Filipa I. P. Samarra results 16
· Newest (Page 1/1, per page 25)
Author: Filipa I. P. Samarra ×Clear All Filters
Search Results
Ecological divergence in movement and habitat use of long-finned pilot whales (Globicephala melas) across the subpolar North AtlanticNARA Subscribed
Despite their widespread presence across the North Atlantic, it remains unclear how long-finned pilot whales ( Globicephala melas ) differ regionally in their movement patterns and habitat use, and what this means for population structure. Satellite transmitters attached to pilot whales in the Faroe Islands ( n = 11), East Greenland ( n = 6), and Iceland ( n = 2) between 2023 and 2025 revealed consistent regional differences i...
orcAI : A Machine Learning Tool to Detect and Classify Acoustic Signals of Killer Whales in Audio RecordingsNARA Subscribed
Acoustic monitoring is an essential tool for investigating animal communication and behavior when visual contact is limited, but the scalability of bioacoustic projects is often limited by time‐intensive manual auditing of focal signals. To address this bottleneck, we introduce orcAI—a novel deep learning framework for the automated detection and classification of a broad acoustic repertoire of killer whales ( Orcinus orca ),...
Aim The urgency for remote, reliable and scalable biodiversity monitoring amidst mounting human pressures on ecosystems has sparked worldwide interest in Passive Acoustic Monitoring (PAM), which can track life underwater and on land. However, we lack a unified methodology to report this sampling effort and a comprehensive overview of PAM coverage to gauge its potential as a global research and monitoring tool. To address this...
Killer whale ( Orcinus orca ) occurrence in Icelandic waters revealed by passive acoustic monitoringNARA Subscribed
The distribution and occurrence of killer whales around Iceland are primarily studied in coastal herring grounds, with limited knowledge beyond these areas. This study employed opportunistic passive acoustic monitoring (PAM) data from four regions across Icelandic inshore and offshore waters to investigate killer whale distribution between 2018 and 2023. An automatic detector‐and‐classifier algorithm identified killer whale bu...
Icelandic waters are a crucial feeding ground for North Atlantic humpback whales, yet their occurrence in these subarctic waters remains underexplored. This study examined seasonal and diel patterns in humpback whale occurrence off the Vestmannaeyjar archipelago, southern Iceland, from June 2018 to May 2019, using automated acoustic detections from bottom‐moored hydrophones. Vocalizations were manually categorized into social...
Call type repertoire of killer whales ( Orcinus orca ) in Iceland and its variation across regionsNARA Subscribed
Killer whales ( Orcinus orca ) have group‐specific call repertoires that can be used to track groups and populations using passive acoustic monitoring. To provide a detailed description of the Icelandic killer whale repertoire and its variation, we analyzed acoustic data collected in five locations between 1985 and 2016. Calls were classified manually, and CART and random forest analyses were employed to validate the manual cl...
Long-finned pilot whales and killer whales are widely distributed across the North Atlantic, but few studies have reported their occurrence in Icelandic coastal waters. Here, we use sightings data from research platforms and whale watching tours in six regions of Iceland from 2007 to 2020 to show that the occurrence of long-finned pilot and killer whales varied with region and season. Killer whales were regularly encountered i...
Runs of homozygosity in killer whale genomes provide a global record of demographic historiesNARA Subscribed
Runs of homozygosity (ROH) occur when offspring inherit haplotypes that are identical by descent from each parent. Length distributions of ROH are informative about population history; specifically, the probability of inbreeding mediated by mating system and/or population demography. Here, we investigated whether variation in killer whale ( Orcinus orca ) demographic history is reflected in genome‐wide heterozygosity and ROH l...
A comparison of Northeast Atlantic killer whale ( Orcinus orca ) stereotyped call repertoiresNARA Subscribed
Killer whale call repertoires can provide information on social connections among groups and populations. Killer whales in Iceland and Norway exhibit similar ecology and behavior, are genetically related, and are presumed to have been in contact before the collapse of the Atlanto‐Scandian herring stock in the 1960s. However, photo‐identification suggests no recent movements between Iceland and Norway but regular movement betwe...
Reconstruction of the demographic and evolutionary history of populations assuming a consensus tree‐like relationship can mask more complex scenarios, which are prevalent in nature. An emerging genomic toolset, which has been most comprehensively harnessed in the reconstruction of human evolutionary history, enables molecular ecologists to elucidate complex population histories. Killer whales have limited extrinsic barriers to...
Geographic variation in the time‐frequency characteristics of high‐frequency whistles produced by killer whales ( Orcinus orca )NARA Subscribed
Investigating intraspecific variation in acoustic signals can indicate the extent of isolation and divergence between populations and adaptations to local environments. Here we analyze the variation in killer whale high‐frequency (>17 kH z) whistles recorded off Norway, Iceland, and in the North Pacific. We used a combination of methods including multivariate comparisons of spectral and temporal parameters and categorization o...
Previous1Next