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Southern right whales use the Brazilian coast as a wintering area. This population was severely depleted by whaling up until 1973. Since the 1980s, studies have shown that this species is now restricted to the southern waters of Brazil. Using photo‐identification data obtained via standardized aerial surveys from Florianópolis, State of Santa Catarina (SC) (−27.797°/−48.533°) to Torres, State of Rio Grande do Sul (RS) (−29.396°/−49.763°), mark‐recapture methods were used to estimate survival capture and recruitment probability, population size using the POPAN model for reproductive females. Data were collected between 2004 and 2021. The final model was selected based on the lowest Akaike Information Criterion value. Of the 396 female whales identified, 41.41% were recaptured at least once. The final POPAN model showed time dependence in all parameters. The population size was estimated to be 397 reproductive females. This is the first update on the population trends for southern right whales in Brazilian breeding grounds since 2010. [ABSTRACT FROM AUTHOR]

North Atlantic right whale (NARW) distribution shifts have led to increased presence in the US mid‐Atlantic, which includes the New York Bight (NYB), an area with substantial vessel traffic. NARW vessel strikes are mitigated by a seasonal management area (SMA) that is active November–April. Within the SMA, vessels ≥ 19.8 m must travel at ≤10 knots. However, until recently, surveys of the NYB were not conducted after the NARW distribution shifted. Thus, it was unclear whether the SMA captured NARW presence in the NYB. Outside the SMA, voluntary speed restrictions are implemented over a limited area when NARW calls are acoustically detected; therefore, it was important to quantify NARW vocal activity. Acoustic recordings (2016–2020) were analyzed to determine NARW presence, vocal states, and diel pattern of vocal activity. NARWs were detected outside SMA boundaries, and medium/high vocal states (21–69 calls over 3–6 h) occurred while the SMA was inactive. Therefore, the SMA spatiotemporal boundaries should be revised. Vocal activity was highest at night (22:00–1:00), and NARWs were acoustically detected when they were not detected by aerial surveys, illustrating acoustic detections are a viable method for triggering mitigation measures when NARWs are vocalizing but are not visually observed. [ABSTRACT FROM AUTHOR]

The article informs that researcher P.T. Madsen and colleagues present groundbreaking research demonstrating that toothed whales possess a unique nasal structure that allows them to produce a diverse range of sounds across a broad frequency range. The research draws parallels between the vocal production of toothed whales and that of humans, terrestrial mammals, frogs and birds.