I’m pleased to inform on the recent publication of the article "Population estimate and demographic trends of humpback whale Breeding Stock G in Ecuador: insights from 15 years of land-based monitoring" Abstract Population abundance and demographic trends of the humpback whale Breeding Stock G (BSG) were estimated from land-based monitoring at the Santa Elena Peninsula tip, Ecuador (2°11.35′S, 81°0.63′W). The study was conducted between May and December from 2010 to 2024. The effort included 3,479.5 hours of observation from a land station, during which 7,218 whale groups were recorded. Boat-based data were used to complement land-based observations. Humpback whales arrived in early May, and last observations occurred in December. The northbound migration peak occurred in late June. The observation rate increased from 0.699 whales per hour in 2010 to 4.19 whales per hour in 2024, concordant with an increase in the population. Based on an estimated intrinsic population growth rate of 0.119, we estimated the population to be 27,864 (CI 95% 26,354-29,293) whales in 2024. The calf production rate for the period was 0.152. The average annual survival rate of the population was 0.956. The observed interannual variability on whale migration behavior was associated with El Niño Southern Oscillation (ENSO). During strong El Niño years (2015 and 2023), the calf production rate increased, likely because a portion of the population did not reach the breeding area, artificially inflating the rate. In the years following a strong El Niño (2016 and 2024), the calf production rate decreased, while the population increased considerably as females that did not reached the breeding area the previous year joined with pregnant females in the former year. This relationship between migration behavior and environmental conditions warrants further analysis, particularly in light of increasing ocean climate variability and its implications for population assessments. Citation: Félix, F., & Haase, B. (2025). Population estimate and demographic trends of humpback whale Breeding Stock G in Ecuador: insights from 15 years of land-based monitoring. Latin American Journal of Aquatic Mammals, 20(2), 122-135. The article can be reach through this link: https://www.lajamjournal.org/index.php/lajam/article/view/1739/687 Fernando Félix
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