conservation biogeography of a rare prairie grouseumanitoba.ca/faculties/environment/media/... ·...

Conservation biogeography

of a rare prairie grouse

Michael A. Patten

University of Oklahoma Oklahoma Biological Survey, Department of Biology, and

Sutton Avian Research Center

use of biogeographical techniques and principles to guide conservation planning

for example, island biogeography • species-area relationships

• degree of isolation

areas of endemism

patterns of species richness

trait variation across space

can consider the past and future, too

Conservation Biogeography

lower panel: Smith-Patten and Patten (2015, Biotropica 47:128–135)

Examples include: o forecasts

o reserve selection

o invasive species

Single species or entire communities.

Does one size fit all?

The Lesser Prairie-Chicken

photos by Noppadol Paothong

o a medium-sized grouse endemic to southern shortgrass and mixed grass prairies

o endemic to the south-central United States (i.e., it is found nowhere else, and never has been)

Lekking

o lek mating system

o as with other open-country grouse, males gather communally to display to females . . . and to squabble with other males

photos by Greg W. Lasley, Noppadol Paothong, and Joel Sartore

o the goal is to lure a female to mate . . . at which point the male continues to display and the female heads off to

• build a nest

• guard her eggs

• (with luck) raise her young

Data Collection

Sample Sizes

• 898 radiotagged birds (>1000 banded) 550 in Oklahoma, 1999–2014 348 in New Mexico, 2000–2005

• 267 nests 142 in Oklahoma, 1999–2014 125 in New Mexico, 2000–2005

• >60,000 individual tracking locations

• ~18,000 vegetation samples 6483 vegetation and general cover transects 10488 “cone of vulnerability” and microclimate 737 1-m2 grass and forb plots

The Data

o survivorship and cause of mortality

o movements (and home range)

o habitat use (including for leks and broods) – woody vegetation – grasses and forbs – “cone of vulnerability” – microclimate

o nest placement

o demography (clutch size, nest success, reproductive effort, etc.)

o mitochondrial DNA and microsatellites

o nutrition (blood screening)

Southern Shortgrass Prairie

Habitat Loss

Samson et al. (2004, Wildlife Society Bulletin 32:6–15)

Population Decline

• total world population numbers 20,000–35,000

• population has declined by >90% in the past century

trend from Hagen et al. (2009, Journal of Wildlife Management 73:1325–1332)

The U.S. Endangered Species Act

almost exactly a year ago today . . .

the species was listed as threatened under the U.S. Endangered Species Act

Controversy

Capitol Hill Outsider (2014)

Ecoregions

Ecoregions

10.4 birds / km2

23.3 birds / km2

13.0 birds / km2

18.1 birds / km2

Ecoregions

plot from Oyler-McCance, DeYoung, Hagen, Johnson, Larsson, and Patten (in prep., targeted for Conservation Genetics)

STRUCTURE plot for 13 microsatellite loci

Selectivity

Patten et al. (2005, Journal of Wildlife Management 69:1270–1278)

Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Me

an

Exp

osu

re A

ngle

(o)

0

10

20

30

40occupied

random

2003 2004

Microclimate


Larsson et al. (2013, Southwestern Naturalist 58:135–149)

Predator Avoidance

Larsson et al. (2013, Southwestern Naturalist 58:135–149)

summer '03 autumn '03 winter '03/04 spring '04 summer '04 autumn '04

Mean A

ppare

nt T

em

pera

ture

(oC

)

0

5

10

15

20

25

30

Mean E

xposure

Angle

(o)

4

6

8

10

12

14

16

18

20depredations

angle

temperature

Woody Vegetation and Adult Survival

Days

0 200 400 600 800 1000

Pro

ba

bili

ty o

f S

urv

iva

l

0.0

0.2

0.4

0.6

0.8

1.0

shrub cover <10%

shrub cover 10–20%

shrub cover >20%


Too Many Shrubs

cedar photos by Donald H. Wolfe

Loss of Shrub Cover

Sagebrush Steppe Treatment Evaluation Project <http://www.sagestep.org/>

Too Few Shrubs

Patten and Kelly (2010, Ecological Applications 20:2148–2156)

Mean Shrub Cover (%)

5 10 15 20 25 30

Num

ber

of N

ests

0

2

4

6

8

10 tebuthiuron

untreated

Solutions

The Prairie Has Changed

Pruett et al. (2009, BioScience 59:257–262)

The Future

photos by Donald H. Wolfe

Avoidance of Highways

Pruett et al. (2009, Conservation Biology 23:1253–1259)


Avoidance of Power Lines


Highways + Power Lines


< 100 m 100–500 m

Lesser Prairie-Chicken

transmission line 6 (88–129) 156 (398–471)

Highway 412 24 (25–48) 182 (125–165)

Highway 283 20 (135–181) 166 (586–674)

Greater Prairie-Chicken

transmission line 0 (16–35) 5 (83–121)

no evidence of avoidance > 500 m from any feature

Avoidance Behavior*

*Behaviour

meters (± SE)

0 200 400 600 800 1000 1200 1400

oil or gas wellheads

center-pivot fields

unimproved roads

improved roads

roads (any type)

buildings

transmission lines

nests

birds

data from Robel et al. (2004, Transactions of the N. Am. Wildlife Natural Resources Conference 69:251–266)

Other Manmade Features

Nest Placement

data from Pitman et al. (2005, Journal of Wildlife Management 69:1259–1269) meters

0 500 1000 1500 2000

tranmission line

wellhead

building

unimproved road

improved road

center-pivot

transmission line

And so on . . .

Winder et al. (2014, Ecosphere 5[1]:3)

Hagen et al. (2011, Studies in Avian Biology 39:63–75

Planning Tools

Correlations

Truism 1: Where there is a powerline or a road there typically is a fence.

Spellerberg (1998, Global Ecology and Biogeography Letters 7:317–333)

Truism 2: And where there is a fence there typically is:

o habitat loss o livestock o woody vegetation encroachment

Fence Collisions

Determining Cause of Death

o radio-transmitters on our Lesser Prairie-Chickens equipped with a mortality switch

o recovered carcasses are examined to determine one of four causes of death: o raptor kill o mammal kill o collision — fence, power line, or car o other (or unknown) — this category has included, for

example, drowning in a stock tank

o note that collisions are associated with habitat fragmentation

Mortality Cause

proportion of mortalities

0.0 0.1 0.2 0.3 0.4 0.5

raptor

mammal

fence

powerline

vehicle New Mexico

Oklahoma

data from Wolfe et al. (2007, Wildlife Biology 13[supp. 1]:95–104)

n = 260

Days

0 200 400 600 800 1000

Pro

ba

bili

ty o

f S

urv

iva

l

0.0

0.2

0.4

0.6

0.8

1.0

New Mexico

Oklahoma

Days

0 200 400 600 800

Pro

ba

bili

ty o

f S

urv

iva

l

0.0

0.2

0.4

0.6

0.8

1.0

New Mexico

Oklahoma

Survival by Sex

♂

♀

Patten et al. (2005, Evolutionary Ecology Research 7:235–249)

Month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Pra

irie

-chic

ke

n k

ills d

ue

to

pre

da

tio

n

5

10

15

20

25

Pro

po

rtio

n o

f m

ale

s k

ille

d

4

6

8

10

12

14

16

18

predation

male mortality

Month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Pra

irie

-chic

ke

n k

ills d

ue

to

co

llisio

ns

0

3

6

9

12

15

18

Pro

po

rtio

n o

f fe

ma

les k

ille

d

0

6

12

18

24

30

36collisions

female mortality

♀♀ and collisions

♂♂ and predation


Life-history Evolution

o Lifetime reproductive value o a species-specific trait

o roughly constant among populations

o Trade-offs o both fecundity and lifespan contribute

o r selection vs. K selection

o common in birds

Predictions! Higher mortality of Oklahoma ♀♀ o larger clutch sizes

o more fledglings

o attempt more nests in a season

Fecundity

New Mexico Oklahoma

fre

que

ncy

0

2

4

6

8

10

12 clutch size

fledglings

adapted from Patten et al. (2005, Evolutionary Ecology Research 7:235–249)

Mean nest attempts

/ year (± SE) 1.07 ± 0.04 1.55 ± 0.11

Proportion re-nesting

in same year 0.15 0.94

Fragmentation


New Mexico Oklahoma o mean parcel size ~1300 ha ~180 ha o roads / 10-km2 8.0 ± 2.3 14.5 ± 1.7 o fencing sections* ¼-sections

o land tenure differences have a historical basis (Homestead

Act vs. Spanish Land Grant)

o land tenure in the Texas Panhandle is much more like that in Oklahoma than in New Mexico


Land Tenure

*1 section ≈ 260 ha and is 1.6 km per side

Plasticity?

Cumulative Precipitation (cm)

0 2 4 6 8 10 12 14 16

Me

an C

lutc

h S

ize

7

8

9

10

11

12

13 New Mexico

Oklahoma2002 (7)

2003 (4)

2000 (5)

2001 (7)

2001 (15)

1999 (2)

2002 (25)

2000 (2)

2003 (13)


Nutrition?

retinol (vitamin A)

0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

clu

tch

siz

e

8

9

10

11

12

13

vitamin E

0 2 4 6 8 10

lutein

0 2 4 6 8

clu

tch

siz

e

8

9

10

11

12

13

zeaxanthin

0 2 4 6

canthaxanthin

0.0 0.5 1.0 1.5 2.0

clu

tch

siz

e

8

9

10

11

12

13

xanthophylls

0 2 4 6 8 10 12 14 16

Only vitamin A (as retinol) is correlated with clutch size . . . but in the “wrong” direction:

New Mexico ♀♀ have higher levels of vitamin A but lay smaller clutches.

Sutton Avian Research Center unpubl. data

o ♀♀ in Oklahoma die from fence collision far more often than do ♀♀ in New Mexico

o more roads more fences more collisions (ultimately a result of historic land parceling)

o survivorship in Oklahoma has (apparently) selected for clutch size and re-nesting rate

o larger clutches do not appear to be the result of variation in rainfall or nutrition

In summary . . .

The fate of the mixed

grass prairie population?

Years

0 5 10 15 20 25 30

Pro

ba

bili

ty o

f E

xtin

ctio

n

0.0

0.2

0.4

0.6

0.8

1.0

2005 Patten et al. (2005, Evolutionary Ecology Research 7:235–249)

2022

Year

2004 2006 2008 2010 2012 2014 2016 2018

Po

pula

tio

n S

ize

0

500

1000

1500

2000

2500

Oklahoma

New Mexico

100% of simulations forecast a population crash in Oklahoma, yielding

Management Strategies

Option 1: Increase fecundity

Requires clutch sizes approaching 30 (!).

Requires 3 successful nests / year.

i.e., reproductive output must double.

Pruett et al. (2011, Conservation Genetics 12:1205–1214)

Option 2: Reduce ♀ mortality

At current Ne, raising adult ♀ survivorship to the level of that elsewhere (e.g., New Mexico) would ensure population persistence.

Reducing Mortality

see Baines and Andrew (2003, Biological Conservation 110:169–176)

Reducing mortality

Wolfe et al. (2009, Ecological Restoration 27:141–143)

Fence marking

Does marking work?

efficacy not assessed fully, but . . . all except one collision 2007–2014 have been along unmarked fences!

Stevens et al. (2012, Wildlife Society Bulletin 27:141–143)

Winder et al. (2015, Ecosphere in press)

o kernel HR estimators

o land cover from aerial photos & GIS layers

o software estimates of habitat proportions & edge

Extent of Contiguous Habitat (ha)

0 10000 20000 30000 40000

Ho

me

Ra

nge

(ha

)

500

1000

1500

2000

2500

Patten et al. (2011, Studies in Avian Biology 39:51–62)

Wrapping Up

One size does not fit all!

A single, all-encompassing plan that would benefit each Lesser Prairie-Chicken population in the same way cannot be devised.

Instead, we must consider geographic variation among populations to guide management and conservation.

Thank You Save the prairie chicken!

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