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Mar. 18th, 2006 01:54 amI just cleaned my room. FO SHO.
Today I learned all sorts of really interesting things about hormones and song birds. As I understand it, increasing day length stimulates the secretion of GnRH-I in the hypothalamus, which causes gonadal maturation and increased volume of certain cell nuclei in the brain which when stimulated make birds want to sing. And then when autumn comes round, birds effectively go back to prepubescence, possibly as an adaptation to flight to minimise body mass by investing less in gonads (as a simplified view; any evolutionary biologist would not be happy with that wording). And also birds may interrupt someone else's song with their own, and a female is less likely to choose a male who has been overlapped because it's a sign of inferiority or something, so the overlapped male will just stop short. It sounds kind of like a game - you try to surprise someone else into playing the inferior part, but when someone else sings you cut your own song short so you're still on the same level as them, and you both have to keep singing to spread your seed innit. And colouration varies throughout the year not just due to moulting, so there's visible evidence that male quality can vary depending on food availability etc.
And this morning I had an interesting lecture about fire. Next week I have to wear wellies to class. :)
I have a dusty nose now. *sneeze*
Today I learned all sorts of really interesting things about hormones and song birds. As I understand it, increasing day length stimulates the secretion of GnRH-I in the hypothalamus, which causes gonadal maturation and increased volume of certain cell nuclei in the brain which when stimulated make birds want to sing. And then when autumn comes round, birds effectively go back to prepubescence, possibly as an adaptation to flight to minimise body mass by investing less in gonads (as a simplified view; any evolutionary biologist would not be happy with that wording). And also birds may interrupt someone else's song with their own, and a female is less likely to choose a male who has been overlapped because it's a sign of inferiority or something, so the overlapped male will just stop short. It sounds kind of like a game - you try to surprise someone else into playing the inferior part, but when someone else sings you cut your own song short so you're still on the same level as them, and you both have to keep singing to spread your seed innit. And colouration varies throughout the year not just due to moulting, so there's visible evidence that male quality can vary depending on food availability etc.
And this morning I had an interesting lecture about fire. Next week I have to wear wellies to class. :)
I have a dusty nose now. *sneeze*
