Blue tit eggs that were laid in urban parkland were 5% larger than eggs laid in a nearby forest, which could be due to differences in the amount of calcium available to birds in urban and forest environments, a study finds.
City-dwelling blue tits may lay bigger eggs because of what they eat
Blue tit eggs that were laid in urban parkland were 5% larger than eggs laid in a nearby forest, which could be due to differences in the amount of calcium available to birds in urban and forest envir..
