Results

Interactions with enrichment items

The vultures were observed interacting with only two of the enrichment items: the large carcass (522 times) and the mirror (16 times).

Large carcass
Mirror

Comparison of the behavioural categories between the baseline period, the large carcass and mirror enrichment

A. Mirror vs. baseline period

None of the behavioural categories were significantly or non-significantly higher in frequency during the mirror enrichment compared to the baseline period.

B. Large carcass vs. baseline period

The behavioural category agonistic was significantly higher in frequency during the large carcass enrichment compared to the baseline period. Feeding and affiliative had a non-significantly higher frequency during the large carcass enrichment compared to the baseline period.

Comparison of the average frequency, per hour, on each behavioural category between the baseline period (B), the mirror enrichment (M) and the large carcass enrichment (LC). Asterisk (*) indicate significance of P<.01 and asterisks (**) indicates significance of P<.001.
 

Comparison of the single behaviours between the baseline period, large carcass and mirror enrichment.

A. Mirror vs. baseline period

Standing on perch was the only single behaviour that was significantly higher in frequency during the mirror enrichment compared to the baseline period. Standing on shelter, drying, ruffle, sunbathing, and open wings had a non-significantly higher frequency during the mirror enrichment compared to the baseline period.

B. Large carcass vs. baseline period

Feeding enrichment and kick were the only single behaviours that were significantly higher in frequency during the large carcass enrichment compared to the baseline period. Standing on perch, standing on shelter, fly, aggressive walk, chase, conflict, flee, peck, greeting, opening wings and vocalization had a non-significantly higher frequencies during the large carcass enrichment compared to the baseline period.

Comparison of the average frequency, per hour, on the different single behaviours of standing (A), locomotion (B), body care (C), feeding (D), agonistic (E), affiliative (F), other (G) and resting (H), between the baseline period (black), the mirror enrichment (dark grey) and the large carcass enrichment (light grey). Asterisk (*) indicate significance of P<.01 and asterisks (**) indicates significance of P<.001.