Navigation Links
Bobbing birds do it for a reason

Pronounced head-bobbing behavior during walking is a characteristic of diverse species of birds, but how this behavior benefits the birds and under what circumstances it proves useful have remained uncertain. Researchers this week report findings that strongly suggest that for some birds head bobbing is critical for the stabilization of their visual world, despite the motion of their bodies, and thereby enables the accurate detection of objects such as food items.

The motion associated with the head-bobbing behavior consists of alternate phases of holding the head still and rapidly thrusting it forward during each step. This behavior, found in birds but in no other vertebrates, gives them a vaguely comic appearance but is known to be critical for visual stabilization during body movement. What was not known was whether or not this means of avoiding "motion blur" was essential for high-quality vision in birds; many animals, including humans, stabilize visual fields only transiently, through the use of eye movements alone, and accept quite a lot of so-called "visual flow" when in motion.

In new work addressing this question, Thomas Cronin and Matthew Kinloch at the University of Maryland, Baltimore County, with the collaboration of Glenn Olsen of the Patuxent Wildlife Research Center, observed how foraging whooping cranes control head-bobbing as they search for food in the grass near their feet. The tallest birds in North America--their eyes can be more than 5 feet above the ground--whooping cranes exhibit high-amplitude head movements during locomotion, making the measurement of the speed of the head relatively easy via non-invasive computer-video techniques. The cranes search both for mobile prey (frogs and insects) and for items such as acorns, seeds, and tubers. The research team found that the time devoted to holding the head still decreased with walking speed; at a very slow pace, the head was still most of the time, but when the birds began to ru n, it never went through a stable phase. The critical observation, however, was that when the birds are searching for food, they walk at a moderate pace that allows the head to be held still more than 50% of the time. In other words, when foraging, whooping cranes favor visual fixation.

This result strongly suggests that visual fixation not only removes motion blur but also plays a critical role in permitting the detection, localization, and recognition of objects. Head-bobbing behavior, so characteristic of birds, permits the close and stable examination of objects in view during the immobile phase and allows the birds to change their point of gaze and probably to gather a sense of space and of the relative positions of objects when the head is thrust forward.


'"/>

Source:Cell Press


Related biology news :

1. Migratory songbirds have a specialized night-vision brain area
2. The lopsided brain: Attention bias is shared by humans and birds
3. Mother birds increase progesterone to hatch females
4. Overbearing colored light may reveal a second mechanism by which birds interpret magnetic signals
5. Industrial contaminants spread by seabirds in High Arctic, new Canadian study shows
6. Displaced songbirds navigate in the high Arctic
7. Oil spills and climate change double the mortality rate of British seabirds
8. Wild birds help to create human flu vaccine
9. Uniquely human component of language found in gregarious birds
10. Attractive birds more immune against bird flu
11. Not just the birds
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:2/3/2017)... 2017 A new independent identity strategy consultancy ... (IdSP) . Designed to fill a critical niche in ... founding partners Mark Crego and Janice ... in identity expertise that span federal governments, the 9/11 ... Crego-Kephart combined expertise has a common theme born from ...
(Date:1/31/2017)... Mass. , Jan. 31, 2017  Spero ... novel therapies for the treatment of bacterial infections, ... set of antibacterial candidates from Pro Bono Bio ... increased prevalence of multi-drug resistant forms of Gram-negative ... Cantab Anti Infectives Ltd, a PBB group company. ...
(Date:1/24/2017)... YORK , Jan. 24, 2017 ... study of the laboratory use of nuclear magnetic ... 363 experienced end-users and profiled current practices, developments, ... years, as well as growth and opportunities. These ... Instrument suppliers, NMR instruments, needs and innovation requirements, ...
Breaking Biology News(10 mins):
(Date:2/28/2017)...  Xencor, Inc. (NASDAQ: XNCR), a clinical-stage biopharmaceutical company ... autoimmune diseases, asthma and allergic diseases and cancer, ... and full year ended December 31, 2016 and ... and clinical highlights. "During 2016, we ... by starting five clinical trials across our XmAb ...
(Date:2/28/2017)... ... February 28, 2017 , ... FireflySci is a small cuvette manufacturer ... late 2014, FFS had a mission to bring affordable and quality lab equipment to ... product that gives a lab everything needed to get started with using cuvettes. , ...
(Date:2/28/2017)... ... February 28, 2017 , ... ACEA Biosciences, a pioneer in cell analysis instrumentation ... Dr. Roger (Feng) Luo as the new Vice President of Global Clinical Development. ... drug companies, Dr. Luo will now team with Dr. Li Xu, Chief Medical Officer, ...
(Date:2/28/2017)... ... February 28, 2017 , ... GigaGen ... from millions-diverse immune repertoires, today announced a strategic partnership with Trianni, Inc. ... to express human antibodies. The partnership will use GigaGen technology to discover immuno-oncology ...
Breaking Biology Technology: