Talk Outline:

• Introduction– Conceptual backgroundp g– Natural history

• Mayfly case studyMayfly case study• Implications

Population Biology: How many are there?

Nt+1 = Nt + Births - Deaths + Immigrants - Emigrants

Population Biology:Historical assumption

Nt+1 = Nt + Births - Deaths + Immigrants - Emigrants

Closed PopulationImmigration = Emigration

Metapopulation:Levins (1969, 1970)

Population of populations, connected by somePopulation of populations, connected by some degree of dispersal

Metapopulation:

Population of populations, connected by some

Levins (1969, 1970)Population of populations, connected by some

degree of dispersal.

Problem-driven Investigations: Collect data to address hypotheses about a specific species, population. “Applied” science.

Concept-driven Investigations: Collect data to address general hypotheses. Find a system amenable to question. “Basic” science.

Life Cycle of Callibaetis ferrugineus hageni:

2 weeksSubimagoImago

2 weeks

Terrestrial Habitat

1 2 3 BWP

Aquatic Habitat

50 weeks

Aquatic Habitat

Si F dit C llib ti

r2 = 0.9651800

2000e

Size-Fecundity, Callibaetis

1200

1400

1600

1800

r Fem

ale

600

800

1000

1200

Eggs

per

200

400

600

No.

E

2.0 3.0

Female Mesonotum Length (mm)

Populations of populationsPopulations of populations

ffer

ualit

y

atch

es D

ifSource-Sink

Balanced Dispersal

Patc

h Q

u P Balanced Dispersal

tions

ulat

ions

rium

ance

in P

hy P

opul

at

Met

apop

u

on-E

quili

b

Varia

All

Equ

al “Classic” Patc

hM

No

Isolated Connected

A

Degree of Exchange Among Patchesg g g

After Harrison and Taylor 1997

Talk Outline:

• Introduction– Conceptual backgroundp g– Natural history

• Mayfly case studyMayfly case study• Implications

Emerald Lake

BellviewSpatial Patterns

Friends Cut

Bellviewof Abundance:

Quigley

Rustlers

MarmotAvery

TxFsBr

Gothic

1 km

FS 401

UBBP

TxFsBrN

Pond With TroutFishless Pond

RMBL

Avalanche

UBBP

Levy

S.E

.) 3000

Trout Ponds(m

-2 +

/- S

2000

Trout PondsFishless Ponds

P <0 001

Den

sity

1000

Pfish<0.001n = 12 ponds

allib

aetis

1000

Bare FSedge F

Bare NF

Sedge NF

Ca

0

ffer

ualit

y

atch

es D

ifSource-Sink

Balanced Dispersal

Patc

h Q

u P Balanced Dispersal

tions

ulat

ions

rium

ance

in P

hy P

opul

at

Met

apop

u

on-E

quili

b

Varia

All

Equ

al “Classic” Patc

hM

No

Isolated Connected

A

Degree of Exchange Among Patchesg g g

After Harrison and Taylor 1997

-Which model best describes the Callibaetis metapopulation?

Nonselective Dispersal:Nonselective Dispersal: Source-Sink Dynamic

Source Patch, K > 1: Sink Patch, K= 0:

R i P d iRecruitment Production Recruitment Production(eggs) (eggs)

Net MigrationNet Export Net ImportNet Export Net Import

Selective DispersalSelective DispersalBalanced Dispersal Dynamic

Patch with high K Patch with low K

Recruitment Production Recruitment Production

P it

(eggs) (eggs)

Per capita exchange equal

“Balanced” Dispersal

No net import or export of eggs

J A S O N M J J A S O N

1997 1998

J A S O N- M J J A S O N

IceIce

AdultsAdults

1997-8 CohortLarvae

1998-9 CohortProduction

R iRecruitment

Microhabitat Scale: Adult Emergence Rate

7000

from the Sedge Microhabitatm

-2

5000

6000Emergence p=0.029Recruitment p=0.298n=12

Rat

ebe

r * y

r-1 *

3000

4000

5000

Num

b

2000

3000

UBBPllview

Averyanche

FS 401iends

QuigleyMarmot

stlersTxFsBr

LevyGothic

0

1000

UBBellvi Av

AvalancFS 4

FrienQuig

MarmRustl

TxFs Le Got

Pond

Emigration Index (EI):Closed Populations

EIi = Recruitmentexpected / Recruitmentobserved

where

Recruitmentexpected = Ni * Fecundityi * Mortalityadult

Emigration Index (EI):Source Sink Dynamic:

Sink = Net Importer:

Production

Source = Net Exporter:

Recruitment(Observed)

Production(Expected

Recruitment) RecruitmentProduction( )

EI > 1 EI < 1

Emigration Index (EI):Balanced Dispersal:

High K: L K

RecruitmentP d ti

High K: Low K:

RecruitmentProduction RecruitmentProduction

EI = 1EI = 1 EI 1EI 1

Emigration Index on

d-1)

200000

300000w/ Observed Adult Mortality Rate

Net Exporter ~ Source

mal

es *

Po

100000

200000p

ndex

(Fem

-100000

0

mig

ratio

n I

-200000

-100000Net Importer ~ Sink

BellviewAvery

UBBPFS 401

AvalancheLevy

GothicFriends

QuigleyTxFsBr

RustlersMarmot

Em

-300000

Pond

Patch Selection Behavior:3Patch Selection Behavior:

nsity

) p = 0.513

2

tion

Den

m-2

yr-1

) p

1

Ovi

posi

t(N

o.

0No Fish Trout

O

• Conclusions: Patterns of Abundance:• Conclusions: Patterns of Abundance:– Source-Sink Metapopulation:

L Diff i E R t• Large Differences in Emergence Rate• Local Production = Local Recruitment

E i i I d N Mi i• Emigration Index: Net Migration• Non-Selective Oviposition

• Mayfly as model system

Obj ti• Objectives:- Spatial Patterns- Patch Quality (Fish)- Dispersal- Larval Plasticity

Beaver Pond Patches:

3Pond Type: Treatment:

3

3Fishless

d i

Fishless Control

3

3

Trout Reduction

3With Trout

3

Trout Introduction

3 Trout Control

20

Trout Density by Treatment

Avalanche

12

16

20Bellview FS 401

% C

.I.)

uctio

n

0

4

8

2 +/

- 95

%

ntro

du

BeforeAdded

After *0

BeforeAdded

After *Before

AddedAfter *

Friends(#/1

00 m

16

20Levy Quigley

InFriends

Den

sity

(

8

12

16 Levy Quigley

duct

ion

Before After

Trou

t

0

4

Before After Before After

Red

Trout Density by Treatmenty ysi

ty

5 %

C.I.

)

Gothic16

20MarmotTexas Fishing

Trout Controls:

out D

ens

m2

+/- 9

5

4

8

12 Bridge

Tro

(#/1

00 m

Before After0

4

Before AfterBefore After

Local Population Growth Rate:

λ = S(l )i * S( d lt ) * Fiλ S(larvae)i S(adults) Fi

λ 1 Si kλ > 1 = Sourceλ < 1 = Sink

Terrestrial AdultStages:

S(adult)

Fi

1997-8 Cohort

Aquatic Larvae:S(larvae)i1997 8 Cohort

1998-1999 Larval Cohort

(larvae)i

1998 1999

J J A S O M J J A SSnowCover

Do Trout Reduce Patch Quality? o ou educe c Qu y?Callibaetis Population Growth Rate (λ ):

With Trout

te 4

5O

With Trout

Fishless3

row

th R

at

3

4

O

2

pula

tion

G

2O

O

Sources1

Pop

0

1 Sinks

0

Trout Density (# / 100 m2)0 1 2 3 4 5 6 7

00

Conclusions:• Patch Quality

d λ– Trout reduce λ– > 1 Trout 100 m-2 = SinkS– < 1 Trout 100 m-2 ~ Source

• Objectives:

- Spatial Patterns

- Patch Quality

- Dispersal

L l Pl i i- Larval Plasticity

15N Stable Isotope Mark-Recapture Experiment: 2 Patches

5 15NH Cl5 g 15NH3Cl

26,000

Addition Pond Unmarked Pond

300,000 250 m

(No Fish)

Ovipositing FemalesUnmarked PondAddition Pond

12P < 0.001 ed

emal

es

8

10P 0.001

Unm

arke

mbe

r of F

e

4

6

m A

dditi

on

Num

0

2 From

5 July 20 July 29 July 8 August 0

5 July 20 July 29 July 8 August

P k E P k EPeak Emergence Peak Emergence

25

Swarming Males

20

25al

es

p<0.001

ked

15

arm

ing

M

Pond U

nmar

k

10

er o

f Sw

a

Add

ition

P

5

Num

be

From

A0

Addition Pond Unmarked Pond

C l iConclusions:• Dispersal:

–Strongly Sex-BiasedStrongly Sex Biased – Consistent w/ mating system

Hi h P t h E h R t–High Patch Exchange Rate

• Objectives:j- Spatial Patterns

Patch Quality- Patch Quality- Dispersal

l- Larval Responses

“Appropriate” AntipredatorAppropriate Antipredator Traits:

• Behavior:– Reduced Activity

• Life History:– Reduced Growth Rate

– Increased Crypsis – Accelerated Development– Altered Size at Maturity

Fi ld P l ti• Field Populations:– Timing of Emergence– Size at Emergence

• Tank Experiment:– Timing of Emergence– Timing of Emergence– Size at Emergence

B h i– Behavior

D t f E f Fi ld P l ti

29 JulyE.)

Date of Emergence from Field Populations

29 July

e (+

/-1

S.

p = 0.99512 ponds

9 July

Em

erge

nce

of P

eak

E

19 June

Dat

e

High TroutLow Trout

Si t E f Fi ld P l ti3

.) Size at Emergence from Field Populations

0 659

2

+/-1

S.E

.

Males Femalespfish = 0.659psex < 0.0001

1ass

(mg

+

0

1

Dry

Ma

High TroutLow Trout0

High TroutLow Trout

D l t R t i T k

Males24 August

Females

Development Rate in Tanks

p = 0 885Males

20 August

Females pfish 0.885psex < 0.000112 tanks

16 A t16 August

12 August

Size at Emergence from Tanks

Fishless

1.7 1.9 2.1 2.3 2.5 2.7 1.7 1.9 2.1 2.3 2.5 2.7

pfish = 0.605

100 70

Trout Cues

pfish 0.605psex = 0.0004

Males

60708090

nt

Females

40

50

60

nt20304050

Cou

n

20

30

40

Cou

n~400 Eggs ~1,100 Eggs

1.7 1.9 2.1 2.3 2.5 2.7

Mesonotum Length (mm)

1020

1.7 1.9 2.1 2.3 2.5 2.7

Mesonotum Length (mm)

10

Mesonotum Length (mm) g ( )

Larval Mayfly Behavior in Tanks:

1.5

Larval Mayfly Behavior in Tanks:

30

/ Tan

k

1 0(min

-1)

ues

ues

ues

ues

LateEarlypfish = 0.584ptime < 0.001pperiod < 0.001

Development:

20

ber V

isib

le 1.0

min

g R

ate

Trou

t Cu

No

Trou

t Cu

Trou

t Cu

No

Trou

t Cu

10Num

b 0.5

Sw

imm

0 0.0

C i

• Larval Responses (Not!):

Conclusions:

• Larval Responses (Not!):– No Life History Shift

N Eff t f T t Si– No Effect of Trout on Size– No Anti-predator Behavior

I d A ti it L t i D l t• Increased Activity Late in Development

S l ti

• Why Not?

Speculation:

• Why Not?– Introduced Predator? Do non-native

trout create “ecological traps”?trout create ecological traps ?– Vulnerable to Native Trout– Strong Response in Baetisg p

– Need to test

Speculation:

• Why Not?

Speculation:

– Introduced Predator?– Lack of Trade-off?– Phylogenetic Inertia

• Ephemeral Larval Habitat• Appropriate Anti-Invertebrate Behavior

Speculation:• Why Not?

I t d d P d t ?

Speculation:

– Introduced Predator?– Lack of Trade-off?– Phylogenetic Inertia

• Ephemeral Larval HabitatA i t A ti I t b t B h i• Appropriate Anti-Invertebrate Behavior

• Dispersal from Sources to Sinks

Summary

• Source-Sink Metapopulation:• Life HistoryLife History• Dispersal / Habitat Selection

BehaviorBehavior• Larval Behavior• Predator Distribution

iffer Callibaetis mayfly population

ualit

y

Patc

hes D

iSource-Sink

ss

Patc

h Q

u P

ibriu

m

pula

tions

pula

tion

ance

in P

Non

-Equ

ili

tchy

Pop

Met

apop

Varia

Non

e “Classic”

N

PatM

Isolated Connected

N

Degree of Exchange Among Patches

After Harrison and Taylor 1997

Traditional View of Complex Life Cycles:p y(Most plants, invertebrates, amphibians, and fishes)

jReproduction & Dispersal

ProductionRecruitment

1 2 3 j-1

Growth Stages

Complex life cycles in spatially complex habitats:

1 2 3 j-1

1 2 3 j-1

Reproduction& Dispersal

Unequal Production

NonselectiveRecruitment p

jec u e

1 2 3 j 1

1 2 3 j-1

1 2 3 j-1

Growth

Source sink dynamics may be common inSource-sink dynamics may be common in groups with “constrained” dispersal:

• Social (Territorial):– Birds– Mammals– some fishes

Source sink dynamics may be common inSource-sink dynamics may be common in groups with “constrained” dispersal:

• Social (Territorial):– Birds

• “Passive” dispersal:– Plankton

– Mammals– some fishes

– Marine invertebrates– Pathogens– Plants– Agricultural Pests

Algae– Algae – Marine & FW Fishes– Aquatic insectsBold = Commercially Important Aquatic insectsBold Commercially Important

Management ImplicationsB h i d h bi li i• Behavior and habitat quality interact to determine regional population dynamicI i id if• Imperative to identify sources– Conservation Targets

P / P h / I i i (– Pests / Pathogens / Invasive species (e.g, Eurasian Water Milfoil)

• Management of “Patch Quality”• Management of Patch Quality– Trout stocking programs

“Ecological Traps”– Ecological Traps