First Satellite Telemetry Study of Movement Behavior of Juvenile Golden Eagles from Mexico

ABSTRACT The southern limit of the Golden Eagle's (Aquila chrysaetos) breeding range in North America is Mexico, where the eagle is the national symbol yet designated as a threatened, high priority species for conservation action. Movement information needed for conserving Mexico's Golden Eagles is sparse; knowledge of dispersal from natal areas is essential to understand the eagle's ecology and help provide for its management. Using satellite telemetry data, we analyzed movements of three males and one female from central Mexico during their first year of life; we documented (1) timing and distance of initial dispersal movements, (2) total distance traveled and maximum distance from natal site by month of age following fledging, and (3) size of areas (based on 95% adaptive local convex hulls) across which eagles ranged following initial dispersal. Individual eagles dispersed from their natal areas between mid-September and mid-November, at 6–8 mo of age. Monthly total distance traveled by males reached approximately 350–1350 km at 8–11 mo; the female's peak monthly travel was 3000 km, at age 7 mo. Monthly proximity to natal sites by individuals at ages 8–12 mo was relatively constant, averaging 17.9 km (SD = 5.7) to 129.1 km (SD = 11.3). After dispersal, the monthly ranging areas overall increased during the first year of life for all eagles, especially the female, due mainly to multiple long-distance excursions. Our data suggest that movement behavior of juvenile Golden Eagles from Mexico is mostly similar to that of conspecifics from nonmigratory populations elsewhere. Our study may help serve as a foundation for future work to better understand movement dynamics and resource selection by Mexico's Golden Eagles.

Download Full-text

Age- and season-specific variation in local and long-distance movement behavior of golden eagles

European Journal of Wildlife Research ◽

10.1007/s10344-016-1010-4 ◽

2016 ◽

Vol 62 (4) ◽

pp. 377-393 ◽

Cited By ~ 10

Author(s):

Sharon A. Poessel ◽

Peter H. Bloom ◽

Melissa A. Braham ◽

Todd E. Katzner

Keyword(s):

Movement Behavior ◽

Long Distance ◽

Golden Eagles ◽

Specific Variation ◽

Long Distance Movement

Download Full-text

Space Use and Habitat Associations of Long-Distance Migratory First-Year Golden Eagles (Aquila chrysaetos) from Interior Alaska in a Changing Landscape

10.33915/etd.6391 ◽

2017 ◽

Author(s):

Mark D. Paulson

Keyword(s):

Space Use ◽

Habitat Associations ◽

First Year ◽

Aquila Chrysaetos ◽

Long Distance ◽

Interior Alaska ◽

Golden Eagles

Download Full-text

Albatross Long-Distance Navigation: Comparing Adults And Juveniles

Journal of Navigation ◽

10.1017/s0373463305003401 ◽

2005 ◽

Vol 58 (3) ◽

pp. 365-373 ◽

Cited By ~ 16

Author(s):

Susanne Åkesson ◽

Henri Weimerskirch

Keyword(s):

Average Distance ◽

Satellite Telemetry ◽

First Year ◽

Long Distance ◽

Juvenile Dispersal ◽

Flight Direction ◽

Tasman Sea ◽

Destination Area ◽

And Migration ◽

Foraging Skills

Albatrosses are known for their extreme navigation performance enabling them to locate isolated breeding islands after long-distance migrations across open seas. Little is known about the migration of young albatrosses and how they reach the adults' navigation and foraging skills during the period of immaturity lasting several years and spent permanently flying across the open ocean. We tracked by satellite telemetry the dispersal and migration of 13 juvenile wandering albatrosses from the Crozet Islands during their first year at sea. The young albatrosses covered an average distance of 184,000 km during the first year, restricting their dispersal movement to the unproductive and low wind subtropical Indian Ocean and Tasman Sea. The juveniles initiated the migration by an innate phase of rapid dispersal encoded as a fixed flight direction assisted by southerly winds towards north and northeast. Thereafter each individual restricted its movement to a particular zone of the ocean that will possibly be used until they start breeding 7–10 years later and return in contact with breeding adults. This dispersal in young birds corresponds well with movements observed for adult non-breeding wandering albatrosses. The results show clearly an inherited ability to navigate back to already visited areas in young wandering albatrosses. The juvenile dispersal behaviour and migration at sea suggest a genetically based migration program, encoding navigation to a destination area used throughout the life.

Download Full-text

The Development of Swallowing Respiratory Coordination

Perspectives on Swallowing and Swallowing Disorders (Dysphagia) ◽

10.1044/sasd18.1.19 ◽

2009 ◽

Vol 18 (1) ◽

pp. 19-24

Author(s):

Maggie-Lee Huckabee

Keyword(s):

Cortical Activation ◽

First Year ◽

Healthy Children ◽

Nasal Airflow ◽

Single Session ◽

Primary Finding ◽

Patterns Of Behavior ◽

Cortical Modulation ◽

First Year Of Life ◽

Swallowing Apnea

Abstract Research exists that evaluates the mechanics of swallowing respiratory coordination in healthy children and adults as well and individuals with swallowing impairment. The research program summarized in this article represents a systematic examination of swallowing respiratory coordination across the lifespan as a means of behaviorally investigating mechanisms of cortical modulation. Using time-locked recordings of submental surface electromyography, nasal airflow, and thyroid acoustics, three conditions of swallowing were evaluated in 20 adults in a single session and 10 infants in 10 sessions across the first year of life. The three swallowing conditions were selected to represent a continuum of volitional through nonvolitional swallowing control on the basis of a decreasing level of cortical activation. Our primary finding is that, across the lifespan, brainstem control strongly dictates the duration of swallowing apnea and is heavily involved in organizing the integration of swallowing and respiration, even in very early infancy. However, there is evidence that cortical modulation increases across the first 12 months of life to approximate more adult-like patterns of behavior. This modulation influences primarily conditions of volitional swallowing; sleep and naïve swallows appear to not be easily adapted by cortical regulation. Thus, it is attention, not arousal that engages cortical mechanisms.

Download Full-text