Re: Sierra zonata . . .

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Posted by Rick Staub on April 14, 2000 at 18:29:04:

In Reply to: Sierra zonata . . . posted by Troy H on April 14, 2000 at 17:25:41:

Actually I have never been to Bass Lake but have seen several animals from that area. There seems to be a population in the central Sierras that runs from Hwy 108 south to just east of Fresno where they have the lower triad counts and higher amounts of red. In areas just north of Bass Lake there seems to be a juxta position of high black and high red populations along an east west alignment. For example animals around Sonora have high amounts of red and low triad counts while animals at Pinecrest Lake have the opposite. Same for the Yosemite Valley where the all black and white morphs are known from compared to animals west of there along Hwy 120. Intermediate populations seem to be quite variable with some perfectly banded animals with triad counts near 20 and others with triad counts well over 30 and very few complete red bands. It is interesting that populations further north and south of this central Sierra zone tend to be of the high black variety no matter what the elevation or the east/west position. This changes again when you get down to Kern County where Brad and friends have been collecting. DNA analysis of zonata from the extreme southern Sierras shows that they have some multifasciata influence even though they look much like animals further north. I have noticed little things like there are little flecks of color on the snout and the white bands tend to be wider like you see from animals on Mount Hamilton which is also believed to be a zonata/multifasciata integrade. Why animals in the central Sierras resemble a multifasciata/zonata integrade is unknown but I believe that there was a trans-valley migration from the Mount Hamilton area to this region in the central Sierras. I did not just simply pull this idea out of my hat as this has been shown for ensantina slamanders and Gilberts skinks at least. Ensantina even show the same east/west positioning between the subspecies in the Sierra. Zonata probably migrate to a greater extent than ensantina so this integrade zone has probably been blurred to a greater extent. DNA analysis did show some similarities between the Mount Hamilton and Bass Lake animals over the surrounding populations but it was not conclusive. I was told that mitochondrial DNA is not effective for determining such recent relationships and that a microsatellite or nuclear DNA analysis with a larger number of animals (10 or more) would be necessary to delineate this trans-valley connection. Getting 10 zonata from the Sierras is not difficult but off Mount Hamilton this could take a decade. Getting grant money to answer such a question is another story. Probably more than you wanted to know!

: rick,

: since you've seen sierra's from the length and breadth of the range, could you maybe delineate the occurrance of "bass lake" type patterns? i know the bass lake area has them, as do ones from down near lake isabella (west of the lake) . . . in relation to bass lake, how far east into the mts do you go b4 they start looking like more "typical" sierras?

: also, where in the sierras are black and white ones more common . . .

: anyway, i'm just asking for generalities . . . no need to post specific locales!

: troy

Follow Ups:

thanks, exactly what i wanted to know . . . one more Q Troy H 04/15/00 (1)
- Re: thanks, exactly what i wanted to know . . . one more Q Rick Staub 04/15/00 (0)

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: Actually I have never been to Bass Lake but have seen several animals from that area. There seems to be a population in the central Sierras that runs from Hwy 108 south to just east of Fresno where they have the lower triad counts and higher amounts of red. In areas just north of Bass Lake there seems to be a juxta position of high black and high red populations along an east west alignment. For example animals around Sonora have high amounts of red and low triad counts while animals at Pinecrest Lake have the opposite. Same for the Yosemite Valley where the all black and white morphs are known from compared to animals west of there along Hwy 120. Intermediate populations seem to be quite variable with some perfectly banded animals with triad counts near 20 and others with triad counts well over 30 and very few complete red bands. It is interesting that populations further north and south of this central Sierra zone tend to be of the high black variety no matter what the elevation or the east/west position. This changes again when you get down to Kern County where Brad and friends have been collecting. DNA analysis of zonata from the extreme southern Sierras shows that they have some multifasciata influence even though they look much like animals further north. I have noticed little things like there are little flecks of color on the snout and the white bands tend to be wider like you see from animals on Mount Hamilton which is also believed to be a zonata/multifasciata integrade. Why animals in the central Sierras resemble a multifasciata/zonata integrade is unknown but I believe that there was a trans-valley migration from the Mount Hamilton area to this region in the central Sierras. I did not just simply pull this idea out of my hat as this has been shown for ensantina slamanders and Gilberts skinks at least. Ensantina even show the same east/west positioning between the subspecies in the Sierra. Zonata probably migrate to a greater extent than ensantina so this integrade zone has probably been blurred to a greater extent. DNA analysis did show some similarities between the Mount Hamilton and Bass Lake animals over the surrounding populations but it was not conclusive. I was told that mitochondrial DNA is not effective for determining such recent relationships and that a microsatellite or nuclear DNA analysis with a larger number of animals (10 or more) would be necessary to delineate this trans-valley connection. Getting 10 zonata from the Sierras is not difficult but off Mount Hamilton this could take a decade. Getting grant money to answer such a question is another story. Probably more than you wanted to know! : : rick, : : since you've seen sierra's from the length and breadth of the range, could you maybe delineate the occurrance of "bass lake" type patterns? i know the bass lake area has them, as do ones from down near lake isabella (west of the lake) . . . in relation to bass lake, how far east into the mts do you go b4 they start looking like more "typical" sierras? : : also, where in the sierras are black and white ones more common . . . : : anyway, i'm just asking for generalities . . . no need to post specific locales! : : troy

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