Table 2 Predictor variables and their explanation used in analysing variation in breeding time
From: Hydrology influences breeding time in the white-throated dipper
| Variable type | Predictor | Explanation |
|---|---|---|
| Territory–indicating microclimate | Altitude | Altitude of most frequented nest site at the territory |
| Distancea | Distance from the river outlet to the most frequented nest site at the territory | |
| Qmeana | Absolute mean annual discharge | |
| Catchment–indicating microclimate | Area | Size of catchment area (m2) |
| Altitude median | Median elevation of catchment (m) | |
| Altitude diff | Altitudinal range of catchment (m) | |
| Bog fraction | Fraction of bogs in catchment, which contribute to flow when saturated | |
| Bog max | Maximum of distance distribution for bogs (m) | |
| Bog mean | Mean of distances (m) between grid-points in the catchment classified as bogs to the nearest river reach, indicating the flow dynamics from saturated bogs | |
| Bog fractionb | Areal fraction of grid cells with zero distance to the river network for bogs | |
| S mean | Mean of distances (m) between grid-points in the catchment classified as soils to the nearest river reach, indicating the flow dynamics from soils | |
| Soil fraction | Areal fraction of grid cells with zero distance to the river network for soils | |
| L mean | Mean of the distances (m) between points in the river network, a measure of river network complexity | |
| L sd | Standard deviation of distances between points in the river network to the outlet, a measure of river network complexity | |
| L max | Maximum of distance distribution of the river network, a measure of river network complexity | |
| Evotranspiration | Degree-day factor for evotranspiration (mm/day/ °C) | |
| Trigger | Trigger day | Trigger day index for first five-day period above 0 °C |
| Qspec* | Specific discharge (l/s/km2, discharge per area unit) | |
| Qnorm* | Normalized discharge (discharge/annual mean discharge) | |
| T* | Temperature (°C) | |
| P* | Precipitation (mm) | |
| Groundwater* | Dynamic groundwater storage (mm). The part of groundwater storage that fluctuates with runoff indicating hydrological drivers | |
| SCA* | Fraction of the lowest 10% of the catchment that is snow covered | |
| SWE* | Snow water equivalent at the lowest 10% of the catchment (mm) | |
| Ql10* | Indicating whether discharge exceeded 10 l/s or not (indicating extreme drought) in period | |
| Ql100* | Indicating whether discharge exceeded 100 l/s or not (indicating drought) in period | |
| Global climate | NAO*b | Daily North Atlantic Oscillation Index |
| NAOcurr | North Atlantic Oscillation Index current year | |
| NAOprev | North Atlantic Oscillation Index previous year | |
| Individual | Age fa | Female age indicating individual experience and possible age restrictions |
| Age ma | Male age indicating individual experience and possible age restrictions | |
| Polyandry | Polyandry status: monogamous or polyandrous brood | |
| Polygyny all | Polygyny status: monogamous, alpha, beta, gamma, successive alpha, and successive beta brood | |
| Polyandry history | 0/1 indicator for whether the female has been polyandrous, 1 = yes | |
| Polygyny history | 0/1 indicator for whether the male has been polygynous, 1 = yes | |
| polygyny indicator | 0/1 indicator for whether the male was detectably polygynous for this brood, 1 = yes | |
| beta polygyny indicator | 0/1 indicator for whether the male was detectably polygynous and this wasn’t the alpha brood, 1 = yes | |
| polyandry indicator | 0/1 indicator for whether the female was detectably polyandrous for this brood, 1 = yes | |
| male first | 0/1 indicator for whether this was the first hatching for this male, 1 = yes | |
| female first | 0/1 indicator for whether this was the first hatching for this female, 1 = yes | |
| M novelty | Male territory novelty, 1 = first time for this male in this territory | |
| F novelty | Female territory novelty, 1 = first time for this female in this territory | |
| Other | lintime | Temporal time trend, indicating possible global climatic change |
| Random effects | Yeara | Annual variation not explained by climatic variables |
| M id | Male identity (ring number) indicating individual variation | |
| F id | Female identity (ring number) indicating individual variation | |
| Territory id | Territory identity indicating spatial variation not explained by territory and catchment variables |