Journal Article

Responding to inflammatory challenges is less costly for a successful avian invader, the house sparrow (Passer domesticus), than its less-invasive congener

Wikelski, M.C, Lee, K.A, Martin, L.B. II

2005

Overview

When introduced into new regions, invading organisms leave many native pathogens behind and also encounter evolutionarily novel disease threats. In the presence of predominantly novel pathogens that have not co-evolved to avoid inducing a strong host immune response, costly and potentially dangerous defenses such as the systemic inflammatory response could become more harmful than protective to the host. We therefore hypothesized that introduced-populations exhibiting dampened inflammatory responses will tend to be more invasive. To provide initial data to assess this hypothesis, we measured metabolic, locomotor, and reproductive responses to inflammatory challenges in North American populations of the highly invasive house sparrow (Passer domesticus) and its less-invasive relative, the tree sparrow (Passer montanus). In the house sparrow, there was no effect of phytohemagglutinin (PHA) challenge on metabolic rate, and there were no detectable differences in locomotor activity between lipopolysaccharide (LPS)-injected birds and saline-injected controls. In contrast, tree sparrows injected with PHA had metabolic rates 20-25% lower than controls, and LPS injection resulted in a 35% drop in locomotor activity. In a common garden captive breeding experiment, there was no effect of killed-bacteria injections on reproduction in the house sparrow, while tree sparrows challenged with bacteria decreased egg production by 40% compared to saline-injected controls. These results provide some of the first data correlating variation in immune defenses with invasion success in introduced-vertebrate populations.

• Publisher: Springer,Springer Nature B.V
• Subject: Animal and plant ecology / animal pathogenic bacteria / animal reproduction / Animal, plant and microbial ecology / Animals / Animals, Congenic / Aves / Biological and medical sciences / Biological invasions / Bird Diseases / Bird Diseases - chemically induced / Bird Diseases - genetics / Bird Diseases - immunology / Bird Diseases - metabolism / Bird nesting / Birds / chemically induced / Colonizing ability / drug effects / Ecophysiology / Ecosystem / Egg production / Energy Metabolism / Energy Metabolism - drug effects / Female / Female animals / Fundamental and applied biological sciences. Psychology / General aspects / genetics / Immune response / immunology / inflammation / Inflammation - chemically induced / Inflammation - immunology / Inflammation - metabolism / Inflammation - veterinary / introduced species / Invasive plants / Invasive species / lipopolysaccharides / Lipopolysaccharides - pharmacology / locomotion / Locomotor activity / Male / metabolism / Motor Activity / Motor Activity - drug effects / Parasite hosts / Passer domesticus / Passer montanus / Pathogens / pharmacology / physiology / phytohemagglutinin / Phytohemagglutinins / Phytohemagglutinins - pharmacology / Reproduction / Reproduction - drug effects / Reproduction - physiology / resistance mechanisms / Rodents / Sparrows / Sparrows - genetics / Sparrows - immunology / Sparrows - metabolism / Species Specificity / Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution / veterinary / Wild birds