Supplemental Table 1. Summary of simulation results to assess the relative effect of the adaptive response rate (ARR) on songbird populations subjected to habitat loss and fragmentation. In these simulations, the adaptive response was assumed to emerge immediately, within the first generation after habitat loss began (i.e., during the second year of the simulation model run). The total habitat lost in these scenarios was set by the minimum habitat threshold (hmin) at which population declines accelerated (Schrott et al. 2005a). Habitat was lost at one of three rates (0.5%/year, 1.0%/year, or 5%/year) andfragmented to varying degrees(fragmented, H = 0.0; moderately fragmented, H = 0.5, and clumped, H = 1.0). A full factorial was performed only for populations in moderately fragmented landscapes (H = 0.5), as these exhibited the greatest range of response. A color-coded key to the table is given at the bottom.

Total habitat lost
(Years to lose habitat) / Fragmented
H = 0.0 / Moderately Fragmented
H = 0.5 / Clumped
H = 1.0
Habitat loss rate, r = 5.0%/year
10% (2 years) / Effects stable over time
Relative effect of adaptive response rate:
very little to none / Effects stable over time
Relative effect of adaptive response rate:
very little to none / Effects stable over time
Relative effect of adaptive response rate:
none
20% (4 years) / Effects stable over time
Relative effect of adaptive response rate:
very little to none / Effects stable over time
Relative effect of adaptive response rate:
very little to none / Effects stable over time
Relative effect of adaptive response rate:
none
30% (6 years) / Effects stable over time
Relative effect of adaptive response rate:
very little to none / Effects stable or gradually increasing over time
Relative effect of adaptive response rate:
very little to none / Effects stable over time
Relative effect of adaptive response rate:
none
40% (8 years) / Effects stable or gradually increasing over time
Relative effect of adaptive response rate:
very little to none
50% (10 years) / Effects stable or increasing over time
Relative effect of adaptive response rate:
very little to none
Habitat loss rate, r = 1.0%/year
10% (10 years) / Effects stable or increasing over time
Relative effect of adaptive response rate:
very little to none / Effects stable or increasing over time
Relative effect of adaptive response rate:
very little to none / Effects stable over time
Relative effect of adaptive response rate:
none
20% (20 years) / Effects stable or increasing (staircase) over time
Relative effect of adaptive response rate:
>10 gens: little to no effect
10 gens: moderate effect
3-5 gens: very great to great effect / Effects stable or increasing (staircase) over time
Relative effect of adaptive response rate:
10 gens: little to no effect
3-5 gens: little to moderate effect / Effects stable or increasing over time
Relative effect of adaptive response rate:
little to no effect
30% (30 years) / Effects increase rapidly, peak (~30 years), and then decline gradually over time
Relative effect of adaptive response rate:
20 gens: little to no effect
10 gens: moderate to little effect
5 gens: very great to moderate effect
3 gens: very great to great effect / Effects increase rapidly, peak (~35 years), and then decline gradually over time
Relative effect of adaptive response rate:
20 gens: little to no effect
10 gens: great to little effect
3-5 gens: very great to great effect / Effects increase gradually, peak (~116 years), and then decline gradually over time
Relative effect of adaptive response rate:
20 gens: little to no effect
10 gens: moderate effect
3-5 gens: very great to great effect
40% (40 years) / Effects increase rapidly, peak (~35 years), and then decline gradually over time
Relative effect of adaptive response rate:
>20 gens: little to no effect
10 gens: great to little effect
3-5 gens: very great to great effect
Habitat loss rate,r = 0.5%/year
10% (20 years) / Effects stable or increasing (staircase) over time
Relative effect of adaptive response rate:
>10 gens: very little to no effect
10 gens: little effect
3-5 gens: very great to great effect / Effects stable or increasing (staircase) over time
Relative effect of adaptive response rate:
10 gens: very little to no effect
3-5 gens: little effect / Effects stable or increasing over time
Relative effect of adaptive response rate:
little to no effect
20% (40 years) / Effects increase rapidly, peak (~40 years), and then decline gradually over time
Relative effect of adaptive response rate:
20 gens: little to no effect
10 gens: great to moderate effect
3-5 gens: very great to great effect

Table Key:

Relative effect of adaptive responseon populations (relative to control population without an adaptive response):

No to very little effect: relative change = 0-10

Little effect: relative change = 11-50

Moderate effect : relative change = 51-100

Great effect: relative change = 101-200

Very great effect: relative change >200

Types of Population Response (color-coded cells in table)

Effects stable over time; ARR has very little to no effect
Populations have been subjected to <10 years of habitat loss; little erosion of demographic potential so population growth rates not severely impacted by habitat loss/fragmentation at this point; adaptive response therefore not important
Effects stable or increasing over time; ARR has little to no effect
Populations subjected to 10 years of habitat loss; little erosion of demographic potential so population growth rates not severely impacted by habitat loss/fragmentation; adaptive response still not very important, therefore
Effects stable or increasing (staircase) over time; ARR has little to moderate effects
Populations subjected to 20 years of habitat loss; some erosion of demographic potential has occurred by now, and thus an adaptive response can have some effect if it spreads rapidly through the population (i.e., within 3-5 generations)
Effects increase rapidly, peak, and then decline gradually over time; variable effects of ARR, but very great to great effectswhen adaptive response spreads rapidly (<10 generations)
Populations have been subjected to >20 years of habitat loss/fragmentation; the population’s demographic potential has been seriously eroded and thus adaptive responses have the greatest effect in these scenarios. Nevertheless, the greatest effects occur only when the adaptive response spreads rapidly through the population; the effects of the adaptive response are most pronounced in the early stages of habitat removal in landscapes that are being fragmented (H 0.5), but wanes over time as populations shift and become increasingly less edge-sensitive (i.e., adapted to the changing landscape conditions)

Supplemental Table 2. Summary of simulation results to assess the effect of delaying the onset of the adaptive response(1-10 generations after habitat loss began) within songbird populations. As with the first set of runs (cf. Supplemental Table 1), the total habitat lost in these scenarios was set by the minimum habitat threshold (hmin) at which population declines accelerated (Schrott et al. 2005a). Habitat was removed at one of three rates (0.5%/year, 1.0%/year, or 5%/year) to produce moderately fragmented landscapes (H = 0.5). In light of the results from the first experiment (Supplemental Table 1), the effect of the adaptive response rate (ARR) was also evaluated in the context of delayed onset. Notice that the effects listed in the first column, in which the adaptive response occurs immediately within the first generation (2 years) after habitat loss begins, are taken from the “Moderately Fragmented” column in Supplemental Table 1. A color-coded key to the table is given at the bottom.

Total habitat lost
(Years to lose habitat) / Delay in adaptive response (approximate number of generations and years)
1 generation
(2 years) / 3 generations
(7 years) / 5 generations
(12 years) / 8 generations
(18 years) / 10 generations
(23 years)
Habitat loss rate, r = 5.0%/year
20% (4 years) / Effects stable over time
Relative effect of adaptive response rate:
very little to none / Effects stable over time
Relative effect of adaptive response rate:
none / Effects stable over time
Relative effect of adaptive response rate:
none / Effects stable over time
Relative effect of adaptive response rate:
none / Effects stable over time
Relative effect of adaptive response rate:
none
30% (6 years) / Effects stable or gradually increasing over time
Relative effect of adaptive response rate:
very little to none / Effects stable over time
Relative effect of adaptive response rate:
none / Effects stable over time
Relative effect of adaptive response rate:
none / Effects stable over time
Relative effect of adaptive response rate:
none / Effects stable over time
Relative effect of adaptive response rate:
none
40% (8 years) / Effects stable or gradually increasing over time
Relative effect of adaptive response rate:
very little to none / Effects stable or gradually increasing over time
Relative effect of adaptive response rate:
very little to none / Effects stable over time
Relative effect of adaptive response rate:
none / Effects stable over time
Relative effect of adaptive response rate:
none / Effects stable over time
Relative effect of adaptive response rate:
none
Habitat loss rate, r = 1.0%/year
20% (20 years) / Effects stable or increasing (staircase) over time
Relative effect of adaptive response rate:
10 gens: little to no effect
3-5 gens: little to moderate effect / Effects stable or increasing (staircase) over time
Relative effect of adaptive response rate:
10 gens: no effect
3-5 gens: little effect / Effects stable or increasing (staircase) over time
Relative effect of adaptive response rate:
10 gens: no effect
3-5 gens: very little to no effect / Effects stable over time
Relative effect of adaptive response rate:
none / Effects stable over time
Relative effect of adaptive response rate:
none
30% (30 years) / Effects increase rapidly, peak (~35 years), and then decline gradually over time
Relative effect of adaptive response rate:
20 gens: little to no effect
10 gens: great to little effect
3-5 gens: very great to great effect / Effects stable or increasing (staircase) over time
Relative effect of adaptive response rate:
10 gens: very little to no effect
3-5 gens: little effect / Effects stable or increasing (staircase) over time
Relative effect of adaptive response rate:
10 gens: no effect
3-5 gens: very little to no effect / Effects stable over time
Relative effect of adaptive response rate:
none / Effects stable over time
Relative effect of adaptive response rate:
none
Habitat loss rate, r = 0.5%/year
10% (20 years) / Effects stable or increasing (staircase) over time
Relative effect of adaptive response rate:
10 gens: very little to no effect
3-5 gens: little effect / Effects stable or increasing (staircase) over time
Relative effect of adaptive response rate:
10 gens: very little to no effect
3-5 gens: little effect / Effects stable or gradually increasing over time
Relative effect of adaptive response rate:
very little to none / Effects stable or gradually increasing over time
Relative effect of adaptive response rate:
very little to none / Effects stable
Relative effect of adaptive response rate:
none
20% (40 years) / Effects increase rapidly, peak (~40 years), and then decline gradually over time
Relative effect of adaptive response rate:
20 gens: little to no effect
10 gens: great to moderate effect
3-5 gens: very great to great effect / Effects increase rapidly, peak (~40 years), and then decline gradually over time
Relative effect of adaptive response rate:
20 gens: little to no effect
10 gens: moderate to little effect
3-5 gens: great to moderate effect / Effects increase rapidly, peak (~40 years), and then decline gradually over time
Relative effect of adaptive response rate:
20 gens: no effect
10 gens: little to no effect
3-5 gens: moderate to little effect / Effects stable or increasing (staircase) over time
Relative effect of adaptive response rate:
10 gens: very little to no effect
3-5 gens: little effect / Effects stable or increasing (staircase) over time
Relative effect of adaptive response rate:
10 gens: no effect
3-5 gens: very little to no effect

Table Key:

Relative effect of adaptive response on populations (relative to control population without an adaptive response):

No to very little effect: relative change = 0-10

Little effect: relative change = 11-50

Moderate effect : relative change = 51-100

Great effect: relative change = 101-200

Very great effect: relative change >200

Types of Population Response (color-coded cells in table)

Effects stable over time; ARR has very little to no effect
Populations subjected to either <5 years of habitat loss, or 10 years if the adaptive response is delayed by 7-12 years; no effect of an adaptive response because so little habitat has been lost and populations have been exposed to the effects of habitat loss/fragmentation for only a short time. Alternatively, no effect is evident in populations subjected to a gradual loss of habitat (0.5%/year) over a 20-year period when the adaptive response was similarly delayed for 23 years; in this case, the adaptive response was simply too little too late to have much of an effect on populations that have declined for more than two decades without mounting an adaptive response
Effects stable or increasing over time; ARR has little to no effect
Populations exposed to relatively brief periods of habitat loss (6-8 years) when an adaptive response occurs within the first few years of habitat loss/fragmentation (2-7 years). Alternatively, this sort of minimal response is also evident in populations that have been subjected to a gradual loss of habitat (0.5%/year) over a period of two decades, but still managed to mount an adaptive response within that period (i.e., within 12-18 years)
Effects stable or increasing (staircase) over time; ARR has little to moderate effects
Populations exhibited minimal to moderate effects when the adaptive response spread quickly (3-5 generations) and was initiated within 12 yearsif habitat loss occurred at a moderate rate (1%/year), or if the adaptive response was initiated within 7 years when populations were subjected to more gradual rates of habitat loss (0.5%/year)
Effects increase rapidly, peak, and then decline gradually over time; variable effects of ARR, but very great to great effects when adaptive response spreads rapidly (<10 generations)
The greatest effect of different adaptive response rates is seen in populations that mount a rapid response (<10 generations) within 12 years of gradual habitat loss (0.5%/year) and the population is exposed to several decades of habitat loss/fragmentation; effects decline after this point because much of the population has adapted and become less edge-sensitive