Common Loon reproductive success model selection results (1992-2010) - best model (Table 3)

Sep 2, 2026

Model selection for Common Loon reproductive success across southern Canada between 1992 and 2010 evaluates 25 candidate models using longitude, year, lake area (LLA), and pH, with QAICc and Akaike weights guiding inference. Results compare parameter sets including main effects and interaction terms (e.g., Year*pH, LLA*pH), identify the best-supported model, and summarize how predictor combinations explain spatial-temporal variation. Confidence limits are referenced from best-model parameter estimates and model-averaged effects in related tables.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages16

Reading Time40 min

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Model selection results

Candidate models and selection criteria (QAICc, w)

Best-supported predictor structure

| Model | K | QAICc | ∆QAICc | w | | --- | --- | --- | --- | --- | | Longitude + Year + Log Lake Area +
Longitude*Year† | 6 | 7854.6 | 0.0 | 0.95 | | Year + Log Lake Area | 4 | 7860.6 | 6.0 | 0.05 | | Longitude + Year + Longitude*Year | 5 | 7873.1 | 18.5 | 0.00 | | Longitude + Year | 4 | 7873.4 | 18.8 | 0.00 | | Longitude + Log Lake Area | 4 | 7877.5 | 22.9 | 0.00 | | Year | 3 | 7877.7 | 23.1 | 0.00 | | Log Lake Area | 3 | 7881.8 | 27.2 | 0.00 | | Longitude | 3 | 7895.5 | 40.9 | 0.00 | | Intercept-only | 2 | 7898.2 | 43.6 | 0.00 | | † Loge(Six-week-old young per pair per year) = −0.0074(−0.012, −0.0029) Longitude + 0.0099(−0.025, 0.045)Year + 0.16(0.097, 0.23)Log lake area + 0.0003(−0.0001, 0.0007)Longitude*Year − 1.41(−1.82, −1.01) | | | | | | Table 2. Descriptive statistics, interquartile range (IQR), and model-averaged parameter estimates (Estimate) and associated 95% confidence limits (95% CLs) for explanatory variables used to model patterns in Common Loon (Gaviaimmer)reproductive success across southern Canada between 1992 and 2010. Model-averaged parameter estimates and associated 95% CLs for longitude, year, log lake area, and intercept are based on the models in part one of the analysis (Table 1); for pH they are based on models in part two of the analysis (Table 3) . | | | | | | | | | --- | --- | --- | --- | --- | --- | --- | --- | | Variable | | Median | Min | Max | IQR | Estimate | 95% CLs (lower, upper) | | Longitude | | −78.7 | −127.6 | −52.8 | 7.5 | −0.0044 | −0 .0076, −0.0012 | | Year† | | 2000 | 1992 | 2010 | 8 | −0.014 | −0 .021, −0.0093 | | Lake Area‡ | | 256 | 3.8 | 2908 | 840 | 0.16 | 0.11, 0.23 | | pH | | 7.1 | 4.2 | 10.9 | 1.4 | 0.19 | 0.13, 0.24 | | Intercept | | -- | -- | -- | -- | 0.80 | −0 .95, −0.67 | | †
‡ | Year was re-coded as 1992=1, 1993=2, . .. , 2010=19 for all analyses; uncoded values are given here for ease of interpretation. Lake area was log10-transformed for all analyses; back-transformed values are given here in ha for ease of interpretation. | | | | | | | | Table 3. Model selection results for 25 candidate models explaining patterns in Common Loon (Gavia immer) reproductive success as a function of longitude, year, lake area, and pH across southern Canada between 1992 and 2010. K = number of parameters; QAICc = quasiliklihood Akaike’s information criterion; w = Akaike weight; LLA = log lake area . Parameter estimates with 95% confidence limits (lower, upper) are shown below for the best model; model-averaged estimates are given in Table 2. | | | | | | --- | --- | --- | --- | --- | | Model | K | QAICc | ∆QAICc | w | | Year + LLA + pH† | 5 | 6610.2 | 0.0 | 0.30 | | Year + LLA + pH + Year*pH | 6 | 6610.5 | 0.4 | 0.25 | | Year + LLA + pH + LLA*pH | 6 | 6611.4 | 1.2 | 0.16 | | Year + pH | 4 | 6612.8 | 2.6 | 0.08 | | Year + pH + Year*pH | 5 | 6613.1 | 2.9 | 0.07 | | Longitude + Year + pH + Longitude*Year | 6 | 6613.3 | 3.2 | 0.06 | | Longitude + Year + pH | 5 | 6614.0 | 3.9 | 0.04 | | Longitude + Year + pH + Year*pH | 6 | 6614.3 | 4.2 | 0.04 | | LLA + pH | 4 | 6623.5 | 13.4 | 0.00 | | Longitude + LLA + pH | 5 | 6624.0 | 13.9 | 0.00 | | LLA + pH + LLA*pH | 5 | 6624.7 | 14.5 | 0.00 | | Longitude + LLA + pH + LLA*pH | 6 | 6625.1 | 14.9 | 0.00 | | pH | 3 | 6626.0 | 15.8 | 0.00 | | Longitude + pH | 4 | 6626.6 | 16.5 | 0.00 | | Year + LLA | 4 | 6649.2 | 39.1 | 0.00 | | Longitude + Year + LLA + Longitude*Year | 6 | 6649.7 | 39.6 | 0.00 | | Longitude + Year + LLA | 5 | 6650.5 | 40.3 | 0.00 | | Longitude + Year + LLA + pH + Longitude*Year + Year*pH + LLA*pH | 10 | 6659.3 | 49.1 | 0.00 | | LLA | 3 | 6660.4 | 50.2 | 0.00 | | Year | 3 | 6661.5 | 51.4 | 0.00 | | Longitude + Year + Longitude*Year | 5 | 6661.9 | 51.8 | 0.00 | | Longitude + Year | 4 | 6662.0 | 51.8 | 0.00 | | Longitude + LLA | 4 | 6662.1 | 51.9 | 0.00 | | Intercept-only | 2 | 6672.1 | 61.9 | 0.00 | | Longitude | 3 | 6673.2 | 63.0 | 0.00 | | † Loge(Six-week-old young per pair per year) = 0.013(−0.018, −0.0

FAQs

What response variable is modeled in these tables?

The modeled response is Common Loon reproductive success across southern Canada.

Which predictors are considered for explaining reproductive success?

Models use longitude, year, log lake area (LLA), and pH, including possible interaction terms.

How are candidate models compared and selected?

Models are compared using QAICc and Akaike weights (w); the best model is the one with the lowest QAICc (and highest support by weight).

Sep 2, 2026

Uploaded by Oliver Hayes