The tradeoff between catch-up growth and escape speed: variation between habitats in the cost of compensation

Compensatory growth is the faster-than-normal growth that some species exhibit after a period of resource deprivation. Using three-spined sticklebacks as model species we tested the impact of compensatory growth on subsequent escape performance in populations from diverse habitats. We found clear population differences in the rate of compensatory growth, and strong inter-habitat differences in the impact that catch-up growth had on burst swimming performance when measured weeks later. In pond populations growth compensation had little effect on burst swimming, whereas fish from stream populations that exhibited rapid catch-up growth subsequently had slower escape speeds. Those differences could be explained by the non-linear nature of the tradeoff curve, suggesting that habitat-specific selection pressures lead to differences in the importance of burst swimming performance.