True grit: ingestion of small stone particles by hummingbirds in West Mexico  

作　　者：Omar Maya-García Mauricio Ortega-Flores Jorge E.Schondube 

机构地区：[1]Posgrado en Ciencias Biológicas,Unidad de Posgrado,Coordinación del Posgrado en Ciencias Biológicas,Universidad Nacional Autónoma de México,Edificio D,1er piso,Circuito de Posgrados,Ciudad Universitaria,Del.Coyoacán,C.P.04510 México D.F.,Mexico [2]Laboratorio de Ecología Funcional,Instituto de Investigaciones en Ecosistemas y Sustentabilidad,Universidad Nacional Autónoma de México,Antigua Carretera a Pátzcuaro No.8701,Col.Ex Hacienda de San Joséde la Huerta,C.P.58190 Morelia,Michoacán,Mexico

出　　处：《Avian Research》2021年第4期739-749,共11页鸟类学研究（英文版）

基　　金：Granted to JES by PAPIIT-UNAM (IN212216)。

摘　　要：Background: Grit is used by birds mainly for grinding hard food items but can also serve a nutritional role as a source of minerals. Ingestion of grit by birds has been documented primarily in species that feed on seeds and invertebrates.Although feeding mainly on nectar and small arthropods, hummingbirds also ingest grit, but why they do so is unclear. We quantified the number of grit particles in the stomachs of six species of hummingbirds during an annual cycle in a seasonal ecosystem of West Mexico.Methods: We compared the number of grit particles in the stomachs of different hummingbird species(Mexican Violetear Colibri thalassinus, Amethyst-throated Mountaingem Lampornis amethystinus, White-eared Hummingbird Basilinna leucotis, Rivoli's Hummingbird Eugenes fulgens, Broad-tailed Hummingbird Selasphorus platycercus, and Rufous Hummingbird S. rufus), and between sex and age categories during the different seasons of a year. To deter-mine if grit was used to grind ingested arthropods, we examined the relationships between the number of grit parti-cles, the biomass of arthropods ingested, and their chitin content.Results: Although species did not differ in the number of grit particles in their stomachs, we found that grit was mostly ingested by female individuals, with only one male of one species(Mexican Violetear) presenting grit in its stomach. We also found that female hummingbirds had grit in their stomachs during the rainy and the cold-dry season(June-February) but not during the warm-dry season(March-May). Our analyses revealed no relationship between the number of grit particles and the amount of ingested arthropods and arthropod chitin content. However,high grit consumption was related to wasp ingestion on Mexican Violetears.Conclusions: Our results indicate that grit is used mainly by female hummingbirds. The seasonal variation in the ingestion of grit by female individuals suggests that it can be used to meet mineral requirements related to breed-ing;however, this topic needs further exploration. Addi

关 键 词：Arthropod chitin content Arthropod digestion Breeding season Mineral nutritional requirements 

分 类 号：Q958[生物学—动物学]