxes (indicated by the open squares) located at corners B and D. B) One example viewpoint of the virtual training environment.</p

Predicted encoding strategies.

<p>As an example, each panel shows the corners that are predicted to be selected by group AC. A) A schematic representation of the training environment. The filled squares in the corners of the rectangle represent the response boxes that participants in group AC were trained to select. B–F) Schematic representations of the L-shaped environment. The filled squares in the corners of the L-shaped environment represent the response boxes that participants in group AC are predicted to select according to a given strategy. The open squares in the L-shaped environment represent the response boxes that participants should not select according to a given strategy. The dashed lines indicate the location of the major principal axis (B–D) and the medial axes (E).</p

Testing Environment.

<p>A) Schematic representation of the virtual L-shaped testing environment. The open squares represent the response boxes located at each corner. B) One example viewpoint of the virtual testing environment shown from corner U.</p

Mean (± SE) latency (sec) to feed (LTF) of nutcrackers during experiment 2.

<p>Filled circles: experimental birds; open circles: non-enriched controls. See text for explanation of time periods.</p

Mean (± SE) counts of nutcracker pecks (exploration, EXP) during experiment 2.

<p>Filled circles: experimental birds; open circles: non-enriched controls. See text for explanation of time periods.</p

Experimental timelines with diagrams illustrating how feather sections reflect periods of the experiments.

<p>Feathers from experiment 1 were cut into three sections corresponding to periods prior to pre-enrichment (A), short-term enrichment (B), and removal of enrichment (C). The first feather from experiment 2 was cut into two sections corresponding to pre-enrichment (A) and short-term enrichment (B), and the second feather from experiment 2 was cut into three sections corresponding to long-term enrichment (C), removal of enrichment (D), and non-novel enrichment (E). See text for descriptions of time periods. Note: illustrations not to scale.</p

Observation schedule for nutcracker behaviors during Experiment 2.

<p>Observation schedule for nutcracker behaviors recorded during Experiment 2. LTF = latency to feed, AL = activity level, EXP = exploration. See text for definitions of behaviors.</p>1<p>All behaviors were measured for 5 mins.</p

Mean (± SE) nutcracker feather CORT values (pg/mm) from experiment 2.

<p>Filled circles: experimental birds; open circles: non-enriched controls. (A) shows the first four time periods of the experiment; (B) shows the fifth time period (non-novel enrichment) and includes short-term (novel) enrichment for comparison. Note different scales on y-axes. See text for explanation of time periods.</p