Individual variation in life-history timing: synchronous presence, asynchronous events and phenological compensation in a wild mammal.

Many animals and plants have species-typical annual cycles, but individuals vary in their timing of life-history events. Individual variation in fur replacement (moult) timing is poorly understood in mammals due to the challenge of repeated observations and longitudinal sampling. We examined factors that influence variation in moult duration and timing among elephant seals (Mirounga angustirostris). We quantified the onset and progression of fur loss in 1178 individuals. We found that an exceptionally rapid visible moult (7 days, the shortest of any mammals or birds), and a wide range of moult start dates (spanning 6-10× the event duration) facilitated high asynchrony across individuals (only 20% of individuals in the population moulting at the same time). Some of the variation was due to reproductive state, as reproductively mature females that skipped a breeding season moulted a week earlier than reproductive females. Moreover, individual variation in timing and duration within age-sex categories far outweighed (76-80%) variation among age-sex categories. Individuals arriving at the end of the moult season spent 50% less time on the beach, which allowed them to catch up in their annual cycles and reduce population-level variance during breeding. These findings underscore the importance of individual variation in annual cycles.

Native knee kinematics are reproduced during the golf swing after total knee arthroplasty apart from rotation: A case control study of hip and knee kinematics of patients returning to golf compared to match controls.

OBJECTIVES: Golf is a popular sport in older adults and this same population has an increasing prevalence of osteoarthritis affecting major joints such as the knee. To the authors' knowledge, the effect of Total Knee Arthroplasty (TKA) on the movements in the golf swing has not been extensively investigated despite the large prevalence of golfers who have undergone TKA. We aimed to determine lower limb joint kinematics during the golf swing and whether these are influenced following TKA. METHODS: A case- control study was undertaken with ten right-handed golfers who had undergone TKA (cruciate-retaining single radius implant) and five matched golfers with native knees. Each golfer performed five swings with a driver whilst being recorded at 200 â€‹Hz by a ten-camera motion capture system. Knee and hip three-dimensional joint angles (JA) and joint angular velocities (JAV) were calculated and statistically compared between the groups at six swing events. RESULTS: The left knee demonstrated large effect sizes for lower external rotation during take away, mid (p â€‹= â€‹0.01) and top of backswing in the TKA group. In contrast, the right knee demonstrated large effect sizes for lower external rotation in the TKA group during the downswing, contact and follow-through phases. There were no differences in knee flexion/extension, ab/adduction, or JAV between the groups. Both hips demonstrated statistically significantly (p â€‹= â€‹0.02 for left and p â€‹= â€‹0.04 for right) lower flexion in the TKA group during the takeaway swing event, and lower internal rotation in the backswing and greater external rotation in the downswing of the right hip. CONCLUSION: Normal knee kinematics were observed during the golf swing following TKA, with the exception of reduced external rotation in the left knee during the backswing and the right during the down swing. The differences demonstrated in the hip motion indicate that they may make compensatory movements to adjust to the reduced external rotation demonstrated in the knee. LEVEL OF EVIDENCE: IV.

Epidemiology of musculoskeletal injury in professional and amateur golfers: a systematic review and meta-analysis.

OBJECTIVE: To determine the prevalence and incidence of musculoskeletal injury in amateur and professional golfers, and to identify common injury sites and factors associated with increased injury frequency. DESIGN: Systematic epidemiological review and meta-analysis. DATA SOURCES: PubMed (Medline), Embase, the Cochrane Library and SPORTDiscus were searched in September 2023. ELIGIBILITY CRITERIA: Studies published in the English language reporting the incidence or prevalence of musculoskeletal injuries in golfers at all anatomical sites. RESULTS: 20 studies (9221 golfers, 71.9% male, 28.1% female) were included, with mean age 46.8 years. Lifetime injury prevalence was significantly greater in professional golfers (73.5% (95% CI: 47.3% to 93.0%)) than amateur golfers (56.6% (95% CI: 47.4% to 65.5%); relative risk (RR)=1.50, p<0.001). Professional golfers had a significantly greater lifetime prevalence of hand and wrist (RR=3.33, p<0.001) and lower back injury (RR=3.05, p<0.001). Soft tissue injuries were most common, and diagnoses were typically non-specific. Injury frequency was not associated with age or sex. Two studies reported a greater injury risk in amateur golfers playing more than three and four rounds per week. CONCLUSION: Over half of golfers are at risk of sustaining a musculoskeletal injury during their lifetime. Risks and patterns of injury differ between professional and amateur golfers, with professionals significantly more likely to develop lower back, and hand and wrist injuries. A recent international consensus statement on the reporting of injury and illness in golf should aid consistency in future research assessing the epidemiology of specific diagnoses, informing golf injury prevention and management strategies. PROSPERO REGISTRATION NUMBER: CRD42023408738.

Genomics of post-bottleneck recovery in the northern elephant seal.

Populations and species are threatened by human pressure, but their fate is variable. Some depleted populations, such as that of the northern elephant seal (Mirounga angustirostris), recover rapidly even when the surviving population was small. The northern elephant seal was hunted extensively and taken by collectors between the early 1800s and 1892, suffering an extreme population bottleneck as a consequence. Recovery was rapid and now there are over 200,000 individuals. We sequenced 260 modern and 8 historical northern elephant seal nuclear genomes to assess the impact of the population bottleneck on individual northern elephant seals and to better understand their recovery. Here we show that inbreeding, an increase in the frequency of alleles compromised by lost function, and allele frequency distortion, reduced the fitness of breeding males and females, as well as the performance of adult females on foraging migrations. We provide a detailed investigation of the impact of a severe bottleneck on fitness at the genomic level and report on the role of specific gene systems.

Contrasting offspring dependence periods and diving development rates in two closely related marine mammal species.

Understanding the ontogeny of diving behaviour in marine megafauna is crucial owing to its influence on foraging success, energy budgets, and mortality. We compared the ontogeny of diving behaviour in two closely related species-northern elephant seals (Mirounga angustirostris, n = 4) and southern elephant seals (Mirounga leonina, n = 9)-to shed light on the ecological processes underlying migration. Although both species have similar sizes and behaviours as adults, we discovered that juvenile northern elephant seals have superior diving development, reaching 260 m diving depth in just 30 days, while southern elephant seals require 160 days. Similarly, northern elephant seals achieve dive durations of approximately 11 min on their first day of migration, while southern elephant seals take 125 days. The faster physiological maturation of northern elephant seals could be related to longer offspring dependency and post-weaning fast durations, allowing them to develop their endogenous oxygen stores. Comparison across both species suggests that weaned seal pups face a trade-off between leaving early with higher energy stores but poorer physiological abilities or leaving later with improved physiology but reduced fat stores. This trade-off might be influenced by their evolutionary history, which shapes their migration behaviours in changing environments over time.

Uptake and Discontinuation of Pre-Exposure Prophylaxis Among Uninsured Transgender and Cisgender Women: A Public-Private Partnership Model in North Carolina.

HIV pre-exposure prophylaxis (PrEP) remains underutilized among cis and trans women. The PrEP Initiative Program (PIP) is a novel public-private partnership implemented at 12 local clinics in North Carolina. PIP provides HIV/sexually transmitted infection (STI) testing and clinical and laboratory monitoring for PrEP to uninsured/underinsured clients. We sought to understand service-related differences among both cis and trans women enrolled in PIP, including STIs diagnoses, clinic type, sources of referral, services needed, and reasons for PrEP discontinuation. The Kaplan-Meier curves display retention on PrEP over the duration of the program. Since 2018, 142 women (cis n = 113; trans n = 29) enrolled, and 136 started PrEP. The majority were ages 25-34 years (31.7%) or 18-24 years (29.6%), Black (57.8%) or Latinx (24.7%). Approximately 20.6% of recipients reported at least one STI while enrolled. Overall, trans women requested fewer services than cis women. After accounting for the amount of time each patient was taking PrEP, there were higher rates of trans women diagnosed with syphilis than cis women. Rates of persons with other STIs were not notably different between trans and cis women. Clinic access varied by gender: 69% of trans women were enrolled at only one site. Trans women were retained significantly longer: The Kaplan-Meier adjusted median time to discontinuation was 560 and 238 days for trans and cis women, respectively. PIP successfully reached historically marginalized and uninsured cis and trans women who may benefit from PrEP. Further investigations into factors contributing to recruitment and retention of women in HIV prevention programs are needed.

What differences exist between the lead and trail wrist in extensor carpi ulnaris activity and golf swing joint kinematics in sub-elite golfers?

This study assessed the lead and trail arm peak and average extensor carpi ulnaris (ECU) muscle activity in association with tri-planar angular velocities of the lead and trail wrists during the golf swing. Fifteen sub-elite, male right-handed golfers (Mage = 34.7 years ±13.3, Mhandicap = 1.5 ± 2.2) were recruited to execute five shots each with their pitching wedge, 7-iron and driver clubs in an indoor golf simulator. Surface electromyography (EMG) sensors were placed over the ECU muscle belly and inertial measurement unit sensors were placed bi-laterally on the distal forearm and dorsum of the hand. There was a statistically greater recruitment of the trail ECU muscle during the downswing (p < 0.001) for all clubs. The lead ECU muscle was recruited more during the backswing (p < 0.001) and follow through (p < 0.024) phases. There were statistically different tri-planar movement patterns between the lead and trail wrist throughout all three phases of the golf swing. No significant relationships were found between downswing EMG data and clubhead kinematics at impact. In conclusion, differing wrist kinematics and associated muscle activity may contribute to the asymmetrical injury pattern seen clinically.

Health Information on Pre-Exposure Prophylaxis From Search Engines and Twitter: Readability Analysis.

BACKGROUND: Pre-exposure prophylaxis (PrEP) is proven to prevent HIV infection. However, PrEP uptake to date has been limited and inequitable. Analyzing the readability of existing PrEP-related information is important to understand the potential impact of available PrEP information on PrEP uptake and identify opportunities to improve PrEP-related education and communication. OBJECTIVE: We examined the readability of web-based PrEP information identified using search engines and on Twitter. We investigated the readability of web-based PrEP documents, stratified by how the PrEP document was obtained on the web, information source, document format and communication method, PrEP modality, and intended audience. METHODS: Web-based PrEP information in English was systematically identified using search engines and the Twitter API. We manually verified and categorized results and described the method used to obtain information, information source, document format and communication method, PrEP modality, and intended audience. Documents were converted to plain text for the analysis and readability of the collected documents was assessed using 4 readability indices. We conducted pairwise comparisons of readability based on how the PrEP document was obtained on the web, information source, document format, communication method, PrEP modality, and intended audience, then adjusted for multiple comparisons. RESULTS: A total of 463 documents were identified. Overall, the readability of web-based PrEP information was at a higher level (10.2-grade reading level) than what is recommended for health information provided to the general public (ninth-grade reading level, as suggested by the Department of Health and Human Services). Brochures (n=33, 7% of all identified resources) were the only type of PrEP materials that achieved the target of ninth-grade reading level. CONCLUSIONS: Web-based PrEP information is often written at a complex level for potential and current PrEP users to understand. This may hinder PrEP uptake for some people who would benefit from it. The readability of PrEP-related information found on the web should be improved to align more closely with health communication guidelines for reading level to improve access to this important health information, facilitate informed decisions by those with a need for PrEP, and realize national prevention goals for PrEP uptake and reducing new HIV infections in the United States.

Golfing after Orthopaedic Surgery: A longitudinal follow-up (GOLF) study protocol.

Aims: The primary aim of this prospective, multicentre study is to describe the rates of returning to golf following hip, knee, ankle, and shoulder arthroplasty in an active golfing population. Secondary aims will include determining the timing of return to golf, changes in ability, handicap, and mobility, and assessing joint-specific and health-related outcomes following surgery. Methods: This is a multicentre, prospective, longitudinal study between the Hospital for Special Surgery, (New York City, New York, USA) and Edinburgh Orthopaedics, Royal Infirmary of Edinburgh, (Edinburgh, UK). Both centres are high-volume arthroplasty centres, specializing in upper and lower limb arthroplasty. Patients undergoing hip, knee, ankle, or shoulder arthroplasty at either centre, and who report being golfers prior to arthroplasty, will be included. Patient-reported outcome measures will be obtained at six weeks, three months, six months, and 12 months. A two-year period of recruitment will be undertaken of arthroplasty patients at both sites. Conclusion: The results of this prospective study will provide clinicians with accurate data to deliver to patients with regard to the likelihood of return to golf and timing of when they can expect to return to golf following their hip, knee, ankle, or shoulder arthroplasty, as well as their joint-specific functional outcomes. This will help patients to manage their postoperative expectations and plan their postoperative recovery pathway.

PrEP awareness, willingness, and likelihood to use future HIV prevention methods among undergraduate college students in an ending the HIV epidemic jurisdiction.

OBJECTIVE: Identify factors associated with PrEP awareness, willingness, and future prevention modalities among undergraduate college students. PARTICIPANTS: Undergraduates (N = 701) were recruited from a private university, a public research university, and a private historically Black college and university for an online survey. METHODS: Upon multiple imputations, a multivariate logistic model, a multivariate multinomial model, and independent multivariate ordinal logistic models were used to calculate Rubin's rules-pooled adjusted odds ratios for PrEP awareness, willingness, and future HIV prevention methods. RESULTS: Only 33.4% of students had heard of and 32.4% were willing to take PrEP. PrEP willingness was higher among sexual minority students compared to heterosexual/straight students (OR = 1.65; 95% CI: 1.03-2.63); p = .036). The likelihood to take a future vaccine or antibody prophylaxis treatment was higher than the likelihood to take injectable PrEP or implants. CONCLUSIONS: Interventions to increase PrEP uptake and willingness among undergraduates should emphasize equity in HIV education and include future prevention modalities.

Cross-sectional study of characteristics and prevalence of musculoskeletal complaints in 1170 male golfers.

Objectives: The primary aim was to describe the characteristics and prevalence of musculoskeletal complaints of a large group of non-professional golfers. Secondary aims were to compare golfers different in (A) skill-level, (B) presence of low back pain (LBP) and (C) performance of prevention exercises. Methods: A sample of 1170 male golfers (mean age 54.98, SD=13.3) were surveyed online on personal and golf-specific characteristics, medical history and complaints in the preceding 7 days. Subgroups (A) with different golfing handicap (0 to 5, >5 to 10, >10), (B) with and without LBP and (C) who performed versus did not perform injury prevention exercises were compared using analysis of variance and χ2 test. Results: The prevalence and severity of musculoskeletal complaints was similar in everyday life and when playing golf. More than one-third of the golfers (n=436; 37.3%) reported LBP in the preceding 7 days, while other frequently affected body parts were the shoulder and knee. Golfers with different skill level differed in age and most golf-related characteristics but not in prevalence and severity of musculoskeletal complaints. Golfers with and without LBP were similar in almost all variables. Golfers who performed prevention exercises (n=371; 27.1%) were older and had a higher prevalence of complaints. Conclusion: The prevalence and severity of musculoskeletal complaints in golfers were similar to the wider population. It seems that injury prevention exercises were implemented after injury, rather than as primary prevention. Prospective studies looking at the epidemiology of injury, risk factors and interventions are required.

Brain activity of diving seals reveals short sleep cycles at depth.

Sleep is a crucial part of the daily activity patterns of mammals. However, in marine species that spend months or entire lifetimes at sea, the location, timing, and duration of sleep may be constrained. To understand how marine mammals satisfy their daily sleep requirements while at sea, we monitored electroencephalographic activity in wild northern elephant seals (Mirounga angustirostris) diving in Monterey Bay, California. Brain-wave patterns showed that seals took short (less than 20 minutes) naps while diving (maximum depth 377 meters; 104 sleeping dives). Linking these patterns to accelerometry and the time-depth profiles of 334 free-ranging seals (514,406 sleeping dives) revealed a North Pacific sleepscape in which seals averaged only 2 hours of sleep per day for 7 months, rivaling the record for the least sleep among all mammals, which is currently held by the African elephant (about 2 hours per day).

Golf participation after rotator cuff repair: functional outcomes, rate of return and factors associated with return to play.

BACKGROUND: Golf is a popular sport involving overhead activity and engagement of the rotator cuff (RC). This study aimed to determine to what level golfers were able to return to golf following RC repair, the barriers to them returning to golf and factors associated with their failure to return to golf. METHODS: Patients preoperatively identifying as golfers undergoing RC repair at the study centre from 2012 to 2020 were retrospectively followed up with to assess their golf-playing status, performance and frequency of play and functional and quality of life (QoL) outcomes. RESULTS: Forty-seven golfers (40 men [85.1%] and 7 women [14.9%]) with a mean age of 56.8 years met the inclusion criteria, and 80.1% were followed up with at a mean of 27.1 months postoperatively. Twenty-nine patients (76.3%) had returned to golf with a mean handicap change of +1.0 (P=0.291). Golf frequency decreased from a mean of 1.8 rounds per week preinjury to 1.5 rounds per week postoperatively (P=0.052). The EuroQol 5-dimension 5-level (EQ-5D-5L) index and visual analog scale (EQ-VAS) score were significantly greater in those returning to golf (P=0.024 and P=0.002), although functional outcome measures were not significantly different. The primary barriers to return were ipsilateral shoulder dysfunction (78%) and loss of the habit of play (22%). CONCLUSIONS: Golfers were likely (76%) to return to golf following RC repair, including mostly to their premorbid performance level with little residual symptomatology. Return to golf was associated with a greater QoL. Persistent subjective shoulder dysfunction (78%) was the most common barrier to returning to golf. Level of evidence: Level IV.

Content and sentiment surveillance (CSI): A critical component for modeling modern epidemics.

Comprehensive surveillance systems are the key to provide accurate data for effective modeling. Traditional symptom-based case surveillance has been joined with recent genomic, serologic, and environment surveillance to provide more integrated disease surveillance systems. A major gap in comprehensive disease surveillance is to accurately monitor potential population behavioral changes in real-time. Population-wide behaviors such as compliance with various interventions and vaccination acceptance significantly influence and drive the overall epidemic dynamics in the society. Original infoveillance utilizes online query data (e.g., Google and Wikipedia search of a specific content topic such as an epidemic) and later focuses on large volumes of online discourse data about the from social media platforms and further augments epidemic modeling. It mainly uses number of posts to approximate public awareness of the disease, and further compares with observed epidemic dynamics for better projection. The current COVID-19 pandemic shows that there is an urgency to further harness the rich, detailed content and sentiment information, which can provide more accurate and granular information on public awareness and perceptions toward multiple aspects of the disease, especially various interventions. In this perspective paper, we describe a novel conceptual analytical framework of content and sentiment infoveillance (CSI) and integration with epidemic modeling. This CSI framework includes data retrieval and pre-processing; information extraction via natural language processing to identify and quantify detailed time, location, content, and sentiment information; and integrating infoveillance with common epidemic modeling techniques of both mechanistic and data-driven methods. CSI complements and significantly enhances current epidemic models for more informed decision by integrating behavioral aspects from detailed, instantaneous infoveillance from massive social media data.

Physiological tipping points in the relationship between foraging success and lifetime fitness of a long-lived mammal.

Although anthropogenic change is often gradual, the impacts on animal populations may be precipitous if physiological processes create tipping points between energy gain, reproduction or survival. We use 25 years of behavioural, diet and demographic data from elephant seals to characterise their relationships with lifetime fitness. Survival and reproduction increased with mass gain during long foraging trips preceding the pupping seasons, and there was a threshold where individuals that gained an additional 4.8% of their body mass (26 kg, from 206 to 232 kg) increased lifetime reproductive success three-fold (from 1.8 to 4.9 pups). This was due to a two-fold increase in pupping probability (30% to 76%) and a 7% increase in reproductive lifespan (6.0 to 6.4 years). The sharp threshold between mass gain and reproduction may explain reproductive failure observed in many species and demonstrates how small, gradual reductions in prey from anthropogenic disturbance could have profound implications for animal populations.

Seasonal habitat preference and foraging behaviour of post-moult Weddell seals in the western Ross Sea.

Weddell seals (Leptonychotes weddellii) are important predators in the Southern Ocean and are among the best-studied pinnipeds on Earth, yet much still needs to be learned about their year-round movements and foraging behaviour. Using biologgers, we tagged 62 post-moult Weddell seals in McMurdo Sound and vicinity between 2010 and 2012. Generalized additive mixed models were used to (i) explain and predict the probability of seal presence and foraging behaviour from eight environmental variables, and (ii) examine foraging behaviour in relation to dive metrics. Foraging probability was highest in winter and lowest in summer, and foraging occurred mostly in the water column or just above the bottom; across all seasons, seals preferentially exploited the shallow banks and deeper troughs of the Ross Sea, the latter providing a pathway for Circumpolar Deep Water to flow onto the shelf. In addition, the probability of Weddell seal occurrence and foraging increased with increasing bathymetric slope and where water depth was typically less than 600 m. Although the probability of occurrence was higher closer to the shelf break, foraging was higher in areas closer to shore and over banks. This study highlights the importance of overwinter foraging for recouping body mass lost during the previous summer.

Rate and Timing of Return to Golf After Hip, Knee, or Shoulder Arthroplasty: A Systematic Review and Meta-analysis.

BACKGROUND: The physical and mental health benefits of golf are well recognized, and as a moderate-intensity activity, it is an ideal sport for patients after joint arthroplasty. PURPOSE: To assess the rate and timing of returning to golf and the factors associated with these after hip, knee, or shoulder arthroplasty. STUDY DESIGN: Meta-analysis; Level of evidence, 4. METHODS: A search of PubMed and Medline was performed in March 2021 in line with the 2009 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Search terms included sport, golf, and arthroplasty. The criterion for inclusion was any published research article studying return to golf after arthroplasty. Random-effects modeling was used to measure rates of returning to golf for each type of arthroplasty. RESULTS: A total of 23 studies were included for review. All studies were retrospective in their methodology. The mean age of patients was 66.8 years (SD, 3.37). Four studies reported on hip arthroplasty, 6 on knee arthroplasty, and 13 on shoulder arthroplasty. Among 13 studies, the mean rate of returning to golf was 80% (95% CI, 70%-89.9%). Hip, knee, and shoulder arthroplasty had mean return rates of 90% (95% CI, 82%-98%), 70% (95% CI, 39%-100%), and 80% (95% CI, 68%-92%), respectively. Among 9 studies, the mean time to return to golf was 4.4 months (95% CI, 3.2-6). Change in handicap was reported in 8 studies (35%) with a mean change of -0.1 (95% CI, -2.4 to +2.2). There were no studies presenting factors associated with return to golf. CONCLUSION: This is the first meta-analysis of returning to golf after joint arthroplasty. The study reports a high rate of returning to golf, which was greatest after hip arthroplasty. However, the study highlights the paucity of prospective data on demographic, surgical, and golf-specific outcomes after arthroplasty. Future prospective studies are required to eliminate response bias and accurately capture golf and patient-specific outcomes.

Delayed acromioclavicular joint reconstruction using a modern suspensory device does not increase the risk of fixation failure or major complications.

BACKGROUND: Management of displaced acromioclavicular joint (ACJ) injuries remains contentious. It is unclear if delayed vs. acute reconstruction has an increased risk of fixation failure and complications. The primary aim of this study was to compare complications of early vs. delayed reconstruction. The secondary aim was to determine modes of failure of ACJ reconstruction requiring revision surgery. METHODS: A retrospective study was performed on all patients who underwent operative reconstruction of ACJ injuries over a 10-year period (Rockwood III-V) using suspensory devices with or without hamstring allograft. Reconstruction was classed as early (<12 weeks from injury) or delayed (≥12 weeks). Patient demographics, fixation method, and postoperative complications were noted, with 1-year follow-up a minimum requirement for inclusion. Patient-reported outcomes with the Disabilities of the Arm, Shoulder, and Hand score and EuroQol-5 Dimension were undertaken. Fixation failure was defined as loss of reduction requiring revision surgery. RESULTS: A total of 104 patients were analyzed (n = 59 early and n = 45 delayed). The mean age was 42.0 (standard deviation: 11.2; 17-70 years); 84.6% were male and 15.4% were smokers. No difference was observed between fixation failure (P = .39) or deep infection (P = .13) with regard to acute vs. delayed reconstruction. No patient demographic or timing of surgery was predictive of fixation failure on regression modeling. Overall, 11 patients underwent revision surgery for loss of reduction and implant failure (n = 5 suture fatigue, n = 2 endobutton escape, n = 2 coracoid stress fracture, and n = 2 deep infection). The EuroQol-5 Dimension (P = .084) and Disabilities of the Arm, Shoulder, and Hand score (P = .062) were comparable for early and delayed groups respectively and below the minimal clinically important difference. CONCLUSION: This study found that delayed surgical management of ACJ injuries using a modern device has comparable functional outcomes and is not associated with a higher incidence of fixation failure or major complications.

Whiskers as hydrodynamic prey sensors in foraging seals.

The darkness of the deep ocean limits the vision of diving predators, except when prey emit bioluminescence. It is hypothesized that deep-diving seals rely on highly developed whiskers to locate their prey. However, if and how seals use their whiskers while foraging in natural conditions remains unknown. We used animal-borne tags to show that free-ranging elephant seals use their whiskers for hydrodynamic prey sensing. Small, cheek-mounted video loggers documented seals actively protracting their whiskers in front of their mouths with rhythmic whisker movement, like terrestrial mammals exploring their environment. Seals focused their sensing effort at deep foraging depths, performing prolonged whisker protraction to detect, pursue, and capture prey. Feeding-event recorders with light sensors demonstrated that bioluminescence contributed to only about 20% of overall foraging success, confirming that whiskers play the primary role in sensing prey. Accordingly, visual prey detection complemented and enhanced prey capture. The whiskers' role highlights an evolutionary alternative to echolocation for adapting to the extreme dark of the deep ocean environment, revealing how sensory abilities shape foraging niche segregation in deep-diving mammals. Mammals typically have mobile facial whiskers, and our study reveals the significant function of whiskers in the natural foraging behavior of a marine predator. We demonstrate the importance of field-based sensory studies incorporating multimodality to better understand how multiple sensory systems are complementary in shaping the foraging success of predators.