What does the poet Wole Soyinka mean by "dawn's lone trumpeter" in "Death in the Dawn"?

The poem "Death in the Dawn" is a poem that makes a stereotypical comparison that life is a journey. The poem then intentionally leans toward showing readers that the journey is a lot like a road trip in a car, giving the readers several images associated with cars. One of my favorites is the right foot and left line.

The right foot for joy, the left, dread

Generally speaking, the right foot is for the gas pedal, and I believe that most drivers find great pleasure in accelerating. The left pedal is the brake pedal and is generally only slammed on when something bad is imminent.
Despite the poem's emphasis on cars and man's machinery, the poem also doesn't shy away from giving readers some solid animal images and references. The first two stanzas quite obviously list specific animals—dogs and earthworms are referenced.
The lone trumpeter line appears in stanza four, and it is referring to a rooster that "trumpets" out an announcement each morning. The following line's mentioning of feathers helps alert readers to the specific bird species and act.