Not Too Hot, Not Too Cold

How adaptable are shorebirds to variable breeding conditions?

Rebecca McGuire, Richard Lanctot, Sarah Saalfeld, Dan

Ruthrauff, Chris Latty, and Stephen Brown

Shorebird Declines

Nearly half of shorebird populations worldwide, including 61% of populations in North America and 88% of species in the East Asian–Australasian Flyway, have shown long-term population declines associated with anthropogenic change

• The Arctic Coastal Plain is one of the most important avian breeding grounds in the world

• Millions of breeding birds, of over 90 species

• Greater variability, less predictable weather

• Increased precipitation, primarily in winter, delayed snowmelt

Climate Change on the Arctic Coastal Plain

How will increasing variability of climatic conditions impact tundra-nesting shorebirds?

Comparing shorebird nesting parameters between two early and two late summers

Utqiagvik

Colville RiverPrudhoe Bay

Canning River

Early20152016

Late20172018

Early June, 2016

Early June, 2018

Who Wins in the Climate Change Game?

Conservative

Site faithful, territorial, monogamous, bi-parental, relatively evenly spaced

Opportunistic

Uniparental, polygamous, not site faithful, not evenly spaced

Nest searching, floating eggs, nest checks, etc.

Conservative Species: AMGP, BARG, BBPL, DUNL, RUTU, SESA, STSAS, WESA, and LBDO

Opportunistic Species: RNPH, REPH, BBSA, PESA

Methods

156

158

160

162

164

166

168

170

172

Barrow Colville Prudhoe Canning

Ave

rage

Init

iati

on

Dat

e Early

Late

Results- Nest Initiation

F= 35.4, p<0.001

Results- Nest Initiation

150

155

160

165

170

175

Ave

rage

Init

iati

on

Dat

e

Early

Late

0.000

0.500

1.000

1.500

2.000

2.500

3.000

3.500

4.000

4.500

Barrow Colville Prudhoe Canning

Den

sity

(n

est

s/h

a)

Early

Late

Results- Nest Density

Results- Nest Density

0.00

0.50

1.00

1.50

2.00

2.50

3.00

Barrowconservative

Barrowopportunistic

Colvilleconservative

Colvilleopportunistic

Prudhoeconservative

Prudhoeopportunistic

Den

sity

(n

est

s/h

a)

Early

Late

Barrow Early

amgp barg bbpl bbsa dunl lbdo pesa

reph rnph rutu sesa stsa wesa

Colville Early

amgp barg bbpl bbsa dunl lbdo pesa

reph rnph rutu sesa stsa wesa

Prudhoe Early

amgp barg bbpl bbsa dunl lbdo pesa

reph rnph rutu sesa stsa wesa

Barrow Late

amgp barg bbpl bbsa dunl lbdo pesa

reph rnph rutu sesa stsa wesa

Colville Late

amgp barg bbpl bbsa dunl lbdo pesa

reph rnph rutu sesa stsa wesa

Prudhoe Late

amgp barg bbpl bbsa dunl lbdo pesa

reph rnph rutu sesa stsa wesa

Results- Species composition

Early: mean = 8.86, 95%CI = 8.14 - 9.71Late: mean = 8.13, 95%CI = 7.38 - 8.88

Mean difference: 0.73 (95% CI: -0.34 - 1.86)

Model AICc ΔAICc wi K

Site*Spring type 5750.78 0.00 0.68 8Site*Spring type*Breeding strategy 5752.32 1.54 0.32 16

Spring type 6054.28 303.50 0.00 2

Site*Spring type 6108.93 358.15 0.00 4

(.) 6140.81 390.03 0.00 1

Breeding strategy 6142.52 391.73 0.00 2

Results- Nest Survival Model Selection

0.82

0.84

0.86

0.88

0.9

0.92

0.94

0.96

0.98

1

Barrow Colville Prudhoe Canning

Dai

ly S

urv

ival

Rat

e

Early

Late

Results- Nest Survival

Results- Nest Survival

0.8

0.82

0.84

0.86

0.88

0.9

0.92

0.94

0.96

0.98

1

1.02

Dai

ly S

urv

ival

Rat

e

Conservative

Opportunistic

Early SpringsEarlier initiationHigher nest density Slightly higher species richness

Late SpringsLater initiationLower nest densitySlightly lower species richness

Summary

Nest survival pattern does not vary by reproductive strategy within sites, between early and late springs

Did predators obscure the importance of breeding strategy in variable springs?

Predator control?Sites with human presence?

Is breeding strategy less important than habitat selection?

Did my groupings of strategy obscure effects?

Does effect of spring type decrease as we head east?

Does spring condition impact chick survival rather than nest survival?

Special thanks to the hard working technicians!

Questions?