Habitat dependent effects of experimental immune challenge on lizard anti-predator responses
- 186 Downloads
Lizards often respond to predators by hiding in sunless refuges, but this eliminates opportunities for thermoregulatory basking. Hiding can therefore lower body condition. Furthermore, in ectotherms basking is important to induce fever and activate an immune response. A potential trade-off therefore exists between lowering predation risk and elevating body temperature to fight infection. Such a trade-off could be habitat dependent if habitats differ in the relative risk of predation versus that of acquiring or countering an infection. Here we take an experimental approach to test whether lizard basking behavior is affected by a trade-off between predator avoidance and fighting an infection. We quantified the anti-predator behavior of male lizards (Podarcis liolepis) both before and after they were immune challenged (injected with LPS) or not (injected with PBS control). To test the generality of any trade-off, we tested lizards from both an urban and a natural habitat. We found that males spent less time hiding following a simulated predator attack after they had been immune challenged than before, but this decline was only significant for males from the natural habitat. We also tested whether morphological traits, body condition, and immune response level explained variation in male hiding time. In the natural habitat, but not in the urban habitat, males with relatively small heads hid for significantly longer. In conclusion, we show that lizard anti-predator behavior is affected by an immune challenge. Habitat differences in the factors that predict hiding time offers potential insights into why this might be the case.
There is a potential trade-off for ectotherms between remaining in a place protected from predators and countering an immune challenge. This is because hiding in sunless refuges eliminates opportunities for thermoregulatory basking that induce a fever. The optimal response to this trade-off might change depending on the habitat. Here, we compare the hiding behavior of males from natural and urban habitat following an experimental immune challenge. We found that the hiding time of immune-challenged males decreased but only for those from the natural habitat.
KeywordsImmunity Life history Podarcis liolepis Predation costs Trade-off Urban habitat
- Aierbe T, Olano M, Vázquez J (2001) Atlas of nesting birds in Gipuzkoa. Munibe Ciencias Naturales 52:5–138Google Scholar
- Cabido C, Gonzalo A, López P, Martín J (2008) Poblaciones urbanas de la lagartija ibérica: uso Como bioindicador de los efectos del ambiente urbano. Caja de Ahorros y Monte de Piedad de Segovia, SegoviaGoogle Scholar
- Carrillo M (1979) El Castillo de Santa Cruz de la Mota y las murallas de San Sebastián. Grupo Dr. Camino de Historia Donostiarra, Donostia/San SebastiánGoogle Scholar
- Contesse P, Hegglin D, Gloor S, Bontadina F, Deplazes P (2004) The diet of urban foxes (Vulpes vulpes) and the availability of anthropogenic food in the city of Zurich, Switzerland. Mamm Biol 69:81–95Google Scholar
- R Core Team (2015) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria, http://www.R-project.org/
- Janeway CA, Travers P, Walport M, Shlomchik M (2001) Immunobiology. The immune system in health and disease. Garland Publishing, New YorkGoogle Scholar
- Kokko H, Rankin DJ (2006) Lonely hearts or sex in the city? Density-dependent effects in mating systems. Proc R Soc Lond B 361:319–334Google Scholar
- Polo V, López P, Martín J (2005) Balancing the thermal costs and benefits of refuge use to cope with persistent attacks from predators: a model and an experiment with an alpine lizard. Evol Ecol Res 7:23–35Google Scholar
- Sorace A (2002) High density of bird and pest species in urban habitats and the role of predator abundance. Ornis Fennica 79:60–71Google Scholar