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ORNITOLOGIA NEOTROPICAL 18: 21–36, 2007 © The Neotropical Ornithological Society DIETS OF CRACIDS: HOW MUCH DO WE KNOW? Marcia C. Muñoz1 & Gustavo H. Kattan Fundación EcoAndina/Wildlife Conservation Society Colombia Program, Avenida 2 Oeste, No. 10-54, Cali, Colombia. E-mails: [email protected] & [email protected] Resumen. – Dietas de crácidos: ¿qué tánto sabemos? – Los Cracidae son una familia Neotropical de 50 especies de aves galliformes, muchas de las cuales están amenazadas. A través de una revisión de litera- tura, evaluamos el conocimiento actual de los hábitos alimentarios de los crácidos y establecimos algunos patrones generales. La dieta ha sido relativamente bien documentada para 17 especies, mientras que para otras 19 especies hay información anecdótica, y para 14, no hay información disponible. La fruta es la cate- goría de alimento más importante para los crácidos y se han documentado 672 especies de frutas de todos los tipos en sus dietas (tales como drupas, bayas y arilos). Las familias de plantas más importantes en la dieta de la mayoría de los crácidos son también las más comunes y diversas en los bosques Neotropicales. El follaje, las flores y el material animal (vertebrados e invertebrados) también son comunes en la dieta. El consumo de follaje en particular es común en la mayoría de las especies, pero la folivoría no ha sido ade- cuadamente estudiada en estas aves. Las especies de la subfamilia Penelopinae generalmente pasan las semillas intactas a través del tracto digestivo y son potenciales diseminadoras de semillas. Las especies de Cracinae, en cambio, tienen mollejas fuertes y se alimentan de las semillas grandes; sólo las semillas peque- ñas pasan por el tracto intactas. En general los crácidos parecen tener dietas amplias y generalistas, aunque se han documentado dietas restringidas en respuesta a condiciones locales. Pocos estudios han evaluado las variaciones estacionales y entre hábitats en la disponibilidad de recursos y las respuestas de los crácidos a tales variaciones. El estudio de los patrones de uso y disponibilidad de recursos es esencial para entender los patrones de uso de hábitat, las necesidades de espacio y la dinámica poblacional de los crácidos. Abstract. – The Cracidae are a Neotropical family of 50 species of galliform birds, many of which are threatened. Through a literature review, we evaluated current knowledge of cracid food habits and estab- lished general dietary patterns. Diet has been relatively well documented for 17 species, anecdotal informa- tion is available for 19 species, and no information is available for 14 species. Fruit is the most important food category for cracids, and 672 species in all fruit types (e.g., drupes, berries, arillate fruits) are reported. For most species, the most important plant families in their diets are also the most common and diverse families in Neotropical forests. Foliage, flowers and animal foods (invertebrate and vertebrate) are also common items in cracid diets. Consumption of foliage, in particular, is widespread but folivory has not been adequately studied in these birds. Penelopinae usually pass seeds intact through the digestive tract and are potential seed dispersers. Cracinae, in contrast, have strong gizzards and usually feed on large seeds, with only small seeds passing intact. In general, cracids seem to have broad and generalist diets, although restricted diets in response to local conditions have been reported. Few studies have evaluated seasonal and habitat variations in resource availability and cracid responses to such variation. An understanding of patterns of resource use and availability is essential for understanding habitat use, space needs and popula- tion dynamics of Cracids. Accepted 14 October 2006. Key words: Cracidae, Cracinae, diet, frugivory, folivory, Penelopinae, seed dispersal. ______________ 1Present address: Department of Biology, University of Puerto Rico, San Juan, PR 00931. 21 MUÑ0Z & KATTAN INTRODUCTION We conducted a literature search to com- pile information on cracid diets. From each The Cracidae (chachalacas, guans and curas- study we extracted information on geo- sows) are a family of 50 species of large-bod- graphic location, methods, and food items ied, galliform birds with a Neotropical reported in the diet. Because of the heteroge- distribution. Most species inhabit dense tropi- neity in methods and the nature of data, we cal and subtropical forest; only a few species quantified diets in terms of the number of of chachalacas are found in open woodlands taxonomic units (number of items) reported (del Hoyo 1994, Delacour & Amadon 2004). for each cracid species. For plants (fruits, Almost all species in this family are under leaves and flowers), items represent species, some degree of threat because of habitat loss but for insects items represent orders or fami- and hunting (Strahl & Grajal 1991, Collar et al. lies, and vertebrates include items such as 1992, del Hoyo 1994, Stattersfield & Capper "frog" or "rat". 2000, Brooks & Strahl 2000, BirdLife Interna- We organized this review as a series of tional 2004). This situation has led to the topics or questions. After presenting the two development of conservation action plans for cracid subfamilies, we review information on some species (e.g., Brooks & Strahl 1998, the qualitative and quantitative composition Kattan & Valderrama 2006). of cracid diets. Next, we discuss food quality One limitation for developing conserva- and digestive adaptations, and review our tion plans for these species is the lack of knowledge of seasonal and geographic varia- detailed knowledge of their biology, particu- tion in cracid diets. Then we discuss the ques- larly in basic aspects such as patterns of habi- tion whether cracids are selective or have tat and space use. Some species are sedentary, generalist diets. We finish by discussing the but others apparently perform seasonal role of cracids as seed dispersers. movements (habitat shifts or regional migra- tions) (Chaves-Campos 2004). This knowl- THE CRACIDAE edge is critical for designing conservation areas that can sustain viable populations. The family Cracidae is divided into two sub- An important factor determining move- families, the Penelopinae and the Cracinae ment patterns is resource use. Cracids are (del Hoyo 1994, Pereira et al. 2002). Penelopi- omnivores, feeding on fruit, foliage and nae (36 species of guans and chachalacas, 42– insects (Delacour & Amadon 2004), but 91 cm in total length, and 385–2430 g in body curassows have also been reported feeding on mass) have arboreal habits. Cracinae (14 spe- vertebrates and seeds (Érard et al. 1991, cies of curassows) are larger (50–95 cm in Yumoto 1999, Santamaría & Franco 2000, total length and 1250–4800 g in body mass) Jiménez et al. 2001). However, the diet of few and mostly terrestrial, although they may species has been studied in detail, and it is roost and nest in trees (del Hoyo 1994). unclear to what extent they have specialized Recently, the genera Ortalis and Oreophasis or generalized diets. Here we present a review were transferred to the subfamily Cracinae of studies on cracid diets. In addition to (Pereira et al. 2002). These birds, however, are reviewing current knowledge on the food ecologically more similar to the Penelopinae, habits of this family, information provided and we followed del Hoyo (1994) and Dela- here could be useful for guiding future studies cour & Amadon (2004) in retaining them in and developing models for understanding this subfamily. Both genera are old, having cracid ecology. diverged about 31.1 and 30.9 million years 22 DIETS OF CRACIDS TABLE 1. Species of cracids with information about diet, type of study in which information was obtained, country where studied, and conservation priority according to IUCN/Cracid Specialist Group. Species Conservation Type of Country References3 priority1 study2 Ortalis O. vetula Sp, Co Unites States 7, 19, 27 O. garrula O. cinereiceps Co 7 O. poliocephala Sp Mexico 12 O. wagleri O. leucogastra O. ruficauda INCP Sp Venezuela 2, 7 O. erythroptera VHCP Co Ecuador 15 O. canicollis Sp, Co Argentina 5, 7 O. guttata Co 7 O. superciliaris ICP O. motmot Penelope P. purpurascens INCP Co, Tc Colombia, Costa Rica 26, 28 P. perspicax ICP Tc, Co Colombia 22, 23, 30, 35 P. albipennis ICP Co Peru 7, 36 P. ortoni HCP P. marail Sp Guyana, Surinam 14, 37 P. jacquacu Sp, Co Colombia, Venezuela 3, 40 P. ochrogaster HCP Co Brazil 24 P. pileata HCP P. dabbenei HCP P. jacucaca HCP P. superciliaris Tc, Co Brazil 7, 21 P. obscura INCP Tc, Co Argentina 6, 18, 20 P. argyrotis INCP Co 7 P. barbata APC P. montagnii INCP Co Colombia 23 Pipile P. pipile INCP Co Trinidad 7, 16 P. cumanensis Sp, Co Venezuela 7, 40 P. cujubi INCP P. jacutinga VHCP Tc, Co Brazil 9, 25 Aburria Aburria aburri HCP Co Colombia 32 Chamaepetes C. goudotii INCP Co Colombia 7, 23, 29 C. unicolor VHCP Co Costa Rica 7, 38 Penelopina P. nigra HCP Co Mexico 7, 11 Oreophasis O. derbianus ICP Co, Tc Mexico 7, 10 23 MUÑ0Z & KATTAN TABLE 1. Continued. Species Conservation Type of Country References3 priority1 study2 Nothocrax N. urumutum Co Colombia 3 Mitu M. mitu ICP Co 7 M. tuberosa INCP Co Peru 7, 13 M. salvini INCP Tc Colombia 7, 33, 39 M. tomentosa Sp Venezuela 40 Pauxi P. pauxi ICP Co Venezuela 4, 7 P. unicornis VHCP Co Bolivia 7, 31 Crax C. rubra HCP Tc Salvador 7, 34 C. alberti ICP C. alector Tc, Sp, Co Colombia, Guyana, Surinam, 1, 3, 8, 14, 17, 40 Venezuela C. daubentoni HCP C. fasciolata HCP Co 7 C. globulosa HCP C. blumenbachii ICP Co 7 1ICP: Immediate conservation priority, VHCP: very high conservation priority, HCP: high conservation priority, INCP: intermediate conservation priority. 2Co: Casual observations in short-term studies, Sp: data obtained from specimens, Tc: methodical studies with temporal continuity. 31 (Álvarez-Cordero 1997), 2 (Arriaga & Bermúdez 1997), 3 (Benett & Defler 1997), 4 (Calchi & Pérez 1997), 5 (Caziani & Protomastro 1994), 6 (Chalukian 1997), 7 (Del Hoyo 1994), 8 (Érard et al.