“Conflict, in turn, produces another problem: how to win or lose without the disagreeing parties incurring too great a cost. This latter point is particularly important. Imagine that two birds engage in a squabble about a desirable nesting area. The interaction can easily degenerate into outright physical combat. Under such circumstances, one bird, usually the largest, will eventually win—but even the victor may be hurt by the fight. That means a third bird, an undamaged, canny bystander, can move in, opportunistically, and defeat the now-crippled victor. That is not at all a good deal for the first two birds. Conflict—and Territory Over the millennia, animals who must co-habit with others in the same territories have in consequence learned many tricks to establish dominance, while risking the least amount of possible damage”

Fairy Tales (1835)
Source: The Ugly Duckling

Song 17: "Love between Brothers and Sisters".
1710s, Divine Songs Attempted in the Easy Language of Children (1715)

In the event, we got both. Thanks @jeremycorbyn.
Series of tweets following Jeremy Corbyn's sacking of shadow ministers who defied a Labour whip not to support an amendment calling for the UK to stay in the single market after Brexit https://twitter.com/DanielJHannan/status/880721871720808448 (30 June 2017)
2010s

“Nests,” p. 55
The Creator (2000), Sequence: “The Whisper of Eternity”

Vetoing a Bill that would have imposed fines on owners who allowed cats to run at large. (23 April 1949)
Context: The problem of cat versus bird is as old as time. If we attempt to resolve it by legislation who knows but what we may be called upon to take sides as well in the age old problems of dog versus cat, bird versus bird, or even bird versus worm. In my opinion, the State of Illinois and its local governing bodies already have enough to do without trying to control feline delinquency.
For these reasons, and not because I love birds the less or cats the more, I veto and withhold my approval from Senate Bill No. 93.

Stanislaus Grumman in Ch. 10 : The Shaman
His Dark Materials, The Subtle Knife (1997)
Context: People here cannot conceive of worlds where dæmons are a silent voice in the mind and no more. Can you imagine my astonishment, in turn, at learning that part of my own nature was female, and bird-formed, and beautiful?

Source: The Notebook