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Table 2 A priori models (n = 22) considered for known-fate estimation of monthly survival probabilities (MSP) of PTT-implanted tundra swans from Alaska, USA, 2008–2012. Ten swans were marked and released at each of 5 breeding areas: Lower Alaska Peninsula (LAP), Bristol Bay Lowlands (BBL), Yukon-Kuskokwim Delta (YKD), Kotzebue Sound Lowlands (KSL), and Colville River Delta (CRD). Year 1 refers to the 12 months following release in August of 2008. K = number of model parameters

From: Demographic outcomes of diverse migration strategies assessed in a metapopulation of tundra swans

MSP model

K

Model description

Location models

 S(Migration distance)

2

Survival varies relative to annual migration distance

 S(Management population)

2

Survival varies by Western Population (LAL, BBL, YKD, KSL) and Eastern Population (CRD)

 S(Wintering area)

3

Survival varies by location of wintering area (BBL, YKD, KSL + LAL + CRD)

 S(Breeding area)

5

Survival varies by 5 breeding areas (LAL + BBL + YKD + KSL + CRD)

Time models

 S(.)

1

Survival is constant

 S(Yr)

4

Survival varies by year

Season models

 S(Migration)

2

Survival during migration seasons (Autumn, Spring) varies from sedentary seasons (Winter, Breed)

 S(Autumn)

2

Survival during Autumn varies from other seasons (Spring, Winter, Breed)

 S(Season)

4

Survival varies by 4 seasons (Spring + Autumn + Winter + Breed)

Age and breeding status models

 S(Age*Yr1 + Yrs2-4)

3

Survival varies between SY and ASY birds in Year 1 and is constant thereafter

 S(Breeding status*Yr1 + Yrs2-4)

3

Survival varies by breeders and non-breeders in Year 1 and is constant thereafter

Transmitter effect models

 S(Yr1 + Yrs2-4)

2

Survival in Year 1 varies from years thereafter

 S(Yr1*Trend + Yrs2-4)

3

Survival varies in a linear monthly trend during Year 1 and is constant thereafter

 S(Mo1-2 + Mo3-12 + Yrs2-4)

3

Survival varies by Months 1-2 and Months 3-12 and is constant thereafter

 S(Yr1*Trend + Yr)

5

Survival varies in a linear monthly trend during Year 1 and by year thereafter

 S(Mo1-2 + Mo3-12 + Yr)

5

Survival varies by Months 1-2 and Months 3-12 and by year thereafter

Season * Year models

 S(Migration*Yr1 + Yrs2-4)

3

Survival during migration seasons (Autumn,Spring) varies from sedentary seasons (Winter, Breed) in Year 1 and is constant thereafter

 S(Autumn*Yr1 + Yrs2-4)

3

Survival during Autumn varies from other seasons (Spring, Winter, Breed) in Year 1 and is constant thereafter

 S(Season*Yr1 + Yrs2-4)

5

Survival varies by 4 seasons (Spring + Autumn + Winter + Breed) in Year 1 and is constant thereafter

 S(Migration*Yr1 + Yr)

5

Survival during migration seasons (Autumn, Spring) varies from sedentary seasons (Winter, Breed) in Year 1 and by year thereafter

 S(Autumn*Yr1 + Yr)

5

Survival during Autumn varies from other seasons (Spring,Winter,Breed) in Year 1 and by year thereafter

 S(Season*Yr1 + Yr)

7

Survival varies by 4 seasons (Spring + Autumn + Winter + Breed) in Year 1 and by year thereafter