Effects of whale-watching activities on southern right whales in Encounter Bay, South Australia

Sprogis, Kate R.; Holman, Dirk; Arranz, Patricia; Christiansen, Fredrik

doi:10.1016/j.marpol.2023.105525

Cited by 6 publications

(1 citation statement)

References 34 publications

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“…This is particularly important when travelling towards their feeding grounds on the southern migration as individuals will most likely be in a more sensitive state due to the nutritional loss over the breeding season, leading to reduced energy stores to overcome potential stressors. Furthermore, the current whale-watching guidelines in Australia do not account for vessel noise disturbance (Sprogis et al, 2023). This is especially important for cow/calf pairs, where the mother has finite resources to give to her calf, making it vital to decrease disturbance and mitigate any negative impacts that could affect the energetic budget of the mother.…”

Section: Management Implicationsmentioning

confidence: 99%

Cost of migration and migratory timing in Western Australian humpback whales

Russell,

Cagnazzi,

Colefax

et al. 2023

Marine Mammal Science

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Migratory humpback whales (Megaptera novaeangliae) cover the cost of reproduction in low‐latitude breeding grounds with stored energy accumulated from polar feeding grounds. The ability to accumulate sufficient energy reserves during feeding periods is vital for key life history stages during migration, including mating, calving, and lactation. This study aimed to investigate the relationship between migration timing and body condition of Western Australian humpback whales. We used unmanned aerial vehicles to measure body condition (residual of body volume vs. length) in 2017 and 2021. Morphometric measurements were obtained from 460 individuals (71 calves, 83 juveniles, 235 adults, and 71 lactating females) during the northbound (toward breeding grounds) and southbound (toward feeding grounds) migration between May and November. Body condition decreased by 23 and 13 percentage points for juveniles and adults, respectively. The body condition of juveniles was shown to be correlated with migration timing for their northern migration, with individuals in better body condition migrating to the breeding grounds earlier. While stored energy is vital for humpback whales to successfully complete their vast migration to‐and‐from breeding grounds, we found no evidence that body condition affects the migration timing for adults, lactating females, and calves.

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Section: Management Implicationsmentioning

confidence: 99%

Cost of migration and migratory timing in Western Australian humpback whales

Russell,

Cagnazzi,

Colefax

et al. 2023

Marine Mammal Science

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Allosuckling in southern right whale calves

Sprogis,

Christiansen

2024

Mamm Biol

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Allosuckling, the suckling of milk from a non-biological mother, occurs in some species of mammals. Allosuckling has not been quantified in baleen whale calves; therefore, we examine allosuckling in southern right whales (SRWs; Eubalaena australis) off Australia. SRWs are listed as Endangered under the Australian Environment Protection and Biodiversity Conservation Act as their numbers remain below the estimated historical abundance. On a small aggregation area, where there were three mother–calf pairs present, we aimed to quantify the proportion of time that calves allosuckled relative to the time spent filial suckling. To achieve this, we conducted unmanned aerial vehicle focal follows on mother–calf pairs and video recorded all interactions among pairs (n = 22 interactions, 3 h total observation time). During interactions, allosuckling occurred in seven interactions, and filial nursing occurred in 11 interactions. One of the calves performed allosuckling, and it was the largest calf with the largest mother. The calf allosuckled from both of the non-biological mothers present. The average proportion of time allosuckling per interaction was 4% (95% CI = ± 0.01, range = 0–0.25), whilst filial nursing for the same calf was 8% (95% CI = ± 0.02, range = 0–0.37). It is important to understand the frequency of allosuckling, and to quantify the energetic benefits for allosuckling calves and the energetic cost incurred by targeted non-biological mothers. This is particularly pertinent for capital breeders who do not replenish lost energy reserves until they migrate to their feeding grounds.

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