EN
Marbled Murrelet Brachyramphus marmoratus



Taxonomy

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- A2bce+3bce+4bce A2bce+3bce+4bce

Red List history
Year Category Criteria
2020 Endangered A2bce+3bce+4bce
2018 Endangered A2bce+3bce+4bce
2016 Endangered A2bc+3bc+4bc
2012 Endangered A2bc+3bc+4bc
2010 Endangered A2c; A3c; A4c
2008 Endangered A2c; A3c; A4c
2005 Endangered
2004 Endangered
2000 Vulnerable
1994 Not Recognised
1988 Not Recognised
Species attributes

Migratory status not a migrant Forest dependency High
Land mass type Land-mass type - continent
Land-mass type - shelf island
Average mass 220 g
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 4,790,000 medium
Extent of Occurrence non-breeding (km2) 6,800,000 medium
Number of locations 11-100 -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 240000-280000 medium estimated 2015
Population trend Decreasing medium estimated -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 50-79 - - -
Decline (10 years/3 generation past and future) 50-79 - - -
Number of subpopulations 2-100 - - -
Percentage in largest subpopulation - - -
Generation length (yrs) 7.15 - - -

Population justification:

COSEWIC (2012) estimated the total population to number 358,200-417,500 individuals, rounded here to 350,000-420,000 individuals, based on 271,000 individuals in Alaska (Piatt et al. 2007), 72,600-125,600 in British Columbia (Bertram et al. 2007), and 15,400-23,900 individuals in Washington, Oregon and California (Falxa et al. 2014, Falxa and Raphael 2016). This range equates to 238,800-278,300 mature individuals, rounded here to 240,000-280,000. The latest estimate from Partners in Flight (2019) suggests a population of mature individuals of 260,000.



Trend justification: The population was estimated to have declined by c.11% in 2000-2013 in Washington, Oregon, and California (Falxa et al. 2014), with a 50% decrease in Alaska in 1972-1992 (Piatt and Naslund 1995). Although population declines in Oregon and California are reported to have been stabilising in recent years (Falxa and Raphael 2016, A. Burger in litt. 2020), declines have continued in Washington State with adult Murrelet densities declining on the shores of the San Juan Islands from 11.16 to 5.76 individuals/km2 between 1995-2012, mirroring declines witnessed by large-scale at-sea surveys (Lorenz and Raphael 2018). Population declines in Washington are currently estimated at ~4.6% per year (Falxa and Raphael 2016). At-sea surveys over the past 25 years in British Columbia suggest declines of c.1% per year (Piatt et al. 2006), although radar surveys suggest the population may have been relatively stable since 1999 with declines in some regions of British Columbia (COSEWIC 2012, Bertram et al. 2015). Availability of nesting habitat in British Columbia, which is strongly correlated with local breeding populations (Burger 2001, Burger et al. 2004), has declined by 22% between 1978 and 2008, and is continuing (COSEWIC 2012). Overall declines are suspected to be very rapid and on-going due to very low measured productivity rates.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Canada N Extant Yes Yes Yes
Mexico V Extant Yes
USA N Extant Yes Yes Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Canada Langara Island
Canada White Islets and Wilson Creek
Canada Sidney Channel
Canada Little Qualicum Estuary to Nanoose Bay
Canada Baynes Sound
Canada Mitlenatch Island
Canada Desolation Sound
Canada Carmanah Walbran Forest
Canada Barkley Sound
Canada Cleland Island and Southeast Clayoquot Sound
Canada Megin, Moyeha, Watta and Pretty Girl Watersheds
Canada Hesquiat Lake area
Canada Nootka Island banks
Canada Kyuquot Channel Islets
Canada Checleset Bay
Canada Solander Island and Brooks Bay
Canada Klaskish River and East Creek Watersheds
Canada Goose Island Group and Banks
Canada Moore and Byers Islands and Banks
Canada Mussel and Kynoch Inlet and Sheep Passage
Canada Kunghit Island and Luxana Bay
Canada Dodge Point and Gogit Passage Island Chain
Canada Laskeek Bay
Canada Skidegate Inlet
Canada Cumshewa Inlet north to Sheldens Bay
USA Port Snettisham
USA Harriman Fjord
USA Uganik Bay & Viekoda Bay
USA Icy Bay
USA Point No Point
USA Samish/Padilla Bays
USA Glacier Bay & Icy Strait
USA Glacier Bay Outer Coast Marine
USA Kachemak Bay
USA Kenai Fjords
USA Prince William Sound
USA Stephens Passage & Tracy-Endicott Arms
USA Pelican Bay, CA MAMU
USA Klamath, CA MAMU
USA Cape Blanco Nearshore Ocean
USA Cape Meares Marbled Murrelet
USA Marbled Murrelet IBA
USA Chetco Point Nearshore
USA Rogue River Reef Nearshore
USA North Olympic Marbled Murrelet
USA Olympic Coast Marbled Murrelet
USA Port Angeles Marbled Murrelet
USA Half Moon Bay, CA MAMU
USA Central CA MAMU
USA Del Norte Coast
USA Humboldt Lagoons
USA Ano Nuevo Area
USA Skagit Bay
USA Humboldt Bay
USA Olympic Continental Shelf

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Temperate major breeding
Marine Coastal/Supratidal Coastal Brackish/Saline Lagoons/Marine Lakes suitable non-breeding
Marine Neritic Pelagic suitable resident
Marine Oceanic Epipelagic (0-200m) suitable non-breeding
Wetlands (inland) Permanent Freshwater Lakes (over 8ha) major non-breeding
Wetlands (inland) Permanent Freshwater Marshes/Pools (under 8ha) major non-breeding
Altitude   Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Fishing & harvesting aquatic resources - Unintentional effects: (large scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Indirect ecosystem effects, Reduced reproductive success, Species mortality
Biological resource use Logging & wood harvesting - Unintentional effects: (large scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Very Rapid Declines High Impact: 8
Stresses
Ecosystem degradation, Reduced reproductive success
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Indirect ecosystem effects, Reduced reproductive success
Human intrusions & disturbance Recreational activities Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Indirect ecosystem effects, Reduced reproductive success
Human intrusions & disturbance Work & other activities Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Species disturbance, Reduced reproductive success
Invasive and other problematic species, genes & diseases Problematic native species/diseases Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Reduced reproductive success
Pollution Industrial & military effluents - Oil spills Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Reduced reproductive success, Species mortality

Recommended citation
BirdLife International (2021) Species factsheet: Brachyramphus marmoratus. Downloaded from http://www.birdlife.org on 16/10/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/10/2021.