Grizzly Bear / Connor Crawford
Grizzly Bear
Ursus Arctos Horribilis
Connor Crawford
Bio 227
Description and Ecology of the Grizzly
The Ursus arctos horribilis, commonly called the grizzly
bear, originated in Eurasia and traveled to North America approximately 50,000
years ago. It is a subspecies of the brown bear, or Ursus arctos. Most adult
species weigh in between 290-400 pounds and 400-790 pounds for female and male
genders respectively. The average total length of the subspecies is 6.50 ft
with a shoulder height of 3.35 ft. Typically, grizzly bears hibernate for 5-7
months except where the climate is warm. This is the period where female
grizzlies give birth to their offspring whom grow during the remaining
hibernation period. Grizzlies have very low reproductive rates due to several
ecological reasons. They reach late sexual maturity, miscarriages, and a two-year
grace period where the mother cares for her cubs delaying her next mating
period.
Grizzlies
are of the order Carnivora but have a diet that consists of both plants and
animals. They feed from many things ranging from bird eggs to large prey to
berries often depending on geographic location. For example, a coastal grizzly
bear grizzly bear with more access to protein sources will consume more protein
through fish such as salmon, trout, or bass. This often leads to larger sized
grizzly bear in coastal areas. Even though they are large animals they have impressive
speed and have been measured at 30 miles per hour.
Geographic and Population Changes
Historically grizzly
bears roamed through the vast western part of North America all the way down to
Mexico until European settlement gradually eliminated and push them from the
area farther northwest. Contemporarily speaking, grizzlies are common to find
in Alaska and the western ranges of Canada where they are pursued as big game trophies
by hunters. Even though Grizzlies are the symbol of California they are not
naturally found in the region any longer. Ursus arctos horribilis were predominantly
found in Canada where the largest population of 25,000 lived. That population
has been reduced down to under 17,000 grizzlies. Grizzlies are typically not
social animals and will live in solitary with the exception of mothers and
cubs. However, in coastal areas grizzlies can be spotted in groups near streams
in common pursuit of water and fish.
Listing Date and Type of Listing
The grizzly bear was originally listed as threatened on July
28th, 1975 under the Endangered Species Act. It’s recovery plan was revised
in 1993 and is still in place. They have made a remarkable recovery due a plan
that has increased the grizzly bear population in the Yellowstone area from 136
to about 690 today. However, recently they have been delisted essentially
meaning that they can be hunted outside of national parks in pursuit of
managing bear population such as Yellowstone.
Cause of Main Listing and Threats to Continued Existence
Grizzly bears were considered competitors for most food
valued by humans and sometimes even threatened human safety. As a result, they
were sought out and killed by European settlers as pest control and for their
pelts. Between the period of 1850 and 1920 they were wiped out from 95% of their
original historical range by European settlers moving west. The killing of
bears was unregulated and due to their slow reproductive history, their
population suffered a traumatic decline. Human related deaths and habitat loss
remain the only significant threats to grizzly bears and their recovery.
Description of Recovery Plan
The main goal of the grizzly bear’s recovery
plan is to sustain its habitat and reduce the threats to that habitat. In
addition, the original plan included an emphasis on hunting bears for game trophies.
Following this original initiative, there has been an increased effort on
protecting the habitat of the grizzly bear. They need a secure habitat to roam
that is not full of human populated roads, industrial sites, and towns.
Finally, climate change is influencing the population and lifestyles of the
grizzly bear. Due to global warming the grizzlies are denning later leaving
them vulnerable to unexpected encounters with humans and other species they don’t
normally interact with.
What Can You Do to Help Grizzlies
With populations of grizzlies in the lower 48
diminishing from 50,000 to 2,000 it is necessary for human help to preserve
their population. Considering that human encounters, habitat destruction, and
climate change are the main threats to grizzlies, it is clear that humans have
a large responsibility on their preservation. Reducing pollution and the destruction
of their habitat will aid in the recovery of grizzly bears. Things like
minimizing waste, following rules when in the wilderness, and refraining from
aggravating grizzlies will certainly help their recovery.
Sources
I find it interesting that they are not social animals and they like to live in solidarity, I never new that! Also, when we read about the grolar bear, how grizzly and polar bears were interacting, I didn't know that grizzly bears were also threatened (not as much as polar bears but still) so it's actually bad for both species to mix. Good work!
ReplyDelete-Maeve Calanog
Truly sad to see that there are less than 17,000 bears all mainly due to humans. I think thats what makes the "what can you do" section so special. Because it really is our job to help them! Really nice work, I learned a lot from this blog. Thank you
ReplyDelete-Maddie Brogno
The historic range of these grizzles is amazing! It is so sad how they were once so abundant through out the continent, but now they are only found mainly in Canada and Alaska. I have to admit these grizzles are so scary, but they are truly magnificent as well. To be honest I didn't know the species was threatened! I'm glad to see they were delisted; however, the population is still small and needs to grow more to sustain itself through the years. Overall, really good post and great pictures! - Amber Buzzard
ReplyDeleteBeing they are our State Mammal, I wonder if they have a plan to re-introduce the grizzly bear in California. Great info, I feel like I should have known a lot more about them by now but I definitely learned a lot with this blog. Well written and a great read. - Xavier Caldera
ReplyDeleteSo sad to see our state bear no longer living in California. I like your suggestions on how we can help these bears! It's sad that so many people killed these bears for trophies and their pelts :(
ReplyDelete-Christine Bradley
Its so crazy how large Grizzlies' ranges used to be. Really sad to see a creature we seem to idolize here in California being treated so terribly. I loved all the pictures you included of the bears standing up, always cool to see them like that. I thought your suggestions for what we can do section was awesome, really important given the small remaining population to not further the endangerment of these bears. Great job! -Tanner Coolidge
ReplyDeleteThe rate of decline from 50,000 to a mere 2,000 in the lower 48 is astonishing and unfortunate. However, it is great to hear that there is good progress occurring in Yellowstone that is helping to bring the population back up. Great post, I learned a lot! - Sirena Chu
ReplyDeleteThis was a very well put together blog! It is crazy how these bears were wiped out from 95% of their historical range. Clearly from an early time period, humans have been negatively impacting the habitats of Grizzly Bears, even now with pollution. As we are do have a large responsibility in this, we should be the ones to reduce pollution to help these animals.
ReplyDelete-Adrienne Chin