Climate comparisons

[GeoTerraTestudo]

Climate is very important for the tortoise health. I wanted to compare the climate of America's lower 48 states to other countries where tortoises come from. So, I tabulated existing data from the internet and plotted mean annual precipitation (in mm) against mean annual temperature (in °C). You can find the PDF based on my Excel spreadsheet attached to this thread (feel free to PM me if you want the original spreadsheet). Here is the resulting graph:

In my case, Colorado grouped fairly close to Kazakhstan, which is nice, since I keep Russian tortoises from that part of the world (Testudo horsfieldi kazakhstanica). It would be interesting to see other comparisons on this thread. Enjoy!

 

[Tom]

I can't make out the little initials covered in red. Does it show how CA compares to South Africa, for example? Also, CA (for example) is a HUGE state and the wether in San Diego is going to be FAR different than the weather in the Northern part of the state. How do I use this practically?

 

[GeoTerraTestudo]

To zoom in on it, just open the attached PDF and magnify that. Threads do not permit the posting of XLS spreadsheets, but if you want a copy, just contact me and I'll send you one.

Yes, a few of the places there are very big, so one MAT and MAP data point is probably not enough for them. I'm talking about states like California and Texas, as well as the nation of Russia, which of course along with Canada, is one of the biggest countries by area in the whole world. This was just a big overview, but we can always go back and insert particular locations for which we have data. For example, it would make sense to have several entries for California: one for Southern California, one for the Valley, one for the Bay Area, and one for Northern California.

To my mind, this graph gives an indication as to whether or not it's safe to leave your tortoise out year round. If I want to know whether a tortoise would survive in a state without the aid of housing, heat lamps, etc., I just check to see if that state is close to a country where that tortoise is from. For example, this graph does seem to corroborate the claim that California and South Africa both have a Mediterranean climate, similar to countries like Greece, Israel, and Tunisia.

Of course, annual averages do not tell you about the range in temperature or precipitation. Two countries with similar averages may nevertheless have different maximum and minimum temperature or rainfall. To confirm whether the conditions are a match or not, you would need to look up the country in question, and see just how similar the climate profiles are.

 

[tortuga_please]

This is a very cool idea, could definitely take a lot of time though. Very jealous that I didn't think of it, sounds fun :-D

 

[Tccarolina]

I compared my area's precipitation (11.5 in), time of year it falls (Mediterranean winter and spring precip.), and the high and low temps for different months of the year.
I found that it is VERY similar to the inland regions of Israel, Syria, and most of Jordan.
Sometimes I set my ten day forcast for Amman, Jordan, or some other city in that region, to compare how my forcast matches their's for a given time of year.

It's a closer than I would have thought.

Steve

 

[GeoTerraTestudo]

Plant Hardiness Zone applied to tortoises
Horticulturalists and gardeners use the USDA Plant Hardiness Zone Map to see which plants can survive in what parts of the USA (see also: http://planthardiness.ars.usda.gov/PHZMWeb/ ). More recently, the Plant Encyclopedia has also developed the World Plant Hardiness Zone Map, for use with areas outside the USA as well.

It occurred to me that, if this map can be used to figure out the hardiness of plants, it might also be useful for figuring out the hardiness of animals like tortoises as well. So, for your infotainment, below is the World Plant Hardiness Zone Map. I hope you find it helpful for determining whether the climate you live in is in the same temperature zone as those where your tortoise is from. If it is in the same zone, then perhaps your tortoise can survive there more easily.

See also:
http://en.wikipedia.org/wiki/Hardiness_zone

 

[yagyujubei]

I match North Korea. Yea!

 

[Maggie Cummings]

I guess I'm just a dumb half blind old lady cuz I can't read it or figure it out, and in all seriousness it does make me feel pretty dumb. Anybody tell me what the Willamette Valley in Oregon compares to...

 

[nicoleandrocky]

this is really cool

 

[GeoTerraTestudo]

I guess I'm just a dumb half blind old lady cuz I can't read it or figure it out, and in all seriousness it does make me feel pretty dumb. Anybody tell me what the Willamette Valley in Oregon compares to...

Looks like temperatures in Willamette Valley, besides being similar to parts of the southeastern US, are also similar to southern and southeastern Europe, northern Turkey, and southern China.

 

[Maggie Cummings]

I guess I'm just a dumb half blind old lady cuz I can't read it or figure it out, and in all seriousness it does make me feel pretty dumb. Anybody tell me what the Willamette Valley in Oregon compares to...

Looks like temperatures in Willamette Valley, besides being similar to parts of the southeastern US, are also similar to southern and southeastern Europe, northern Turkey, and southern China.

Thanks so much. So with the exception of lack of sun, Oregon is a good place for tortoises to live

 

[Madkins007]

Geo- I like it- especially the plant hardiness map idea. I've been playing around with a similar idea based on local turtle/tortoise populations. For example:

- Desert, gopher, or Texas tortoises: Most species. Forest species would need humidity support.
- Ornate box turtle: Russians. Can probably be left outside all year if the soil is sandy enough for them to burrow in.
- Eastern box turtle: Most kinds of tortoises, although winter accommodations will be needed if they do not hibernate.
- Alligator snappers (or just plain alligators!): Any species, especially 'forest' tortoises

 

[GeoTerraTestudo]

Geo- I like it- especially the plant hardiness map idea. I've been playing around with a similar idea based on local turtle/tortoise populations. For example:

- Desert, gopher, or Texas tortoises: Most species. Forest species would need humidity support.
- Ornate box turtle: Russians. Can probably be left outside all year if the soil is sandy enough for them to burrow in.
- Eastern box turtle: Most kinds of tortoises, although winter accommodations will be needed if they do not hibernate.
- Alligator snappers (or just plain alligators!): Any species, especially 'forest' tortoises

Good point. If native tortoises, box turtles, or even other reptiles live in the area, we can infer that exotic tortoises with similar requirements would do well, too.

I read a great scientific article in PLoS One about a year ago that covers this topic very well (Richmond et al. 2010). The article is actually about Pleistocene rewilding, a proposal dealing with animal introductions in general, not just tortoises. Here is the link to it:

"Is the Climate Right for Pleistocene Rewilding? Using Species Distribution Models to Extrapolate Climatic Suitability for Mammals across Continents"

Basically, Richmond et al. (2010) use species distribution models (SDMs) to predict where in the US animals from other parts of the world would survive if introduced. The model takes temperature, precipitation, and the present and historical distributions of these species into account to create a map that shows in which parts of the country they would be expected to do well. The animals in these models are the lion, cheetah, elephant, and oryx, but they could just as easily be tortoises.

I think it would be wonderful to make an SDM for tortoise species in the US. That would give us our best estimate for where a tortoise species might be able to survive outdoors year-round. Maybe at some point I will learn how to make an SDM, and apply it to this problem. Wouldn't that be great?