Ecological Archives A018-040-A1

Arnaud Ghilain and Marc Bélisle. 2008. Breeding success of Tree Swallows along a gradient of agricultural intensification. Ecological Applications 18:1140–1154.

Appendix A. Akaike weights of the models explaining nestbox occupancy by Tree Swallows at seven spatial scales along a gradient of agricultural intensification in southern Québec, 2005–2006.

TABLE A1. Akaike weights of the models explaining nestbox occupancy by Tree Swallows at seven spatial scales along a gradient of agricultural intensification in southern Québec, 20052006. Models are generalized mixed model with logit link and a binomial error distribution with farm ID as random factor (n = 800). See Table 1 for variable definition and justification.

Scale (km)

Nestbox

Intensive

Nestbox + Intensive

Extensive

Nestbox + Extensive

1

0.824

0.000

0.170

0.000

0.006

2

0.777

0.000

0.194

0.000

0.029

3

0.740

0.000

0.251

0.000

0.009

4

0.484

0.000

0.505

0.000

0.011

5

0.541

0.000

0.449

0.000

0.011

10

0.359

0.000

0.619

0.000

0.022

20

0.628

0.000

0.362

0.000

0.010

Notes: mAICc weights depict the relative strength of each model for a given spatial scale (i.e., radius).

List of models and their variables:

Nestbox = year + competition + clearance + previous year occupancy × previous year fledging success

Intensive = year + water + intensive culture + manure tanks + intensive culture × manure tanks

Nestbox + Intensive = year + competition + clearance + previous year occupancy × previous year fledging success + water + intensive culture + manure tanks + intensive culture× manure tanks

Extensive = year + water + extensive culture + manure tanks + extensive culture × manure tanks + cattle + extensive culture × cattle

Nestbox + Extensive = year + competition + clearance + previous year occupancy × previous year fledging success + water + extensive culture + manure tanks + extensive culture × manure tanks + cattle + extensive culture × cattle


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