1993/12/01 by Michael Kaspari, Anthony Joern · 2 citations
Agricultural and Biological Sciences · Environmental Science · #Plant and animal studies #Avian ecology and behavior #Ecology and Vegetation Dynamics Studies #Insectivore #Predation #Biology #Foraging #Grasshopper #Ecology #Grassland #Optimal foraging theory #Blattodea #Cockroach
paper · doi:10.2307/3544909
openalex publication_date 1993/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
Assemblages of breeding grassland birds have typically been considered dietary opportunists. We studied prey selection by an assemblage of three breeding insectivores grasshopper sparrows, lark sparrows, and western meadowlarks ― in the Sandhills grasslands of Nebraska, USA and we contrast three foraging models with a null model of opportunism. Handling times and %-chitin varied among prey taxa. The profitability (grams of non-chitin intake/handling time) of acridids, a major part of the diet of all three birds, declined with body size of grasshoppers. We measured Selectivities by comparing arthropods recovered from avian guts with those recovered from sweep sampling. Birds preferred some prey taxa (e.g., acridids, tettigoniids, small Coleoptera) over others (e.g., Homoptera, Hymenoptera, spiders)