One objective of ongoing demographic studies of Florida scrub-jays (Aphelocoma coerulescens) on KSC is to identify principal predators of eggs and nestlings. Studies have shown that failure of scrub-jay nests can be particularly high in degraded, overgrown scrub. On KSC and in scrub habitat throughout the state, fire suppression has degraded scrub-jay habitat. A previous study of an inland population of scrub-jays revealed that diurnal snakes and birds were the principal predators of scrub-jay nests. However, the scrub habitat on KSC differs from inland scrub in several respects, and nest predation may differ as well.

This study utilizes a relatively new technique – remote video monitoring. A small camera is concealed in vegetation near the nest. The camera operates in both visual and infrared wavelengths for 24-hour monitoring. The camera is connected to a time-lapse videocassette recorder by a 75-meter cable so that observer activity (i.e., changing video tapes) does not disturb the birds. Time-lapse videos are recorded at 6 real time to allow a full day of recording to fit on a single VHS tape. Video monitoring is an effective way to study nest predation because it allows for identification of predator to species and for observation of behavioral patterns of the nesting species.

Preliminary results of this study implicate the yellow rat snake (Elapheobsoleta quadrivittata) as an important predator of scrub-jay nests on KSC. Unlike the inland study mentioned earlier, predation events typically occurred at night. Continuing studies may modify these results. Other observed predators include black racer (Coluber constrictor), corn snake (Elaphe guttata), and spotted skunk (Spilogale putoris). Also, all observed predations were successful (i.e., predator was not repelled by adults).

Female nest activity was also examined by comparing the frequency of leaving and arriving at the nest. Activity around the nest may attract predators, and activity levels may vary from nest to nest depending on habitat features or individual behavior. Preliminary results indicate that nest activity is similar during egg and nestling stages of the nesting cycle (figure 1). However, activity levels do appear to have a diurnal pattern (figure 2) that is probably related to ambient temperature (figure 3). Activity is lower during hot midday hours.

This project is ongoing and will continue for at least one more breeding season. The data gathered during this study will be helpful in ascertaining the predator regime of Florida scrub-jay eggs and nestlings on KSC. Preliminary results have already contradicted previous knowledge.

Key accomplishments:

• Captured over 4,800 hours of video footage from 14 scrub-jay nests.
• Documented 10 predation events.

Key milestone:

• Continue to monitor nest predation, ascertaining the predator regime of Florida scrub-jay eggs and nestlings on KSC.

Contact: Dr. W.M. Knott (William.Knott-1@ksc.nasa.gov), YA-D3, (321) 867-6988
Participating Organization: Dynamac Corporation (G.M. Carter)