DIET COMPOSITION OF BIRDS ASSOCIATED TO AN URBAN FOREST PATCH IN NORTHERN VENEZUELA Cristina Sainz-Borgo SUMMARY Studies about diet composition are of importance to under- Ants were consumed mainly in the dry season, and Coleoptera, stand the biology and ecological strategies of birds. The pres- Clusia, and Diptera during the wet season. Atalotriccus pilaris ent study aims to quantitatively describe the diet of 33 bird was the most common captured bird, with high prevalence of species (4 orders and 16 families) that inhabit a semi-decid- insects in its feces and occasional fruit consumption. Formiciv- uous urban forest patch in Caracas, Venezuela, and its vari- ora grisea, Thamnophilus doliatus and Campyloramphus tro- ations between dry and rain seasons. One hundred and thir- chilirostris, among others, were found to be strictly insectivo- ty seven fecal samples were collected from September 2013 to rous; while Columbina talpacoti, Leptotila verreauxi and Tiaris July 2014 using mist nets. The most abundant families in fecal bicolor were predominantly granivorous. Thraupis episcopus, T. samples were Tyrannidae (45 samples), Thraupidae (18), Tham- glaucocolpa, Coereba flaveola, Cychlaris gujanensis, Euphonia nophillidae (12), Turdidae (12) and Galbulidae (10). The 63.5% trinitatis and Saltator coerulescens had the highest fruit content of fecal samples contained only insects, 14.5% fruit and seeds, in their diet. The study is the first work generating information 12.4% fruits and insects, and 9.5% seeds and insects. The most about the diet of birds living in urban habitats in Venezuela. abundant food items were insects from the Formicidae family Further research is necessary to understand the processes of and the Coleoptera order, and fruits from the Clusia genus. adaptation of birds to urban habitats in the neotropics. Introduction have demonstrated the conve- and Zuria, 2011; Reis et al., people and has a great di- nience of feces’ studies to 2012) and many showed that versity of birds: about 300 Diet studies are necessary determine feeding guilds in cities retain a considerable species have been recorded for the understanding of the birds (Rouges and Blake, diversity of bird species that find refuge in many biological and ecological strat- 2001; Piratelli and Pereira, (Clergeau et al., 1998; parks and other green areas egies of birds. In Venezuela, 2002; Carvallo Lima, 2008; Marzluff et al., 2001). of city (Aveledo, 1968; few studies about the diet of Navas, 2009). The disadvan- However, few explore how Goodwin 1987; Fundación birds have been carried out, tage of this technique is that urban habitats can affect the La Salle, 1997; Caula and restricted to dry forests and certain food items may be diet of birds. The majority of Levin, 1999; Levin et al., arid zones (Poulin et al., misrepresented due to differ- studies are restricted to a sin- 2000; FJBC-SCAV, 2006; 1994, Quilarque et al., 2010, ences in digestibility (Voiter gle species, mainly Falco- SCAV, 2007; Sainz-Borgo Pérez et al., 2001). In the neo- et al., 2003). Carlisle and niformes and owls (Yalden, and Levin, 2012; Sainz- tropics, however, there are Holberton (2006) found that 1980; Tatner, 1983; Gavett and Borgo, 2012, 2014, 2015). abundant studies, mostly by increasing the number of Wakeley, 1986; Roth and The aim of this work was based on stomach contents fecal samples between five Lima, 2003; Delgado and to study the diet composition using emetics (Loiselle and and 17, the results obtained Calderón, 2007; Hernández- of a bird community associat- Blake, 1990; Pérez et al., are similar to the number of Muñoz and Mancina, 2011). ed with an urban patch of 2001; Duraes and Marini, taxa detected in regurgitated Several studies have reported semi-deciduous forest, using 2005; Gaiotti and Pinho, samples. that certain bird species tend quantitative analysis of their 2013) and on stomach con- Studies on urban birds are to consume anthropogenic fecal contents. tents of collected birds becoming more relevant due to food (Ottoni et al., 2009) such (Remsen et al., 1993; the growth of urban areas and as bread and food scraps Methods Rosenberg, 1993; Lópes et al., the concomitant increase in (Rollinson et al., 2003). 2005). The use of emetics has anthropic effects on bird biol- In Venezuela, there is Study area the disadvantage that they ogy. In the neotropics, several scarce information about ur- may cause accidental death of studies have focused on ban birds (Caula et al. 2003; The study involved two the studied specimens, while urban bird communities 2010; Seijas et al., 2011; Sanz field visits per month, from fecal analysis is a non-inva- (Stiles, 1990; Rivera-Gutiérrez, and Caula, 2014), and none September 2013 to July 2014, sive method that does not en- 2006; Villegas and Garitano- about their diets. Caracas is a to a 2ha patch of semi-decid- danger birds. Several studies Zavala, 2010; Carbó-Ramírez city with over five million uous, seasonal, premontane KEYWORDS / Birds / Feces / Feeding Guilds / Seasonal Variation / Received: 05/30/2015. Modified: 01/22//2016. Accepted: 01/25/2016. Cristina Sainz-Borgo. Biologist, Sciences, Universidad Simón Venezuela. Address: Departa- Bolívar, Apartado 89000, Universidad Central de Bolívar, Venezuela. Professor, mento de Biología de Orga- Caracas 1080A, Venezuela e- Venezuela. Ph.D. in Biological Universidad Simón Bolívar, nismos, Universidad Simón mail: [email protected] FEBRUARY 2016, VOL. 41 Nº 2 0378-1844/14/07/468-08 $ 3.00/0 119 COMPOSICIÓN DE LA DIETA DE LAS AVES ASOCIADAS A UN PARCHE DE BOSQUE URBANO EN EL NORTE DE VENEZUELA Cristina Sainz-Borgo RESUMEN El estudio de la composición de la dieta de las aves per- sia y Diptera mayoritariamente durante la estación lluviosa. mite comprender sus estrategias biológicas y ecológicas. Atalotriccus pilaris fue el ave con mayor cantidad de captu- El objetivo del presente estudio consistió en realizar una ras, encontrándose que consumía mayoritariamente insectos y descripción cuantitativa de la dieta de 33 especies de aves ocasionalmente frutas. Las especies insectívoras estrictas fue- (pertenecientes a 4 órdenes y 16 familias) que habitan en un ron Formicivora grisea, Thamnophilus doliatus y Campylor- parche de bosque semideciduo urbano en la ciudad de Cara- hamphus trochilirostris, entre otras; mientras que Thraupis cas, Venezuela; y de su variación entre las estaciones de se- episcopus, T. glaucocolpa, Coereba flaveola, Cychlaris guja- quía y lluvia. Fueron colectadas 137 muestras de heces desde nensis, Euphonia trinitatis y Saltator coerulescens tuvieron septiembre 2013 a julio 2014. Las familias más abundantes los contenidos más altos de frutas en su dieta. El presente fueron Tyrannidae (45 muestras), Thraupidae (18), Thamno- estudio es el primer trabajo en generar información sobre la phillidae (12), Turdidae (12) and Galbulidae (10). Los ítems dieta de aves que viven en ambientes urbanos en Venezuela. alimentarios más abundantes fueron hormigas y escarabajos, Una mayor cantidad de estudios sobre esta línea de investi- y frutas del genero Clusia. Las hormigas fueron consumidas gación son necesarios para entender los procesos de adapta- principalmente durante la estación seca, y Coleoptera, Clu- ción de las aves en ambientes urbanos del neotropico. COMPOSIÇÃO DA DIETA DAS AVES ASSOCIADA A UMA TRECHO DE FLORESTA URBANA NO NORTE DA VENEZUELA Cristina Sainz-Borgo RESUMO Estudos da dieta são de importância para a compreensão Clusia na maior parte durante a estação chuvosa. As espécies da biologia e ecologia de aves. Este estudo é uma descrição com o maior número de sacas era Atalotriccus pilaris, sendo quantitativa da dieta de 33 espécies de pássaros (pertencen- consumido principalmente insetos e ocasionalmente frutas. Es- tes a quatro ordens e 16 famílias) que vivem em um trecho pécies insectívoras rigorosos foram Formicivora grisea, Tham- de floresta semi-decídua urbana na cidade de Caracas, Vene- nophilus doliatus e Campylorhamphus trochilirostris. Thraupis zuela e sua variação ao longo do ano. Foram coletadas 137 episcopus, T. glaucocolpa, C. flaveola, Cychlaris gujanensis, amostras fecais de setembro 2013 a julho de 2014. As famílias Euphonia trinitatis e Saltator coerulescens teve o mais alto mais abundantes foram Tyrannidae (45 amostras), Thraupidae conteúdo frutas em sua dieta. O presente estudo é o primeiro (18), Thamnophillidae (12), Turdidae (12) and Galbulidae (10). trabalho na geração de informações sobre a dieta de aves que Os itens alimentares mais abundantes foram formigas e besou- vivem em habitats urbanos na Venezuela. Mais deste tipo de ros, e frutas do gênero Clusia. As formigas foram consumidos pesquisa são necessários para entender os processos de adap- principalmente durante a estação seca, e Coleoptera, Diptera e tação das aves nos habitats urbanos na região neotropical. forest located at the Expe- grasses and shrubs, mixed Data collection glass tube containing 4ml of rimental Station Arboretum with abundant trees. Tree 70% ethanol. The items in the (Instituto de Biología Ex- species are predominantly Eight mist nets (12×2.8, diet were identified to order perimental, Universidad deciduous, while in the shrub 36mm mesh) were used along or family using a stereo-mi- Central de Venezuela, Cara- layer there are abundant the main path of the study croscope (Wild Heerbrugg- cas, Venezuela, 1100m, vines, thorny shrubs and ever- area, placed twice a month MSA), in the Ornithology 10°30’36”N - 66°53’ 92”W), green species (Hokche and from September 2013 to July