title: Biofilm grazing in a higher vertebrate: the western sandpiper, Calidris mauri.
abstract: We show that a higher vertebrate can graze surficial intertidal biofilm, previously only considered a food source for rasping invertebrates and a few specialized fish. Using evidence from video recordings, stomach contents, and stable isotopes, we describe for the first time the grazing behavior of Western Sandpipers (Calidris mauri) and estimate that biofilm accounts for 45-59% of their total diet or 50% of their daily energy budget. Our finding of shorebirds as herbivores extends the trophic range of shorebirds to primary consumers and potential competitors with grazing invertebrates. Also, given individual grazing rates estimated at seven times body mass per day and flock sizes into the tens of thousands, biofilm-feeding shorebirds could have major impacts on sediment dynamics. We stress the importance of the physical and biological processes maintaining biofilm to shorebird and intertidal conservation.
authors.affiliation: Coastal and Estuarine Environment Research Group, Port and Airport Research Institute, 3-1-1, Nagase, Yokosuka 239-0826, Japan. kuwae@ipc.pari.go.jp
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kuwae
authors.forename: Peter G
authors.initials: PG
authors.lastname: Beninger
authors.forename: Priscilla
authors.initials: P
authors.lastname: Decottignies
authors.forename: Kimberley J
authors.initials: KJ
authors.lastname: Mathot
authors.forename: Dieta R
authors.initials: DR
authors.lastname: Lund
authors.forename: Robert W
authors.initials: RW
authors.lastname: Elner
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D018441:Biofilms; D046091:Charadriiformes / Q000254:growth & development / Q000502:physiology*; D003247:Conservation of Natural Resources; D017753:Ecosystem; D005247:Feeding Behavior; D020387:Food Chain; D011156:Population Density; D011157:Population Dynamics; D014741:Video Recording