4.3 Results
4.3.3 Four-fragment scenario
forested cells that were not visited (Figure 11A). This was because of an increased number of simulations generated a landscape with two fragments (and one simulation with three fragments;
Table 14, Figure 11B), where mean distances between them exceeded 708 m (Table 13, Figure 11C). As a result, more simulations resulted in a scenario where at least one fragment was not visited at all (Table 14, Figure 11D). At 60% forest cover, 27% of simulations resulted in two fragments, and no simulations yielded a landscape with three fragments (Table 14, Figure 11B).
Only 25% of the two-fragment scenarios yielded a landscape in which peccaries did not use one of the fragments (Table 14, Figure 11D). At 50% forest cover, 43% of simulations resulted in two fragments and 3% resulted in three fragments (Table 14, Figure 11B). In 62% of the two fragment scenarios, peccaries did not use all fragments on the landscape; yet, peccaries used all forested fragments in the single scenario where there were three fragments on the landscape (Table 14, Figure 11D).
At 40% forest cover and below, there was a qualitative change in forest use patterns, as demonstrated by the wide variation in the number of forested cells that were not used per simulation (Figure 11A). At 40% forest cover, 68% of simulations resulted in more than one forested fragment on the landscape (Table 14, Figure 11B), and the average distance between fragments was 1,164 m (Table 13, Figure 11C). Therefore, at least one fragment was not used by peccaries in 71% of the scenarios with more than one forested fragment on the landscape (Table 14, Figure 11D). At 10% forest cover, 93% of simulations resulted in more than one fragment on the landscape (Figure 11A) and the average distance between them was 1,759 m (Table 13, Figure 11C). Of those, 82% resulted in at least one fragment not used by peccaries (Table 14, Figure 11D).
Results from the three-fragment scenario show that below 50% forest cover, most
simulations resulted in a landscape where forest fragments were too isolated to support peccaries using all fragments on the landscape.
A B
C D
Figure 12: Results 4-fragment scenario: A) The percent of forested cells in the landscape that were never visited by peccaries for each habitat loss scenario (i.e. percent of forest cover); B) For each habitat loss scenario, the number of simulations resulting in 1, 2, 3, or 4 forest fragments on the landscape; C) Average distance between fragments for the three shortest distances in each habitat loss scenario. Blue numbers indicate the sample size (n); D) For scenarios where there were two or more forest fragments on the landscape, bar plot depicting the number of simulations in which at least one forested fragment was not visited by peccaries. For figures A and C, the single line within each box represents the median value, while the upper and lower boundaries of the box represent the first and third quartiles, respectively. Lines extending perpendicularly from the outer boundaries of the box encompass data falling outside of the first and third quartiles, with the end points of these lines not exceeding 1.5 * inner quartile range (distance between lower and upper quartile). Isolated black dots are outliers.
Table 15: Four-fragment scenario: the amount of forest cover, the number of simulations that resulted in 1, 2, 3 or 4 fragments on the landscape, and the number of simulations in which at least one of the fragments was not used by the peccaries.
Forest Cover (%)
# of fragments on the landscape
# simulations with 1, 2, 3 or 4 fragments on the landscape
# simulations where at least one fragment is not used
10
1 0 0
2 2 1
3 11 10
4 17 17
20
1 3 0
2 5 3
3 10 8
4 12 12
30
1 4 0
2 14 10
3 9 8
4 3 3
40
1 6 0
2 12 9
3 10 7
4 2 1
50
1 13 0
2 11 4
3 6 4
4 0 0
60
1 19 0
2 8 1
3 3 1
4 0 0
70
1 27 0
2 3 1
3 0 0
4 0 0
80
1 26 0
2 4 0
3 0 0
4 0 0
90
1 30 0
2 0 0
3 0 0
4 0 0
100 1 30 0
average distance between them was only 207 m (Table 15, Figure 12C). Therefore, at this forest cover threshold, habitat use patterns mimicked those seen in the one-fragment simulations.
Between 70% and 60% forest cover, an increased number of simulations resulted in scenarios where a greater number of forested cells were not used (Figure 12A). This was a consequence of an increased number of simulations generating a landscape with multiple fragments (Table 15, Figure 12B), where the average distance between fragments ranged from 390 m to 751 m (Table 13, Figure 12C). As a result, an increased number of simulations resulted in a scenario where at least one of the forested fragments was not visited (Table 15, Figure 12D).
At 70% forest cover, there were no three-fragment scenarios and only 10% of simulations yielded two fragments (Table 15, Figure 12B). In the two-fragment scenario, only 3% of simulations yielded a landscape where peccaries did not use one of the fragments (Table 15, Figure 12D). At 60% forest cover, 10% of simulations yielded three fragments and 27% yielded two fragments (Table 15, Figure 12B). Of those multi-fragment scenarios, only 18% resulted in at least one fragment not used by peccaries (Table 15, Figure 12D).
At 50% forest cover and below, there is a qualitative change in forest habitat use patterns, resulting in a wide variation in the number of forested cells that were not used (Figure 12A). At 50% forest cover, 57% of simulations resulted in more than one fragment on the landscape (Table 15, Figure 12B) and the average distance between them was 902 m (Table 13, Figure 12C). Therefore, 47% of simulations with multiple fragments resulted in peccaries unable to use at least one of the fragments (Table 15, Figure 12D). At 10% forest cover, all simulations
resulted in multiple fragment scenarios (Table 15, Figure 12B) and the average distance between them was 1,752 m (Table 13, Figure 12C). Of those, 93% resulted in scenarios where at least one fragment was never used by peccaries (Table 15, Figure 12D).
Results from the four-fragment scenario show that below 60% forest cover, the majority of simulations resulted in a landscape where forest fragments were too isolated to facilitate peccaries using all forest fragments on the landscape.