Max Planck Institute of Animal Behavior Media & Outreach Overview News studying-animal-behavior-without-markers Publications of Robert E. Ricklefs All genres Journal Article (3) Journal Article (3) 1. Journal Article Lee, K. A.; Martin, L. B.,. I.; Hasselquist, D.; Ricklefs, R. E.; Wikelski, M.: Contrasting adaptive immune defenses and blood parasite prevalence in closely related Passer sparrows. Oecologia 150 (3), pp. 383 - 392 (2006) MPG.PuRe DOI 2. Journal Article Ricklefs, R. E.; Wikelski, M.: The physiology/life-history nexus. Trends in Ecology and Evolution 17 (10), pp. 462 - 468 (2002) MPG.PuRe DOI 3. Journal Article Wikelski, M.; Ricklefs, R. E.: The physiology of life histories. Trends in Ecology and Evolution 16 (9), pp. 479 - 481 (2001) MPG.PuRe DOI