RT info:eu-repo/semantics/article T1 Diet and grit characteristics in young Eurasian Bullfinches (Pyrrhula pyrrhula) inhabiting Iberian hedgerows A1 Hernández Lázaro, Ángel K1 Grit characteristics K1 Hedgerows K1 Nestling diet K1 Pyrrhula pyrrhula K1 2401.20 Ornitología K1 2401.02 Comportamiento Animal AB For the first time, the diet of young Iberian Bullfinches (Pyrrhula pyrrhula iberiae)is studied, specifically in a hedgerow habitat in northwestern Spain, through stomach(younger nestlings up to 8 days of age, which died without researcher intervention) andfaecal sac (older nestlings) analysis, and secondarily direct observation (nestlings anddependent juveniles). Also, for the first time, grit use by bullfinch nestlings is describedin some detail. Bullfinches fed their young with a mixture of seeds and invertebrates,with greater quantitative importance of the former. The identity of the seeds variedconsiderably between spring and summer, and animal fraction gradually decreased fromMay to July for older nestlings, in both cases presumably because of the seasonal changesin food availability. Caterpillars and spiders were the most important arthropod prey inthe diet. Apparently, the young were not fed non-arthropod invertebrates. The relativeimportance of invertebrates, which are very rich in proteins, was greater for youngernestlings than for older ones. Difficult to digest hard-bodied prey, such as beetles, werenot present in the stomachs of the youngest nestlings. The frequency of occurrence andamount of grit in stomachs increased with nestling age, along with the need to grindfood. There were no remarkable differences in number of units, size, or number of colourtypes of gastroliths between months. The high floristic diversity in the study area, whichhas great overall conservation value, provides a wide range of resources for bullfinches,including plenty of food for their young. PB BirdLife SN 0030-5685 YR 2022 FD 2022 LK https://uvadoc.uva.es/handle/10324/64930 UL https://uvadoc.uva.es/handle/10324/64930 LA eng NO Ornis Fennica, 2022, vol. 99, n. 4, p. 163–183 NO Producción Científica DS UVaDOC RD 18-dic-2024