Effects of parental effort on blood stress protein HSP60 and immunoglobulins in female blue tits: a brood size manipulation experiment
José Luis Osorno died on 2 April 2004. We mourn the loss of a bright behavioural ecologist and excellent colleague.
Santiago Merino, Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales – CSIC, J. Gutiérrez Abascal 2, E-28006 Madrid, Spain. E-mail: email@example.com
- 1Physiological stress in animals may impose a limit for investment in current reproduction in the wild. A brood manipulation experiment was conducted in a population of blue tits Cyanistes caeruleus to study the effect of parental effort on changes in two types of proteins related with stress: the blood stress protein HSP60 and the plasma immunoglobulins.
- 2Levels of HSP60 were reduced across the experiment for females attending reduced broods, and females attending enlarged broods experienced a reduction of immunoglobulin levels. Moreover, the overall changes in the levels of both proteins were positively related.
- 3By controlling for the change in immunoglobulin levels we found an increase in HSP60 for females in the enlarged treatment, presumably to offset deleterious effects derived from increased effort.
- 4Maternal effort was able to partially compensate for the effect of treatment as nestlings did not differ in mass and levels of immunoglobulins and HSP60 among treatments.
- 5Physiological stress as reflected in stress and immunoglobulin proteins may limit maternal effort in breeding blue tits.