Am Nat - plasticity and MHC - NetLogo model online v. 45

The model code in Netlogo format. Download (http://ccl.northwestern.edu/netlogo) and install NetLogo for free, and you can open and run the model directly

Supplementary Material - model code

The Netlogo code for the program used to run the simulations. This program was developed using NetLogo 5.0 (http://ccl.northwestern.edu/netlogo). The program is free of use for research and education. If you use this program or model for your own research, please refer to our paper “Pim Edelaar, Roger Jovani & Ivan Gomez-Mestre 2017. Should I change or should I go? Phenotypic plasticity and matching habitat choice in the adaptation to environmental heterogeneity. The American Naturalist”

Relationships between climatic and life-history variables in pelobatoid frogs using phylogenetic generalized least squares (PGLS).

<p>Significant relationships (<i>P</i><0.05) are boldfaced. Median larval periods and median hatching times refers to the midpoint between the highest and lowest values reported for a species (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0096637#pone.0096637.s005" target="_blank">Appendix S1</a>). Minimum refers to the lowest value. For climatic variables, mean refers to the mean among localities for a species, and min. the lowest value among localities within a species.</p

Estimation of phylogenetic signal in the traits analyzed here, based on fit to a Brownian motion model of trait evolution using Pagel's [51] lambda.

<p>Lambda varies from 0 to 1, with higher values indicating stronger phylogenetic signal.</p

Developmental responses to decreased water levels.

<p>(A) Western spadefoot toad tadpoles accelerated development (required a shorter time to reach the target developmental stage) when water level was experimentally decreased. (B) Faster development resulted in smaller animals at each developmental stage. Bars indicate mean values + SE.</p

Experimental design and sample distribution.

<p>(A) Field collected eggs were brought into the laboratory. Once they reached the free feeding stage (Gonser stage 25), 140 tadpoles were individually raised in 3 L plastic containers until Gosner stage 35. (B) As tadpoles reached stage 35, they were assigned to either constant water volume (3L), or reduced water volume (350 mL). (C) Tadpoles were then raised up to predetermined stages: Gosner stages 38 and 42 (stages at which the physiological parameters were determined), or until metamorphosis was complete (Gosner stage 46). (D) Corticosterone (CORT) was determined by electroimmuno assays from plasma samples obtained from 80 tadpoles across developmental stages and water treatments. Tail tissue from those tadpoles was used for thyroid hormone (TH) radioimmuno assays and determination of the level of expression of the thyroid hormone receptor TRβ via qPCR. Levels of oxidative stress and activity of antioxidant enzymes were determined after whole body homogenization.</p

Relationships between selected life-history variables and genome size (from among the significant relationships in Table 1).

<p>For ease of visualization, we plot the raw data and standard regression lines (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0096637#pone-0096637-t001" target="_blank">Table 1</a> for PGLS results). Larval periods and hatching times are given in days; genome sizes are given as C-values in picograms.</p

Spadefoot toad juveniles emerging from reduced water treatment were smaller and had proportionately shorter hind legs.

<p>Spadefoot toad juveniles emerging from reduced water treatment were smaller and had proportionately shorter hind legs.</p

Mechanisms of tadpole developmental acceleration.

<p>Levels of corticosterone (A), thyroid hormone (B), and expression of thyroid hormone receptor TRβ (C) were higher for tadpoles exposed to decreased water levels (black bars) than for those in constant water (white bars). Error bars indicate + SE.</p

Table1.docx

<p>Competition and predation alter individual traits of organisms, and these effects can scale-up to have consequences on community structure and dynamics. The relative importance of competition and predation will depend largely on the local assemblage of species, the type of predators, or the degree of niche segregation. We experimentally investigated the interplay of competition and predation on the structure and trophic level (measured via stable isotope analysis) of a seven-species Neotropical freshwater guild using a mesocosm approach in central Panama. We tested the effect of two types of predators (dragonfly nymphs or adult water bugs) in combination with the presence/absence of a common competitor, the red-eyed treefrog (Agalychnis callidryas), on four core species of tadpoles. We also distinguished between consumptive and non-consumptive effects of each type of predator by presenting them to tadpoles caged or freely roaming. Dragonfly larvae were more efficient predators than water bugs, but these effects were not uniform for all tadpole species. All amphibian species grew bigger when raised in the presence of an uncaged dragonfly nymph, presumably due to reduced competition through thinning, but tadpoles were smaller when exposed to caged dragonfly nymphs indicating the existence of non-consumptive predator effects as well. Predator presence also altered the relative trophic position of the different amphibian species, causing some tadpole species to increase and others to decrease their trophic status. Despite the presumed ecological similarity of tadpole species in the guild, the interplay of competition and predation had varying effects on the trophic status of nearly every species. Our results indicate that community composition can greatly affect the trophic level of larval amphibians, and that predation may have a greater role than competition in structuring Neotropical larval amphibian guilds.</p