cranial measurements): See measurements and plates 9-11. As
described in _Mustela erminea richardsonii_ except that: Weight,
0.96 (0.7-1.1) grams; basilar length, 32.7 (31.9-33.2); breadth of
rostrum more or less than (about equal to) 30 per cent of basilar
length.
From _richardsonii_, _alascensis_ differs in that the skull of the male
averages smaller in every measurement taken and is 28 per cent
lighter. Relative to the basilar length, the orbitonasal length is more
and the braincase is shallower as measured at the anterior end of the
basioccipital. The four adult females seen of _alascensis_ are more
variable than those of _richardsonii_ and average smaller in some
measurements and larger in others but give no proof of any consistent
difference.
From _haidarum_, _alascensis_ differs in that the rostrum and entire
preorbital part of the skull is actually as well as relatively much
smaller in both sexes. In males of _alascensis_ the length of the
skull, and other cranial measurements of length, is more. In males, the
mastoid breadth and zygomatic breadth are about the same as in
_haidarum_, as also is the weight. M1 is larger but m1 and P4 are
smaller. In females the anteroposterior extent of the inner moiety of
M1 and length of tympanic bulla are about the same in the two
subspecies but all other cranial and dental measurements in
_alascensis_ are less. It is 29 per cent lighter. The difference in the
preorbital region is of about the same degree as in the males.
Comparisons of the skull with those of _arctica_, _salva_, _initis_,
_celenda_, and _seclusa_ are made in the accounts of those subspecies.
_Remarks._--The relatively few specimens known of this race seem always
to have been referred to in the literature by the name _alascensis_ and
the nomenclatural history is therefore simple. The original materials
were obtained by the collector Clark P. Streator and the additional
series of skeletons, one with skin, from Windham were procured by
Stanton Price, a resident there.
The subspecies is well differentiated from both _arctica_ and
_richardsonii_. Although actual intergrades are lacking between
_alascensis_ and the two races just mentioned I have no doubt that
intergradation occurs with _richardsonii_ and think it probably does
also with _arctica_.
The assignment of the three females from Mitkof Island, Zarembo Island,
and Loring on Revillagigedo Island, is tentative because each is so
young as not to show diagnostic cranial characters. The two other
specimens from Revillagigedo Island (Carroll Inlet), labeled as males,
are in white winter pelage. Only one, no. 136358, a subadult, is
accompanied by a skull. The small size of each specimen, and its
cranial characters which are intermediate between those of males and
females of _alascensis_ of the adjacent mainland, indicate the
existence of a distinct race of weasel on Revillagigedo Island. On the
chance that the one specimen with a skull is a dwarf, or is wrongly
sexed as seems improbable, the population is tentatively referred to
_alascensis_.
[Illustration: FIG. 26. Map showing known occurrences and probable
geographic ranges of the subspecies of _Mustela erminea_ in
southeastern Alaska.]
_Specimens examined._--Total number, 24, arranged by localities
from north to south. Unless otherwise indicated, specimens are in
the Museum of Vertebrate Zoölogy, University of California.
=Alaska.= Juneau, 5[91]; Taku River, 1; Windham, 9; Mitkof Island,
1; St. John Harbor, Zarembo Island, 1; Wrangel, 1[91]; Helm Bay,
Cleveland Peninsula, 1; Cleveland Peninsula, 2[91]; Revillagigedo
Island, Carroll Inlet, 2[91]; Loring, 1[91].
=Mustela erminea salva= Hall
Ermine
Plates 2, 3, 4, 9, 10 and 11
_Mustela erminea salva_ Hall, Proc. Biol. Soc. Washington, 57:35,
June 28, 1944; Hall, Journ. Mamm., 26:180, July 19, 1945.
_Type._--Male, adult, skull only; no. 74641, Mus. Vert. Zoöl.;
Mole Harbor, Admiralty Island, Alaska, December 27, 1936; obtained
by A. Hasselborg.
The skull (plates 2-4) shows malformation of the frontal sinuses
owing to parasites and lacks osseous tissue where the parasitic
infestation was localized. The skull is unbroken. The teeth all
are present and entire.
_Range._--Admiralty Island, Alaska. See figures 25, 26 on pages
95, 134.
_Characters for ready recognition_ (known only from
skulls).--Differs from males of _M. e. alascensis_ in overall
depth of braincase which is more than 89 per cent of orbitonasal
length; from _M. e. initis_, in males, in that orbitonasal length
and mastoid breadth total less than 35 mm., weight of skull and
lower jaws less than 2.1 grams; from _M. e. celenda_, in males, in
that breadth of rostrum measured across lacrimal processes less
than a third of basilar length.
_Description._--_Size._--Male: An adult from Gambier Bay measures:
Total length, 320; length of tail, 95; length of hind foot, 45 (41
in dry skin).
Female: A subadult from Hawk Inlet, measures: Total length, 250;
length of tail, 70; length of hind foot, 33.
_Color._--As described in _Mustela erminea richardsonii_ except
that least width of color of underparts in four individuals 40
(38-43) per cent of greatest width of color of upper parts. Black
tip of tail, in two individuals for which external measurements
are given, amounting to 50 and 40 mm. respectively which is 53 and
57 per cent of length of tail-vertebrae.
_Skull._--Male (type and 4 adult topotypes): See measurements and
plates 2-4. As described in _Mustela erminea richardsonii_ except
that: Weight, 1.7 (1.5-1.9) grams; basilar length, 37.8
(36.4-39.5, extremes are in subadults); length of tooth-rows more
or less (usually more) than length of tympanic bulla; interorbital
breadth rarely more than distance between glenoid fossa and
posterior border of external auditory meatus.
Female (2 ad. and 1 ad.-sad. topotypes): See measurements, and
plates 9-11. As described in _Mustela erminea richardsonii_ except
that: Weight, 0.9 (0.8-1.0) grams; basilar length, 33.0
(32.0-33.6); length of tooth rows approximately same as length of
tympanic bulla; breadth of rostrum approximately 30 per cent of
basilar length.
From _alascensis_, _salva_ differs in that males have the preorbital
region slightly wider in relation to the length of the tympanic bulla;
also the braincase is smaller, actually as well as in comparison with
the preorbital part of the skull. The tympanic bullae do not project so
far below the squamosals and the braincase itself is shallower, in
adults averaging only 11.5 mm. as against 12.5 mm. The overall depth of
the braincase, including the tympanic bullae, when divided into the
orbitonasal length gives an average of 93 (90-97) per cent whereas in
_alascensis_ the figure is only 85 (78-88) per cent. On this basis
alone, everyone of the adult skulls of the two races can be
distinguished. The females and subadult males show the same tendency to
reduction in depth of braincase but not every individual among them can
be surely distinguished. By weight the skull of _salva_ of
corresponding sex is only about 6 per cent smaller. Comparisons with
_initis_ and _celenda_ are made in the accounts of those subspecies.
_Remarks._--Most of the specimens seen were collected by Allen E.
Hasselborg, resident on Admiralty Island. On the basis of skulls--few
skins, and measurements taken in the flesh, are available--_salva_ more
closely resembles _alascensis_ than does any other subspecies so far
known from southeastern Alaska. The race on Admiralty Island is only
slightly differentiated from _alascensis_ of the adjacent mainland.
_Specimens examined._--Total number, 26, all from Admiralty
Island, Alaska, arranged in general by localities from north to
south, and unless otherwise indicated in the Museum of Vertebrate
Zoölogy, University of California.
=Alaska.= Admiralty Island: Hawk Inlet, 2; Seymour Canal, 4; Mole
Harbor, 18 (skulls only); Gambier Bay, 1; no locality more
definite than Admiralty Island, 4 (1 in U. S. Nat. Mus.).
=Mustela erminea initis= Hall
Ermine
Plates 4, 5 and 6
_Mustela erminea initis_ Hall, Proc. Biol. Soc. Washington, 57:37,
June 28, 1944; Hall, Journ. Mamm., 26:180, July 19, 1945.
_Type._--Male, adult, skull and skin; no. 289, Mus. Vert. Zoöl.;
Saook Bay, Baranof Island, Alaska; October 9, 1907; obtained by A.
Hasselborg, original no. 4.
The top of the skull is fractured on the left side from the
anterior nares posteriorly through the postorbital process to the
posterior root of the zygomatic arch. On the left lower jaw the
canine and three incisors are missing; otherwise the teeth all are
present and entire.
The skin is in process of molt, approximately nine-tenths of the
incoming white pelage being in place. The skin is well made and in
a good state of preservation.
_Range._--Chichagof and Baranof islands, Alaska. See figures 25,
26 on pages 95, 134.
_Characters for ready recognition_ (only males known).--Differs
from _M. e. arctica_, in that proximal two-thirds of under side of
tail colored same as upper parts rather than same as underparts,
zygomatic breadth less than distance between last upper molar and
jugular foramen; from _M. e. salva_ in that orbitonasal length and
mastoid breadth total more than 35 mm., weight of skull and lower
jaws more than 2.1 grams; from _M. e. alascensis_, by total length
more than 317, black tip of tail more than 57 per cent of length
of tail-vertebrae, interorbital breadth more than 10.3 and equal
to, instead of less than, distance between glenoid fossa and
posterior border of external auditory meatus; from _M. e. celenda_
by chest white (not mostly covered by brown patch), breadth of
rostrum measured across lacrimal processes less than a third of
basilar length; from _M. e. seclusa_ in zygomatic breadth more
than distance between last upper molar and jugular foramen.
_Description._--_Size._--Male: The type and an adult topotype
measure, respectively, as follows: Total length, 330, 320; length
of tail, 95, 95; length of hind foot, 45, 45.
Female: No external measurements available.
_Color._--As described in _Mustela erminea richardsonii_ except
that least width of color of underparts averages, in two young
female topotypes, 50 (49, 50) per cent of greatest width of color
of upper parts. Black tip of tail in three young female topotypes
averaging 54 (52-55) mm. which is 67 (63-69) per cent of length of
tail-vertebrae.
_Skull._--Male (illustrated by type and 1 ad. topotype): See
measurements and plates 4-6. As described in _Mustela erminea
richardsonii_ except that: Weight, 2.3 and 2.5 grams; basilar
length, 39.6, and 40.5; interorbital breadth equal to distance
between glenoid fossa and posterior border of external auditory
meatus.
Female: No adults available.
From _salva_, _initis_ differs in that skulls of males average larger
in every measurement taken, being 41 per cent heavier. Relative to the
basilar length, the interorbital and preorbital parts of the skull are
larger; the relatively greater interorbital and mastoid breadths are
particularly noticeable. Although the depth of the braincase, including
the tympanic bullae, is both relatively as well as actually more than
in _salva_, the depth is relatively less than in _alascensis_ which
otherwise differs from initis in about the same way that _salva_
differs from _initis_. Whereas the interorbital breadth in _initis_ is
about equal to the distance between the glenoid fossa and the posterior
border of the external auditory meatus, the interorbital breadth is
uniformly less than this distance in both _salva_ and _alascensis_. In
comparison with _seclusa_ the teeth are of the same size but all
measurements of the skull are larger. The skull of _initis_ is 25 per
cent heavier. In relation to the basilar length, the interorbital and
preorbital parts of the skull are much less in _initis_. The preorbital
and interorbital regions in _initis_ are relatively smaller in
comparison also with _arctica_. The one measurement of interorbital
breadth in _initis_ is greater in relation to the basilar length than
in _kadiacensis_ but the rostral region, and all that part of the skull
anterior to the braincase, is relatively smaller in _initis_.
_Remarks._--The two adult males, nos. 286 and 289 from Saook Bay,
provide convincing evidence of the existence of a distinct race of
weasel on Baranof Island. Three other young specimens, almost subadult,
from the same place are labeled as males although the basilar lengths
of these skulls are only 35.5, 35.9 and 37.3 millimeters as against
39.6 and 40.5 in the two adult males. The difference in size is too
great to be age-variation. The fact that 3 are definitely of one
category and 2 of the other makes it doubtful that individual variation
accounts for the differences. The small size of these 3 specimens and
the fact that in each the anterior margin of the tympanic bulla is
flush with the squamosal rather than protruded from the braincase,
suggests that the three are females. If they are females, the amount of
secondary sexual variation is rather less than would be expected by
analogy with the amount obtaining in _alascensis_ on the mainland and
in _salva_ on Admiralty Island. Another possibility that I can not
disprove is that two stocks of weasels persist on Baranof Island, the
two larger specimens being descendants of the stock which first became
established on the island and the three smaller specimens being
descendants of an individual ermine, or of ermines, that were rafted or
otherwise transported to the island at a considerably later date.
Assuming for the moment that there are two stocks, it must be admitted
that each one differs from any stock known from elsewhere. Therefore,
each stock would be presumed to have been long resident on the island.
But--two stocks as closely related as the two in question would not be
expected to persist for long in an area as small as that of Baranof
Island because competition would give one the ascendancy. Therefore,
the first suggestion, namely that the three smaller animals are really
females, seems the more probable. The feasible way to clear up the
present uncertainty is, of course, to obtain additional specimens,
carefully labeled as to sex. Yet another reason why additional
collecting is desirable in this area is to ascertain whether there is
subspecific differentiation between the ermines of Baranof and
Chichagof islands. The one specimen available from the latter island,
although in general like the three smaller animals from Baranof Island,
differs in the fuller (less scooped out) medial side of the tympanic
bulla and to a slight degree in each of some other features. This
specimen from Chichagof Island is labeled as a male also.
_Specimens examined._--Total number, 6, arranged by localities
from north to south, and in the Museum of Vertebrate Zoölogy,
University of California.
=Alaska.= Chichagof Island, Freshwater Bay, 1. Baranof Island,
Saook Bay, 5.
=Mustela erminea celenda= Hall
Ermine
Plates 5, 6 and 7
_Mustela erminea celenda_ Hall, Proc. Biol. Soc. Washington, 57:38,
June 28, 1944; Hall, Journ. Mamm., 26:181, July 19, 1945.
_Type._--Male, adult, skull and skin; no. 130987, U. S. Nat. Mus.,
Biol. Surv. Coll.; Kasaan Bay, Prince of Wales Island, Alaska;
June 16, 1903; obtained by Cyrus Catt; original no. 4407X.
The skull has a piece 1.5 mm. long broken out of the left
zygomatic arch. P2 is absent on both sides. The right I1, and the
left I1 and I2 are missing. The skin, in summer pelage, is fairly
well made. A scrotal pouch attests to the correctness of the sex
recorded on the label. The rostral part of the skull is smaller
than in average-sized males of corresponding age.
_Range._--Prince of Wales, Dall, and Long islands, Alaska. See
figures 25, 26 on pages 95, 134.
_Characters for ready recognition_ (only males known).--Differs
from _M. e. alascensis_ and _initis_ in chest mostly covered by
brown patch, not white, and breadth of rostrum measured across
lacrimal processes more than a third of basilar length, which
cranial character serves to distinguish also _salva_; from _M. e.
seclusa_ in zygomatic breadth less than distance between last
upper molar and jugular foramen; from _M. e. haidarum_ in chest
white (not mostly covered by brown patch), proximal two-thirds of
underside of tail colored like upper parts rather than underparts,
basilar length more than 38.2 mm.
_Description._--_Size._--Male: Seven adults and subadults from
Prince of Wales Island, yield average and extreme measurements as
follows: Total length, 286 (277-304); length of tail, 77 (74-85);
length of hind foot, 36 (35.5-40.5).
Female: No specimen available.
_Color._--As described in _Mustela erminea richardsonii_ except
that upper parts about tone 3 of dark Chocolate Brown of Oberthür
and Dauthenay, pl. 342; lower throat and chest covered by a large
patch of same color as upper parts; color of underparts extending
to toes but in interrupted fashion on both fore-and hind-feet;
least width of color of underparts averaging, in four males from
Prince of Wales Island, 41 (38-49) per cent of greatest width of
color of upper parts. Black tip of tail averaging, in 8 males in
winter pelage, 65 (59-78) mm. which is 84 (69-92) per cent of
length of tail-vertebrae.
From its geographic neighbors _alascensis_ and _initis_, _celenda_
differs in darker color of upper parts, presence rather than
absence of patch of dark color on lower throat and chest, and
longer black tip on tail. From _haidarum_, _celenda_ differs in
darker color of upper parts, presence rather than absence of
patch of dark color on lower throat and chest, narrower
light-colored under parts, black tip of tail averaging less rather
than more than nine-tenths of length of tail-vertebrae and ventral
face of tail colored like upper parts rather than like underparts.
_Skull._--Male (illustrated by 5 adults): See measurements and
plates 5-7. As described in _Mustela erminea richardsonii_ except
that: Weight, 2.3 (2.2-2.5) grams; basilar length, 39.5
(38.9-40.7) mm.; length of tooth-rows more than length of tympanic
bulla; breadth of rostrum measured across lacrimal processes more
than a third of basilar length; interorbital breadth more than
distance between glenoid fossa and posterior border of external
auditory meatus; zygomatic breadth more or less than (about equal
to) distance between last upper molar and jugular foramen.
Female.--Complete skull of adult unavailable.
Differences from _richardsonii_ are indicated in the formal description
just given. Additional to differences therein noted, _celenda_ differs
from _initis_ in larger interorbital and preorbital parts of the skull
although dimensions of other parts of the skull and the teeth are about
the same or even less. From _salva_, _celenda_ differs in larger
average size in every measurement taken, except for the inner moiety of
M1 which is about the same. The skull of _celenda_ is 35 per cent
heavier. In relation to the basilar length the skull of _celenda_ is
wider, especially in the interorbital and preorbital regions. In
comparison with _alascensis_ the tympanic bullae are of approximately
the same length; otherwise essentially the same differences obtain as
are noted in comparison with _salva_ and the zygomatic breadth is
relatively more in _celenda_. From _seclusa_, in which the teeth are of
comparable size, _celenda_ differs in that every cranial measurement is
more and the skull is 28 per cent heavier. Because the skull of
_celenda_ is so much longer, its dimensions in other planes are less in
relation to the length than in _seclusa_. _M. e. celenda_ is larger in
every part measured than _haidarum_, 21 per cent heavier, and in
relation to the basilar length the interorbital, and preorbital, parts
of the skull are smaller, the braincase is shallower, and the skull is
relatively wider across the zygomata and mastoid processes. In
comparison with _kadiacensis_, differences are: 26 per cent lighter,
skull shorter; in relation to the basilar length, braincase shallower
as measured at the anterior end of the basioccipital, tooth-rows
shorter but orbitonasal length more. In comparison with _arctica_ all
parts measured of the teeth and skull of _celenda_ are smaller and its
skull is 34 per cent lighter. In relation to the basilar length, the
interorbital breadth of _celenda_ is only slightly less but its skull
is narrower across the rostrum and zygomata, the tooth-rows are
shorter, and the braincase is shallower.
_Remarks._--The late George Willett in the course of his work in Alaska
collected most of the known specimens of this strongly differentiated
subspecies. In both coloration and cranial characters the
distinguishing features are so well marked that the zoölogist could
with reason accord full specific rank to _celenda_. Nevertheless it
obviously is an ermine. Also, races from other islands of southeastern
Alaska tend to bridge the gap, as regards cranial features, between
_celenda_ and the mainland ermine. The specimen from Dall Island agrees
in all respects with topotypes. The specimen from Howkan on Long Island
is in white winter pelage and the skull has suffered shrinkage from
some chemical solution; the reference of this specimen to _celenda_ is
tentative.
_Specimens examined._--Total number, 25, as follows: Arranged by
localities from north to south. Unless otherwise indicated, in U.
S. National Museum.
=Alaska.= Prince of Wales Island: Craig, 18 (10 in Mus. Vert.
Zoöl., and 8 in Los Angeles Mus. Hist. Art and Sci.); Kasaan Bay,
2; no locality more definite than the Island itself, 3; Dall
Island, Otter Harbor, 1 (Los Angeles Mus. Hist. Art and Sci.).
Long Island, Howkan, 1 (Field Mus. Nat. Hist.).
=Mustela erminea seclusa= Hall
Ermine
Plates 5, 6 and 7
_Mustela erminea seclusa_ Hall, Proc. Biol. Soc. Washington, 57:39,
June 28, 1944; Hall, Journ. Mamm., 26:181, July 19, 1945.
_Type._--Male, adult, skull alone; no. 31232, Mus. Vert. Zoöl.;
Port Santa Cruz, Suemez Island, Alaska; March 24, 1920; obtained
by George Willett.
The skull (plates 5-7) is complete and unbroken. Of the upper
incisors only right I3 is present. Otherwise the teeth are present
and unbroken.
_Range._--Known only from the type locality. See figures 25, 26 on
pages 95, 134.
_Characters for ready recognition_ (only the male known).--Differs
from _M. e. celenda_ in basilar length less than 38.2, from _M. e.
salva_, _initis_ and _haidarum_ in zygomatic breadth more than
distance between last upper molar and jugular foramen.
_Description.--Size_ and _Color._--No external measurements or
skins available.
Skull.--Male: See measurements and plates 5-7. As described in
_Mustela erminea richardsonii_ except that: Weight, 1.8 grams;
basilar length, 34.3; length of tooth-rows about the same as
length of tympanic bulla; breadth of rostrum measured across
lacrimal processes more than a third of basilar length;
interorbital breadth more than distance between glenoid fossa and
posterior margin of external auditory meatus; zygomatic breadth
more than distance between last upper molar and jugular foramen.
Female.--Skull not available.
From _alascensis_ and _salva_, _seclusa_ differs in larger teeth,
shorter skull, much larger preorbital and interorbital regions,
actually as well as in relation to basilar length. Excepting the teeth,
which are of about the same size, the same general differences obtain
in comparison with _initis_ which, however, is 29 per cent heavier.
From _celenda_, _seclusa_ differs in smaller skull in all parts
measured, being 22 per cent lighter. The teeth are about the same size.
In relation to its length the skull of _seclusa_ is much broader and
deeper. From _haidarum_, _seclusa_ differs in: teeth larger; skull
shorter and more convex in dorsal outline along median longitudinal
axis; in relation to basilar length, skull broader, deeper and
braincase relatively shorter.