A question on wild snake growth rates.

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Owen
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A question on wild snake growth rates.

Post by Owen » March 2nd, 2016, 10:37 am

More, specifically, for those with study sites, board lines, etc... have you taken any measurements of the same animals over time? I would be curious to see what the growth rates are.

I've done a few re-captures of gartersnakes from year to year and in young snakes, initial growth seems rapid.

This Diablo Range Gartersnake was measured twice 4 weeks apart. It grew from 9-1/2" to 13-3/4" over that time:
Image

This Coast Gatersnake went from 25-1/4" to 33" in 9-1/2 months:
Image

A mature CA Red-sided Gartersnake went from about 42-43" in 2013 to 47" in 2015.

It would be interesting to me to see if anyone else has any records on how fast wild snakes grow.

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Steve Bledsoe
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Re: A question on wild snake growth rates.

Post by Steve Bledsoe » March 2nd, 2016, 10:52 am

Wouldn't the amount of protein consumption within a given period of time be a direct factor in wild snake growth rates, just as it is with captives?
I'm not sure your question has an answer unless its a comparison of growth rate related to the amount of protein intake.

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Owen
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Re: A question on wild snake growth rates.

Post by Owen » March 2nd, 2016, 11:10 am

Steve, I get that, but with captives, their activity period is 365 days/year if kept indoors. I would expect them to grow faster.

The snakes above all have surface activity of 8 or 9 months, so I would assume that they're not feeding while underground. Just getting a feel for it as it seemed to me that the Coast Gartersnake growing to 33", or nearly 8" in 9-1/2 months, seems really rapid given it is a species that only reaches 43" max.

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Steve Bledsoe
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Re: A question on wild snake growth rates.

Post by Steve Bledsoe » March 2nd, 2016, 11:28 am

I would agree with you that they're probably not feeding when underground, which is during the colder months. I'm just thinking that different individuals are going to be exposed to different conditions in terms of prey availability. If two individuals share the exact same periods of activity, but one is in a habitat with less prey available than what's available to the other in a different habitat, then I would expect the growth rates to be different in terms of size vs time. Just sort of makes sense to me.

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El Garia
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Re: A question on wild snake growth rates.

Post by El Garia » March 2nd, 2016, 2:57 pm

Aside from Hannah, Hoyer, and Boundy, I don't know which other forum members have been monitoring and cataloguing such information. I did send Jeff a pm to notify him of your inquiry.

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Jeff
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Re: A question on wild snake growth rates.

Post by Jeff » March 6th, 2016, 3:43 pm

I have only done mark/recapture on racers and coachwhips, and didn't measure them -- just wanted to check for return offenders in the pine snake traps.

I had a look at Fitch's study on Red-sided Garter Snakes in northeastern Kansas, and he has some growth records. Average snout-vent length of young in August was 8.2", and two months later was 10.4 inches, so an increase of 26%. By the following June the snakes averaged 14.6" SVL, after about 5 months of non-feeding.

Adults also seemed to grow rapidly, and at one site some females grew as much as 3 mm per day in late spring and summer. Example: 18.3" SVL on 29 April, and 30.4" SVL on 15 October.

Owen's documentations are similar to those obtained by Fitch for prey-rich environments.

Jeff

Richard F. Hoyer
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Re: A question on wild snake growth rates.

Post by Richard F. Hoyer » March 6th, 2016, 11:32 pm

Owen,
Recently, I sent folders of data on Contia tenuis to Dr. C. Feldman's grad student. After she finishes up her masters program, current plans are that she will complete a draft on the Common Sharp-tailed Snake which will include information on growth recorded from over 400 recapture events I recorded for the species here in Oregon.

Just from my scanning the recapture information on some specimens, it is clear that the species has the capacity of rapid growth reaching mature status in relatively short time.

On the other hand, I have an over-kill on similar information on the Rubber Boa that awaits treatment in the future by some professional herpetologist. Growth in the boa is much slower. I estimate that on the average, it takes males 5 - 6 years to reach mature status and females about two years longer than males.

Last year, I found a female that I had first captured in 1991 and had recaptured now an then over the years. I am hoping I will be able to find her again this year and if so, that would represent a 25 year span since I first found her.

Richard F. Hoyer

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Owen
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Re: A question on wild snake growth rates.

Post by Owen » March 7th, 2016, 9:57 am

Thanks guys.

I wish that I could have re-captured this guy from 2013 when I saw it again last year.

It was between 39" and 40" in 2013:
Image

Last year, I saw it basking out of reach a couple of times. Here being photo bombed by a 30 incher:
Image

I'll see if any of the lager ones from last year want to be re-captured this year.

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