chumley wrote:I love starting a day by learning new facts!
Hello chumley, Grab a cup of morning coffee (or whatever substance you ingest this early),
bigdog asked a question regarding why Rocky Mt. Bighorn are generally bigger than Desert Bighorn. The answer is summarized by Bergmann’s Rule that “within a broadly distributed taxonomic clade, populations and species of larger size are found in colder environments, and species of smaller size are found in warmer regions. It applies with exceptions to many mammals and birds. It was named after Carl Bergmann who described it in 1847.”
Ecologists/biologists have come up with a number of such Rules:
https://en.wikipedia.org/wiki/Biological_rules
Quick and Dirty on Life Zones
Back in the 1890's, Merriam worked in Arizona an developed his concept of ‘Life Zones’ and biomes. The concept has fallen out of use—but it does provide a ‘snapshot’ that can be useful for hikers here in AZ. We are blessed with so many of the different Life Zones within a few hours drive of everywhere within the state.
https://www.geo.arizona.edu/Antevs/biomes/azlifzon.html
If you really want to investigate this concept:
https://en.wikipedia.org/wiki/List_of_e ... rica_(CEC)
Take-aways for the casual hiker:
(1) You can maximize your species count (be it birds, mammals, plants, etc) by planning a hike that is including several Life Zones. Best opportunity is to get to the top of the San Francisco Peaks, hike down, get to Grand Canyon and hike to the River. The temperature differential from the bottom of the Grand Canyon to the top of San Francisco Peaks, a distance of about 50 miles (as the crow flies) represents a latitude difference of approximately 1,800 miles. Who needs an RV and two months to travel from Mexico to the middle of Canada. LOL.
https://nmgs.nmt.edu/publications/guide ... _p0201.pdf
(2) You will find the most species at the interface between two (or more) of the Life Zones. You’ll get species from both zones at the limits of their expected range. In addition, species diversity increases as one proceeds from high altitude to low altitude and high latitude to low latitude. The temperature and seasonal variability increases with increased altitude and decreased latitude.
(3) Once you become accustomed to which species are found in a given Life Zone, it will cut down on your time to identify a species. This works best with plants. You have a ‘yellow flower’ but you know you are in ‘Desert-Grassland’ so you can temporarily eliminate all the ‘yellow flowers’ expected in ‘Ponderosa Pine Forest.’ There are always exceptions—if that happens rip out the offending plant and grind it underfoot for not obeying the rules.
(4) All the fantastic photo collections posted on this site are actually good training for recognizing the different Life Zones. Don’t read the location of the hike but go straight to the photo collections and see if you can identify the Life Zone in the photos. This will assist should you get drunk and end up somewhere in Arizona without your pants and without a clue.
"I shot a werewolf once. But by the time I went to retrieve it, it changed into my neighbor's dog." D. Schruete
Route Editor
Route Scout
