In a discovery that deepens our understanding of animal social bonds, a study led by University of Oxford researchers in collaboration with the University of Leeds has demonstrated that wild great tits exhibit clear behaviours signalling ‘divorce’ long before the breeding season. The findings, published today (30 /29 July) in Royal Society Proceedings B, provide valuable new insights into how animals navigate complex social decisions.

Salk immunologists discovered that specialized immune cells called T cells increase in mammary glands during late pregnancy and breastfeeding, and that some of the T cells relocate from the gut—suggesting a connection between the gut microbiome and breastfeeding. The findings may help explain the advantages of breastfeeding, prompt solutions for mothers unable to breastfeed, help design better formulas, and inform dietary decisions that enhance breast milk production and quality.