Central Valley Winter Raptor Survey 2007-2010...0.0 0.5 1.0 . 1.5 2.0 2.5 3.0 3.5 4.0 4.5 . 5.0 Tehama ButteS Madera Lincoln LsBanos Kings DunHls Folsom Jepson Shasta Beale LeGrand

Central Valley Winter Raptor Survey 2007-2010

Zach Smith & Ed Pandolfino

Acknowledgements

San Joaquin Audubon Sierra Foothills Audubon Sacramento Audubon Yolo Audubon Altacal Audubon Stanislaus Audubon US Fish & Wildlife Service California Rice Commission

Steve Abbott, Roger Adamson, Dan Brown, Ken Burton, Walt Carnahan, Chuck Carroll, Helene Cavoir, Debbie Daley, Bruce & Kathy Deuel, Julie Dinsdale, J. Frank, Alan England, Tim Fitzer, B. Getty, Jim Groesser, Ed

Harper, Ken Hashagen, Lois Hoy, Scott & Liam Huber, Sami LaRocca, John Lewis, E. Long, Len Mackenzie, Joe Medley, Frances Oliver, Harold & Sue Reeve, Phil Robertson, Jeff Seay, Mike Skram, Dan Stewart, Steve & Priscilla Summers, Craig Swolgaard, Dave Wagner,

Heath Wakelee, Bruce Webb, Gary Woods, Lowell Young, and Bob & Carol Yutzy.

Route Volunteers

Daniel Lee Brown Walt Carnahan Jack Ferrante Ed Harper Peter LaTourrette Robert Lin Diane Pizzo Tom Roach Phil Robertson Zach Smith Larry White

Photography Credits

Study Area

“This geomorphic province more than any other has been altered by activities of humans.” - from A Natural History of California

Tom Roach

Why Winter Raptor Monitoring in CV?

•High raptor abundance/diversity

Highest Winter Raptor Abundance

0

50

100

150

200

250

300

350

400

Ave/Count Circle Ave/100 pty hrs

CA Central Valley

TX/LA Coastal Plain

All Other

High Winter Raptor Species Richness

Species/Circle Range

CA Central Valley 12.1 7.8 - 13.9

TX/LA Coastal Plain 11.4 7.8 - 15.5


•High raptor abundance/diversity •Little data on habitat use


•High raptor abundance/diversity •Little data on habitat use •Increasing urbanization


•High raptor abundance/diversity •Little data on habitat use •Increasing urbanization •Conversion of grasslands to intense ag

- Northern Harrier (CA BSSC; FWS BCC most regions) - White-tailed Kite (CA fully-protected, historical declines) - Ferruginous Hawk (FWS BCC throughout breeding range) - Golden Eagle (FWS BCC most regions) - Prairie Falcon (FWS BCC in CA and throughout range) - American Kestrel (significant, widespread declines) - Loggerhead Shrike (CA BSSC; FWS BCC throughout range)

Species of Conservation Concern

Study Objectives

• Assess species richness, diversity, abundance and habitat associations of open-country raptors in the Central Valley during winter

• Establish simple survey protocol for future monitoring efforts (Repeatability)

• Create dataset useful for future land management decisions affecting critical wildlife habitat in CV

Tehama

Yuba Beale AFB Lincoln

Linden Oakdale

Le Grand

Delta

Butte N Butte S

Shasta

Folsom

Dunnigan Hills Woodland

Davis Jepson

Los Banos Madera

Kings

Survey Routes

Golden Eagle Larry White

Quantification of Habitat

- Assessed every half-mile

- Two blocks per point, one on either side of road

- One block = 500 meters x 800 meters

- Assign dominant habitat type for each block - 12 categories

- GPS coordinates taken for each point

Sample Route (Kings)

Sample Route with habitat (Lincoln)

Survey Protocol • Driving routes through open country 1x per month,

December - February (distance range: 42 - 81 km) • Surveys run mid-morning through early afternoon

(0800 - 1400) • Raptors observed (Area Search, NOT Point Count

methodology) within 500 m of survey road, mileage recorded to nearest tenth of mile for each bird, recorded species, age, sex, morph, behavior

• Distance categories from survey road:

– bird observed along survey road (perched only) – bird observed away from survey road

0%

5%

10%

15%

20%

25%

30%

35%

40%

Habitats Surveyed

% Total Survey

0%

5%

10%

15%

20%

25%

30%

35%

40%

Habitats Surveyed vs. All CV

% Total Survey

% Total CV

Number of Surveys 180 Total Survey Hours 1541 Total Area Surveyed 112,720 ha Total Birds Observed 20976 Average Density (birds/1000 ha) 20 ± 2 Average Species Richness (range) 9.6 ± 0.2 (5-16)

Habitat Associations

Grassland Specialists

Ferruginous Hawk

Ferruginous Hawk

-0.03

-0.02

-0.01

0.01

0.02

0.03

0.04

Grsld Row Rice Orch Urb Pstr Sav Alf Wtld Oth For

Vine other

Ferruginous Hawk (tot obs = 630)

Rough-legged Hawk

-0.005

0.000

0.005

0.010

0.015


Vine other

Rough-legged Hawk (tot obs = 143)

Prairie Falcon

-0.008

-0.006

-0.004

-0.002

0.000

0.002

0.004

0.006

0.008

0.010

0.012


Vine other

Prairie Falcon (tot obs = 232)

Golden Eagle

Wetland Specialists

Northern Harrier

-0.05

0.00

0.05

0.10

0.15


Vine other

Northern Harrier (tot obs = 1396)

Northern Harrier Jack Ferrante

Northern Harrier Jack Ferrante

-0.02

0.00

0.02

0.04

0.06

0.08


Vine other

White-tailed Kite (tot obs = 468)

Bald Eagle

-0.02

-0.01

0.01

0.02

0.03

0.04

0.05


Vine other

Bald Eagle (tot obs = 276)

Habitat Generalists

Red-tailed Hawk Phil Robertson

Red-tailed Hawk

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4


Vine other

Red-tailed Hawk (tot obs = 7950)

American Kestrel

-0.10

-0.05

0.00

0.05

0.10

0.15

0.20


Vine other

American Kestrel (tot obs = 3622)

Loggerhead Shrike

-0.04

-0.03

-0.02

-0.01

0.00

0.01

0.02

0.03

0.04

0.05


Vine other

Diff

eren

ce b

etw

een

habi

tat d

enst

iy a

nd o

vera

ll av

e. d

ensi

ty

Loggerhead Shrike

Impacts of Grazing of Grassland Raptors

0.00

0.02

0.04

0.06

0.08

0.10

WTKI NOHA FEHA RLHA PRFA LOSH

Grazed Grassland

Ungrazed Grassland

0.00

0.02

0.04

0.06

0.08

0.10

WTKI NOHA FEHA RLHA PRFA LOSH

Grazed Grassland

Ungrazed Grassland

Summary of Habitat Associations

TUVU WTKI NOHA BAEA Accipiters RSHA RTHA FEHA RLHA GOEA AMKE MERL PEFA PRFA LOSH

Grassland - - - + + + + - + + Row Crop - - - - - - - - -

Rice - + + + + - - - + - - Orchard - - - - - - - - - -

Urbanized - - - - - - - - Irr. Pasture + + + + + + - + - +

Savannah + - - - - - - - - - Alfalfa - + + - - + - + -

Wetland + + + + + + + - Other

Forage + + + - + Vineyard - - - - - - - -

Other + + - - - - -



Rice - + + + + - - - + - - Orchard - - - - - - - - - -




Forage + + + - + Vineyard - - - - - - - -

Other + + - - - - -



Rice - + + + + - - - + - - Orchard - - - - - - - - - -




Forage + + + - + Vineyard - - - - - - - -

Other + + - - - - -



Rice - + + + + - - - + - - Orchard - - - - - - - - - -




Forage + + + - + Vineyard - - - - - - - -

Other + + - - - - -

Birders should eat more beef...

and drink less wine.

Buy a VERY large dog...

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

Tehama

ButteS

Madera

Lincoln

LsBanos

Kings

DunHls

Folsom

Jepson

Shasta

Beale

LeGrand

Oakdale

Linden

Birds/1000 ha

Grslnd Density of Grslnd Specialists by Route

TOTAL

PRFA

GOEA

RLHA

FEHA

Tehama

Yuba Beale AFB Lincoln

Linden Oakdale

Le Grand

Delta

Butte N &S

Shasta

Folsom

Woodland & Dunnigan Hills

Davis & Jepson

Los Banos Madera

Kings

High Value Grasslands?

0.0

0.5

1.0

1.5

2.0

2.5

3.0

FEHA RLHA GOEA PRFA

ne SJQ Vly

all other

0

2

4

6

8

10

12

14

RTHA

ne SJQ Vly

all other

Fun Stuff...

0%

5%

10%

15%

20%

25%

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35%

40%

45%

RTHA FEHA RLHA

Perch Preferences of Buteos Pole

Tree

Fence

Ground

0%

5%

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30%

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40%

45%

RTHA FEHA RLHA

Perch Preferences of Buteos Pole

Tree

Fence

Ground

Battle of the Sexes!



Honey, you CAN’T be serious...

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AM

KE

Den

sity

(#/1

000

ha)

Female Density

Male Density

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KE

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sity

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Female Density

Male Density

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KE

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sity

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Female Density

Male Density

Hypotheses for AMKE Distribution by Sex


• “Everybody’s Happy”


• “Everybody’s Happy” – (Koplin 1973, Stinson et al. 1981, and Meyer and

Balgooyen 1987 )



Balgooyen 1987 ) • “Girls Rule”




– (Mills 1976, Ardia and Bildstein 1997, 2001, and Ardia 2002 )





• “First come, First Served”





• “First come, First Served”

– (Smallwood 1988)

Summary

• Certain habitats important to wintering raptors in the CV – Wetland, Grassland, Pasture, Alfalfa, Rice

• Some habitats largely avoided

– Urban, Row Crop, Orchard, Vineyard • Grassland species NEED grassland and need it grazed

• Grasslands of the northeast corner of the San Joaquin

Valley seem to be particularly rich. – Combine with other datasets to try to understand why

I’m outta here...

Documents

Central Valley Winter Raptor Survey 2007-2010...0.0 0.5 1.0 . 1.5 2.0 2.5 3.0 3.5 4.0 4.5 . 5.0 Tehama ButteS Madera Lincoln LsBanos Kings DunHls Folsom Jepson Shasta Beale LeGrand