An unknown nocturnal call type in the Mariana Archipelago.

In spring/summer of 2018 and 2021, the Pacific Islands Fisheries Science Center Cetacean Research Program deployed drifting acoustic recorders in the U.S. Exclusive Economic Zones surrounding the Mariana Archipelago. Manual assessments revealed a low-frequency (median 473-554 Hz), short-duration (median 0.596 s), stereotypic tonal nocturnal call throughout the Mariana Archipelago. Based on time of year, spatiotemporal patterns, clear division among calls (i.e., no chorusing), comparisons with known vocalizations of whales, turtles, and fish, and presence of Bryde's whale calls, and because the call has not been detected elsewhere, we hypothesize this 500-Hz pulsed call is produced by Bryde's whales (Balaenoptera brydei).

Acoustic differentiation and classification of wild belugas and narwhals using echolocation clicks.

Belugas (Delphinapterus leucas) and narwhals (Monodon monoceros) are highly social Arctic toothed whales with large vocal repertoires and similar acoustic profiles. Passive Acoustic Monitoring (PAM) that uses multiple hydrophones over large spatiotemporal scales has been a primary method to study their populations, particularly in response to rapid climate change and increasing underwater noise. This study marks the first acoustic comparison between wild belugas and narwhals from the same location and reveals that they can be acoustically differentiated and classified solely by echolocation clicks. Acoustic recordings were made in the pack ice of Baffin Bay, West Greenland, during 2013. Multivariate analyses and Random Forests classification models were applied to eighty-one single-species acoustic events comprised of numerous echolocation clicks. Results demonstrate a significant difference between species' acoustic parameters where beluga echolocation was distinguished by higher frequency content, evidenced by higher peak frequencies, center frequencies, and frequency minimums and maximums. Spectral peaks, troughs, and center frequencies for beluga clicks were generally > 60 kHz and narwhal clicks < 60 kHz with overlap between 40-60 kHz. Classification model predictive performance was strong with an overall correct classification rate of 97.5% for the best model. The most important predictors for species assignment were defined by peaks and notches in frequency spectra. Our results provide strong support for the use of echolocation in PAM efforts to differentiate belugas and narwhals acoustically.

Acoustic classification of false killer whales in the Hawaiian islands based on comprehensive vocal repertoire.

Use of underwater passive acoustic datasets for species-specific inference requires robust classification systems to identify encounters to species from characteristics of detected sounds. A suite of routines designed to efficiently detect cetacean sounds, extract features, and classify the detection to species is described using ship-based, visually verified detections of false killer whales (Pseudorca crassidens). The best-performing model included features from clicks, whistles, and burst pulses, which correctly classified 99.6% of events. This case study illustrates use of these tools to build classifiers for any group of cetacean species and assess classification confidence when visual confirmation is not available.

Headlines and hashtags: communicating science during an outbreak.

Science and medical professionals are often looked to as experts in the event of a health crisis, but relatively few have received formal training in science communication. We provide a brief review of the current outbreak situation and suggestions for engaging in reliable, effective science communication online.

Screen Exposure During Daily Routines and a Young Child's Risk for Having Social-Emotional Delay.

This cross-sectional study assessed associations between social-emotional development in young children and their number of daily routines involving an electronic screen. We hypothesized children with poor social-emotional development have a significant portion of daily routines occurring with a screen. Two hundred and ten female caregivers of typically developing children 12 to 36 months old completed the Ages and Stages Questionnaire: Social-Emotional (ASQ: SE) and a media diary. Caregivers completed the diary for 1 day around 10 daily routines (Waking Up, Diapering/Toileting, Dressing, Breakfast, Lunch, Naptime, Playtime, Dinner, Bath, and Bedtime). Median number of daily routines occurring with a screen for children at risk and not at risk for social-emotional delay (as defined by the ASQ: SE) was 7 versus 5. Children at risk for social-emotional delay were 5.8 times more likely to have ≥5 routines occurring with a screen as compared to children not at risk for delay (χ12 = 9.28, N = 210, P = .002; 95% confidence interval = 1.66-20.39).