Raptor Visual-­‐Spa/al A1en/on of Environmental Enrichment Introduc1on Despite their prevalence in zoos, raptors are
especially understudied in terms of environmental
enrichment (King 1993). This research project aims
to better understand the evolutionary
underpinnings of foraging strategies and to
develop a cost-effective means to employ more
appropriate enrichment to different groups of
raptors (Park 2003). This experiment was meant to
simulate a low-risk hunting opportunity, specifically,
ground and avian prey (Ground vs.
Elevated).Visual cues are differentially processed
by diurnal and nocturnal raptors, due to their
respective eye morphologies, and appear to be a
better indicator of individual enrichment
preference, than variation of foot morphology alone
(Jones et al. 2007). Groups were selected based
on foot morphology, future studies should take into
consideration eye morphology as well. The visual
cue investigated was orientation of the same
enrichment object in the visual field. Latency Time
(seconds) was used, as a proxy, to indicate a
group’s preference of the object’s placement. Hypothesis and Predic1ons H
1: The height of the enrichment object will have an effect on each group’s mean Latency Time(s). The more elevated an enrichment object, the shorter the mean Latency Time(s) will be for Falcons. The lower the object, the shorter the mean Latency Time(s) will be for the Owls & Hawks. H0: The height of the enrichment object will have no effect on each group’s mean Latency Time(s). Groups -­‐ Species Falcons Hawks (Falco femoralis) (Buteo jamaicensis) Owls Ø  Aplomado Falcon Ø  Red-­‐tailed Hawk Ø  Spectacled Owl Ø  Peregrine Falcon Ø  Harris’ Hawk (Falco peregrinus) (Parabuteo unicinctus) (Pulsatrix perspicillata) Ø  Pharaoh Eagle-­‐Owl Alexandra Taylor University of Washington, School of Environmental and Forest Sciences Advisor: Dr. David A. Manuwal Methods •  Prior to the experiment, a trial period was devised to habituate the birds to the novel Elevated Condi/on and to control for neophobia (Bateson 2002). Each bird had to proficiently complete a Long, Medium & Short rope condi/on before being allowed to proceed to the experimental phase. Food item was exposed. •  Environmental enrichment was presented in 2 condi/ons, Elevated & Ground Condi/on, to simulate avian and mammalian prey respec/vely. 1.  Ground Condi1on – object was placed on the ground with food item concealed. 2.  Elevated Condi1on – object was elevated via sisal rope and secured via a clothespin. Once the raptor made contact with the object, it would then release, allowing the raptor to “catch” the object midair. Food item was concealed. Latency Time (seconds) – the /me it takes for a raptor to leave a handler’s glove and physically interact with the object with its feet. Shorter Latency Time(s) indicate a higher preference for an objects’ orienta/on in the raptor’s visual field. Longer Latency Time(s) indicate a lower preference for the environmental enrichment’s orienta/on. Results Ground Condi1on p = .079
Fig1. One-­‐Way Between Subjects ANOVA Evidence suggests that there was no significant difference between groups in terms of mean Latency Time(s). Elevated Condi1on p = .55
Figure 1
Figure 2
Post-­‐hoc Test (Elevated Condi1on) (Bubo ascalaphus) Figure 3
habitua/on. Each subject has been exposed to the Ground condi/on prior to this experiment many /mes. Therefore, they are more habituated to the Ground condi/on, as opposed to the novel Elevated condi/on, and may perceive it as the more reliable and less risky food source (Coppinger 1969, Bateson 2002). •  The results of our Elevated Condi/on post-­‐hoc revealed a significant difference between the Owls group and Hawks group. We may also tenta/vely conclude from the data, that Falcons also outperformed the Owls group, however not significantly. Future experiments should expand sampling methods, so that each species is equally represented and increase sample size. These results suggest that the ini/al grouping based solely on foot morphology as an indicator of foraging strategy is a linear perspec/ve when studying raptors. Future studies will need to take into considera/on respec/ve eye morphology of diurnal and nocturnal raptors when devising future experimental groups. • 
Conclusion Hawks and tenta/vely Falcons demonstrated a higher preference for the Elevated Condi/on and a lower preference to the Ground Condi/on when compared to Owls. •  This evidence may help zookeepers more appropriately apply environmental enrichment to different groups of raptors, u/lizing pre-­‐exis/ng materials. Fig2 One-­‐Way Between Subjects ANOVA Evidence suggests that there was a significant difference between groups in terms of mean Latency Time(s). Further post-­‐hoc tes/ng is necessary to know specifically which groups differed significantly. • 
Discussion The evidence suggests that all three groups equally prefer the Ground condi/on. This may be explained by p = .01
Fig3. Tukey’s HSD test The results indicate that there was significant difference between Hawks and Owls. Hawks and Falcons did not differ significantly. Owls and Falcons are trending towards significance. References 1.  Bateson, M. 2002. Recent advances in our understanding of risksensitive foraging preferences. Proceedings of the Nutrition
Society 61.04: 509-516
2.  Coppinger, R.P. 1969. The effect of experience and novelty on avian
feeding behavior with reference to the evolution of warning coloration
in butterflies part I: reactions of wild-caught adult blue jays to novel
insects. Behaviour 35.1: 45-59.
3.  Jones, M.P., Pierce, K.E., Ward, D. 2007. Avian Vision: A Review of
Form and Function with Special Consideration to Birds of
Prey. Journal of Exotic Pet Medicine 16.2: 69-87.
4.  King, C. E. 1993. Environmental Enrichment: Is It for Birds? Zoo
Biology 12: 509-12.
5.  Park, F. 2003. Behavior and behavioral problems of Australian
raptors in captivity. Seminars in Avian and Exotic Pet Medicine 12.4.