white-crowned forktails
... that white-crowned forktails breed between mountaintops in Borneo, but not with individuals of the same species in adjacent lowlands?
... that <b id="mw0A"><a href="./White-crowned_forktail" id="mw0Q" rel="mw:WikiLink" title="White-crowned forktail">white-crowned forktails</a></b> <i id="mw0g">(example pictured)</i> breed between mountaintops in <a href="./Borneo" id="mw0w" rel="mw:WikiLink" title="Borneo">Borneo</a>, but not with individuals of the same species in adjacent lowlands?