High-resolution archival tags provide new insights into the underwater foraging and echolocation behavior of resident killer whales capturing Pacific salmon

Dtags contain sensors for recording both high resolution animal movement and underwater sound. They provide a valuable tool for examining the foraging behavior of resident killer whales, a specialist predator that relies on echolocation to find and pursue Pacific salmon, its primary prey. We deployed Dtags on 32 northern residents off Vancouver Island, BC, and compared reconstructed whale dive paths to distributions of different salmonid prey. Foraging whales dove deeper, remained submerged longer, swam faster, increased their dive path tortuosity, and rolled their bodies more than during other activities. Foraging dive structure also reflected the deeper vertical distribution of Chinook salmon and revealed several predator evasion strategies used by salmonids. Echolocation by resident killer whales during 17 successful salmon captures was also examined in detail. For each capture, whales produced an average of 14.3 regular click trains with mean repetition rates of 10 clicks s-1, and 2.5 ‘buzzes’ with rapid click rates exceeding 50 clicks s-1. Most buzzes occurred at depths \u3e100 m and preceded prey captures, which is consistent with their presumed function of close-range prey targeting. Once salmon were caught, both the mean proportion of time that whales spent echolocating and the mean clicking rate decreased significantly, confirming that echolocation plays an important role in prey detection and tracking. Distinctive ‘crunches’ were audible at shallow depths (m) following captures, indicating that killer whales brought most fish to the surface for handling and consumption. DFO and NOAA are now conducting a transboundary study using Dtag data to compare the foraging behavior of endangered southern residents with that of the growing northern resident population. Investigating differences in foraging efficiency between these two populations, including the impact of vessel noise exposure, will help to clarify factors impeding the recovery of southern residents, and identify strategies to best mitigate these threats

Human CSF movement influenced by vascular low frequency oscillations and respiration

Cerebrospinal fluid (CSF) movement through the pathways within the central nervous system is of high significance for maintaining normal brain health and function. Low frequency hemodynamics and respiration have been shown to drive CSF in humans independently. Here, we hypothesize that CSF movement may be driven simultaneously (and in synchrony) by both mechanisms and study their independent and coupled effects on CSF movement using novel neck fMRI scans. Caudad CSF movement at the fourth ventricle and hemodynamics of the major neck blood vessels (internal carotid arteries and internal jugular veins) was measured from 11 young, healthy volunteers using novel neck fMRI scans with simultaneous measurement of respiration. Two distinct models of CSF movement (1. Low-frequency hemodynamics and 2. Respiration) and possible coupling between them were investigated. We show that the dynamics of brain fluids can be assessed from the neck by studying the interrelationships between major neck blood vessels and the CSF movement in the fourth ventricle. We also demonstrate that there exists a cross-frequency coupling between these two separable mechanisms. The human CSF system can respond to multiple coupled physiological forces at the same time. This information may help inform the pathological mechanisms behind CSF movement-related disorders

Postreproductive killer whale grandmothers improve the survival of their grandoffspring

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Augmenting Buried In Treasures With In-Home Uncluttering Practice: Pilot Study In Hoarding Disorder

Hoarding disorder is characterized by difficulty parting with possessions and by clutter that impairs the functionality of living spaces. Cognitive behavioral therapy conducted by a therapist (individual or in a group) for hoarding symptoms has shown promise. For those who cannot afford or access the services of a therapist, one alternative is an evidence-based, highly structured, short-term, skills-based group using CBT principles but led by non-professional facilitators (the Buried in Treasures [BIT] Workshop). BIT has achieved improvement rates similar to those of psychologist-led CBT. Regardless of modality, however, clinically relevant symptoms remain after treatment, and new approaches to augment existing treatments are needed. Based on two recent studies - one reporting that personalized care and accountability made treatments more acceptable to individuals with hoarding disorder and another reporting that greater number of home sessions were associated with better clinical outcomes, we tested the feasibility and effectiveness of adding personalized, in-home uncluttering sessions to the final weeks of BIT. Participants (n = 5) had 15 sessions of BIT and up to 20 hours of in-home uncluttering. Reductions in hoarding symptoms, clutter, and impairment of daily activities were observed. Treatment response rate was comparable to rates in other BIT studies, with continued improvement in clutter level after in-home uncluttering sessions. This small study suggests that adding in-home uncluttering sessions to BIT is feasible and effective

Divergent foraging strategies between populations of sympatric matrilineal killer whales

In cooperative species, human-induced rapid environmental change may threaten cost–benefit tradeoffs of group behavioral strategies that evolved in past environments. Capacity for behavioral flexibility can increase population viability in novel environments. Whether the partitioning of individual responsibilities within social groups is fixed or flexible across populations is poorly understood, despite its relevance for predicting responses to global change at the population and species levels and designing successful conservation programs. We leveraged bio-logging data from two populations of fish-eating killer whales (Orcinus orca) to quantify patterns of fine-scale foraging movements and their relationships with demography. We reveal striking interpopulation differences in patterns of individual foraging behavior. Females from the endangered Southern Resident (SRKW) population captured less prey and spent less time pursuing prey than SRKW males or Northern Resident (NRKW) females, whereas NRKW females captured more prey than NRKW males. The presence of a calf (≤3 years) reduced the number of prey captured by adult females from both populations, but disproportionately so for SRKW. SRKW adult males with a living mother captured more prey than those whose mother had died, whereas the opposite was true for NRKW adult males. Across populations, males foraged in deeper areas than females, and SRKW captured prey deeper than NRKW. These population-level differences in patterns of individual foraging behavior challenge the existing paradigm that females are the disproportionate foragers in gregarious resident killer whales, and demonstrate considerable variation in the foraging strategies across populations of an apex marine predator experiencing different environmental stressors

Don\u27t fear the nobodies: A critical youth study of the Columbiner Instagram Community

This research sheds light on how one particular group of young people, Columbiners, use social media to build and maintain a sense of community. Through a content analysis of 200 Instagram posts containing a school shooting fandom hashtag, or #Columbiner, and drawing on both Critical Youth Studies and Sense of Community Theory, this research demonstrates how Columbiners use their hashtag to create a sense of community on Instagram, to explore what it means to be young and cool, and to make sense of the problems that shape their social world, including school shootings. Exploring how this particular group of young people engage with each other on social media provides researchers an opportunity to listen to young people as they develop their understandings of topics as seemingly mundane as homework to those as serious as school shootings

Kinematics and acoustics of foraging behaviour by a specialist predator, the northern resident killer whale (Orcinus orca)

Foragers with narrow dietary niches often exhibit specialized hunting behaviours that improve their efficiency for capturing preferred prey, but can leave them vulnerable if the abundance of this prey declines. I examined the specificity of foraging behaviour by a highly selective predator, the northern resident killer whale (Orcinus orca), which specializes on Chinook salmon (Oncorhynchus tshawytscha). Northern residents are undoubtedly well adapted to capture Chinook, however, their hunting tactics have never been described due to the challenges of quantifying underwater behaviour. To address this research gap, I deployed archival tags (DTAGs) on 32 killer whales to measure their acoustic and kinematic behaviour during foraging dives. Reconstructed 3-dimensional tag tracks indicated that foraging and non-foraging dives were kinematically distinct. While engaged in hunting behaviour, whales dove deeper, remained submerged longer, swam faster, increased their dive path tortuosity, and rolled their bodies more than during other activities. Maximum foraging dive depths reflected both the deeper vertical distribution of Chinook (compared to other salmonids), as well as the tendency of these fish to evade predation by diving steeply. Inferences from whale movements further revealed that salmon engaged in other anti-predation strategies, including increasing swim speeds and evasive manoeuvring. DTAG records also provided the first definitive link between echolocation and prey captures by resident killer whales, who displayed significantly higher clicking rates and spent proportionally more time echolocating prior to capturing a fish than they did afterward. Rapid ‘buzz’ click sequences were often produced before fish captures, which is consistent with their hypothesized function of close-range prey targeting. Furthermore, prey handling ‘crunches’ were usually detected following kills and, with buzzes, provide possible acoustic proxies for capture attempts and successes that could be used to estimate foraging efficiency. My thesis determined that northern resident killer whales possess specialized foraging behaviours for targeting Chinook salmon. The specificity of these behaviours may make the whales less effective at capturing other types of fish. If northern residents have limited flexibility to modify their foraging behaviour to successfully exploit other prey types when Chinook availability is reduced, prey capture efficiency (and thus per capita energy intake) could decline.Science, Faculty ofZoology, Department ofGraduat