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sm:-I.ARY· REPORT •
ON
BRISTOL BA ~ 'H:UR.."l.E ~10RTALITY
April 1970
••
: ~ .
. . ' A Joint Effort by:
U. S. Dcp~rtffient of Interior ·and
AlasY~ Dzpart~cnt of Fish and Ga~e
I'
3 3755 000 12500 5
' . .
OOlviO . . I· . . , .. ··:
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.ARLIS
~' :~:·.
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\ . Ala:s~a Re~our~es · Library & Informat~on SerVices
· ~ f\nch'orag~. Alaska . ..
-. ' '
·~·
, . -rnc~-oaj ct B
....
BRISTOL BAY ~·::'CRRE MORTALITY
At least 86,000 comrnon murres died in Bristol Bay, Alaska during a .I
brief per~od in late April of this year. Although the cause of death m~y
never be completely resolved to eveD•on~'s satisfaction, the evidence
suggests that it was a CGtastrophe of n?ture. The murres, apparently
still o;.;eakened after wintering in·the Bering Sea, probably died fro;n a I
combir.ation of starvation and exhaustion which \.;as aggravated by. a seve~e ~
storm that prevented the~ from feecing during a critical few days.
Post-mortem· examina::ions of c.ur;:es by p31thologists from the Bureau·
of Sport Fisheries and Wildlife research c~nters in North Dakota and
Maryland, the Arctic Health Research Center in Fairbanks, the National
.... ' Disease Laboratory in Iowa, and the_ California Department of Fish and Game .. . in Sacramento found no evidence that pathogenic bacteria or viruses con-
• tributed to the mass mortality. Foods were not found in the digestive .
tracts of these birds. Tests for presence of toxins in the smail quantitie~
of fluid
All
found i_n the in,estines ~ere
sp eci;~ens w'ere .emaciated and
inconclusive.
had no appreciable deposits in sub-
. ·:·--cutaneous,- ·abdoninal and cardiac fat tissue. Thirteen of the dead birds . I ..
varied in weight from S/0 to .786 grams. Althdugh comparable weight data I
!
were not available for this sau.e tine of the year, the 6~~-gram average
weight of these-birds was considerably less than the 972-gram average-
weight for male common ourres and 1022-gram average weight for female . I;:
co~on ~urres from Cap~ Tho~pson in northwestern Alas~~ in late June. The
weight loss, lack of bcidy fat and sorn~ hemorrhaging of the-intestines •
l
. ..
:-~ suggest that the birds died fro::: starvation, although all factors that !
_,·
could contribute to starvation --:::: ... , ~u..-} n~ver be completelY. resolved.
Severe winds and turbulent sea~ ?roba.bly prec:Lpitated the die-off. that
was first reported on'April 24 by Ken Xanthey of theAl'aska Department
of Fish ar:d Game. During the t>;o ?receding days, 'Winds. reached peak vela-.
c~ties of 104'mph at Adak and 84 :-.:?hat Cold Bay,-and wind? gusted at l:ciwer
velocitie;" during this time at other reporting statfons within the Aleutian
IslanC.s. ar.d along the Alaska Pe1:::.nsula. · Three murres found on April 24 . . in the to-..;n of Cold Bay by res::.C.ents vere taken to the headquarters of the
. • I Izembek National Wildlife Range, but the inc~dent seemed insignificant at
• the tiGe because severe stor~s often blow pelagic birds inland.
11"\-t'recks of seabirds," occurre:-.ces v;here seabirds are driven far inland
and are often found dead and dying along the.beaches as a result of severe
stott.s, have been reported freque:l.tly. Leslie H. Tuck, Canadian Wildlife
· ~ervice biologist, sununa~ized wa~.Y. observations of "wrecks of murres" in ~-..
. his oonograph on their life history. P.ass mortalities of thick-billed .. murres during sto~y weather have been recorded over Anadyr in Siberia and·
.· ~ .
- .. ~ -.
.... :-···· ~
at· the Pribilof Islands, both in the Bering Sea.
): The oost significant •
of Beals .~m4 record of 11wrecks of murues" is that
for Unimak Island in 1941; they •,.;rote:
Longworth as reported
"Between Apr.il '2 and 4 nu:::erous dead and sick murres were along all the beaches. 'l-.7 e counted 37 dead birds along 3 miles of beach. · Tne co:l.dition was general along the strait, we ·vrere told. Oldtimers· on •Unimak told us that
' . this happens every ·sp:ri:l.g and, that some years the beach is black with dead birds. Sw'imming in close to the waterline many of the~ appeared to be sick or very weak hardly able to dive in shallow water. Altogether we
.saw 38 dead birds and 40 or ~ore very weak ones along 3 miles of beach. For three days before this~ heavy winds and sno•,.;r ble>l fro~ the southeast."
and-.
i. I '•
Apparently "wrecks of murres" are not uncommon in this region, but seldom
-2-';,
·- -·------------------~--·------------------~---
•.
l
•
~
-~
; ~: ...
·~
-.
.. have the observers had the mobility of those this year whdwere able to
assess the magnitude of l~ss.
Unresolved reports of oil ~hecns seen near the cbast and a·U. S.
Coast G'l,lard report of t\vO Jap.:>nese tra>ders that sank with 36 men aboa-rd
100 miles v:est of Unimak Island durir.g the severe storm gave rise to early
speculation that the birds were succumbir.g to diesel fuel or gasoline • l
escapji1g from the sunken vessels. ~one of the murres ex.:u'Tiined along_ the
beach were oil-stained. Only one obviously oil-killed bird, a fulmar, was
collected by the crevlS that co;r.bed portions of the beach. Organic extracts.
from samples of feathers taken from the dead murres and of beach sands were
analyzed by chemists of the Federal ~ater Quality Administration's Portland ~ .
laboratory. Gas chromatograph and infra-red scan testings revealed no
evidence of petroleuo products in any of the samples.
Tissues fro~ these murres were .tested ~or pesticides. Both DDE (a
metabol.ite of DDT) and hexychlorobenzine were found. in such small quanti~~_e:;:;,
each less than 1 part pe:- million, that they were not regarded as suspect y~ .. -. causes of death.
Because al~ost all affected birds were murres, pollutants seemed to
be an improbabl9 cause of death. Observations of pelagic birds in the •
eastern Bering Sea and B~istol Bay indicate that in winter the murr~s are
the most abundant birds, followed by glaucous-winged gulls and fulmars; . I
and from spring through su~er there are increasingly larger numbers of
kittivmkes, shearwa ters, and puffins. The few dead birds of other species
' found among the murres ~ere in n~~bers that would be expected following ., I "'
}
most storms during April. - .....
Perhaps one of the most unexpected findings from the pathological
examinations of these murres was the presence of arsenic, 2.77 parts per
t
million, in liver tissue. Tne significance of arsenic at this level is not •·
-.3-~
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, __ w-~••" ••• ---- -·--------------------------------
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knovm. However, some of the narine o.rga.nisms upon which murres feed are
reputedly concentrators o£ this ele:7-:ent, and arsenic levels of this .. . ... . . magnitude may be norr:<al in he.:;lthy 6urres. .
Hurres (the "urre" of the word wurre is pronounced like the "ur" in
the word fur) are found throughout the northern h~~misphere. Two species, . ·"'
the corr:raon murre and thick-billed murre,-are found in the Bering Sea and --Bristol Bay area. There is considerable overlap in the distribution of
' . these §pecies, but the thick-'t>illed tlUrre teri.ds to have a more northerly
distribution than the co~on illurre. Studies of summer distribution of . . pelagic birds in Bristol Bay show tha·t commoh murres are most abundant, but
winter populations there may contain p~oportionately more 'thick-bill~d
murres. Nesting colonies of murres in Alaska are found along rocky portions
of the coast from Cape Lisburne, along the Aleutian Islands, to and in-
eluding the Ale:-ander Ar~hipelago in southeastern Alaska. Some of the
~\el\laska "bird cities," or nesting colonies, may contain tens of ~housands
of murres. Following the nesting season, when the pair attempts to raise
a single young on a precipitous cliff, the birds return to the sea until
next year. }1urres feed chiefly on small fish, such· as capclin, sculpins
~ and codfish; but invertE:•rates, such as shrimp,. mollusks and sea worms
furnish a part of their diet .
Leslie H. Tuck ("The Hurres," Canadian 1-lildlif e Service, Ottawa; 1960)
summari·zes the life his tory of the murres as ~ollO'.vS: ... I
"Murres are re=.ative ly large ·sea-birds, weighing on the average two pounds, with sharply defined hi-coloured plumage. The~ are highly specialized for catching small fish under wacer. Specialized developwent for this purP9Se includes reduction ·of the length and area of the wing and so g=eat r:~odification of the bones and muscles of the legs that those birds walk very little and very awkvardly. They nest in large, compact colonies on steep
-4-
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cliffs facing the sea.
Murres are essentially ~arine species and approach .. land only during the breeding season. They obtain most of their.food by flying under water. They are the only sea-1: irds in t..~e ~orthern Hemispher.e which habitually lay their eggs in exposed situat~ons on bare ledges and rocks. They brood but a sinzle egg and yet they "-re probably the most abundant sea-birds in. the. !\orthe:rn Hemisphere.
A murre-colony (loo~ery or bazaar) is an orderly aggregation of birds. It is basical~y composed of a core of experienced adults, surrounded· on the submarginal fr~nge sites by less experienced birds or· those breeding for the first time. Early in the breeding season, cature ~urres ·take part in co~unal displays in the sea at the base of the cliffs. It is believed that those co~munal displays
-5-
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not only stDnulate the birds to breed but enable them to "synchronize''' their breeding cycles so that the maximum number of young ar-e raised in a comparatively short period.
I . I
I .
The eggs and chicks are sut,jec.ted to many dangers, not the least of which is the likelihood of b~ing knocked off the narrow ledges. The surviving chicks are led to sea, and to com?<lrative safety, by single adults, not necessarily their parents~ ·In other ways also, murres show con4"Junal interest in t:he welfare of
- -the eggs and chicks of the colony."
--
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·LIBRARY USFWS
sm:-:.ARY· REPO~T
ON
....
-~
' '\ ¥
BRISTOL BAX HUR.."\E ~lORTALITY -· ~
April 1970
~ •:
••
: e.
' . A Joint Effort by:
U. S. Dc?~rt~ent of Interior ·and
Alas}~ D~part~~nt of Fish and Ga~e
I'
0 0110 0·?~~-!
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. ,. BR:::STOL B .. W ~~.:?.:-zE MORTALITY
At least 86,000 common murres c:.cd in Bristol Bay, Alaska during a
brief per~od in late April of this year. .:J.
Although the cause of death may
never be co;:;1pletely resoLred to eve:-;o~~' s satisfaction, the evidence
suggests that it was a catastrophe o~ n~ture. The murres, apparently
still weakened after wintering in· the Bering Sea, probably died from a , combination of starvation and exhaustion v.rhich \-las aggravated by a seve-!e
~ storm that prevented them from feed:.~g during a critical few days.
Post-morte~·examinations of mu~~es by p~thologists from the Bureau·
of Sport Fisheries and Wildlife research centers in North Dakota and . Maryland, the Arctic Health Research Center in Fairbanks, the National .,.. '
Disease Labor a tory in Io..-a, and the California Departr-.ent of Fish and Game .. in Sacramento found no evidence that pathogenic bacteria or vir~ses con-
• tributed to the !nass mortality. Foods were not found in the digestive .
tracts of these birds. Tests for presence of toxins in the smail quantitie~
of fluid found in the in~estines were inconclusive. t . All specL~ens were a~aciated a~d had no appreciable deposits in sub-
· ··:·--cutaneous,- ·abdominal and cardiac fat tissue. ·J . .
Thirteen of the dead birds
varied in weight from .5J0 to 786 gra::s. Altho'ugh COi:iparable weight data
were not available for this sa~e ti::e of the year, the 6~~-gram average
- -w~ight of these-birds was co~sidera~ly less than the 972-gram average-
weight for male co~on m~rres a~d 1022-gram average weight for female . I,
I .
common murres from Cap~ Thompso~ in northwestern Alasl~ in late June. The ,
weight loss, lack of body fat and sci..e hemorrhaging of the. intesti-nes I#
l
.
'-it suggest that the birds died from stw.:-·,rc..ti_on, althou~;h all factors that
could contribute to starvation may ~_ever be completelY.. resolved.
Severe winds and turbulent seas ?~ob~bly precipitated the die-of~ t~t _.,.
was first re?orted on· Ap-;:-il 24 by ;(..:::-. ~~anthey of the Al"aska Department
of Fish and Game. During the tHO ?receding days' wir.ds. reached peak velo-
cities o.f 104 · wph at Adak and 84 r.:?~ at Cold Bay, and winds gus ted at J:ciwer
velocitie;" d:.~ring this time at othe:- :reporting stat:tons within the Aleut;lan
Islands. and along the Al.o_ska Peni-:-.s·...:.:a. · Three I::turres found on April 24 . . in the to-wn of Cold Bay by residents vere taken to the headquarters of the
• • Izembek National Wildlife Ranze, but the inc~dent se~ed insignificant at
• the time because severe storms ofte~ blow pelagic birds inland.
"Wrecks of seabirds, 11 occurre:-.ces v7here seabirds are driven far inland
and are often found dead and dying a:o~g the.beaches as a result of severe
storms, have been reported freque~:ly. Leslie H. Tuck, Canadian Wildlife
Se.rvice biologist, swr.ma=ized many. o'c:::;ervations of "wrecks of murres 11 in ~-..
his monograph on their l:::.fe history. Y..ass mortalities of thick-billed .. · murres during ston!ly wea:her have bee~ recorded over Anadyr in Siberia and
.· r .
•..; ~
..... :···· c;
at.the Pribilof Islands, both in the 3ering Sea. The ~ost significant
- ~ h . d rec.ord of "wrecks of mur::;es" is that or Beals ~n~ Longwort as reporte ~
fo.r Unimak Island in 1941; they w=ote:
"Between Apr.il '2 and 4 nu::.;;:-ous dead and sick murres were along all the beaches. he counted 37 dead birds along 3 miles of be3ch.· rne co~dition was general along the strait, we -vre::e told. Ole timers· on ·Uni!:-.ak told us that
' . this happens every·spri~; a~d that some years the beach is black with dend bircs. sw'inll!ling in close to the . waterline man; of the~ C..??eared to be sick or very weak hardly able t:> dive in s:-.c..llow water. Altogether we-
_saw 38 dead birds and 40 or more very weak ones along 3 n:.iles of beac:.. For th:-ee days before this~ heavy winds and sno•,.;r ble>~ fro-;n the so-..: theas t. 11
and..
. I:, ,
Apparently "wrecks of murres" are r.c: unco-c:::lon in this region, but seldom
-2-
r
·-
l
~
·- __ ,,. "" ·------------------------
.. have the observers had the mobility of those this year whO' were able to
~~ assess the magnitude of loss.
Unresolv8d reports o~ oil ~hecns seen near the cbast and a·U. S. '\
Coast G\,lnrd report of t\·70 Japanese t:-a•~lers that sank with 36 men aboa-rd
"' 100 miles west of Uni::-.ak Island durir.g the severe storm gave rise to early
·~
speculation that the birds were succuwbing to diesel fuel or gasoline • I
escapj_ilg from the sur.ken vessels. ~one of the murres exainined along the
beach were oil-stained. Only one obviously oil-killed bird, a fulmar, was
collected by the cre>:s tl·.at con:bed portions of the beach. Organic extracts.
from samples of feathers taken from the dead murres and of beach sands were •
analyzed by chemists of the Federal r,.;'ater Qu9.lity Administration's Portland ~ .
labor a tory. Gas chro:na tc·3raph and infra-red scan testings revealed no
evidence of petroleu~ products in any o~ the samples.
Tissues froill these curres were .tested ~or pesticides. Both DDE (a
metabolite of DDT) and hexychlorobenzine were found. in such small quantii~_e9,
each less than 1 part per million, that they were not regarded as suspect ., .. -.. causes of death.
I
Because aln:ost all affected birds were murres, pollutants seemed to
be an improbabl9 cause of death. Observations of pelagic birds in the •
eastern Bering Sea and Biistol Bay indicate that in winter the murr~s are
the most abundant birds, follo~ed by glaucous-winged gulls and fulmars;
• I and from spring through su~er there are increasingly larger numbers of
kit tiv;akes, shear,.; a ters, and puffins. The few dead birds of other species
' found among the murres ~~re in n~~bers that would be expected following .. I •
!
most storms during April. , ___,
Perhaps one of the most unexpected findings from the pathological
examinations of these murres was the presence of arsenic, 2.77 parts per
t
.
million, in liver tissue. The sign~ficance of arsenic at this level is not •.
-.3-rll -·
~--~-~~------~~------~--~--~--------~--------------·----------·
.. ~
1
i
•
~
_,·
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...
known. However, some of the marine orga~iSQS upon which murres feed are
reputedly conce1:trators of this ele:7-.ent, and arsenic levels of this .,. ·,
magnitude rr.a.y be normal :.n he.sl:.hy ~-:..lrres.
Hurres (the "urre" of the ·,.:ord :::.urre is pronounced. like the "ur" in
the word fur) are found :hrougbout t:te northern h_~misphcre. Two species, . ·"'
-the con:::aon murre and thick-billed <.:.L-"rre, ·are found in the Bering Sea and --Bristol Bay area. There is cor..siderable overlap in the distribution of
I • .
these ~pecies, b~t the thick-billed ~urre tends to have a more northerly
distribution than the co:rnon murre. Studies o~ summer distribution of· ; I
pelagic birds in Bristol Bay sho~ t~at commdh murres· are most abundant, but
·winter populations there may contain p~oportionately more 'thick-bill~d
murres. Nesting colonies of m~rres in Alaska are found along rocky portions
of the coast from Cape Lisburne, along the Aleutian Islands, to and in-
eluding the Alexander Ar~hipelago in southeastern Alaska. Some of the
.',J.,laska "bird cities," or nestir.3 co:.onies, !:lay contain tens of ~housands
of murres. Following the nest:.ng season, when the pair attempts to raise
a single young on a precipitous cli:f, the birds return to the sea until
next year. Hurres feed chiefly on sinall fish, such· as capclin, sculpins
and codfish; but invertE~rates, such as shrimp,_ mollusks and sea worms
furnish a part of their diet.
Leslie H. Tuck ("The Hurres ," Canadian \Hldlif e Service, Ottawa; 1960)
summari-zes the life his tory of the :::urres as follo~o~s:
I
"Hurres are relatively la::-ge-'sea-birds, weighing on the average two ~ounds, ~ith sharply defined bi~coloured plumage. They are highly specialized for catching £mall _ fish under water. Specialized developinent for this purp<,:>se include£ reduction of the length and area of the wing and so great ~odification of the bones and muscles of the legs that th~se birds walk vety little and very aw1~ardly. They nest in large, compact colonies on steep
-4-;.
------·- .
t
i
.: ...
~
.. - ~-~., .
, ,::'"!t
_,,
~-
"'
' ~'i.
--· -~
... ·!
·,
cliffs facing the sea.
Murres are essentially ~arine species and approach ~land only during the breeding season. They obtain most of their.food by flying under water. Th~y are the only sea-t irds in t."1e ~orthern Hemispher.e which habitually lay their eggs in exposed situa t.ions on bare ledges and rocks. They brood but a sinzle egg and yet they are prob~bly the most abundant sea-birds in. the !\orthern He:-uisphere.
There are two species; the co~~on murre (Uria aalge), with some tolerance for warmish water, and th·e thickbilled murre .'Uria lomvia), largely restricted to arctic waters. They occupy in the Northern Hemisphere an ecological niche similar to that 'occupied in the Southern Hemisphere by pe~~uins, which they res~mble superficially in coloration and postures.
' The habit of nesting in large colbnies (some colonies contain· more :han one million individuals) has made the species of substantial ec.onOmic importance in some parts of the N.orthe-:--n.Hemisphere. Thei'r .eggs, and to a lesser extent the birds themselves, have been traditionally used in. the Old World for food, 'and were so used for a brief apd over-enthusiastic period in the New World. Reeent investigations indicate that there is more nourishment in a murre's egg than in the equivalent ·volume of a dom~stic fowl 1 s. The utilization of murres, with some minor excepti::ms, has been outlmved in the ~-e-..1 World· for more than half a century. Elsewhere utili.zation has de-
. creased in some places (e.g., Great Britain), remained the same (e.g., the Faeroes), or increased (e.g., Russia).
·There is no evidence that murre populations are appreci-·. ably less numerous today than they were in historical
· times. . . Q . li •
Nesting n1u~re.8 require scarcely one square foot of territory per individual. Such compact colonies are possible. because. the food of murres is al~ost unlimited in sumner. Murres provide a vital •link in the ecology
~ . of the species which are their food. Their excrement, rich in potash, is important1 to the growth, and so to the abundance of soall marine organisms. Their colonies are
. '
in many respects the fertilizi~g factories of the north- · -ern seas.
A murre·color.y (loomery or bazaar) is an orderly aggregation of bird~. It fs bas ical~y composed of a core of experienced cdults, surrounded. on the submarginal fr~nge sites by less experienced birds or· those breeding for the first time. Early in the breeding season, cature rnurres .take part in co~unal displays in the sea at the base of the cliffs. It is believed that those co~~unal displays
-5-
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~
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not only stDnulate the birds to breed but enable them to "synchronize" their breeding cycles so that the maximum number of young ar-e raised in a comparatively short period.
The eggs and chicks are subjected to many dangers, not the least of which is the likelihood of b~ing knocked off the narrow ledges. The surviving chicks are led to sea, and to com?arative safety, by single adults, not necessarily their parents~ ·In other ways also, murres show cor.1:-:1unal interest in the welfare of
- -the eggs and chicks of the colony."
'·
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LIBRARY USFWS -~·
-~
' '\ w
SUll:l.ARY· REPO:'-T
ON
BRISTOL BA'~ HUR.RE ~IORTALITY .-
April 1970
t
I
}
A Joint Effort by; U. S. Dcp~rt~ent of Interior
·a~
••
Alasy~ D~part~cnt of Fish and Ga~e
.. \ )
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-BRISTOL BAY ~~~RRE MORTALITY
At least 86,000 common murres died in Bristol Bay, Alaska during a
brief per~od in late April of this year. .;J.
Although the cause of death m~y
never be completely resolved to eveD'On~'s satisfa~tion, the evidence
' suggests that it was a catastrophe of nfture. The murres, apparently
stilY weakened after wintering in· the Bering Sea, probably died from a , .. .
combination of starvation and exhaustion which was aggravated by. a seve~e ~
storm that prevented them from feeding during a critical few days.
Post-mortem· examinations of 'Glur::=es by p_athologists from the Bureau·
of Spo~t Fisheries and Wildlife research centers in North Dakota and . . l
Maryland, the Arctic Health Research Center in.Fairbanks, the National
.... . Disease Laboratory in IoKa, and the California Department of Fish and Ga:n.e .. in Sacramento found no evidence that pathogenic bacteria or vir~ses con-
- tributed to the mass mortality. Foods were not found in the digestive . . . , c..; tracts of these birds. Tests for presence of toxins in the smail quantitie?
. . of fluid found in the in~estines were inconclusive • . c . All speci;:1ens w"ere .emaciated and had no appreciable deposits in sub- .·
··:·--cutaneous~~bdominal and cardiac fat tissue. Thirteen of the dead birds ·J • .
varied in weight from S7D to .786 grams. Although comparable weight data I
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were not available for this same tine of the year, the 6~~-gram average
- ·-weight of these-birds was considerably less than the 972-gram average-
weight for male cou:rnon m..1rres and 1022-gram average weight for female . I·'
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common murres from Cap~ Thompson in northwestern Alasl~ in late June. The ,·
weight loss, lack of bcidy fat and som~ hemorrhaging of the.intestines I .#
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suggest that the birds died fro::: starvation, although all factors that
could contribute to starvation l.'.ay n_ever be completelY, resolved.
Severe winds and turbulent seas ?rob~bly precipitated the die-of~ t~t
was first reported on.Ap~il 24 by Ken Xanthey of the·Al'aska Department
of Fish and Game. During the t•:o preceding days, winds. reached peak velo-·
c_ities of 104 'mph at Adak and 84 :aph ·at Cold Bay, -.and winds gusted at l'ciwer
--velocities durir,g this tirr,~ at other reporting stat:tons within the Aleut;tan
Islands· and along the Alaska Pe1:insula. · Three tJ.urres found on April 24 . . in the town of Cold Bay by resicents vere taken to the headquarters of the
. . ' Izembek National Wildlife Ranze, but the inc~dent se~ed insignificant at . ~
the time because severe storms often blow pelagic birds inland.
11Wrecks of seabirds, 11 occur:-ences -.;here seabirds are driven far inland
and are often found dead and dying along the.beaches as a result of severe
storms, have been reported frequently. Leslie H. Tuck, Canadian Wildlife
~ervice biologist, summarized oany. observations of "wrecks of murres" in ~-.. his monograph on their life history. Mass mortalities of thick-billed ..
· murres during sto~y weather have been recorded over Anadyr in Siberia and· I .
at· the Pribilof Islands, both in the Bering Sea. The most significant • . ~
record of "wrecks of murtes" is that of Beals {:lnd, Longworth as reported
for Unimak Island in 1941; they wrote:
"Between Apr.il ·2 and 4 nu:::erous dead and sick murres were along all the beaches. We counted 37 dead birds along 3 miles of beach. T'na co:1dition was general along the strait, we vrere told. Old timers· on ·Unimak told us that this happens 'every· spring a:1d, that some years the beach is black with dead birds. Swi~ing in close to the waterline many of the~ ap?eared to be sick or very weak hardly able to dive in shallow ~ater. Altogether we-
_saw 38 dead birds anci 40 or more very weak ones along 3 miles of beach. For three days before this, heavy ~inds and snow ble>J from the southeast. 11
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Apparently "~reeks of murres" are not uncorr:rnon in this region, but seldom
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have the observers had the mobility of those this year 'Who were able to
assess the magnitude of loss .
Unresolved reports of oil .sheens seen near the cbast and a·U. S. ~
Coast Gt,~ard report of two Jap.:lnese tra>o~lers that sank with 36 men aboa-rd
100 miles -;.:est of Unimak Island during the severe store gave rise to early
speculation that the birds were succumbing to diesel fuel or gasoline • l
escapiitg from the sunken vessels. None of the murres exa...-uined along. the
beach v.•ere oil-stained. Only one obviously oil-killed bird, a fulmar, was
collected by the crev.•s that combed portions of the beach. Organic extracts .
from samples of feathers taken from the dead murres and of beach sands were
' analyzed by chemists of the Federal Water Quality Administration's Portland
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laboratory. Gas chromatograph and infra-red scan testings revealed no
evidence of petroleum products in any of the samples.
Tissues frohl these murres were .tested ~or pesticides. Both DDE (a
metabol.ite of DDT) and he.xychlorobenzine were found. in such small quantii:t,.~9,
each less than 1 part per million, that they were not regarded as suspect ~ ... --causes of death.
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Because almost all affected birds were murres, pollutants seemed to
be an improbabl9 cause of death. Observations of pelagic birds in the •
eastern Bering Sea and Baistol Bay indicate that in winter the murr~s are
the most abundant birds, follo'Wed by-glaucous-winged gulls and fulmars;
• I and from spring through ~u~er there are increasingly latger numbers of
kittiv;akes, sh.ear..:aters, and puffins. The few dead birds of other species
' found among the murres were in n~~bers that would be expected following . I •
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most storms during April. : - .....
Perhaps one of the most unexpected findings from the pathological
examinations of these murres 'Was the presence of arsenic, 2.77 parts per
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million, in liver tissue. The significance of arsenic at this level is not • · ·.
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knovm. However, some of the rna ri:-.e orga.'nisms upon which murres feed are
reputedly concelltrators of this ele..=-.ent, and arsenic levels of this ..... ·,
magnitude may be normal in healthy ;::;.Jrres.
Hurres (the "urre'' of the ..._,ord ::-.urre is pronounced like the "ur" in
the w~rd fur) are found throughout the northern h_~misphere. Two species, .< I
the corr=aon mur:e and thick-billed :::urre,-are found in the Bering Sea and --Bristol Bay area. There is consiC.e:-able overlap in the distribution of
' . these ~pecies, but the dlick-billed ~urre tends to have a more northerly
distribution than the ccrrnon murre. Studies of summer distribution of I
' pelagic birds i::: Bristol Bay shor.' t:-.at coromcln murres· are most abundant, but
·winter populations there ~ay contair: proportionately more 'thick-bill~d
murres. Nesti~g colonies of ruurres in Alaska are found along rocky portions
9f the coast from Cape Lisburne, along the Aleutian Islands, to and in-
eluding the Alexander Ar~hipelago in southeastern Alas~~. Some of the
·~J.laska "bird CitieS t II Or nesting COlOnieS t may COntain tenS Of ~hOUSandS
of murres. Following r.he nesting season, when the pair attempts to raise
a single young on a precipitous cliff, the birds return to the sea until
next year. }iurres feed chiefly on s~all fish, such· as capelin, sculpins
and codfish; but invertE~rates, such as shrimp,_ mollusks and sea worms
furnish a part of their diet .
Leslie H. Tuck ("Tbe Hurres," Canadian \-lildlife Service, Ottawa; 1960)
summari·zes the life his :ory of the ::::urres as (ollo~o~s: ' .
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·"Murres are relatively l.a:-ge ·'sea-birds, weighing on the average two pounds, with sharply defined bi-coloured plu:uage. They are hi~hly specialized for catching small 'fish under water. Specialized develop~ent for this purP9Se includes reduction of the length and area of the wing and so great modification of the bones and muscles of the legs ~hat th~se birds walk very little and very aw}~ardly. They nest i~ large, compact colonies on steep
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cliffs facing the sea.
Murres are essentially ~arine species and B??roach ~land only dur::.ng the breeding season. They obtain most of their· food by flying under water. Tney are the only sea-birds in t.~e !\orthern Hemispher.e which habitually la:r their eggs in exposed situa t.ions on bare ledges a~d rocks. They brood but a sinzle egg and yet they are prob~bly the most abundant sea-birds in. the !\orthe:-n Hemisphere.
There are two species; the common murre (Uria aalge), with some tolerance for warmish wa'ter, and the thickbilled murre (Uria lo:nvia), largely restricted to arctic waters. They occupy in the Northern Hemisphere an ecological niche similar to that 'occupied in the Southern Hemisphere by pe~~uins, which they res~mble superficially in coloration and Pfstures.
The.habit of ~esting in lar~e col~nies (so~2 colonies contain· more than one million individuals) has ~ade the species of substantial ec.onOmic importance in some parts of the ~orthern.Hemisphere. Their ~ggs, and to a lesser extent the birds themselves,. have been traditionally used in. the Old Horld for food, 'and were so used for a brief and over-enthusiastic period in the New World. Reeent investigations indicate that there is more nourishment in a murre's egg than in the equivalent ·volume of a dom~stic fowl 1 s. The utilization of murres, with some minor exceptions, has been outlm11ed in the ~~er,y World· for more than hal£ a century. Elsewhere utili.zation has de-
. creased in some places (e.g., Great Britain), remained the same (e.g., the Faeroes), or. increased (e.g., Russia). There is no evidence that murre populations are appreciably less numerous today than they were in historical
·times.
Nesting m~rr,e.~ require scarcely one square foot of territory per individual. Such compact colonies are possible. because' the food of murres is alcost unlimited in sur:uner. Hurres provice a vital •link in the ecology
' . of the species whfch are their food. Their excrement, rich in potash, is fQportant1 to the growth, and so to the abundance of small marine organisms. Their colonies are
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in many respects the fertilizi~g factories of the north- · ~ ern seas •
A murre·color:y (loo-.nery or bazaar) is an orderly aggregation of bird~. It is basicaLl-Y composed of a core of experienced adults, surrounded- on the sub~arginal fr~nge sites by less experienced birds or· those breeding for the first time. Early in the breeding season, ~ature ~urres .take part in con:munal displays in the sea at the base of the cliffs. It is believed that those co~~unal displays
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not only stirrulate the birGs to breed but enable them to "synchronize" their breeding cycles so that the maximum number of young a~e ralsed in a comparatively short period.
The eggs and chicks are s~bjected to many dangers, not the least of which is the likelihood of b~ing knocked off :he narrow ledges. The surviving chicks are led to sea, and to co~?arative safety, by single adults, not necessarily :heir parents~ ·In other ways also, murres show cor.:::n;-:-. .::1 interest in the welfare of
--the eggs and chicks of t:-:e colony."
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