Tree Swallow (Tachycineta bicolor) Science Article 2
The fact that avian eggs contain antibody of maternal origin is well documented, but only recently has this phenomenon been considered in an ecological context. We used tree swallows (Tachycineta bicolor) to examine the possibility of transgenerational immunity and its effect on nestling growth and immune development. We measured cell-mediated immunity with a delayed-hypersensitivity assay and antibody-mediated immunity with a hemagglutination test with sheep red blood cells (SRBCs). We tested for differences in immunocompetence and growth between nestlings from females who had been exposed to a novel antigen prior to egg laying and nestlings from unexposed females. To determine whether the effect, if any, resulted from something transferred to the eggs prior to egg laying or from subsequent changes in parental behaviour, nestlings were exchanged so that at each nest half the nestlings were from females who had been injected with SRBCs and half were from females who had not been exposed to SRBCs. Finally, brood sizes were independently manipulated to either 4 or 6 nestlings.
G.A. Lozano and R.C. Ydenberg, Can. J. Zool. 80: 918-925 (2002)