Spatial and Temporal Variation in the Effects of Climatic Variables on Dugong Calf Production

• Published in: PloS one Vol. 11; no. 6; p. e0155675
• Main Authors: Fuentes, Mariana M P B, Delean, Steven, Grayson, Jillian, Lavender, Sally, Logan, Murray, Marsh, Helene
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 29-06-2016; Public Library of Science (PLoS)
• Subjects: Aerial surveys; Animals; Aquatic mammals; Calves; Caretta caretta; Chelonia mydas; Climate; Climate change; Coasts; Cyclones; Demographics; Dugong; Dugong - growth & development; Dugong - physiology; Dugong dugon; Earth Sciences; El Nino; El Nino-Southern Oscillation; Environmental science; Female; Floods; Geography; Grasses; Knowledge management; Male; Marine mammals; Marine pollution; Mortality; People and Places; Population; Population Dynamics; Pregnancy; Pregnancy, Animal; Queensland; Rainfall; Rainfall anomalies; Regional analysis; Reptiles & amphibians; Sea surface temperature; Southern Oscillation; Spatio-Temporal Analysis; Surface temperature; Surveys; Temperature; Temporal variations; Tropical cyclones; Australia; Queensland Australia; Florida; United States > US; Great Barrier Reef
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0155675

Knowledge of the relationships between environmental forcing and demographic parameters is important for predicting responses from climatic changes and to manage populations effectively. We explore the relationships between the proportion of sea cows (Dugong dugon) classified as calves and four climatic drivers (rainfall anomaly, Southern Oscillation El Niño Index [SOI], NINO 3.4 sea surface temperature index, and number of tropical cyclones) at a range of spatially distinct locations in Queensland, Australia, a region with relatively high dugong density. Dugong and calf data were obtained from standardized aerial surveys conducted along the study region. A range of lagged versions of each of the focal climatic drivers (1 to 4 years) were included in a global model containing the proportion of calves in each population crossed with each of the lagged versions of the climatic drivers to explore relationships. The relative influence of each predictor was estimated via Gibbs variable selection. The relationships between the proportion of dependent calves and the climatic drivers varied spatially and temporally, with climatic drivers influencing calf counts at sub-regional scales. Thus we recommend that the assessment of and management response to indirect climatic threats on dugongs should also occur at sub-regional scales.