Hunter, hunting.
Came across a piece on adult swallow tail streamer length. It suggested that the hen's two tail-streamers would be the aerodynamic ideal, IE that longer or shorter degrades flight functionality. Also that in cock birds the elongated streamers are a stretch beyond that same aerodynamic mean, inferring that their tails are less functional than the hens' similar.
But this seems to consider & assess only one aspect of the plumage jacket, not considering that there may be compensations in other features of the cock birds' tails - or elsewhere in the plumage? - that might confer similar flight manoeuvrability to that of the hen birds. Since these birds' preferred feeding pattern clearly depends very heavily on extreme articulation of their flight paths, being able to twist, turn, dive and ascend in convoluted corkscrew-combinations - allowing them regularly to intercept successfully tiny lightweight wind-borne prey items. If the penalty of longer tails was genuine, that might in turn reduce the cock birds' ability to feed successfully - in order to achieve more regular/reliable breeding success?
I didn't see any reference to whether or not these streamers elongate only in the period of sexual selection of breeding partners, or indeed whether it's the hen birds that select suitable breeding partners. The tail streamer theory seems to suggest that that's the way of it. But other species appear to be able to identify and select nest partners without having any observable difference in their plumage - eg wood pigeons.
If that's so, then why construct a theory like this one
Limited observations are only ever likely to produce reasoning validity of a limited nature - was a lesson I recall learning many, many years ago. Nothing learnt since has tended to overturn that little gem of logic.
"And that's all I have to say about that" - Forrest Gump.
Hunter, hunting.
Came across a piece on adult swallow tail streamer length. It suggested that the hen's two tail-streamers would be the aerodynamic ideal, IE that longer or shorter degrades flight functionality. Also that in cock birds the elongated streamers are a stretch beyond that same aerodynamic mean, inferring that their tails are less functional than the hens' similar.
But this seems to consider & assess only one aspect of the plumage jacket, not considering that there may be compensations in other features of the cock birds' tails - or elsewhere in the plumage? - that might confer similar flight manoeuvrability to that of the hen birds. Since these birds' preferred feeding pattern clearly depends very heavily on extreme articulation of their flight paths, being able to twist, turn, dive and ascend in convoluted corkscrew-combinations - allowing them regularly to intercept successfully tiny lightweight wind-borne prey items. If the penalty of longer tails was genuine, that might in turn reduce the cock birds' ability to feed successfully - in order to achieve more regular/reliable breeding success?
I didn't see any reference to whether or not these streamers elongate only in the period of sexual selection of breeding partners, or indeed whether it's the hen birds that select suitable breeding partners. The tail streamer theory seems to suggest that that's the way of it. But other species appear to be able to identify and select nest partners without having any observable difference in their plumage - eg wood pigeons.
If that's so, then why construct a theory like this one
Limited observations are only ever likely to produce reasoning validity of a limited nature - was a lesson I recall learning many, many years ago. Nothing learnt since has tended to overturn that little gem of logic.
"And that's all I have to say about that" - Forrest Gump.