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THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 124. No. 3. September 2012 
TABLE 3. Indices of dominance. Shannon diversity, evenness, and equilability. Numbers are averages for each 
agroforestry class obtained from the abundance data of all point and transect counts in three sampling seasons. D = 
dominance; H = Shannon diversity index; E = evenness; E-J = equitability: AA = animal agroforestry: AF = agroforest: 
LA = linear agroforestry: SA = sequential agroforestry; C'T = crops under tree cover. 
Season 
index 
Rainy season 
Northern winds 
D 
H 
E 
E-J 
D 
H 
E 
E-J 
AA 
0.20 
2.00 
0.69 
0.84 
0.19 
1.96 
0.74 
0.86 
AF 
0.17 
2.00 
0.74 
0.86 
0.13 
2.25 
0.83 
0.92 
LA 
0.18 
1.90 
0.83 
0.91 
0.16 
2.02 
0.84 
0.92 
SA 
0.17 
2.04 
0.74 
0.87 
0.15 
2.14 
0.82 
0.91 
CT 
0.22 
1.77 
0.79 
0.88 
0.17 
2.02 
0.74 
0.87 
Average 
0.19 
1.92 
0.75 
0.87 
0.16 
2.07 
0.78 
0.89 
Season 
Dry season 
All seasons 
index 
D 
H 
E 
E-.I 
15 
H 
E 
E-J 
AA 
0.14 
2.21 
0.77 
0.89 
0.18 
2.06 
0.73 
0.86 
AF 
0.13 
2.34 
0.78 
0.90 
0.16 
2.11 
0.78 
0.89 
LA 
0.12 
2.29 
0.88 
0.95 
0.15 
2.08 
0.85 
0.93 
SA 
0.18 
1.92 
0.80 
0.89 
0.17 
2.03 
0.79 
0.89 
CT 
0.13 
2.27 
0.81 
0.91 
0.17 
2.02 
0.78 
0.89 
Average 
0.14 
2.24 
0.80 
0.91 
0.17 
2.06 
0.78 
0.89 
0.033) (Table 3). Evenness was less in animal 
agroforestry and crops under tree cover than in 
linear agroforestry (Mann-Whitney U-test, P < 
0.001 and P = 0.023). No significant differences 
among classes were observed (Kruskal-Wallis 
tests, P all >0.096) when analyzing the indices 
separately for the three seasons. H-diversily 
indices varied among seasons and were higher in 
the dry season than in the rainy season and the 
season of northern winds (ANOVA, F = 10.51, 
P < 0.001; Tukey’s HSD-test, P = 0.01 and P = 
0.034). Dominance indices varied among seasons 
(Kruskal-Wallis test. P < 0.001) and were higher 
in the rainy season than in the season of northern 
winds and dry season (Mann-Whitney (/-test, P = 
0.033 and P < 0.001), and higher in the season 
of northern winds than in the dry season (Mann- 
Whitney U- test, P = 0.027). Great-tailed Grackle 
(■Quiscalus mexicamts), Golden-fronted Wood¬ 
pecker ( Melanerpes aurifrons), American Red¬ 
start {Seiophaga rit tic ilia), and Brown Jay 
(Psilorhinus mono) were the most abundant 
species (Appendix). Each included >6% of the 
total number of observed birds. The Great-tailed 
Grackle was the most abundant species in 
agroforests and animal agroforestry, American 
Redstart in linear agroforestry, Melodious Black¬ 
bird (Dives dives) in sequential agroforestry, and 
Golden-fronted Woodpecker in crops under tree 
cover. 
Bird communities in the agroforestry system 
classes had from 56.3 to 83.7% of the observed 
species in common, when considering all sam¬ 
pling seasons (Table 4). Chao-Jaccard indices of 
estimated similarity ranged from 0.71 to 0.98. 
Agroforests and sequential agroforestry were least 
similar, and agroforest and animal agroforestry 
had comparatively low similarity. Chao-Jaccard 
estimates of similarity were not different among 
seasons (ANOVA. F = 2.595. P = 0.093). The 
average number of observed species in com¬ 
mon was significantly different among seasons 
(ANOVA, = 8.706. P = 0.001), and was higher 
in the dry season (23.0 species) than in the rainy 
season (15.4 species) (Tukey HSD-test. P = 
0.001). This was related to the total number of 
species in most classes in the dry season 
(Table 2); the proportions of shared species of 
those observed were not different among seasons 
(ANOVA. F = 1.592, P = 0.222 and F = 0.735. 
P = 0.489). The fraction of the number of 
sampling points where the 25 most abundant 
species were observed did not vary among classes 
in the rainy and dry seasons (Kruskal-Wallis test. 
P = 0.986 and P - 0.282), and when considering 
all sample points of all seasons. The relative 
frequency of abundant species was significantly 
different in the season of northern winds (Kruskal- 
Wallis test, P = 0.001). Abundant species had 
higher relative frequencies in agroforests than in 
