scholarly journals Underwater acrobatics by the world's largest predator: 360° rolling manoeuvres by lunge-feeding blue whales

2013 ◽  
Vol 9 (1) ◽  
pp. 20120986 ◽  
Author(s):  
Jeremy A. Goldbogen ◽  
John Calambokidis ◽  
Ari S. Friedlaender ◽  
John Francis ◽  
Stacy L. DeRuiter ◽  
...  

The extreme body size of blue whales requires a high energy intake and therefore demands efficient foraging strategies. As an obligate lunge feeder on aggregations of small zooplankton, blue whales engulf a large volume of prey-laden water in a single, rapid gulp. The efficiency of this feeding mechanism is strongly dependent on the amount of prey that can be captured during each lunge, yet food resources tend to be patchily distributed in both space and time. Here, we measured the three-dimensional kinematics and foraging behaviour of blue whales feeding on krill, using suction-cup attached multi-sensor tags. Our analyses revealed 360° rolling lunge-feeding manoeuvres that reorient the body and position the lower jaws so that a krill patch can be engulfed with the whale's body inverted. We also recorded these rolling behaviours when whales were in a searching mode in between lunges, suggesting that this behaviour also enables the whale to visually process the prey field and maximize foraging efficiency by surveying for the densest prey aggregations. These results reveal the complex manoeuvrability that is required for large rorqual whales to exploit prey patches and highlight the need to fully understand the three-dimensional interactions between predator and prey in the natural environment.

2015 ◽  
Vol 1 (9) ◽  
pp. e1500469 ◽  
Author(s):  
Elliott Lee Hazen ◽  
Ari Seth Friedlaender ◽  
Jeremy Arthur Goldbogen

Terrestrial predators can modulate the energy used for prey capture to maximize efficiency, but diving animals face the conflicting metabolic demands of energy intake and the minimization of oxygen depletion during a breath hold. It is thought that diving predators optimize their foraging success when oxygen use and energy gain act as competing currencies, but this hypothesis has not been rigorously tested because it has been difficult to measure the quality of prey that is targeted by free-ranging animals. We used high-resolution multisensor digital tags attached to foraging blue whales (Balaenoptera musculus) with concurrent acoustic prey measurements to quantify foraging performance across depth and prey density gradients. We parameterized two competing physiological models to estimate energy gain and expenditure based on foraging decisions. Our analyses show that at low prey densities, blue whale feeding rates and energy intake were low to minimize oxygen use, but at higher prey densities feeding frequency increased to maximize energy intake. Contrary to previous paradigms, we demonstrate that blue whales are not indiscriminate grazers but instead switch foraging strategies in response to variation in prey density and depth to maximize energetic efficiency.


2009 ◽  
Vol 277 (1683) ◽  
pp. 861-868 ◽  
Author(s):  
Jeremy A. Goldbogen ◽  
Jean Potvin ◽  
Robert E. Shadwick

Rorqual whales (Balaenopteridae) represent not only some of the largest animals of all time, but also exhibit a wide range in intraspecific and interspecific body size. Balaenopterids are characterized by their extreme lunge-feeding behaviour, a dynamic process that involves the engulfment of a large volume of prey-laden water at a high energetic cost. To investigate the consequences of scale and morphology on lunge-feeding performance, we determined allometric equations for fin whale body dimensions and engulfment capacity. Our analysis demonstrates that larger fin whales have larger skulls and larger buccal cavities relative to body size. Together, these data suggest that engulfment volume is also allometric, increasing with body length as . The positive allometry of the skull is accompanied by negative allometry in the tail region. The relative shortening of the tail may represent a trade-off for investing all growth-related resources in the anterior region of the body. Although enhanced engulfment volume will increase foraging efficiency, the work (energy) required to accelerate the engulfed water mass during engulfment will be relatively higher in larger rorquals. If the mass-specific energetic cost of a lunge increases with body size, it will have major consequences for rorqual foraging ecology and evolution.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8906 ◽  
Author(s):  
Leigh G. Torres ◽  
Dawn R. Barlow ◽  
Todd E. Chandler ◽  
Jonathan D. Burnett

To understand how predators optimize foraging strategies, extensive knowledge of predator behavior and prey distribution is needed. Blue whales employ an energetically demanding lunge feeding method that requires the whales to selectively feed where energetic gain exceeds energetic loss, while also balancing oxygen consumption, breath holding capacity, and surface recuperation time. Hence, blue whale foraging behavior is primarily driven by krill patch density and depth, but many studies have not fully considered surface feeding as a significant foraging strategy in energetic models. We collected predator and prey data on a blue whale (Balaenoptera musculus brevicauda) foraging ground in New Zealand in February 2017 to assess the distributional and behavioral response of blue whales to the distribution and density of krill prey aggregations. Krill density across the study region was greater toward the surface (upper 20 m), and blue whales were encountered where prey was relatively shallow and more dense. This relationship was particularly evident where foraging and surface lunge feeding were observed. Furthermore, New Zealand blue whales also had relatively short dive times (2.83 ± 0.27 SE min) as compared to other blue whale populations, which became even shorter at foraging sightings and where surface lunge feeding was observed. Using an unmanned aerial system (UAS; drone) we also captured unique video of a New Zealand blue whale’s surface feeding behavior on well-illuminated krill patches. Video analysis illustrates the whale’s potential use of vision to target prey, make foraging decisions, and orient body mechanics relative to prey patch characteristics. Kinematic analysis of a surface lunge feeding event revealed biomechanical coordination through speed, acceleration, head inclination, roll, and distance from krill patch to maximize prey engulfment. We compared these lunge kinematics to data previously reported from tagged blue whale lunges at depth to demonstrate strong similarities, and provide rare measurements of gape size, and krill response distance and time. These findings elucidate the predator-prey relationship between blue whales and krill, and provide support for the hypothesis that surface feeding by New Zealand blue whales is an important component to their foraging ecology used to optimize their energetic efficiency. Understanding how blue whales make foraging decisions presents logistical challenges, which may cause incomplete sampling and biased ecological knowledge if portions of their foraging behavior are undocumented. We conclude that surface foraging could be an important strategy for blue whales, and integration of UAS with tag-based studies may expand our understanding of their foraging ecology by examining surface feeding events in conjunction with behaviors at depth.


Nutrients ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1168 ◽  
Author(s):  
Hye Kang ◽  
Sang Lee ◽  
Dammah Otieno ◽  
Kyoungsoo Ha

Obesity results from the body having either high energy intake or low energy expenditure. Based on this energy equation, scientists have focused on increasing energy expenditure to prevent abnormal fat accumulation. Activating the human thermogenic system that regulates body temperature, particularly non-shivering thermogenesis in either brown or white adipose tissue, has been suggested as a promising solution to increase energy expenditure. Together with the increasing interest in understanding the mechanism by which plant-derived dietary compounds prevent obesity, flavonoids were recently shown to have the potential to regulate non-shivering thermogenesis. In this article, we review the latest research on flavonoid derivatives that increase energy expenditure through non-shivering thermogenesis.


2014 ◽  
Vol 27 (1) ◽  
pp. 57-68 ◽  
Author(s):  
K.M. Madden ◽  
L.A. Fuiman ◽  
T.M. Williams ◽  
R.W. Davis

AbstractWeddell seals are polar predators that must partition their time between many behaviours, including hunting prey at depth and breathing at the surface. Although they have been well studied, little is known about how foraging behaviour changes when access to breathing holes is restricted, such as in the isolated-hole paradigm. The current study took advantage of previously gathered data for seals diving at an isolated hole to compare with foraging behaviour of free-ranging seals that had access to multiple holes. We examined dive structure, hunting tactics, and allocation of time, locomotor activity and energy based on three-dimensional dive profiles and video imagery of prey encounters for two free-ranging and six isolated-hole seals. Midsummer foraging dives of free-ranging seals were remarkably similar to those of seals diving at an isolated hole, but there were differences in two behavioural states and the frequency of several behavioural transitions. Results indicate that seals employ an energetically more conservative foraging strategy when access to breathing holes is limited and prey are less abundant. These results highlight the importance of understanding the complex interactions between breathing hole access, prey abundance and other factors that may result in different Weddell seal foraging strategies under changing future conditions.


Author(s):  
O. Faroon ◽  
F. Al-Bagdadi ◽  
T. G. Snider ◽  
C. Titkemeyer

The lymphatic system is very important in the immunological activities of the body. Clinicians confirm the diagnosis of infectious diseases by palpating the involved cutaneous lymph node for changes in size, heat, and consistency. Clinical pathologists diagnose systemic diseases through biopsies of superficial lymph nodes. In many parts of the world the goat is considered as an important source of milk and meat products.The lymphatic system has been studied extensively. These studies lack precise information on the natural morphology of the lymph nodes and their vascular and cellular constituent. This is due to using improper technique for such studies. A few studies used the SEM, conducted by cutting the lymph node with a blade. The morphological data collected by this method are artificial and do not reflect the normal three dimensional surface of the examined area of the lymph node. SEM has been used to study the lymph vessels and lymph nodes of different animals. No information on the cutaneous lymph nodes of the goat has ever been collected using the scanning electron microscope.


Author(s):  
L. Yarmots ◽  
G. Yarmots ◽  
A. Belenkaya

For ruminants, especially high-yielding animals in addition to the complete supply of animals with protein, its digestibility in the rumen is important. With low protein digestibility in the rumen, the released ammonia will be more effectively used by the rumen microflora, and the undigestible protein in the subsequent sections of the digestive tract can serve as a source of amino acids for the body. The use of concentrate mixtures with the inclusion of local, affordable and cheaper grain feeds, in particular a high-energy and protein ingredient- rapeseed presscake makes it possible to increase the milk productivity of cows throughout lactation. These presscakes are well balanced in their amino acid composition and belong to feeds whose protein has a low degree of digestibility in the rumen. The purpose of the researches was to study the digestibility of nutrients and milk productivity of cows when using the concentrate mixture with the inclusion of rapeseed presscake. In the scientific and economic experiment has been carried out on lactating cows, where the cows of the experimental group in the concentrate mixture of peas has been replaced with rapeseed presscake the digestibility of nutrients in the ration, energy metabolism and milk productivity have been studied. Studies have shown that almost all the nutrients were significantly better digested by the animals of the experimental group. Energy in milk was more allocated by cows of the experimental group by 6,29 MJ. From cows of the experimental group for 100 and 305 days of lactation has been obtained more milk by 6,27 and 7,06 %, respectively, than from control herdmates. The biochemical parameters of blood were within the limits of the physiological norm in animals of both groups. Thus, the replacement of peas with rapeseed presscake in the concentrate mixture did not have a negative influence on the metabolic processes and helped to increase the milk productivity of cows.


2002 ◽  
Author(s):  
John Calambokidis ◽  
John Francis ◽  
Greg Marshall ◽  
Don Croll ◽  
Mark McDonald ◽  
...  
Keyword(s):  

2000 ◽  
Vol 15 (15) ◽  
pp. 2269-2288
Author(s):  
SANATAN DIGAL ◽  
RAJARSHI RAY ◽  
SUPRATIM SENGUPTA ◽  
AJIT M. SRIVASTAVA

We demonstrate the possibility of forming a single, large domain of disoriented chiral condensate (DCC) in a heavy-ion collision. In our scenario, rapid initial heating of the parton system provides a driving force for the chiral field, moving it away from the true vacuum and forcing it to go to the opposite point on the vacuum manifold. This converts the entire hot region into a single DCC domain. Subsequent rolling down of the chiral field to its true vacuum will then lead to emission of a large number of (approximately) coherent pions. The requirement of suppression of thermal fluctuations to maintain the (approximate) coherence of such a large DCC domain, favors three-dimensional expansion of the plasma over the longitudinal expansion even at very early stages of evolution. This also constrains the maximum temperature of the system to lie within a window. We roughly estimate this window to be about 200–400 MeV. These results lead us to predict that extremely high energy collisions of very small nuclei (possibly hadrons) are better suited for observing signatures of a large DCC. Another possibility is to focus on peripheral collisions of heavy nuclei.


Author(s):  
So Young Joo ◽  
Seung Yeol Lee ◽  
Yoon Soo Cho ◽  
Sangho Yi ◽  
Cheong Hoon Seo

Abstract Hands are the part of the body that are most commonly involved in burns, and the main complications are finger joint contractures and nerve injuries. Hypertrophic scarring cannot be avoided despite early management of acute hand burn injuries, and some patients may need application of an exoskeleton robot to restore hand function. To do this, it is essential to individualize the customization of the robot for each patient. Three-dimensional (3D) technology, which is widely used in the field of implants, anatomical models, and tissue fabrication, makes this goal achievable. Therefore, this report is a study on the usefulness of an exoskeleton robot using 3D technology for patients who lost bilateral hand function due to burn injury. Our subject was a 45-year-old man with upper limb dysfunction of 560 days after a flame and chemical burn injury, with resultant impairment of manual physical abilities. After wearing an exoskeleton robot made using 3D printing technology, he could handle objects effectively and satisfactorily. This innovative approach provided considerable advantages in terms of customization of size and reduction in manufacturing time and costs, thereby showing great potential for use in patients with hand dysfunction after burn injury.


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