Table 1 Summary of cross-correlation and regression results between mean apparent calving interval (CI) of Southern right whales and six environmental variables: the El Niño-Southern Oscillation (ONI), Antarctic Oscillation (AAO), mid-latitude sea surface temperature (SST), sea ice concentration (SIC), and cumulative summer chlorophyll-a at mid and high latitudes (Chl). Reported are the lag (in years) at which the maximum cross-correlation (acf) occurred, and the lag yielding the highest adjusted R². Only lags ≤ 0 were considered, as positive lags (i.e., CI leading environmental change) are not biologically interpretable. Also shown are the adjusted R² and corresponding p-value at the optimal lag. Statistically significant relationships are denoted by * (p < 0.05) and ** (p < 0.01).

From: Climate-driven reproductive decline in Southern right whales