This study investigated the repertoire, call-type variability and call rates of southern right whales on a calving ground off Brazil in the western South Atlantic. Acoustic tag data were collected from four lactating females and one juvenile. Pulsive, hybrid, and upcalls showed the greatest variability among call-types with up to 23% of non-standard forms detected. Quiet sounds (grunt, single, and double pulse) were detected for the first time in this species on the calving grounds. Although the sample size was limited, results suggest that social interaction increased call-type diversity and call rates, in line with other acoustic studies on right whales.
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http://dx.doi.org/10.1121/10.0001391 | DOI Listing |
The reduced genetic diversity and frequent inbreeding associated with small population size may underpin the accumulation and expression of deleterious mutations (mutation load) in some declining populations. However, demographic perturbations and inbreeding coupled with purifying selection can also purge declining populations of deleterious mutations, leading to intriguing recoveries. To better understand the links between deleterious genetic variation and population status, we assess patterns of genetic diversity, inbreeding, and mutation load across the genomes of three species of whale with different demographic histories and recoveries following the end of commercial whaling in the 1980s.
View Article and Find Full Text PDFSci Total Environ
December 2024
Instituto Oceanográfico, Universidade de São Paulo, Praça do Oceanográfico, 191, São Paulo, SP 05508-120, Brazil.
Sci Adv
December 2024
Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD, Australia.
We fit ongoing 40+-year mark-recapture databases from the thriving southern right whale (SRW), , and highly endangered North Atlantic right whale (NARW), , to candidate survival models to estimate their life spans. Median life span for SRW was 73.4 years, with 10% of individuals surviving past 131.
View Article and Find Full Text PDFGenome Biol Evol
December 2024
Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, Guangdong, China.
Protamines (PRMs) and transition nuclear proteins (TNPs) are two key classes of sperm nuclear basic proteins that regulate chromatin reorganization and condensation in the spermatozoon head, playing crucial roles in mammalian spermatogenesis. In scrotal mammals, such as humans, cryptorchidism, the failure of the testes to descend into the scrotal sac is generally associated with higher rates of defective spermatozoon quality and function. However, ascrotal mammals, such as cetaceans, with naturally undescended testes, produce normal spermatozoa similar to their scrotal counterparts.
View Article and Find Full Text PDFJ Physiol
December 2024
Marine Mammal Research Program, Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, Hawai'i, USA.
Given recent declines in North Pacific humpback whale (Megaptera novaeangliae) reproductive output and calf survival, there is additional urgency to better understand how mother-calf pairs allocate energy resources across their migratory cycle. Here, unoccupied aerial system (UAS; or drone) photogrammetry was used to quantify the body size and condition (BC) of humpback whales on their Hawai'i (HI) breeding and Southeast Alaska (SEAK) feeding grounds. Between 2018 and 2022, we collected 2410 measurements of 1659 individuals.
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