University of Central Florida Undergraduate Research Journal - Self-Injurious Behavior of a Captive <i><i><i>Coragyps atratus</i></i></i>
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Self-Injurious Behavior of a Captive
Coragyps atratus

By: Jennifer Bouchenot | Mentor: Frank Logiudice

Results and Discussion

Despite a daily dose of Gabapentin during the first meal at 9 AM and again at dinner near 4 PM, Lurch's feather picking was largely undiminished during the non-adjacency periods of the study in his solitary enclosure (Figure 2, p = 0.2687). During the initial days of observation, Lurch had a lower frequency of feather picking, possibly because the observer was learning to gauge the extent of his problem area and the subject was becoming accustomed to the observer's presence.

Lurch's self-mutilation experienced a drop, despite keepers being present, when he was in the enclosure adjacent to the C. cheriway (Figure 2). There was a statistically significant change in the amount of feather picking from his previous enclosure and during the enclosure adjacency with the C. cheriway (p = 0.0466). A statistically significant change in feather picking was also observed between the enclosure adjacency with C. cheriway and his return to his old enclosure (p = 0.00002). During the adjacent enclosure environment, Lurch showed a lot of interest in the C. cheriway, though the latter bird did not show much interest in Lurch. Droppings from the nights before showed that C. cheriway and Coragyps atratus roosted as close as 1 meter to one another.

While alone in his chainlinked enclosure, Lurch spent 3.2% of his time engaged in self-injurious behavior. After the introduction of the C. cheriway into the adjacent enclosure, this percentage dropped to 0.70%. After the two birds were separated, the time spent feather picking increased to 8%. An explanation for the decreased rates during the initial observations may be the observer's less experienced recording of feather picking behavior, but differences in feather picking were still significant. Lurch self-mutilated within his chainlinked enclosure with keepers present the most, which concurs with the study completed the previous year (Morris, 2017).

Figure 2: Lurch feather picking with keepers present. Gold points indicate days Coragyps atratus was adjacent to C. cheriway.

Jeff rested significantly less daily than Lurch (Figure 3, p< 0.00001). A common side effect of Gabapentin is drowsiness, which may explain the exceptional duration of Lurch's resting. A linear regression was added to the data and Lurch increased his resting throughout the day whereas the amount of time devoted to rest by Jeff was constant throughout the day. Jeff's resting was sporadic and brief during her observations, while Lurch's resting was seemingly high between 11:00 AM to 3:30 PM.

Figure 3: Average resting times over a day for both Coragyps atratus' with dotted linear regression (p < 0.000001).

On days when Lurch was administered Gabapentin, his rest appeared to increase 2 hours after initial treatment. Parrots experience a mild sedation after the administration of Gabapentin, with the half-life of Gabapentin in Amazon parrots recorded as 4.5 hours (Baine, Jones, Cox, & Martín-Jiménez, 2015). Here, it seems the sedative effect showed a similar decrease at 4.5 hours.

Figure 4: Lurch's typical resting with equal Gabapentin medication administration.

Jeff preened for longer periods of time compared to Lurch (Figure 5, p < 0.00001). Lurch frequently switched between feather picking and preening and would divide time between the two activities. Percent of time spent preening differed in all phases as Lurch's environment changed. Average preening before the move was 5.9% and remained the same during the adjacent enclosure time at 5.5%. Upon separation, the amount of time spent preening rose to 9%. Both feather picking and preening rose to higher averages after the separation of Coragyps atratus and C. cheriway.

Figure 5: Average preening times over a day for both Coragyps atratus

Jeff's preening was her only feather manipulation activity. The observer totaled Lurch's preening and feather picking activity and compared it to Jeff's only manipulative activity, as shown in Figure 6. Lurch was not only preening less than Jeff (Figure 5), but he was also spending less time on feather manipulative behavior in general, approximately 20% less time than Jeff. This result may be an unintended side effect of the Gabapentin. The medication is aimed to reduce self injurious activity but may inadvertently reduce normal preening behavior. This outcome was further reinforced with Lurch's extraordinary resting time (Figure 3).

Figure 6: Total average feather manipulation of Jeff and Lurch.

Future Work

Keepers at the Central Florida Zoo are developing a vest as an alternate blocking device for Lurch. Unfortunately, blocking devices alone only work temporarily and the bird returns to old habits upon removal of the device (Grindlinger, 1991). Keepers hope that the vest will enable Lurch to participate in public appearances and, therefore, increase his daily enrichment, which may result in decreased feather picking. Feather picking was rarely observed during flight training sessions, which may translate to less feather picking during a rigorous show schedule.

The bird team at the Central Florida Zoo is also considering placing Lurch back into an adjacent enclosure to an American Crow (Corvus brachyrhynchos). While this pairing is not typical, the stimulation of a nearby similar bird may be productive as seen in a 1951 study where cooperative behavior was observed between a captive Raven (Corvus corax) and a Coragyps atratus with a C. corax purposely placing bits of meat outside of its enclosure and a Coragyps atratus descending from a nearby tree to devour the meat (Malcolm, 1952).