Circumpolar phylogeography and demographic history of beluga whales reflect past climatic fluctuations.

Several Arctic marine mammal species are predicted to be negatively impacted by rapid sea ice loss associated with ongoing ocean warming. However, consequences for Arctic whales remain uncertain. To investigate how Arctic whales responded to past climatic fluctuations, we analysed 206 mitochondrial genomes from beluga whales (Delphinapterus leucas) sampled across their circumpolar range, and four nuclear genomes, covering both the Atlantic and the Pacific Arctic region.

[Parental behavior of the beluga whale (Delphinapterus leucas) in natural environment].

The parental behavior of beluga whales observed in a summer reproductive gathering (near Solovetsky Island, Onega Bay, White Sea) is described, including the parturition process. A tight association between the female and its newborn infant has been traced by the case study of a stillborn calf. Individual behavioral patterns of a mother and calves observable only in natural habitats are detailed.

[Behavioral and acoustical characteristics of the reproductive gathering of beluga whales (Delphinapterus leucas) in the vicinity of Myagostrov, Golyi Sosnovets, and Roganka Islands (Onega Bay, the White Sea)].

The structure of the summer reproductive gathering of beluga whales Delphinapterus leucas was studied in the vicinity of Myagostrov, Golyi Sosnovets, and Roganka islands (Onega Bay, the White Sea) in 2006 and 2008. The abundance, age and sex structure, behavior, and swimming and acoustic behavior were studied in detail.

[Mother-infant spatial relations in wild beluga (Delphinapterus leucas) during postnatal development under natural conditions].

Elements of behavior under natural conditions, their duration, and frequency are described in three age groups of belugas calves: newborn, one-month-old, and two-month-old. The quantitative and qualitative indices of the recognized behavioral elements allowed us to evaluate the mother-infant contacts and to analyze their dynamics during calf growth. The most common calf positions relative to the mother during this period were "at the cow's tail" and "at the cow's side.