Journal Article

Resource Selection Plasticity and Community Responses to Experimental Reduction of a Critical Resource

Martin, Kathy, Aitken, Kathryn E. H.

2008

Overview

Resource selection plasticity and behavioral dominance may influence the ability of a species to respond to changes in resource availability, particularly if dominant species have highly specialized resource requirements. We examined the response of several dominant and subordinate cavity-nesting species to a reduction in the availability of an essential resource (nesting cavities) using the novel experimental approach of blocking the entrances to high-quality cavities. We monitored nest abundance on seven treatment and 13 control sites (aspen groves in a grassland matrix) in British Columbia, Canada, for two years pretreatment (2000—2001), two years during treatment (2002—2003), and two years posttreatment (cavities reopened; 2004—2005). At the community level, nest abundance declined by 50% on treatment sites following cavity blocking and returned to pretreatment levels following cavity reopening. Nest abundance of European Starlings (Sturnus vulgaris), a dominant secondary cavity-nester (SCN), declined by 89% and failed to recover posttreatment. Conversely, nest abundance of Mountain Bluebirds (Sialia currucoides; a subordinate SCN) increased following cavity blocking and remained high following reopening. Tree Swallows (Tachycineta bicolor) were unaffected by cavity blocking. We suggest that starlings, while being the dominant SCN, may be limited by availability of suitable nest sites, whereas bluebirds may be limited by starling abundance. We propose that plasticity in nest site preferences of subordinate cavity-nesters may enable them to contend with natural variation in availability of critical resources, such as nest cavities and food, in addition to coping with interspecific competition. This is the first community-level, multiyear study involving manipulation of nest site availability via experimental cavity blocking.

• Publisher: Ecological Society of America
• Subject: Animal and plant ecology / Animal populations / Animal, plant and microbial ecology / Animals / Aves / Biological and medical sciences / Biological variation / Bird nesting / Birds / British Columbia / cavity-nesting birds and mammals / Communities / Community involvement / Competitive Behavior / dominant and subordinate species / Dominant species / Ecological competition / Ecosystem / European Starling / Evolutionary biology / Forest conservation / Forest ecology / Fundamental and applied biological sciences. Psychology / General aspects / Grasslands / groves / interspecific competition / Mountain Bluebird / natural cavities / nest site limitation / Nesting / Nesting Behavior / Nesting sites / nests / Plasticity / plasticity in resource selection / Population Dynamics / Resource availability / resource limitation / resource quality / secondary cavity-nesters / Sialia currucoides / social dominance / Songbirds - physiology / Starlings / Sturnus vulgaris / Swallows / Synecology / Tachycineta bicolor / Time Factors / Tree cavities / Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution