Ecological Archives E091-125-A2

Jill E. Jankowski, Scott K. Robinson, and Douglas J. Levey. 2010. Squeezed at the top: interspecific aggression may constrain elevational ranges in tropical birds. Ecology 91:1877–1884.

Appendix B. Mixed model results for each species pair for closest approach and latency to approach the speaker.

TABLE B1. Mixed model results for each species pair for closest approach to speaker and latency to approach to 10 m of speaker for individuals close to the replacement zone (≤ 100 m for wood-wrens, ≤ 200 m for nightingale-thrushes). Variables in the model include stimulus, or the song stimulus delivered to the target individual, and species, which is the species of the target individual. “Total N” shows the total sample size followed by the number of individuals tested (including both species). Statistics from post hoc tests are provided in text.

 

 

Closest approach

Latency to approach

 

H. leucosticta/H. leucophrys

H. leucosticta/H. leucophrys

Stimulus

F2,11 = 142.0; P < 0.0001

F2,11 = 49.4; P < 0.0001

Species

F1,11 = 1.93; P = 0.19

F1,11 = 1.05; P = 0.33

Total N

50 obs, 13 ind

50 obs, 13 ind

 

C. aurantiirostris/C. mexicanus

C. aurantiirostris/C. mexicanus

Stimulus

F2,12 = 42.1; P< 0.0001

F2,22 = 29.7; P < 0.0001

Species

F1,12 = 20.7; P = 0.0007

F1,11 = 0.06; P = 0.81

Stimulus × species

F2,12 = 4.3; P = 0.04

F2,22 = 3.0; P = 0.07

Total N

56 obs, 14 ind

52 obs, 13 ind

 

C. mexicanus/C. fuscater

C. mexicanus/C. fuscater

Stimulus

F2,21 = 71.4; P < 0.0001

F2,41 = 63.5; P < 0.0001

Species

F1,21­ = 1.5; P = 0.24

F2,21 = 7.0; P = 0.02

Stimulus × species

F2,21 = 3.1; P = 0.07

F2,41 = 2.9; P = 0.06

Total N

88 obs, 23 ind

90 obs, 23 ind

 


 

TABLE B2. Mixed model results for each species pair for closest approach to speaker and latency to approach to 10 m of speaker for individuals at varying distance from the replacement zone (shown as “distance” below). Other variables in the model include Stimulus, the song stimulus delivered to the target individual, and species, which is the species of the target individual. “Total N” shows the total sample size followed by the number of individuals tested (including both species). Statistics from post hoc tests are provided in text.

 

Closest Approach

Latency to Approach

H. leucosticta/H. leucophrys

H. leucosticta/H. leucophrys

Stimulus

F2,49 = 24.7; P < 0.0001

F1,141 = 8.9; P = 0.0002

Species

F1,49 = 0.1; P = 0.73

F1,141 = 2.2; P = 0.14

Distance

F1,49 = 14.0; P = 0.0005

F1,141 = 0.14; P = 0.70

Stimulus × distance

F2,49 = 19.5; P < 0.0001

F2,141 = 8.20; P = 0.0004

Total N

198 obs, 52 ind

198 obs, 52 ind

C. aurantiirostris

C. mexicanus

C. aurantiirostris

C. mexicanus

Stimulus

F2,25 = 43.2; P < 0.0001

F2,25 = 25.5; P < 0.0001

F1,50 = 9.4; P = 0.003

F1,52 = 5.8; P = 0.02

Distance

F1,25 = 4.7; P = 0.04

F1,25 = 0.02; P = 0.89

F1,50 = 2.0; P = 0.16

F1,52 = 0.02; P = 0.9

Stimulus × distance

F2,25 = 9.0; P = 0.001

F­2,25 = 4.1; P = 0.03

F1,50 = 7.1; P = 0.01

F1,52 = 1.5; P = 0.2

Total N

105 obs, 27 ind

108 obs, 27 ind

79 obs, 27 ind

81 obs, 27 ind

C. mexicanus

(C. fuscater)

C. mexicanus

(C. fuscater)

Stimulus

F2,20 = 25.5; P < 0.0001

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F1,40 = 12.1; P < 0.0001


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Distance

F1,20 = 2.2; P = 0.15

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F1,41 = 0.08; P = 0.78

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Stimulus × distance

F2,20 = 0.34; P = 0.72

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ns*

----

Total N

84 obs, 22 ind

----

64 obs, 22 ind

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* Interaction term not significant; without this term, stimulus is significant in simpler model.


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