Facilitation of Sap-Feeding Birds by the White-Fronted Woodpecker in the Monte Desert, Argentina

Sap Consumption by the White-fronted Woodpecker and Its Role in Avian Assemblage Structure in Dry Forests

“…DIET AND SAP FEEDING BY THE WHITE-HEADED WOODPECKER Sap feeding was markedly seasonal, as observed in other populations of this species (Genise et al 1993, Blendinger 1999 inhabiting regions with a climate more adverse than that of our study area. In the Monte desert, Blendinger (1999) suggested that sap feeding by birds might be associated with lack of access to water.…”

“…Specifically, (1) we investigated the seasonal diet of the White-fronted Woodpecker, with special emphasis on sap consumption. Sap is the major source of water and energy for the White-fronted Woodpecker during periods of resource shortage in autumn and winter (Blendinger 1999), so we expect a marked seasonal pattern in sap consumption in semiarid Chaco forests. We also investigated (2) sap consumption by other birds that use the woodpecker's sap wells, seasonality in their use of this resource, and their capacity to assimilate sucrose as a functional factor determining this interaction.…”

“…En el sistema carpinteros-savia-aves consumidoras de savia, el consumo de este recurso depende de características fisiológicas y comportamentales de las especies, como así también de la disponibilidad de otros recursos alimenticios en los ambientes que habitan. months of low productivity (Blendinger 1999), which coincide with autumn (May-June) and winter (July-August), when the availability of arthropods, flowers, and fruits declines (Caziani 1996, Codesido andBilenca 2004). Fifteen species of birds, diverse in ecological attributes and taxonomic affinities, have been reported to feed on sap from wells in arid and semiarid environments in western Argentina (Genise et al 1993, Blendinger 1999, including species as highly dependent on energy-rich resources as the Glittering-bellied Emerald (Chlorostilbon aureoventris), which closely tracks trees with active wells (Macchi et al 2011).…”

“…Among these are species of Sphyrapicus (Tate 1973, Daily et al 1993, Eberhardt 2000, Melanerpes (MacRoberts 1970, Kattan 1988, Genise et al 1993, Winkler and Christie 2002, Picoides (Kozma 2010), and Campephilus (Schlatter and Vergara 2005). In turn, sap wells made by these woodpeckers are used by other animals, such as insects, birds, and mammals, to reach this energy-rich food resource (Foster and Tate 1966, Holmes 1990, Blendinger 1999. Sap can be a key resource for certain species during periods of resource scarcity (Smith and Russell 1982, Daily et al 1993, Blendinger 1999, Winkler and Christie 2002, especially for nectarivorous species such as hummingbirds (Trochilidae) and sunbirds (Nectariniidae)] that require high levels of energy (Kilham 1964, O'Donnell and Dilks 1989, Eberhardt 2000, Pejchar and Jeffrey 2004.…”

“…In turn, sap wells made by these woodpeckers are used by other animals, such as insects, birds, and mammals, to reach this energy-rich food resource (Foster and Tate 1966, Holmes 1990, Blendinger 1999. Sap can be a key resource for certain species during periods of resource scarcity (Smith and Russell 1982, Daily et al 1993, Blendinger 1999, Winkler and Christie 2002, especially for nectarivorous species such as hummingbirds (Trochilidae) and sunbirds (Nectariniidae)] that require high levels of energy (Kilham 1964, O'Donnell and Dilks 1989, Eberhardt 2000, Pejchar and Jeffrey 2004. For these species, sap is a food resource of high energy content, similar to that of flower nectar, because nectar sugars are derived from sucrose translocated in phloem sap (Paton 1980, Gaze and Clout 1983, Nicolson and Fleming 2003.…”