Sounds of Senescence

Moving swiftly across the swamp

the sparrow tentatively

spreads out his territory;

a phonic palisade, which

he surveys with

vain conviction.

Contented in solitude,

he slides into

symphonic soliloquy;

preening at the

sumptuousness of

his stereotypic

performance.

 

Halfway through the encore

An unwanted response

echoes his call.

Susceptible to the vulgarity

of this disturbance,

he jumps down from his perch

to confront his admirer;

the repetition of his retort

parading his position.

 

Bemused by his

audience’s apparition

he turns his ear

to the ground,

shakes his head,

and returns to his

own self-worth:

the virility of youth

untroubled by

the artifice of age.

A swamp sparrow (Image Credit: U.S. Fish and Wildlife Service).

This poem is inspired by recent research, which has found that male swamp sparrows are less intimidated by the songs of their ageing rivals.

During the early spring, male swamp sparrows stake out their breeding territories, threatening any other males who dare to trespass. If a potential rival encroaches on their territory and begins to sing, then the resident male tries to evict the interloper by singing back with a rapid ‘weet-weet-weet’ sound, before flying towards them and (if all else fails), attacking their unwanted guest. Previous research has shown that male swamp sparrows reach their peak vocal ability at the age of two, singing less frequently and less consistently as they get older and in this new study, researchers wanted to find out if other males take note of these changes in vocal quality.

In order to address this question, the researchers set up speakers in the territories of 35 different male swamp sparrows across a Pennsylvanian marsh, playing them five-minute audio clips of two different male swamp birds: those from a two-year old, and those from a ten-year-old swamp sparrow. After measuring how closely each male approached the speaker, the researchers found that males approached (on average) seven feet closer when they heard the song of a two-year old in comparison to a ten-year-old potential rival. These findings suggest that male swamp sparrows are more aggressive towards younger-sounding rivals, and whilst further research is needed, the researchers believe that these changes in the song quality of male swamp sparrows could reflect the consequences of physical decline, indicating to other males that they pose less of a threat, and are thus perhaps less worthy of getting worked up about.

An audio version of this poem can be heard here:

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