Online Resource 1 (supplementary table)
Article: Implications of newly-formed seed-dispersal mutualisms between birds and introduced plants in northern California, USA
Journal: Biological Invasions
Author: Clare E. Aslan, University of California-Santa Cruz,
Supplementary table. Estimated removal of study species fruits by birds of different behavioral guilds. FG = feeding guild. No. obs. = the number of periods in which bird species was observed in the relevant tree species. Average flock size is derived from scan sampling data, and is given per tree. FDI = flock dispersal importance (average number of fruits dispersed per minute per tree by this bird species over all observed stands); FRI = flock removal importance (for seed predators, average number of fruits removed per minute per tree). ODI = overall dispersal importance (FDI x number of observations in which this bird species was present in observed trees); ORI = overall removal importance (for seed predators, FRI x number of observations in which this bird species was present). Each subtable pertains to a different study species: a. Triadica sebifera; b. Ligustrum lucidum; c. Olea europaea; d. Heteromeles arbutifolia. Since seed predators do not disperse seeds but may contribute significantly to fruit removal, tables are subdivided by handling guild. Note that yellow-rumped warbler is considered a seed predator on T. sebifera, because it forages by scraping the waxy aril off the seedbut never swallowing and dispersing the seed itself; this behavior makes the fruit less attractive to other foragers. For L.lucidum, by contrast, the yellow-rumped warbler swallows fruits whole and is therefore considered a disperser.
a. Triadica sebifera
Bird Species / FG / No. obs. / Avg. flock size / FDI / ODIHandling guild: Dispersers
European starling / Pulse / 7 / 0.104 ± 0.013 / 3.02 ± 0.92 / 21.12 ± 6.47
American robin / Pulse / 13 / 0.095 ± 0.023 / 0.54 ± 0.27 / 7.07 ± 3.46
Northern flicker / Background / 8 / 0.018 ± 0.002 / 0.50 ± 0.13 / 4.02 ± 1.08
Nuttall’s woodpecker / Background / 6 / 0.069 ± 0.009 / 0.32 ± 0.20 / 1.94 ± 1.19
Western-scrub jay / Background / 21 / 0.024 ± 0.002 / 0.08 ± 0.03 / 1.66 ± 0.73
Northern mockingbird / Background / 10 / 0.014 ± 0.002 / 0.13 ± 0.07 / 1.26 ± 0.73
American crow / Pulse / 3 / 0.009 ± 0.001 / 0.33 ± 0.27 / 0.98 ± 0.80
Cedar waxwing / Pulse / 7 / 0.080 ± 0.012 / 0.03 ± 0.03 / 0.24 ± 0.22
Hermit thrush / Background / 1 / 0.007 ± 0.000 / 0.14 ± 0.20 / 0.14 ± 0.20
Black phoebe / Background / 5 / 0.009 ± 0.001 / 0.01 ± 0.01 / 0.03 ± 0.03
Handling guild: Seed predators / FRI / ORI
Yellow-rumped warbler / Background / 45 / 0.351 ± 0.030 / 0.01 ± 0.01 / 0.59 ± 0.25
House finch / Background / 28 / 0.093 ± 0.010 / 0.02 ± 0.01 / 0.56 ± 0.21
Lesser goldfinch / Background / 20 / 0.074 ± 0.007 / 0.01 ± 0.01 / 0.25 ± 0.18
Dark-eyed junco / Background / 8 / 0.025 ± 0.004 / 0.01 ± 0.01 / 0.06 ± 0.06
House sparrow / Background / 4 / 0.008 ± 0.001 / 0.005±0.003 / 0.02 ± 0.01
b. Ligustrum lucidum
Bird Species / FG / No. obs. / Avg. flock size / FDI / ODIHandling guild: Dispersers
Cedar waxwing / Pulse / 13 / 0.096 ± 0.014 / 16.78 ± 3.70 / 217.97 ± 48.12
American robin / Pulse / 17 / 0.101 ± 0.015 / 3.39 ± 0.50 / 57.61 ± 8.49
Northern mockingbird / Background / 27 / 0.015 ± 0.001 / 0.84 ± 0.21 / 22.58 ± 5.64
Hermit thrush / Background / 21 / 0.068 ± 0.011 / 1.04 ± 0.26 / 21.75 ± 5.38
Northern flicker / Background / 6 / 0.011 ± 0.001 / 2.21 ± 0.48 / 13.27 ± 2.85
Yellow-rumped warbler / Background / 38 / 0.137 ± 0.012 / 0.15 ± 0.05 / 5.71 ± 2.07
Western-scrub jay / Background / 27 / 0.030 ± 0.003 / 0.19 ± 0.06 / 5.13 ± 1.75
American crow / Pulse / 7 / 0.047 ± 0.004 / 0.05 ± 0.04 / 0.36 ± 0.27
Handling guild: Seed predators / FRI / ORI
House finch / Background / 26 / 0.139 ± 0.019 / 5.72 ± 0.79 / 148.79 ± 20.49
Dark-eyed junco / Background / 14 / 0.079 ± 0.010 / 1.37 ± 0.23 / 19.20 ± 3.16
Purple finch / Background / 4 / 0.010 ± 0.001 / 0.14 ± 0.08 / 0.54 ± 0.32
Mourning dove / Background / 2 / 0.040 ± 0.004 / 0.21 ± 0.21 / 0.43 ± 0.43
White-crowned Sparrow / Background / 3 / 0.033 ± 0.000 / 0.07 ± 0.00 / 0.21 ± 0.00
c. Olea europaea
Bird Species / FG / No. obs. / Avg. flock size / FDI / ODIHandling guild: Dispersers
European starling / Pulse / 22 / 0.143 ± 0.018 / 4.91 ± 1.58 / 108.00 ± 34.81
Western-scrub jay / Background / 50 / 0.046 ± 0.004 / 0.55 ± 0.22 / 27.36 ± 11.04
Western meadowlark / Background / 5 / 0.242 ± 0.000 / 1.30 ± 0.70 / 6.49 ± 3.52
American robin / Pulse / 24 / 0.081 ± 0.012 / 0.23 ± 0.08 / 5.58 ± 1.80
Wild turkey / Pulse / 1 / 0.039 ± 0.000 / 2.28 ± 0.00 / 2.28 ± 0.00
Western bluebird / Pulse / 4 / 0.027 ± 0.003 / 0.13 ± 0.09 / 0.51 ± 0.36
Northern mockingbird / Background / 12 / 0.019 ± 0.003 / 0.04 ± 0.03 / 0.48 ± 0.36
American crow / Pulse / 6 / 0.030 ± 0.005 / 0.04 ± 0.04 / 0.24 ± 0.26
Hermit thrush / Background / 21 / 0.035 ± 0.008 / 0.002 ± 0.002 / 0.002 ± 0.05
Handling guild: Seed predators / FRI / ORI
California quail / Pulse / 3 / 0.063 ± 0.003 / 0.70 ± 0.00 / 2.10 ± 0.00
White-crowned sparrow / Background / 28 / 0.156 ± 0.015 / 0.07 ± 0.04 / 1.91 ± 1.14
Spotted towhee / Background / 14 / 0.103 ± 0.007 / 0.09 ± 0.02 / 1.31 ± 0.33
Golden-crowned sparrow / Background / 28 / 0.142 ± 0.015 / 0.005 ± 0.003 / 0.15 ± 0.09
d. Heteromeles arbutifolia
Bird Species / FG / No. obs. / Avg. flock size / FDI / ODIHandling guild: Dispersers
Hermit thrush / Background / 39 / 0.038 ± 0.004 / 1.87 ± 0.26 / 72.92 ± 10.26
American robin / Pulse / 22 / 0.231 ± 0.028 / 2.57 ± 0.32 / 56.52 ± 6.94
Cedar waxwing / Pulse / 6 / 0.082 ± 0.007 / 6.76 ± 3.05 / 40.54 ± 18.27
Northern mockingbird / Background / 33 / 0.041 ± 0.004 / 0.62 ± 0.16 / 20.39 ± 5.15
Western bluebird / Pulse / 2 / 0.020 ± 0.002 / 0.76 ± 0.39 / 1.51 ± 0.79
Western-scrub jay / Background / 23 / 0.023 ± 0.001 / 0.004 ± 0.002 / 0.09 ± 0.05
Handling guild: Seed predators / FRI / ORI
Golden-crowned sparrow / Background / 12 / 0.012 ± 0.001 / 0.66 ± 0.45 / 7.87 ± 5.39
House finch / Background / 4 / 0.006 ± 0.001 / 0.60 ± 0.29 / 2.41 ± 1.15
Purple finch / Background / 1 / 0.005 ± 0.000 / 0.39 ± 0.55 / 0.39 ± 0.55
Spotted towhee / Background / 10 / 0.028 ± 0.002 / 0.01 ± 0.01 / 0.14 ± 0.10