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PIANKA, E. R., AND W. S. PARKER. 1975. Ecology of horned lizards: a reviewwith special reference to Phrynosoma platyrhinos. Copeia1975:141–162.RUXTON, G. 2006. Grasshoppers don’t play possum. Nature 440:880.––––––, T. N. SHERRATT, AND M. P. SPEED. 2004. Avoiding Attack: TheEvolutionary Ecology of Crypsis, Warning Signals and Mimicry. OxfordUniversity Press, Oxford, United Kingdom.SHERBROOKE, W. C. 1981. Horned Lizards: Unique Reptiles of WesternNorth America. Southwest Parks and Monuments Association, Globe,Arizona.––––––. 1987. Defensive head posture in horned lizards (Phrynosoma:Sauria: Iguanidae). Southwest. Nat. 32:512–515.––––––. 2003. Introduction to Horned Lizards of North America. Universityof California Press, Berkeley.––––––. 2008. Antipredator responses by Texas horned lizards to twosnake taxa with different foraging and subjugation strategies. J.Herpetol. 42:145–152.––––––, AND C. J. MAY. 2008. Phrynosoma solare (Regal Horned Lizard).Crotalus envenomation. Herpetol. 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GREENEYandRUDY A. GELISYanayacu Biological Station, Cosanga, Napo, EcuadorandW. CHRIS FUNKDepartment of Biology, Colorado State UniversityFort Collin, Colorado 80523-1878, USAe-mail: Chris.Funk@colostate.eduCaecilians are limbless, subterranean or aquatic amphibiansfound throughout much of the tropics (Duellman and Trueb 1994;Himstedt 1996). Although amphibians are declining dramatically(Stuart et al. 2004), the conservation status of caecilians is largelyunknown due to lack of information on their ecology and naturalhistory (Gower and Wilkinson 2005). A handful of studies havedocumented caecilian life histories (e.g., Funk et al. 2004; Gans1961; Kupfer et al. 2005; Malonza and Measey 2005; Parker 1936,1958; Sanderson 1937; Sarasin and Sarasin 1887–1890; Taylor1968; Wake 1980). Nevertheless, 114 out of 172 species (66%) ofcaecilians remain too poorly known for an accurate status assessment,and thus are listed as “Data Deficient” by the IUCN (2006).Perhaps because of their elusive nature, there is an increasing interestin the biology of caecilians (Kupfer et al. 2006; Measey andHerrel 2006).Predator-prey interactions are widely recognized to have importanteffects on population dynamics (e.g., Krebs et al. 1995;Lotka 1925; Volterra 1926), but in the case of caecilians, little iseven known about which taxa act as predators. Snakes are consideredthe main predators of caecilians (Duellman and Trueb 1994;Kupfer et al. 2003), although some other predators such as turtles(Zamprogno and Zamprogno 1998), spiders (Boistel and Pauwels2002), and ants (Measey 2004) have been documented preying oncaecilians. Identifying predators of amphibians is important in thecontext of amphibian declines, because predation may tip alreadydeclining populations over the edge toward extinction (Corn 1993;Parker et al. 2000). Here we show that a tropical hawk acts as animportant predator of the caecilian Caecilia orientalis and thatthis unexpected ecological interaction depends strongly on weather.Methods.—We filmed a Barred Hawk (Leucopternis princeps)nest using a hidden camera from 15 February–8 May 2004 and 7–28 January 2005 for a total of 599 h in the private reserve ofCabañas San Isidro, next to Yanayacu Biological Station (00°35'S,77°53'W; 1950 m elev.). During most days of filming, the nestwas filmed continuously during daylight hours (from morning toevening) when the hawks were active. The Barred Hawk is a rare,large hawk (total length = 52–61 cm) found from northern Peru toCosta Rica (700–2200 m; Ridgely and Greenfield 2001). The 1700ha reserve comprises a mosaic of primary and secondary growthin humid, montane, evergreen forest about 3 km W of the town ofCosanga in the Napo Province of northeastern Ecuador (for a morecomplete site description, see Greeney et al. 2006).Each year, the same Barred Hawk pair raised a single chick inthe same nest. The nest was located on a rocky ledge 5 m from arushing waterfall. The blind was installed 3.5 m above and 10 mfrom the nest, on the opposite side of a stream. All videos weretranscribed at a later date. In addition to recording prey brought tothe nest, we recorded whether it rained during each hour-long timeinterval. Since video quality was excellent, most taxa were clearlyidentifiable, but seven unknown taxa were excluded from the analysis.Because caecilians surface primarily during heavy rains andsnakes are active at Yanayacu when it is clear and sunny, we hypothesizedthat Barred Hawks would bring more caecilians to thenest, but fewer snakes, when it was raining. We tested this in 2004using a Fisher’s exact test. This was the second Barred Hawk nestever documented (Muela and Valdez 2003) and the first closelymonitored to document feeding behavior. Details of the breedingecology of these Barred Hawks are being prepared separately foran ornithological journal (R. A. Gelis and H. F. Greeney, unpubl.ms.).Results.—To our surprise, a caecilian species (Caeciliaorientalis) was the main prey item brought to the nest by two BarredHawk parents to feed a single chick brooded each year (Fig. 1;videos available upon request). Caecilia orientalis is a large caecilian(total length = 31–62.5 cm) found in the Andes of Ecuadorand Colombia and is the only caecilian known from this site (Funket al. 2004; IUCN 2006). Prey items delivered to nestlings included50 caecilians (48.1% of diet), 36 snakes (34.6%; Atractusoccipitoalbus and two unidentified colubrid species), five giant162 Herpetological Review 39(2), 2008