insistent

adj

1. (obsolete)Standing or resting on something.
2. Urgent in dwelling upon anything; persistent in urging or maintaining.
3. Extorting attention or notice; coercively staring or prominent; vivid; intense.

   “Hadadas roost in numbers among the trees in the leafier parts of Nairobi and their eponymous call is one of the more insistent elements of the dawn chorus in that part of the world, though they may be heard at any time of the day.”

4. Standing on end: specifically said of the hind toe of a bird when its base is inserted so high on the shank that only its tip touches the ground: correlated with incumbent.