Back in high school I ran an obstacle course race at Camp Pendleton, a marine corps base outside San Diego. I entered the team division with some of my high school cross country teammates, but unlike other XC races where you score the top 5 by place, the entire team had to cross the finish line linking arms. You truly were only as strong as the weakest link (Ben, I’m looking at you).
And in many ways fledging young is much the same way. In birds, the burden of rearing young is largely shared – some 81% of bird species share the responsibility of fledgling nestlings (source). It takes smaller species 2-3 weeks to take the hatched young to independence, larger species closer to 3-5 weeks (some birds, like ducks and shorebirds, are precocial, born ready to leave the nest).. During that time, the parents are tied to the young. Where one goes, so go the others. Sure, sexual reproduction may be the road to genetic immortality, but it is an arduous road full of obstacles, traps, and terrifying predators. The family unit races races towards that finish line, frantically stuffing food into the young, fattening them up and teaching them how to ultimately forage on their own.