Assessing personality in the laboratory.

(A) Schematic illustration of the experiments. (B) A 3D plot of the three behavioral traits, estimated during Trial 1. (C1-3) Behavioral traits were consistent over time. The behavioral traits of the first and third (post-enrichment) trial are presented. Positive correlations were found for all three behavioral traits over a period of more than 10 weeks. For the enriched (blue lines), the impoverished (orange lines), and both environments together (not shown), respectively: (C1) Boldness; (C2) exploration; and (C3) activity. (D) Boldness of the first and fifth (post-release 2) trial. Dashed line represents the Y=X line.

Pearson’s correlation test.

Personality measurements over time.

(A) The behavioral traits of the first and second baseline trials, performed in two consecutive nights, are presented. Positive correlations were found for all three behavioral. Boldness (Pearson r=0.59, p=5.8e-05) (A1); exploration (Pearson r=0.70, p=5.3e-07) (A2); and activity (Pearson r=0.52, p=0.0005) (A3). Dashed line represents the Y=X line. (B) Box plots depicting the bats’ behavior across the five trials according to three traits: Boldness (B1), exploration (B2), and activity levels (B3). (C) Paired box plots show individual bat values in the first trial (baseline 1) and the fifth trial (post-release 144 days apart on average) for each trait: Boldness (C1), exploration (C2), and activity levels (C3). Lines connect repeated measurements from the same individual, illustrating within-individual behavioral changes over time. The number of bats participated in each trial is given in Methods, Table 8. In the baseline trials, no significant differences were found between the two environmental conditions (enriched / impoverished) for any of the three behavioral traits we measured (P = 0.62, P = 0.84, P = 0.72 for boldness, exploration, and activity levels, respectively, n=40, Table S1). Figure S2 also shows the indication. The experimental phase and the time in days from the day of the first trial are depicted on the X-axis. Box plots show the 25% and 75% percentile. Medians and whiskers based on 1.5 IQR are shown.

mixed GLM results for the comparison between trials 1 and 5 response ∼ trial + (1 | bat ID).

mixed GLM results for all tested trials (1-5) response ∼ 1 + Trial*EnvironmentalCondition + (1 | bat ID).

Early environmental exposure affects outdoor foraging behavior.

(A1) Time spent by the bats outside the colony each night (in minutes). (A2) Distance to the furthest point from the colony per night. (A3) The area explored by the bats. The data for each bat were estimated for the period between its 15th and 20th day outdoors (n=17 bats). Median and whiskers based on 1.5 IQR are shown. (B-C) The complete movement of four individuals - two from each colony. (B) Individuals raised in the enriched colony, data shown for two individuals, each representing a different measured season (B1,B2); (C) Individuals raised in the impoverished colony, data shown for two individuals, each representing a different measured season (C1,C2). Colors depict time in days. The open colony is marked by a white circle. Insert in C1-2 zooms-in on the tracks. More examples of individual bat movement maps are presented in Figure S3.

GLMM results for outdoors measurements with the first boldness as predisposition.

The lines depicting results for the environmental and the predisposition effects are highlighted in green and blue respectively. response ∼ 1 + Environmental_condition + Baseline_boldness + Sex + Age + Days_spent_outside + (1 | Bat_ID)

GLMM results for outdoors measurements with the baseline trial PC1 as predisposition.

The lines depicting results for the environmental and the predisposition effects are highlighted in green and blue respectively. response ∼ 1 + Environmental_condition + Baseline_PC1 + Sex + Age + Days_spent_outside + (1 | Bat_ID)

Pearson correlation test results.

Egyptian Fruit bat pups were captured with their mothers in rural and urban colonies and then divided between two environmental conditions, enriched and impoverished.

Experimental set-up schematic.

Each bat is placed in a tent with 6 foraging boxes

Full time-line of the experiment.

Number of bats that participated in each of the trials.

PCA analysis for trial 1 (baseline) and 5 (post-release 2); positive correlation was found between the individual scores on PC1 (Pearson correlation P=0.03, r=0.58).

Full bat behavioral traits over time.

Box plots depicting the bats’ behavior across the five trials according to three traits: Boldness (A), exploration (B), and activity levels (C). The experimental phase and the time in days from the day of the first trial are depicted on the X-axis. Box plots show the 25% and 75% percentiles. Medians and whiskers based on 1.5 IQR are shown. A1, B1, and C1 represent all bats tested, while A2, B2, and C2 represent only the bats that were tracked outdoors using GPS devices.

Early environmental exposure affects outdoor foraging behavior.

The complete movement of four individuals - two from each colony. (A) Individuals raised in the enriched colony, data shown for two individuals (A1,A2); (B) Individuals raised in the impoverished colony, data shown for two individuals (B1,B2). Colors depict time in days. The open colony is marked by a white circle. Insert in B1 zooms-in on the tracks.

Early environmental exposure affects outdoor foraging behavior.

(A1) Time spent by the bats outside the colony each night (in minutes). (A2) Distance to the furthest point from the colony per night. (A3) The area explored by the bats. The data for each bat were estimated for the period between its 21st and 26th day outdoors (n=17 bats). Median and whiskers based on 1.5 IQR are shown.

Mixed GLM results for baseline trials of two environmental conditions response ∼ 1 + Environmental_condition + Trial_number + (1| Bat_ID)’.

GLMM results for proportion of nights foraging outside the roost (%).

DaysOutProportion ∼ 1 + EnvironmentalCondition + Sex + Age + (1∣Bat_ID) With Y ∼ Binomial (TotalExperimentDays) and link=logit