T Mob and Sprint are weak siblings relative to Verizon and ATT.

It is appear common for the younger, weaker siblings to stop begging for food after sibling aggression starts and the parent eagles do not feed the nestlings unless they beg.

They would have to absorb enormous long-term costs to support their weaker siblings - either in terms of inflation or simple cash transfers.

All that remained was a tiny sun, joining its slightly older companions, a weak and inconstant sibling.

The newly hatched chicks will display cainism, which is prevalent in some raptor species where the older or stronger sibling will kill its younger or weaker sibling.

In most cases, the first chick will kill its smaller, weaker sibling after it hatches.

Intrauterine cannibalism is an even more unusual mode of vivipary, in which the largest embryos eat weaker and smaller siblings.

While stronger chicks are not aggressive towards weaker siblings, as is the case in some species, weak or small chicks are sometimes killed by their parents.

The question then becomes 'why not wait until fall before ejecting the weaker siblings?'

The eggs, hatched downstream, would produce a brood of insanely competitive monsters who fought each other for the prime hunting grounds, driving their weaker siblings farther and farther south.