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The Grizzly Bears of Colorado
By
EDWARD R. WARREN
In making a revision of my hook, "The Mammals of Colorado, " I have of
course had occasion to examine what I)r. C. Hart Merriam has written concerning
the grizzly hears in North American Fauna No. 41— " Review of the
Grizzly and Big Brown Bears of North America "—and 1 must confess that I
am somewhat confused by his findings. It is with much diffidence that I venture
to criticize the work of Dr. Merriam, for whom I have great respect and the
most friendly feelings, but I cannot accept his conclusions in this case.
While there is very likely more than one species or subspecies of grizzly
hear ranging through western North America, I cannot bring myself to believe
that there are five species, or subspecies, however we may choose to regard them,
in the comparatively small area of the mountains of Colorado. Yet this is the
number Dr. Merriam lists as occurring within those limits.
All of Merriam's distinctions are founded on skull characters, which are
notoriously variable. While I have to confess that I have done nothing with
the hears, I have worked on the skulls of smaller mammals, and the variations
in cranial characters are sometimes surprising, even between specimens from the
same locality. For that reason I think that too much reliance should not he
placed on these variations in the hears.
Bears are promiscuous in their mating habits, not mating permanently, and
the sexes separating after the breeding season. It would seem not at all improbable
that a male may mate with more than one female at this time. Their
roaming proclivities would tend toward interbreeding.
I have had no opportunity to study the skulls of the various forms of
grizzlies though I have been able to make a comparison between two or more of
the species by means of a photograph. The type skull of Ursus horribilis bairdi
(Merriam) was formerly in my private collection, and I photographed it for
an illustration in the Mammals of Colorado. Fortunately I still have the
negative, the image in which is almost exactly the same length as the figure of
Ursus hurria'us in Merriam's paper (pl. 15), rendering a comparison easy by
means of a tracing. Both are side views. The outlines and proportions of the
two skulls are almost identical. The most striking difference is the greater depth
of the lower jaw of bairdi, especially immediately behind the posterior end of
the lower tooth row. The portion hack of the canine is also wider, though not
as much so. The skull of horria'us is imperfect, and therefore full comparisons
cannot he made.
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If a line be drawn through the tracing of the skull of bairdi at a distance
below the lower tooth row corresponding to that in horria'us, and the tracing
then laid over the cut of the latter species with this line as a base to correspond
with the base line of the other, the similarity is remarkable, to say the least. I
cannot help thinking that this bairdi skull should he referred to horrierus, rather
than he made a subspecies of hor-ihilis, as Merriam has done. Perhaps it is
hardly right to base an opinion in a matter of this sort upon the profiles alone,
as shown in a cut and a photograph, but there is so much similarity between the
pictures of hor-ia'us and hairdi, and the reverse between horribilis and bairdi
that it impresses me.
The type of horrieeus came from the Coppermines, near Santa Rita, Grant
County, southwestern New Mexico, and Vernon Bailey says that there is no
other specimen known than the type; that grizzlies since collected in that vicinity
belong to other forms. However, Merriam mentions the skull of an old female
assumed to be horrifeus from the mountains north of Silver City, N. M., near
the type locality.
It is, however, the distribution as given by Merriam of the five forms of
grizzlies attributed to Colorado that aroused my doubts as to the correctness of
his conclusions.
Although I)r. Merriam, besides describing the type specimens, occasionally
mentions other specimens which he examined, it is to be regretted that he does
not follow his descriptions with lists of the localities from which specimens
were examined. Such lists would be of much service as showing upon what
grounds he based his statements of the ranges.
It is impracticable to show on a map the ranges of these five forms of
grizzlies with the few records at hand of identified specimens. I have indicated
upon the accompanying map the type localities of niacrodon, hairdi and shoshone,
and the four records of ,naerodon, hairdi, planiceps and texensis. Though
scattered, they collectively pretty well cover the whole mountain region of
Colorado. A'Vhat was the original easterly range of grizzly bears in Colorado is
not known, probably at least to the base of the foothills, as is indicated by the
(lash line on the map. Even at the present day black bears are occasionally found
in the foothills and mountains close to Colorado Springs. From the foothills the
grizzlies were found westward over practically the whole State.
Detailed comments on the type localities and ranges of the various Colorado
forms follow, in the order as given by Merriam:
Ursus hor-ibilis bairdi (Merriam), Proc. Biol. Soc. Washington, vol. 27,
pp. 192-3, 1914. Baird's Grizzly.
Type locality.—Blue River, Summit County, Colorado.
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Range.—Southern Rocky Mountain region, from the San Juan Mountains,
southwestern Colorado, northward through Wyoming to Montana, and perhaps
to southeastern British Columbia. (Merriam, 1. c.)
As above mentioned, the type skull of Ursus bairdi was once in my private
collection. I purchased it from V. H. Borcherdt of Denver. All that he could
tell me was that the hear was killed on the Blue River; he could give neither
the date when it was killed, nor the name of the party who killed it. The Blue
is approximately fifty miles long, heading in the mountains west of the
Continental Divide above Breckenridge, and emptying into the Colorado
(Grand) River at Kremmling. Much the greater part of its drainage system
lies within the boundaries of Summit County, so that the assumption that the
skull was taken in that county is a reasonable one. Even so, the animal might
have been killed anywhere within a considerable area, making the type locality
somewhat indefinite.
I)r. Merriam published no other record of Baird 's grizzly in Colorado.
"There is, however, in the collection of the Biological Survey, the skull of a bear
killed on Lone Cone Mountain in May, 1907. In a letter Dr. Merriam says
this is typical bairdi. Lone Cone is at the west end of the San Miguel Range,
on the boundary line between San Miguel and Dolores Counties, and the bear
was killed on the San Miguel County slope. Merritt Cary gave in North
American Fauna No. 33, "A Biological Survey of Colorado, " an excellent description
of the skin of this animal.
The name "San Juan Mountains" is a somewhat indefinite term. On the
maps of Colorado it is applied to the southernmost portion of the Continental
Divide, extending from the San Juan-Hinsdale County line southeasterly to the
south boundary of the State. Asa matter of fact, however, I think the name
is collectively applied to the whole of the rugged mountain country known as
the San Juan mining region, which is composed of a complex of short high ranges.
Now as to the range of this bear. Bailey says that it might range down
through the Sangre de Cristos into New Mexico. The air-line distance between
the Sangre de Cristos and Lone Cone is about 160 miles. We have no data as
to the width of its range at the type region, but there is plenty of country on
either side of Summit County where it might have lived, and where presumably
some of the few survivors still persist.
Merriam mentions a skull from Sabille Hole, Laramie County, Wyoming.
This is approximately north of Summit County.
With the range given by Merriam northward through Wyoming and
Montana, and perhaps to southeastern British Columbia, this form must cross
the ranges of several other grizzlies described by Merriam, and I do not see how
interbreeding with these can possibly be avoided. "This range would bring
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bairdi into the territory of Ursus horrihilis iurperator, U. minis, U. rogersi
rogersi, U. absarokus, and U. u'ashake.
Ursus texensis texensis (Merriam). Proc. Biol. Soc. Wash., vol. 27, p.
191, 1914. Texas Grizzly.
Type locality.—Davis Mountains, Texas.
Range.—Restricted, so far as known, to Davis :Mountains, Texas, and
mountains of southern Colorado ( Navajo Range, near Chromo). ( Merriam I. e.)
Merriam cities two localities from which the Texas Grizzly has been
recorded, both of which are mentioned in the above statement of the range. The
Davis Mountains are in extreme southwestern Texas; the Navajo Range is in
southern Colorado, not far north of the New Mexico boundary. Between these
two points there are no records of this hear, and it seems to me decidedly farfetched
to refer the Colorado examples to texensis when they come from a region
so close to the ranges of other grizzlies occurring in G)lorado, if, indeed, the
region is not actually within the range of those forms. If Baird 's Grizzly
occurs in the Sangre de Cristos its range would most certainly include this record
of texensis.
Vernon Bailey says that no specimens of the Texas Grizzly have been
recorded from New Mexico. He suggests a probable range for it through New
Mexico is indicated along the Guadalupe, Sacramento, White, Capitan,
Manzano, and possibly the Jemez Mountains. He also says that Ursus texensis
navaho might occupy part of the territory where the Sangre de Cristos extend
into New Mexico, which would make navaho cut across this supposed range of
typical texensis. He states that no skin of texensis was ever seen by a naturalist.
The Colorado record of the Texas grizzly is based on four specimens which are
in the Colorado Museum of Natural History, Denver, so that after all, skins of
this hear have been seen by naturalists and many others.
Ursus planieeps Merriam, North Amer. Fauna No. 41, p. 37, 1918. Flatheaded
Grizzly.
The type locality of this form is unknown. The type is a skull and
mandibles in the U. S. National Museum, collected by Dr. F. V. Hayden ( No.
13,289, U. S. N. M.). It was catalogued in December, 1873.
Dr. Merriam apparently assumed that it was collected in 1869, as Hayden
was in Colorado that year. He worked from Cheyenne down along the foothills
region as far as Santa Fe, and then turned north through the San Luis Valley in
Colorado. After that he was in the South Park, in the mountains about Fairplay,
and then in Middle Park, another mountain region.
In 1873 Hayden and his parties did much work in Colorado and covered
a great deal of the State, especially in the mountains. His own party went
through South Park, crossed to the headwaters of the Arkansas, thence across
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the Continental Divide by way of Lake Pass to Taylor Park, and spent much
time in the Elk Mountain region. He was on Eagle River, and also in Middle
Park again. Other parties under his supervision were in various parts of the
State. Incidentally it may be mentioned that in one of the years between 1869
and 1873 he was in North Park.
In neither of his reports does he make mention of bears of any sort. The
fact that the specimen was catalogued in December, 1873, would seem to me to
indicate that it was collected in that year. As to the type locality, when the wide
area covered by Hayden in the two years above mentioned is considered, it is
anybody 's guess as to where it may he.
In a later paper (Proc. Biol. Soc. Wash., Vol. 42, pp. 171-172), Merriam
refers to planiceps a skull from Middle Creek, near the head of the Rio Grande,
collected October 18, 1927.
Ursus nmcrodon Merriam, North Amer. Fauna No. 41, p. 38, 1918. Twin
Lakes Grizzly.
Type locality.—Twin Lakes, Colorado.
No range is given by Merriam for this bear.
The type is the skin and skull of a male from Twin Lakes, Colorado, July
28, 1876, collected by C. W. Derry.
Merriam also refers to this form the skin and skull of a female from the
South Branch of the Williams River, in Routt or Moffat County, Colorado.
Collected or presented by J. P. Bird, September 13, 1895. This is a hundred
miles or more northwesterly from the type locality.
Ursus Shoshone Merriam, Proc. Biol. Soc. Wash., vol. 27, p. 184, 1914.
Shoshone Grizzly.
Type locality.—Estes Park, Colorado.
Range.—Mountains of Colorado and Wyoming. (Merriam, 1. e.)
The type is the skull of an old male. Merriam also mentions the skull of
a female from Fort Fred Steele, Wyoming, and skulls from the Wind River
and Absaroka Mountains, Wyoming.
The type locality of this hear is the mountainous region east of the Continental
Divide, in northern Colorado. From there it would seemingly range
northwesterly across Wyoming to the Absaroka Range east of Yellowstone Park,
and, like bairdi, would trespass on the territory of others of Dr. Merriam ' s
species.
An examination of the map herewith shows that the type localities of
macrodon, bairdi, and shoshone to be distributed along a line approximately a
hundred miles long, bairdi being somewhere near halfway between the other two
2:;
—a curious state of affairs. The type locality of planiceps is presumably somewhere
in Colorado, but where? The museum record gives no locality.
My conclusion is that there is but one species of grizzly bear in Colorado,
and that it ranged widely over the mountains of the State from the eastern foothills
westward. As for the name, if all of our Colorado grizzlies should prove
to be one form, and that distinct from any other, then shoshone has priority.
This is a matter I am not especially interested in, however, at least at present.
I wish to acknowledge the kindness of Dr. Alexander Wetmore, Assistant
Secretary in charge of the National Museum, in obtaining for me the catalogue
records of Ursus planiceps and Ursus nracro(Ion.
LITERATURE CITED
Bailey, Vernon. 1931. North American Fauna No. 53, Mammals of New
Mexico. Washington, December, 1931.
Merriam, C. Hart. 1914. Descriptions of thirty apparently new Grizzly and
Brown Bears from North America. Proc. Biol. Soc. Wash., vol. 27, pp.
173-196.
1918. North American Fauna No. 41. Review of the grizzly and Big
Brown Bears (Genus Ursus). With Description of a new Genus,
I'etularetos.
1929. Additional Information on the Range of Ursus planiceps, a Colorado
Grizzly. Proc. Biol. Soc. Wash., 42, pp. 171-172.
EDWARD R. WARREN
1511 Wood Avenue,
Colorado Springs, Colo.
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