The City of Portland The City of Portland

Bird SurveysBird SurveysP

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BES Avian SurveysBES Avian Surveys

�� West Hayden IslandWest Hayden Island

�� PAWMAPPAWMAP

�� Elk Rock IslandElk Rock Island

�� Columbia Slough Project sitesColumbia Slough Project sites

�� Oaks BottomOaks Bottom

�� Mt. TaborMt. Tabor

�� Stephens Creek ConfluenceStephens Creek Confluence

�� Ecoroof MonitoringEcoroof Monitoring

Why Survey Birds?Why Survey Birds?

�� Bird are important bioBird are important bio--indicatorsindicators�� proverbial canary in the coal mineproverbial canary in the coal mine

�� Birds have been selected as a terrestrial indicator for the Birds have been selected as a terrestrial indicator for the Portland Watershed Management PlanPortland Watershed Management Plan

�� Easy to detect visually and by sound (songs, calls, and Easy to detect visually and by sound (songs, calls, and some by the sound their feathers make during flight some by the sound their feathers make during flight and/or courtship displays)and/or courtship displays)

�� Protection: native species are protected by federal laws Protection: native species are protected by federal laws ―― the Lacy Act of 1900 and Migratory Bird Treaty Act the Lacy Act of 1900 and Migratory Bird Treaty Act of 1918.of 1918.

Avian Point CountsAvian Point Counts

http://www.pwrc.usgs.gov/Point/view/images/PointCountMethodDiagram.gif

Counting birds inside vs. outside a 50-meter circle in set blocks of time

Field method used Field method used

to study:to study:

�� Response to Response to

treatment treatment

�� Population Population

trendstrends

�� Relationships Relationships

between birds between birds

and habitatand habitat

Long Term Studies: Population Long Term Studies: Population

Trends and Response to TreatmentTrends and Response to Treatment

�� Conducting counts over extended periods of Conducting counts over extended periods of

time help account for variables such as:time help account for variables such as:

�� Weather conditionsWeather conditions

�� Disturbance (noise, human or other activity)Disturbance (noise, human or other activity)

�� Observer bias:Observer bias:

�� Surveyors have different strengths which will affect what Surveyors have different strengths which will affect what

birds are notedbirds are noted

�� YearYear--toto--year seasonal differencesyear seasonal differences

REQUIRED SKILLSREQUIRED SKILLS�� Ability to identify birds by sight AND sound, the latter being Ability to identify birds by sight AND sound, the latter being

vital to collecting good data as many more are heard than seen vital to collecting good data as many more are heard than seen when trees are leafed out.when trees are leafed out.

�� Knowledge of birdKnowledge of bird’’s natural historys natural history

�� Good judgment: are birds flying over during the count using Good judgment: are birds flying over during the count using the habitat in the count circle or not?the habitat in the count circle or not?

Many are much

easier to hear than

see, particularly

cryptic species such

as Hutton’s Vireo

(left) and Brown

Creeper (right)

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Tools & FormsTools & Forms

Mount Tabor Invasive Plant Mount Tabor Invasive Plant Control & Revegetation Project Control & Revegetation Project

and its affect on Birdsand its affect on Birds

2009-2012

Spotted TowheePhoto by Greg Gillson

Why Monitor Birds at Mt. Tabor?Why Monitor Birds at Mt. Tabor?

�� The general level of interest in birds is high The general level of interest in birds is high within the Portland community :within the Portland community :

�� neighborhoods, Portland Audubon, birders neighborhoods, Portland Audubon, birders

�� There is concern as to how the project will There is concern as to how the project will affect birds, particularly breedersaffect birds, particularly breeders

�� Part of the Tabor to the River ProgramPart of the Tabor to the River Program

�� Perfect citizen science project, establishing a Perfect citizen science project, establishing a relationship between BES and Audubon, using relationship between BES and Audubon, using their volunteers to conduct the counts.their volunteers to conduct the counts.

PRIMARY PROJECT GOALSPRIMARY PROJECT GOALS

To Improve Watershed and To Improve Watershed and

Wildlife Habitat Health by:Wildlife Habitat Health by:

�� Reducing nonReducing non--native invasive plant speciesnative invasive plant species

�� ReRe--vegetating with native shrubs, trees and vegetating with native shrubs, trees and

grassesgrasses

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REVEGETATION PARTNERSREVEGETATION PARTNERS�� BES BES (Naomi Tsurumi, Ryan Durocher and Ken Finney)(Naomi Tsurumi, Ryan Durocher and Ken Finney)

�� Portland Parks and Recreation Portland Parks and Recreation

�� Friends of Mt. Tabor Park (FMTP) and their Weed Friends of Mt. Tabor Park (FMTP) and their Weed

Warrior Volunteer ServiceWarrior Volunteer Service

�� FY 2012 FY 2012 –– 2490 hours 2490 hours

�� FY 2011 FY 2011 –– 2060 hours2060 hours

BIRD SURVEYSBIRD SURVEYSPARTICIPANTSPARTICIPANTS

�� BESBES

�� Herrera Environmental ConsultantsHerrera Environmental Consultants�� Established point count locations and protocolEstablished point count locations and protocol

�� Conducted surveys during initial season (2009)Conducted surveys during initial season (2009)

�� Audubon Society of PortlandAudubon Society of Portland�� Conducted surveys (2010Conducted surveys (2010--2012)2012)

Project TimelineProject Timeline �� September 2010September 2010

�� Invasive plant removal beginsInvasive plant removal begins

�� Fall 2010Fall 2010

�� Nuisance tree removal throughout natural areas Nuisance tree removal throughout natural areas in the parkin the park

�� February 2011February 2011

�� Native tree and shrub planting in select Native tree and shrub planting in select locationslocations

�� Spring / Fall 2011Spring / Fall 2011

�� Ongoing invasive plant controlOngoing invasive plant control

�� Fall 2011Fall 2011

�� Native grass and forb seeding and plantingNative grass and forb seeding and planting

�� February 2012February 2012

�� Primary native tree and shrub plantingPrimary native tree and shrub planting

�� Spring / Fall 2012Spring / Fall 2012

�� Ongoing invasive plant control and planting Ongoing invasive plant control and planting area maintenancearea maintenance

�� January to March 2013January to March 2013

�� Native tree and shrub planting in Phase 2 areasNative tree and shrub planting in Phase 2 areas

English Ivy Removal 2009English Ivy Removal 2009--20102010

BEFORE AFTER

Himalayan Blackberry RemovalHimalayan Blackberry Removal

BEFORE AND AFTER

AUGUST 2011

BirdBird’’s Eye View of Mt Tabors Eye View of Mt Tabor

Why is Mt Tabor so Why is Mt Tabor so attractive to birds?attractive to birds?

�� Island of contiguous green habitat within a Island of contiguous green habitat within a

an otherwise highly urbanized area.an otherwise highly urbanized area.

�� Provides habitat for:Provides habitat for:

�� YearYear--around residentsaround residents

�� Summer breeders (winter elsewhere)Summer breeders (winter elsewhere)

�� Neotropical migrants (only pause during spring Neotropical migrants (only pause during spring

and/or fall migration)and/or fall migration)

�� Wintering species (breed elsewhere)Wintering species (breed elsewhere)

Point Count LocationsPoint Count Locations

Work Zones Work Zones

by Yearby Year

�� 14 revegetation units14 revegetation units

�� 23 point count sites23 point count sites

�� 14 in reveg units14 in reveg units

�� 9 outside reveg units9 outside reveg units

�� Work done in phasesWork done in phases

�� Good for budgetGood for budget

�� Good for birdsGood for birds

�� Data analysis difficult Data analysis difficult

due to all the variablesdue to all the variables

AVIAN SURVEYSAVIAN SURVEYS

�� Between 15 May and 30 June each of the 23 sites are Between 15 May and 30 June each of the 23 sites are

surveyed three times.surveyed three times.

�� Due to large number of sites, each set of surveys takes Due to large number of sites, each set of surveys takes

two days to complete.two days to complete.

�� Surveys are conducted between dawn and 9:00 AM Surveys are conducted between dawn and 9:00 AM

when avian activity is highest.when avian activity is highest.

�� During four years of counts 68 species were detected. During four years of counts 68 species were detected.

The allThe all--time bird list for Mt. Tabor is approximately time bird list for Mt. Tabor is approximately

154 species (pers. com. Adrian Hinkle).154 species (pers. com. Adrian Hinkle).

Interpreting the DataInterpreting the Data

�� Drawing meaningful conclusions is complicated due to Drawing meaningful conclusions is complicated due to variables, including some not captured directly during variables, including some not captured directly during the counts:the counts:�� Multiple work phasesMultiple work phases

�� How degraded was habitat originally vs. amt of regenerationHow degraded was habitat originally vs. amt of regeneration

�� Vegetation structure conversions (i.e. closed canopy to open Vegetation structure conversions (i.e. closed canopy to open canopy, complete ground cover to bare ground)canopy, complete ground cover to bare ground)

�� Slope and aspectSlope and aspect

�� Human and dog disturbanceHuman and dog disturbance

�� Other factors not consideredOther factors not considered

�� Data was separated into either treated or untreated Data was separated into either treated or untreated categories.categories.

Ten Most Abundant Species Recorded during four years of surveys

0 20 40 60 80 100 120 140

American Crow

Spotted Towhee

Black-headed Grosbeak

Chestnut-backed Chickadee

Pine Siskin

Dark-eyed Junco

Lesser Goldfinch

Song Sparrow

House Finch

American Robin

Com

mon

Nam

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Avg # of individuals detected /yr (all stations)

American Robin

0123

4567

2009 2010 2011 2012

Years

Avg

# o

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uals

/site

Pretreatment

Treated

Untreated

�� The most widespread and numerousThe most widespread and numerous---- are habitat generalistsare habitat generalists----

preferring a more open canopy. preferring a more open canopy.

�� It would appear that robins are moving into the treated areas It would appear that robins are moving into the treated areas

and away from the untreated areas.and away from the untreated areas.

Spotted Towhee

0

0.5

1

1.5

2

2.5

2009 2010 2011 2012

Avg

# o

f ind

ivid

uals

/site

Pretreatment

Treated

Untreated

�� Spotted Towhees need bare ground under a dense subSpotted Towhees need bare ground under a dense sub--

canopy of shrubs and ferns.canopy of shrubs and ferns.

�� Use Himalayan blackberry for shelter, nesting and food.Use Himalayan blackberry for shelter, nesting and food.

�� Removing ivy most likely benefit providing more open Removing ivy most likely benefit providing more open

ground to feed on.ground to feed on.

Song Sparrow

0

1

2

3

4

5

6

2009 2010 2011 2012

Avg

# o

f ind

ivid

uals

/site

Pretreatment

Treated

Untreated

�� Song Sparrow is locally widespread preferring moist Song Sparrow is locally widespread preferring moist

habitat low to the ground in brushy or riparian areashabitat low to the ground in brushy or riparian areas

�� Needs open ground and shrubs to feed and shrubs to Needs open ground and shrubs to feed and shrubs to

nest in. nest in.

�� Overall numbers appear stable, but with a preference for Overall numbers appear stable, but with a preference for

treated areas.treated areas.

PostPost--treatment Declinestreatment Declines

Black-capped Chickadee

0

0.5

1

1.5

2

2.5

2009 2010 2011 2012

Avg

# o

f ind

ivid

uals

/site

Pretreatment

Treated

Untreated

Brown Creeper

0

0.5

1

1.5

2

2.5

2009 2010 2011 2012

Avg

# o

f ind

ivid

uals

/site

Pretreatment

Treated

Untreated

�� Both are tree dwellersBoth are tree dwellers

�� Brown Creeper forages on Brown Creeper forages on

trees and nests in the barktrees and nests in the bark

�� BlackBlack--capped Chickadee is a capped Chickadee is a

cavity nester, occurring in a cavity nester, occurring in a

wide variety of habitats.wide variety of habitats.

�� Excluding 2009 data, there Excluding 2009 data, there

seems to be a slight decline in seems to be a slight decline in

overall numbers, but an overall numbers, but an

increase in the treated areas. increase in the treated areas.

Is slight decline in treated Is slight decline in treated

areas due to cavity tree loss?areas due to cavity tree loss?

Bushtit

0

0.5

1

1.5

2

2.5

3

3.5

2009 2010 2011 2012

Avg

# o

f ind

ivid

uals

/site

Pretreatment

Treated

Untreated

�� An example of a species that is moving from the treated areas toAn example of a species that is moving from the treated areas to

untreated areas while natives become reestablished. Bushtits likuntreated areas while natives become reestablished. Bushtits like e

more shrubby habitat where they eat lots of insects.more shrubby habitat where they eat lots of insects.

�� This is an example of data that doesnThis is an example of data that doesn’’t make sense. There shouldnt make sense. There shouldn’’t t

be such a discrepancy in 2009 between the two areas before any be such a discrepancy in 2009 between the two areas before any

treatment were done given Bushtits are generalists. treatment were done given Bushtits are generalists.

Hutton's Vireo

0

0.2

0.4

0.6

0.8

1

1.2

2009 2010 2011 2012

Avg

# o

f ind

ivid

uals

/site

Pretreatment

Treated

Untreated

�� Observer bias and/or loss of vireos? Perceived losses may Observer bias and/or loss of vireos? Perceived losses may

or may not be related to this project. Some birders feel they or may not be related to this project. Some birders feel they

have noticed reduced numbers of Huttonhave noticed reduced numbers of Hutton’’s Vireos in the s Vireos in the

Willamette Valley. Insectivorous.Willamette Valley. Insectivorous.

�� Habitat preference is evergreen forests, particularly oaks.Habitat preference is evergreen forests, particularly oaks.

Increasing SpeciesIncreasing SpeciesBlack-headed Grosbeak

0.00

0.50

1.00

1.50

2.00

2.50

2009 2010 2011 2012

Avg

# o

f ind

ivid

uals

/site

Pretreatment

Treated

Untreated

Northern Flicker

00.20.40.60.8

11.21.41.61.8

2009 2010 2011 2012

Avg

# o

f ind

ivid

uals

/site

Pretreatment

Treated

Untreated

�� Both species showed Both species showed

increases in both treated increases in both treated

and untreated areas, though and untreated areas, though

more so in the treated.more so in the treated.

�� Both like more open mixed Both like more open mixed

forests and edges, complex forests and edges, complex

understory, preferring understory, preferring

larger trees.larger trees.

�� Flickers often feed on the Flickers often feed on the

ground.ground.

�� Removing trees and ivy Removing trees and ivy

appear to benefit them. appear to benefit them.

Chestnut-backed Chickadee

0

0.5

1

1.5

2

2.5

2009 2010 2011 2012

Avg

# o

f ind

ivid

uals

/site

Pretreatment

Treated

Untreated

�� ChestnutChestnut--backed Chickadee numbers are backed Chickadee numbers are

increasing overall, unlike Blackincreasing overall, unlike Black--capped capped

which show a slight decline. which show a slight decline.

�� Like dark, dense, moist woods, but also Like dark, dense, moist woods, but also

found in suburbs. Mostly insectivorous.found in suburbs. Mostly insectivorous.

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Anna's Hummingbird

0

0.5

1

1.5

2

2.5

2009 2010 2011 2012

Avg

# o

f ind

ivid

uals

/site

Pretreatment

Treated

Untreated

�� A recent arrival, AnnaA recent arrival, Anna’’s Hummingbird thrive in urban s Hummingbird thrive in urban

habitats with its array of exotic plants.habitats with its array of exotic plants.

�� To date they are still increasing in the degraded areas. To date they are still increasing in the degraded areas.

Prefer urban or open habitats with lots of insects.Prefer urban or open habitats with lots of insects.

�� In treated areas with more native plants its numbers In treated areas with more native plants its numbers

appear to be stabilizing.appear to be stabilizing.

Mt. Tabor discussionMt. Tabor discussion

�� Most of the species discussed today appear to be benefitting froMost of the species discussed today appear to be benefitting from the m the project. project.

�� Treated areas show increased numbers of birds using treated areaTreated areas show increased numbers of birds using treated areas s while the untreated, presumably less desirable habitats are showwhile the untreated, presumably less desirable habitats are showing ing losses.losses.

�� How quickly will species who are negatively impacted by removal How quickly will species who are negatively impacted by removal of of invasives respond positively to native vegetation growth, if at invasives respond positively to native vegetation growth, if at all?all?

�� Look at the species that eat ivy and blackberry fruit and see whLook at the species that eat ivy and blackberry fruit and see which ich native plants they switch to. Will their abundance change?native plants they switch to. Will their abundance change?

�� Are HuttonAre Hutton’’s Vireos really declining and if so why?s Vireos really declining and if so why?

�� With work continuing on the project and invasive species controlWith work continuing on the project and invasive species controlongoing, how long should annual point counts be conducted?ongoing, how long should annual point counts be conducted?

�� Would a more refined analysis factoring in vegetation types and Would a more refined analysis factoring in vegetation types and changes be beneficial?changes be beneficial?

�� Additional years of point counts will provide more solid and Additional years of point counts will provide more solid and interesting data as to how birds respond to this project longinteresting data as to how birds respond to this project long--term.term.

Questions?Questions?