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How healthy are Mt. Tam's natural resources?

 

Birds

Birds

81
% occupation by Northern Spotted Owl pairs
26.7
Average # number of active Osprey nests
Conifer Forest Birds

Conifer Forest Birds

The overall condition of conifer forest birds is Good.

Oak Woodland Birds

Oak Woodland Birds

The overall condition of oak woodland-associated birds is Good.

Shrubland Birds

Shrubland Birds

The overall condition of shrubland-associated birds is Good.

Climate-vulnerable Birds

Climate-vulnerable Birds

The overall condition of climate change-vulnerable birds is Good.

Riparian Birds

Riparian Birds

The overall condition of riparian-associated birds is Good.

Grassland Birds

Grassland Birds

The overall condition of grassland-associated birds is Unknown.

Osprey

Osprey

The overall condition of Kent Lake’s Osprey colony is Good.

Northern Spotted Owl

Northern Spotted Owl

Northern Spotted Owls are in Good condition.

The Health of Mt. Tam's Birds

Below is an assessment of the overall health of the mountain’s avian communities obtained by combining the health assessments of a number of bird communities.

 

Additional details about the health of these bird communities is available through links in the photos below. There are also links to two individual species of birds for which enough is known to asses their condition and trend: Osprey and Northern Spotted Owls.

 

Agencies within the One Tam area of focus have a relatively long history of bird monitoring, enabling estimates of population trends for multiple species in multiple vegetation communities (see Bird Species of Mt. Tam in Appendix 9). Birds are also a highly visible resource with a great deal of public interest attracting many bird watchers to the One Tam region and delighting regular visitors and residents. Their songs and behavior (e.g., long distance migration) also inspire great interest.

The images and links below provide more information about the condition and trends of these three species on Mt. Tam.

Why Was This Indicator Chosen?

Birds are recognized as indicators of ecological change (Carignan & Villard, 2002). They also provide a wide variety of important ecosystem services including devouring pests, pollinating flowers, dispersing seeds, scavenging carrion, cycling nutrients, and modifying the environment in ways that benefit other species (Whelan et al., 2015). Agencies within the One Tam area of focus have a relatively long history of bird monitoring, enabling estimates of population trends for multiple species across a range of vegetation communities.

 

What is Healthy?

A healthy population of birds on Mt. Tam would be stable or increasing over the next five years. Given environmental stressors beyond our control, it may not be realistic to try to maintain a certain abundance for all species. However, overall population size and fitness are likely to be important components of a species’ ability to track environmental change (Williams et al. 2008).

 

What is The Current Condition?

Overall, Mt. Tam’s birds are currently in Good condition.

 

What is the Current Trend?

Birds on Mt. Tam currently appear to be experiencing No Change in their trend.

 

How Sure Are We?

Confidence in this assessment is High, as Mt. Tam’s birds have been fairly well studied, and because of the large number of species considered in this assessment. Bird species were aggregated to reach a summarized confidence level for individuals sharing similar traits, as well as overall.

 

What is This Assessment Based On?

  • Marin Municipal Water District (Cormier et al., 2014)
  • National Park Service (Gardali & Geupel, 1997) and just riparian areas (Humple & Porzig, 2012)
  • Marin County Parks (Gardali et al., 2010)

 

What Don’t We Know?

Key information gaps include:

  • Data on grassland-associated species, wintering and migratory bird populations, and time series data for agencies other than the Marin Municipal Water District
  • Population demographics such as survival and reproductive success

 

Health Score
Condition, Trend & Confidence

all birds

  • Condition: Good
  • Trend: No Change
  • Confidence: High

 

oak wooodland birds

  • Condition: Good
  • Trend: No Change
  • Confidence: High

 

conifer–mixed hardwood forest birds

  • Condition: Good
  • Trend: Improving
  • Confidence: High

 

grassland birds

  • Condition: Unknown
  • Trend: Unknown
  • Confidence: Unknown

 

scrub and chaparral birds

  • Condition: Good
  • Trend: No Change
  • Confidence: High

 

riparian birds

  • Condition: Good
  • Trend: No Change
  • Confidence: High

 

climate change vulnerable birds

  • Condition: Good
  • Trend: No Change
  • Confidence: High

Bird Species in the One Tam Area of Focus

Life Form

Scientific Name

Common Name

Occurrence Within One

Tam Area of Focus

Blackbirds and Allies

Euphagus cyanocephalus

Brewer's Blackbird

Uncommon

Blackbirds and Allies

Molothrus ater

Brown-headed Cowbird

Uncommon

Blackbirds and Allies

Icterus bullockii

Bullock's Oriole

Uncommon

Blackbirds and Allies

Icterus cucullatus

Hooded Oriole

Irregular/ accidental visitor

Blackbirds and Allies

Agelaius phoeniceus

Red-winged BlackBird

Common

Blackbirds and Allies

Sturnella neglecta

Western Meadowlark

Uncommon

Cardinals, Grosbeaks, and Allies

Pheucticus melanocephalus

Black-headed Grosbeak

Common

Cardinals, Grosbeaks, and Allies

Passerina amoena

Lazuli Bunting

Uncommon

Cardinals, Grosbeaks, and Allies

Piranga ludoviciana

Western Tanager

Uncommon

Chickadees, Titmice and Bushtits

Psaltriparus minimus

Bushtit

Common

Chickadees, Titmice and Bushtits

Poecile rufescens

Chesnut-backed Chickadee

Common

Chickadees, Titmice and Bushtits

Baeolophus inornatus

Oak Titmouse

Common

Cranes and Rails

Fulica americana

American Coot

Common

Cranes and Rails

Laterallus jamaicensis ssp. coturniculus

California Black Rail

Rare

Cranes and Rails

Rallus obsoletus ssp. obsoletus

California Ridgway’s Rail

Rare

Cranes and Rails

Gallinula galeata

Common Gallinule

Rare

Cranes and Rails

Porzana carolina

Sora

Uncommon

Cranes and Rails

Rallus limicola

Virginia Rail

Uncommon

Dippers

Cinclus mexicanus

American Dipper

Irregular/ accidental visitor

Ducks, Geese and Swans

Anas americana

American Wigeon

Uncommon

Ducks, Geese and Swans

Bucephala islandica

Barrow's Goldeneye

Irregular/ accidental visitor

Ducks, Geese and Swans

Bucephala albeola

Bufflehead

Uncommon

Ducks, Geese and Swans

Branta canadensis

Canada Goose

Common

Ducks, Geese and Swans

Aythya valisineria

Canvasback

Uncommon

Ducks, Geese and Swans

Anas cyanoptera

Cinnamon Teal

Uncommon

Ducks, Geese and Swans

Bucephala clangula

Common Goldeneye

Uncommon

Ducks, Geese and Swans

Mergus merganser

Common Merganser

Common

Ducks, Geese and Swans

Anas strepera

Gadwall

Uncommon

Ducks, Geese and Swans

Aythya marila

Greater Scaup

Uncommon

Ducks, Geese and Swans

Anas crecca

Green-winged Teal

Uncommon

Ducks, Geese and Swans

Lophodytes cucullatus

Hooded Merganser

Uncommon

Ducks, Geese and Swans

Aythya affinis

Lesser Scaup

Uncommon

Ducks, Geese and Swans

Anas platyrhynchos

Mallard

Common

Ducks, Geese and Swans

Anas acuta

Northern Pintail

Uncommon

Ducks, Geese and Swans

Anas clypeata

Northern Shoveler

Uncommon

Ducks, Geese and Swans

Aythya collaris

Ring-necked Duck

Uncommon

Ducks, Geese and Swans

Oxyura jamaicensis

Ruddy Duck

Uncommon

Ducks, Geese and Swans

Aix sponsa

Wood Duck

Rare

Finches and Allies

Spinus tristis

American Goldfinch

Uncommon

Finches and Allies

Carpodacus mexicanus

House Finch

Common

Finches and Allies

Spinus lawrencei

Lawrence's Goldfinch

Irregular/ accidental visitor

Finches and Allies

Spinus psaltria

Lesser Goldfinch

Uncommon

Finches and Allies

Spinus pinus

Pine Siskin

Uncommon

Finches and Allies

Carpodacus purpureus

Purple Finch

Common

Finches and Allies

Loxia curvirostra

Red Crossbill

Uncommon

Gnatcatchers

Polioptila caerulea

Blue-gray Gnatcatcher

Uncommon

Goatsuckers

Phalaenoptilus nuttallii

Common Poorwill

Uncommon

Grebes

Aechmophorus clarkii

Clark's Grebe

Rare

Grebes

Podiceps nigricollis

Eared Grebe

Uncommon

Grebes

Podilymbus podiceps

Pied-billed Grebe

Common

Grebes

Aechmophorus occidentalis

Western Grebe

Common

Grouse, Quail, and Allies

Callipepla californica

California Quail

Common

Grouse, Quail, and Allies

Meleagris gallopavo

Wild Turkey

Common

Gulls and Terns

Larus californicus

California Gull

Rare

Life Form

Scientific Name

Common Name

Occurrence Within One

Tam Area of Focus

Gulls and Terns

Hydroprogne caspia

Caspian Tern

Common

Gulls and Terns

Sterna hirundo

Common Tern

Irregular/ accidental visitor

Gulls and Terns

Sterna forsteri

Forster's Tern

Uncommon

Gulls and Terns

Larus glaucescens

Glaucous-winged Gull

Rare

Gulls and Terns

Larus argentatus

Herring Gull

Rare

Gulls and Terns

Larus delawarensis

Ring-billed Gull

Common

Gulls and Terns

Larus occidentalis

Western Gull

Rare

Herons and Allies

Ardea herodias

Great Blue Heron

Common

Herons and Allies

Ardea alba

Great Egret

Common

Herons and Allies

Butorides virescens

Green Heron

Uncommon

Herons and Allies

Egretta thula

Snowy Egret

Common

Jays, Magpies, and Crows

Corvus brachyrhynchos

American Crow

Common

Jays, Magpies, and Crows

Corvus corax

Common Raven

Common

Jays, Magpies, and Crows

Cyanocitta stelleri

Steller's Jay

Common

Jays, Magpies, and Crows

Aphelocoma californica

Western Scrub-Jay

Common

Kingfishers

Megaceryle alcyon

Belted Kingfisher

Common

Kinglets

Regulus satrapa

Golden-crowned Kinglet

Uncommon

Kinglets

Regulus calendula

Ruby-crowned Kinglet

Common

Larks

Eremophila alpestris

Horned Lark

Uncommon

Loons

Gavia immer

Common Loon

Irregular/ accidental visitor

Loons

Gavia pacifica

Pacific Loon

Irregular/ accidental visitor

MockingBirds and Thrashers

Toxostoma redivivum

California Thrasher

Rare

MockingBirds and Thrashers

Mimus polyglottos

Northern Mockingbird

Uncommon

New World Sparrows and Allies

Artemisiospiza belli

Bell's Sparrow

Rare

New World Sparrows and Allies

Spizella atrogularis

Black-chinned sparrow

Rare

New World Sparrows and Allies

Melozone crissalis

California Towhee

Common

New World Sparrows and Allies

Spizella passerina

Chipping Sparrow

Uncommon

New World Sparrows and Allies

Junco hyemalis

Dark-eyed Junco

Common

New World Sparrows and Allies

Passerella iliaca

Fox Sparrow

Common

New World Sparrows and Allies

Zonotrichia atricapilla

Golden-crowned Sparrow

Common

New World Sparrows and Allies

Ammodramus savannarum

Grasshopper Sparrow

Rare

New World Sparrows and Allies

Pipilo chlorurus

Green-tailed Towhee

Irregular/ accidental visitor

New World Sparrows and Allies

Chondestes grammacus

Lark Sparrow

Uncommon

New World Sparrows and Allies

Melospiza lincolnii

Lincoln's Sparrow

Rare

New World Sparrows and Allies

Aimophila ruficeps

Rufous-crowned Sparrow

Rare

New World Sparrows and Allies

Passerculus sandwichensis

Savannah Sparrow

Uncommon

New World Sparrows and Allies

Melospiza melodia

Song Sparrow

Common

New World Sparrows and Allies

Pipilo maculatus

Spotted Towhee

Common

New World Sparrows and Allies

Zonotrichia leucophrys

White-crowned Sparrow

Common

New World Sparrows and Allies

Zonotrichia albicollis

White-throated Sparrow

Rare

Nuthatches and Creepers

Certhia americana

Brown Creeper

Common

Nuthatches and Creepers

Sitta pygmaea

Pygmy Nuthatch

Uncommon

Nuthatches and Creepers

Sitta canadensis

Red-breasted Nuthatch

Common

Nuthatches and Creepers

Sitta carolinensis

White-breasted Nuthatch

Uncommon

Old World Sparrows

Passer domesticus

House Sparrow

Uncommon

Owls

Tyto alba

Barn Owl

Common

Owls

Strix varia

Barred Owl

Rare

Owls

Bubo virginianus

Great Horned Owl

Common

Owls

Asio otus

Long-eared Owl

Uncommon

Owls

Glaucidium gnoma

Northern Pygmy-Owl

Rare

Owls

Aegolius acadicus

Northern Saw-whet Owl

Rare

Owls

Strix occidentalis ssp. caurina

Northern Spotted Owl

Uncommon

Owls

Megascops kennicottii

Western Screech-Owl

Uncommon

Pelicans and Allies

Pelecanus erythrorhynchos

American White Pelican

Rare

Life Form

Scientific Name

Common Name

Occurrence Within One

Tam Area of Focus

Pelicans and Allies

Phalacrocorax penicillatus

Brandt's Cormorant

Irregular/ accidental visitor

Pelicans and Allies

Pelecanus occidentalis

Brown Pelican

Irregular/ accidental visitor

Pelicans and Allies

Phalacrocorax auritus

Double-crested Cormorant

Common

Pelicans and Allies

Phalacrocorax pelagicus

Pelagic Cormorant

Irregular/ accidental visitor

Pigeons and Doves

Patagioenas fasciata

Band-tailed Pigeon

Common

Pigeons and Doves

Zenaida macroura

Mourning Dove

Common

ShoreBirds

Haematopus bachmani

Black Oystercatcher

Irregular/ accidental visitor

ShoreBirds

Himantopus mexicanus

Black-necked Stilt

Uncommon

ShoreBirds

Tringa melanoleuca

Greater Yellowlegs

Uncommon

ShoreBirds

Charadrius vociferus

Killdeer

Common

ShoreBirds

Actitis macularius

Spotted Sandpiper

Uncommon

ShoreBirds

Gallinago delicata

Wilson's Snipe

Uncommon

Shrikes

Lanius ludovicianus

Loggerhead Shrike

Rare

Starlings and Allies

Sturnus vulgaris

European Starling

Common

Swallows

Riparia riparia

Bank Swallow

Irregular/ accidental visitor

Swallows

Hirundo rustica

Barn Swallow

Common

Swallows

Petrochelidon pyrrhonota

Cliff Swallow

Common

Swallows

Stelgidopteryx serripennis

Northern Rough-winged Swallow

Uncommon

Swallows

Progne subis

Purple Martin

Uncommon

Swallows

Tachycineta bicolor

Tree Swallow

Common

Swallows

Tachycineta thalassina

Violet-green Swallow

Common

Swifts and HummingBirds

Selasphorus sasin

Allen's Hummingbird

Common

Swifts and HummingBirds

Calypte anna

Anna's Hummingbird

Common

Swifts and HummingBirds

Chaetura vauxi

Vaux's Swift

Uncommon

Swifts and HummingBirds

Aeronautes saxatalis

White-throated Swift

Rare

Thrushes

Turdus migratorius

American Robin

Common

Thrushes

Catharus guttatus

Hermit Thrush

Common

Thrushes

Catharus ustulatus

Swainson's Thrush

Common

Thrushes

Myadestes townsendi

Townsend's Solitaire

Rare

Thrushes

Ixoreus naevius

Varied Thrush

Common

Thrushes

Sialia mexicana

Western BlueBird

Common

Tyrant Flycatchers

Myiarchus cinerascens

Ash-throated Flycatcher

Uncommon

Tyrant Flycatchers

Sayornis nigricans

Black Phoebe

Common

Tyrant Flycatchers

Contopus cooperi

Olive-sided Flycatcher

Uncommon

Tyrant Flycatchers

Empidonax difficilis

Pacific-slope Flycatcher

Common

Tyrant Flycatchers

Sayornis saya

Say's Phoebe

Uncommon

Tyrant Flycatchers

Tyrannus verticalis

Western Kingbird

Rare

Tyrant Flycatchers

Contopus sordidulus

Western Wood-Pewee

Common

Vireos

Vireo cassinii

Cassin's Vireo

Uncommon

Vireos

Vireo huttoni

Hutton's Vireo

Common

Vireos

Vireo gilvus

Warbling Vireo

Common

Vultures, Hawks and Falcons

Falco sparverius

American Kestrel

Common

Vultures, Hawks and Falcons

Haliaeetus leucocephalus

Bald Eagle

Uncommon

Vultures, Hawks and Falcons

Buteo platypterus

Broad-winged Hawk

Rare

Vultures, Hawks and Falcons

Accipiter cooperii

Cooper's Hawk

Uncommon

Vultures, Hawks and Falcons

Aquila chrysaetos

Golden Eagle

Rare

Vultures, Hawks and Falcons

Falco columbarius

Merlin

Rare

Vultures, Hawks and Falcons

Circus cyaneus

Northern Harrier

Uncommon

Vultures, Hawks and Falcons

Pandion haliaetus

Osprey

Common

Vultures, Hawks and Falcons

Falco peregrinus

Peregrine Falcon

Rare

Vultures, Hawks and Falcons

Falco mexicanus

Prairie Falcon

Rare

Vultures, Hawks and Falcons

Buteo lineatus

Red-shouldered Hawk

Common

Vultures, Hawks and Falcons

Buteo jamaicensis

Red-tailed Hawk

Common

Vultures, Hawks and Falcons

Buteo lagopus

Rough-legged Hawk

Irregular/ accidental visitor

Life Form

Scientific Name

Common Name

Occurrence Within One

Tam Area of Focus

Vultures, Hawks and Falcons

Accipiter striatus

Sharp-shinned Hawk

Common

Vultures, Hawks and Falcons

Cathartes aura

Turkey Vulture

Common

Vultures, Hawks and Falcons

Elanus leucurus

White-tailed Kite

Common

Waxwings

Bombycilla cedrorum

Cedar Waxwing

Common

Wood-warblers

Setophaga nigrescens

Black-throated Gray Warbler

Rare

Wood-warblers

Setophaga occidentalis

Hermit Warbler

Rare

Wood-warblers

Geothlypis tolmiei

MacGillivray's Warbler

Uncommon

Wood-warblers

Oreothlypis celata

Orange-crowned Warbler

Common

Wood-warblers

Setophaga townsendi

Townsend's Warbler

Common

Wood-warblers

Cardellina pusilla

Wilson's Warbler

Common

Wood-warblers

Setophaga petechia

Yellow Warbler

Common

Wood-warblers

Setophaga coronata

Yellow-rumped Warbler

Common

Woodpeckers

Melanerpes formicivorus

Acorn Woodpecker

Common

Woodpeckers

Picoides pubescens

Downy Woodpecker

Common

Woodpeckers

Picoides villosus

Hairy Woodpecker

Common

Woodpeckers

Colaptes auratus

Northern Flicker

Common

Woodpeckers

Picoides nuttallii

Nuttall's Woodpecker

Common

Woodpeckers

Dryocopus pileatus

Pileated Woodpecker

Uncommon

Woodpeckers

Sphyrapicus ruber

Red-breasted Sapsucker

Common

Wrens

Thryomanes bewickii

Bewick's Wren

Common

Wrens

Troglodytes aedon

House Wren

Uncommon

Wrens

Cistothorus palustris

Marsh Wren

Uncommon

Wrens

Troglodytes pacificus

Pacific Wren

Common

Wrens

Salpinctes obsoletus

Rock Wren

Rare

Wrentits

Chamaea fasciata

Wrentit

Common

This species list represents current information compiled by One Tam partner agencies at this time, and will likely be updated in the

future through further review of additional technical reports, inventories, and validation of other data sources.

Updated 6/16/16