Ecological Archives E096-193-A1

Justin C. Touchon, Michael W. McCoy, Tobias Landberg, James R. Vonesh, and Karen M. Warkentin. 2015. Putting /g in a new light: plasticity in life history switch points reflects fine-scale adaptive responses. Ecology 96:21922202. http://dx.doi.org/10.1890/14-1301.1

Appendix A. Details on the structure of statistical models used in the analyses and three figures showing predation on tadpoles and/or metamorphs after our second census, the relationship between density of tadpoles in mesocosms and resulting SVL of metamorphs, and the predator-induced variation in developmental stages of metamorphs at emergence from the water.

Table A1. Structure of linear and generalized linear mixed models (LMM and GLMM) used in analyses. See text for explanation of fixed and random effects. All random effects are for random intercept except as otherwise noted. Sample sizes may vary across models due to outliers being excluded that caused poor model fit or had undue leverage or because data were not complete for all individuals due to occasional mortality during tail resorption.

Model

N

Response

Fixed effects

Random effects

Error distribution

Larval survival

122
(61 tanks at 2 time points)

# tadpoles alive out of starting number

Time,
Hatching age,
Larval predator

Block,

Time (random slope)

Binomial

Larval size

4264*
(2266 at 1st census, 1998 at 2nd census)

log (total tadpole length)

Time,
Hatching age,
Larval predator

Block, Tank nested within Block, Time (random slope)

Gaussian

Survival to metamorphosis

61

# metamorphs emerged per tank

Hatching age,
Larval predator,

Metamorph predator,
log (Age at metamorphosis)

Block, Tank nested within Block

Binomial

Predation after 2nd census

61

# individuals killed (or missing) per tank

Larval predator,
Metamorph predator,

Block

Gaussian

Time to metamorphosis

2191
(individuals nested within 61 tanks)

log (Age at metamorphosis)

Hatching age,
Larval predator,
Metamorph predator,

Block, Tank nested within Block

Gaussian

Size at metamorphosis

2172
(individuals nested within 61 tanks)

log (SVL at emergence)

Hatching age,
Larval predator,
Metamorph predator,
log (Age at metamorphosis)

Block, Tank nested within Block

Gaussian

Mean size at metamorphosis (effects of thinning)

61

log (SVL at emergence) – mean per tank

Larval predator,
Number of tadpoles alive at 2nd census

Block

Gaussian

Tail length at emergence

2191
>(individuals nested within 61 tanks)

log (Tail length)

Hatching age,
Larval predator,
Metamorph predator,
log (SVL at emergence)

Block, Tank nested within Block

Gaussian

Duration of metamorphosis

2181
(individuals nested within 61 tanks)

log (# days from emergence to Gosner stage 46)

Hatching age,
Larval predator,
Metamorph predator,
log (Tail length)

Block, Tank nested within Block

Gaussian

* Not all tadpoles visible in photos could be accurately measured, and thus the number of tadpoles used for length measurements at each time point is fewer than the number counted for measurements of survival.

 

FigA1

Fig. A1. Predation on Agalychnis callidryas after the second census (at 22 days post-oviposition) was greatest in tanks containing only spider predators. Tanks containing both spiders and water bugs, or only water bugs did not differ. Mortality in the control tanks was minimal. In tanks with both spiders and bugs we cannot separate predation on tadpoles or on emerging metamorphs. Data shown are the number of individuals consumed per tank ± 95% confidence intervals, controlling for random effects of variation between blocks and tanks within blocks.


 

FigA2

Fig. A2. The snout-vent length (SVL) of Agalychnis callidryas at metamorphosis was strongly related to the amount of predation by water bugs during the larval period. The figure shows the density of tadpoles alive in a given tank at 22 days post-oviposition plotted against the mean SVL (mm) of the metamorphs that emerged from that tank. SVL was measured at full tail resorption. Tanks that had more tadpoles alive at 22 days also had, on average, smaller metamorphs. The green line represents a best fit line from a linear mixed model accounting for block effects.


 

FigA3

Fig. A3. The proportions of metamorphs emerging at different stages of development (Gosner 1960). Metamorphs emerged at stage 43 (corner of mouth approximately even with nares), 43.5 (corner of the mouth more than halfway from nare to eye), or 44 (corner of mouth even with center of eye). Metamorphs were raised in a factorial cross of larval predators (water bugs) or predator-free controls, and metamorph predators (fishing spiders) or predator-free controls.


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