Search birdRS Box

Search birdRS blog posts

Browse the Blog Posts

Or scan through the blog archive below for items of interest as only the latest post is shown below, thanks.

Tuesday, 16 December 2014

Journal of Raptor Research - Osprey Special. December 2014: Volume 48 Issue 4, Table of Contents and Abstracts

Journal of Raptor Research

Published by: The Raptor Research Foundation

Table of Contents

Dec 2014 : Volume 48 Issue 4 

Ospreys (Pandion haliaetus) in the 21st Century: Populations, Migration, Management, and Research Priorities 

Richard O. Bierregaard, Alan F. Poole, and Brian E. Washburn
pg(s) 301–308
 Full Text : PDF (80 KB) 
Ospreys (Pandion haliaetus) are remarkable raptors. Their choice of conspicuous nest sites and surprising tolerance for nesting in nearly intimate association with humans render them an iconic piece of aquatic ecosystems in both marine and freshwater habitats across the northern hemisphere and much of Australasia (Australia to Indonesia). Wintering in Central and South America and Africa as well, they are among the few truly cosmopolitan birds of prey.
Ecologically, they might be termed generalized specialists. They are, with exceptions so rare that they can safely be ignored, obligate fish eaters. From their talons to the tip of their bill, every bit of an Osprey's morphology is adapted to taking fish from the water and consuming them efficiently. Beyond this specialization, however, they are remarkably catholic in the species of fish that they prey on (Poole et al. 2002). Inland, the predominant fish species caught vary from watershed to watershed. Along the coasts, the fish brought to the nest will change through the breeding season as different prey species migrate in and out of the hunting range of local populations.
Most notably, because they are perched atop a long food chain, they are vulnerable to, and dramatic indicators of fat-soluble contaminants in the environment. In the 1960s and 1970s this led the species to play a pivotal role in the identification of DDT as a major threat to aquatic ecosystems and the banning of its use in the U.S.

The Spring Migration of Adult North American Ospreys Full Access

Mark S. Martell, Richard O. Bierregaard, Jr., Brian E. Washburn, John E. Elliott, Charles J. Henny, Robert S. Kennedy, and Iain MacLeod
pg(s) 309–324

 Full Text : PDF (438 KB) 
Most North American Ospreys (Pandion haliaetus) are migratory, breeding in northern latitudes and migrating long distances to and from their wintering grounds in the tropics. Although fall migration patterns of North American Ospreys have been described and studied, very little has been published about the spring migration of these birds. We used satellite telemetry to: (1) determine the characteristics (timing, duration, migratory routes) of spring migrations of Ospreys; (2) determine if differences in spring migration patterns existed between sexes and among three breeding populations (east coast, midwestern, and western); and (3) compare consecutive fall and spring migrations of individual Ospreys. The median dates for departure from the wintering grounds and arrival on the breeding grounds did not differ significantly between adult male and female Ospreys. Compared to their fall migrations, all male and all east coast Ospreys spent fewer days on migration, fewer days in stopover periods along the migration route, traveled shorter distances overall, and traveled farther (on average) each day during spring. In contrast, fall and spring migration characteristics of all female and western Ospreys were similar. Our findings suggest that, although sex and breeding location might influence the spring migration strategy used by individual Ospreys, both males and females minimize the time spent on migration to ensure a timely arrival on the breeding grounds to establish or defend a nesting territory.

Wintering Ecology of Adult North American Ospreys Full Access

Brian E. Washburn, Mark S. Martell, Richard O. Bierregaard, Jr., Charles J. Henny, Brian S. Dorr, and Thomas J. Olexa
pg(s) 325–333

 Full Text : PDF (191 KB)
North American Ospreys (Pandion haliaetus) typically migrate long distances to their wintering grounds in the tropics. Beyond the general distribution of their wintering range (i.e., the Caribbean, South America, and Central America), very little is known about the wintering ecology of these birds. We used satellite telemetry to determine the duration of wintering period, to examine the characteristics of wintering areas used by Ospreys, and to quantify space use and activity patterns of wintering Ospreys. Adult Ospreys migrated to wintering sites and exhibited high wintering site fidelity among years. Overall, Ospreys wintered on river systems (50.6%) more than on lakes (19.0%), and use of coastal areas was (30.4%) intermediate. Ospreys remained on their wintering grounds for an average of 154 d for males and 167 d for females. Locations of wintering Ospreys obtained via GPS-capable satellite telemetry suggest these birds move infrequently and their movements are very localized (i.e., <5 km from selected roosting areas). Sizes of home ranges and core-use areas for wintering Ospreys averaged 12.7 km2 and 1.4 km2, respectively. Overall, our findings suggest wintering adult North American Ospreys are very sedentary, demonstrating a pattern of limited daily movements and high fidelity to a few select locations (presumably roosts). We suggest this wintering strategy might be effective for reducing the risk of mortality and maximizing energy conservation.

Magnitude and Timing of Autumn Osprey Migration in Southeastern Cuba Full Access

Freddy Rodríguez-Santana, Yasit Segovia Vega, Malbelis Sánchez Padilla, Carmen Plasencia León, Yasser E. Torres Adán, Margarita Sánchez Losada, Arelis Mustelier Lescay, and Yaquelín Rivera
pg(s) 334–344

 Full Text : PDF (298 KB)
From 2005–2008 we used counts of visible migrants at an inland watchsite (La Gran Piedra) 9 km from the coast and a coastal watchsite (Siboney) to describe the magnitude and timing of Osprey (Pandion haliaetus) autumn migration through southeastern Cuba from 1 August through 30 November. Counts of Ospreys at Siboney averaged 5283 (2006–2008) annually or roughly twice those tallied at other North American watchsites known for the concentration of this species during autumn migration. Nevertheless, simultaneous counts at both watchsites better represent the magnitude of its migration through southeastern Cuba, averaging more than 7000 Ospreys (3 yr). The mean seasonal passage window (95% of the flight) ranged from 78 to 83 d at La Gran Piedra and Siboney. The average peak at both sites occurred in early October, with more than 20 Ospreys/hr. The daily passage window (95% of the daily passage) was more protracted at Siboney, where birds migrated both early in the morning and late in the afternoon, than at the inland mountain site at La Gran Piedra, where Osprey numbers peaked at midday. We believe that Ospreys migrating in southeastern Cuba move from the coast to the mountains at midday in response to thermal convections along the mountains at that time. Osprey flocks observed at watchsites ranged between 2–52 individuals and one flock of 92 individuals was observed at a dam in central Cuba.

Wintering of Ospreys in Argentina: Insights From New Records Between 1993–2008 Full Access

Miguel D. Saggese, Ignacio Roesler, and Claudia F. Marano
pg(s) 345–360

Full Text : PDF (298 KB)
The migratory subspecies of the “American” Osprey (Pandion haliaetus carolinensis) breeds across most of North America. Most of these Ospreys winter north of the equator, although significant numbers travel farther south, reaching Argentina. The number of Osprey sightings in Argentina has increased since the first review of their status in this country. We analyzed records of Osprey migration and distribution in Argentina from 1993 to 2008. We found that Ospreys occur year-round in Argentina, with a higher concentration in spring to summer (1 October to 31 March). Our data confirmed that in northern and northeastern Argentina, Ospreys use river systems and their major tributaries, and in central and northwestern regions, they commonly frequent reservoirs. The apparent increase in the number of Osprey records in Argentina in the last decades may result from an actual population increase but may also reflect a larger number of observers. Recent records suggest that Osprey should be considered a regular visitor to northern Argentina. We confirm the importance of northeastern rivers, and central and northwestern reservoirs as wintering areas. Argentina has been noted as an important wintering area for many migratory birds, but has been underestimated as a wintering area for Osprey.

Post-DDT Recovery of Osprey (Pandion haliaetus) Populations in Southern New England and Long Island, New York, 1970–2013 Full Access

Richard O. Bierregaard, Jr., Augustus Ben David, Lori Gibson, Robert S. Kennedy, Alan F. Poole, Michael S. Scheibel, and Julie Victoria
pg(s) 361–374

Full Text : PDF (2227 KB)
The Osprey (Pandion haliaetus) population nesting between New York City and Boston, Massachusetts, collapsed from approximately 1000 pairs in 1940 to 109 in the early 1970s. In the 1970s, within five or six years of the cessation of DDT use in the region, the Osprey population began recovering. The recovery was asynchronous across the region. Current (2013) distribution and numbers differ dramatically from those of the pre-DDT period. Colonies on Narragansett and Mount Hope bays in Rhode Island, the Connecticut River estuary, and on Gardiners Island, New York, failed to recover their former remarkable densities. Osprey populations expanded from eastern to western Long Island, New York. In Connecticut, Ospreys now occupy the entire coastline and are nesting inland. A new concentration of Ospreys has become established in southeastern Massachusetts on the Westport River, the islands of Martha's Vineyard and Nantucket, and most recently, on Cape Cod. From this area, the species' range has gradually expanded northward. The population in Massachusetts is now contiguous with the New Hampshire population, and pairs are nesting west of the Connecticut River. The current population in southern New England easily exceeds 1200 pairs and is predominantly (ca. 95%) nesting on human-made structures either erected as nest platforms or co-opted by Ospreys as nest support structures.

The Osprey in the Western Palearctic: Breeding Population Size and Trends in the Early 21st Century Full Access

Daniel Schmidt-Rothmund, Roy Dennis, Pertti Saurola
pg(s) 375–386

 Full Text : PDF (246 KB)
The number of Osprey (Pandion haliaetus) nesting pairs in Europe, northern Africa, and the Middle East has reached between 9500 and 11 500 in the early 21st century. Compared to numbers from the 1980s (ca. 5500 pairs), the population has almost doubled. The increase is most obvious in countries like Germany and the United Kingdom. The largest and most important European populations in Sweden, Finland, and Russia seem to be stable. In contrast, Portugal, mainland Spain, and Turkey lost their last breeding pairs in the 1980s and 1990s. Negative trends are also reported from Poland due to persecution and from southeastern Europe and northern Africa, where only very few pairs remain. Reintroductions in England, Spain, and Italy have resulted in a few new breeding pairs in recent years.

Human–Osprey Conflicts: Industry, Utilities, Communication, and Transportation Full Access

Brian E. Washburn
pg(s) 387–395

 Full Text : PDF (187 KB)
Although often perceived as a species of remote settings, Ospreys (Pandion haliaetus) are highly adaptable and currently are abundant in many urban and suburban landscapes. Living in close proximity to humans, Ospreys often come into conflict with people and several important issues require the attention of and management by natural resource professionals. These include effects on: (1) industry (e.g., foraging at aquaculture facilities), (2) utilities (e.g., nesting on electric utility power poles and transmission towers), (3) communication networks (e.g., nesting on cellular towers), and (4) transportation systems (e.g., risks posed to human health and safety due to Osprey–aircraft collisions). Due to the Osprey's migratory and wintering habits, conflicts between Ospreys and humans are generally seasonal in nature (i.e., during the nesting season); Florida is an important exception. Creative mitigation measures (many currently being developed and evaluated) that combine effective management and monitoring will provide a better understanding of human–Osprey conflicts and ensure our successful coexistence with Osprey populations in the future.


Distribution and Natural History of the Caribbean Osprey (Pandion haliaetus ridgwayi) Full Access

James W. Wiley, Alan F. Poole, and Nancy J. Clum
pg(s) 396–407

 Full Text : PDF (636 KB)
Pandion haliaetus ridgwayi is a subspecies that breeds in the Caribbean basin on which little is known. We present an overview of the status and distribution of this subspecies, with emphasis on the delineation of areas of concentration of nesting and providing brief notes on its natural history. Overall P. h. ridgwayi is distributed and dispersed in limited numbers with documented nesting in the south of the Bahamas, Turks and Caicos, and along the coasts of Cuba, Yucatan in Mexico and Belize. Coastal areas are home to the only known breeding pairs, which build their nests in a variety of natural structures and increasingly frequently in artificial structures. Most couples put their eggs in November and December and generally chicks leave the nest in February and March. Limited data suggest that reproductive rates are low compared to those of individuals of P. haliaetus nesting in more temperate latitudes. We recommend renewed for the census of this species, especially in regions where nests can be grouped together and discuss the potential for increasing key populations with artificial nesting platforms for efforts.

The Status of the Osprey (Pandion haliaetus cristatus) in Australia Full Access

Terry E. Dennis and Greg P. Clancy
pg(s) 408–414

 Full Text : PDF (136 KB)
In Australia, most Australasian populations Pandion haliaetus cristatus found in coastal and estuarine habitats along the subtropical and temperate regions of the north. On the lines south coast, the species is distributed more dispersed mode and there is a wide gap in the breeding range in the southeastern corner of the continent below 36 ° south latitude, including Tasmania. The population is mainly sedentary and is considered as stable throughout most of its range. However, there are reports that the population is decreasing at the southern edge of its range in southern Australia, but growing and expanding its breeding range area south into New South Wales. Reproductive rates and population densities for expanding populations on the east coast are equivalent to those reported for populations recovering from P. haliaetusafter declines caused by pesticides in the northern hemisphere. Conversely, the population density is significantly lower in southern Australia where comparatively low productivity more geographic isolation suggest that P. haliaetus could be at risk in the southern end of their breeding range in Australia.

Exploring the Role of Ospreys in Education Full Access

Rebecca Cushing and Brian E. Washburn
pg(s) 414–421

 Full Text : PDF (151 KB) 
Pandion haliaetus , a charismatic species of bird of prey with an almost worldwide distribution, is highly visible and adapted to anthropic environments. Consequently, this species has been extensively studied over most of its range and provides an excellent focus for student learning in primary and secondary education. Recent advances in technology (eg, satellite telemetry, web cameras) used to study P. haliaetus have produced large databases that can be used in a variety of courses in secondary and post-secondary to facilitate the development of critical thinking, problem solving and quantitative over a wide range of geographical and political boundaries skills. The effective use of social media could improve the opportunities to integrate scientific research of P. haliaetus environmental education, scope and citizen science projects. This report describes the use of P. haliaetus in educational programs, particularly in the context of primary education. We further suggest how new technologies and research activities with P. haliaetus (and other migratory birds) can be integrated into educational programs at different levels to improve learning from experience and potentially increase the attitudes and activities for conservation.


'Enter the Realm of the Golden Eagle'

Matthew C. Perry
pg(s) 422–423
 Full Text : PDF (31 KB) 
Enter the Realm of the Golden Eagle is not just a book on the Golden Eagle, but a classic treatise that every raptor specialist will cherish as part of their library. It is very different from any other natural history book because its foundation is good old-fashioned professional biology written in a beautiful and exciting way that makes it great reading as well as an excellent reference on this noble species. The title not only reflects the species of interest, but also reflects that the reader will enter the world of the Golden Eagle from afar and at close range while seemingly with the author.
The book is large format (8.5″ × 11″) with over 400 mostly color images by 15 artists and 21 photographers. There are 18 chapters starting with “The Allure of the Eagle” and ending with “Lothvar's Gifts.” Chapter 1 is available for review at the Hancock House website: The final chapter describes the personal gifts given to Ellis from a long-time captive Golden Eagle, Lothvar, and the sometimes emotional relationship between this eagle and the author. Each chapter has from 3 to 10 subchapters. Discussions include wolf-hunting by eagles, driving huge animals over cliffs, cooperative hunting with coyotes, and how biologists capture eagles by pouncing on them during day and night.
Many of the subchapters are written by colleagues of Ellis from many countries, and reflect his worldwide exposure to this species, and his relationships with other experts. Ellis writes tributes to some of the pioneers who influenced him, using quotes from their writings. An appendix includes all the scientific names of vertebrates, invertebrates, and plants mentioned in the text. A detailed index provides easy access to the many subjects and persons that will be of value for future reference. Many of the chapters have extensive references for documentation and further study by the reader.
Some of the chapters deal with details of the eagle as a uniquely predatory bird. The detailed descriptions of three-inch talons digging deeply into wrists and thighs of the human bander or handler might be hard reading for a modern-day “couch potato” who doesn't look deeper into a predatory bird's lifestyle. Ellis' personal ethics for interacting with wildlife are passed on to the reader in a subtle, but sometimes very direct manner. He mentions John James Audubon's “wanton rapaciousness” in killing birds and actually eating eagle flesh, but then quickly reminds us how different Audubon's time was from the present, when we have our own serious conservation issues.
Ellis is in a class by himself as a student of raptor biology with a lifelong interest in Golden Eagles. His perspective on eagle behavior comes from thousands of hours in blinds in close proximity to eagle nests. He not only worked professionally in the United States as an eagle biologist, but also travelled the world to study the golden and other eagles on terrain and in conditions that few could endure. Ellis was for many years a crane researcher with the U.S. Fish and Wildlife Service and the U.S. Geological Survey, but managed surreptitiously to use his own captive eagle to incubate and hatch crane eggs.
Ellis earned his Ph.D. in Behavioral Ecology at the University of Montana and has over 200 scientific publications on numerous subjects. He is author and/or editor of several books. His wife Cathy was an important partner in the research and publication of this eagle book for the last 17 yr. Ellis dedicated the book to Cathy and gave special recognition of her contributions in the acknowledgments. Cathy is an author in her own right and has published widely in the scientific and popular literature.
This book is a compilation of the personal exploits of Ellis and those of other raptor enthusiasts in many countries, including Scotland, Russia, Mongolia, and Japan. Traditions with eagles in many countries go back thousands of years. Details given in the book open a window to many other areas and help us realize the wide array of fields (e.g., falconry, folklore, mythology, history, etc.) in which eagles, especially Golden Eagles, played important roles. Although Ellis is interested in the past research, he has included in this epic book discussions of the most recent techniques of behavioral ecology and satellite tracking to study these magnificent raptors.
Although the hardbound version sells for $60.00, some may be interested in the deluxe, collector's edition available for $300 plus shipping. This book is limited to 50 signed and numbered copies and includes a leather binding and slipcase. However, it becomes a deluxe edition because (1) the spine has five horizontal ridges beneath the leather, used to simulate the bundles of thread that in medieval times were used to sew signatures together, (2) a hand-painted eagle feather on the spine, (3) the slip-case bound in bonded leather, (4) an original watercolor painting of an eagle's head that accompanies each copy (and is removable for framing), (5) the pages are gilt-edged, and (6) an “eagle in flight” medallion of fine pewter plated with copper, then nickel, then gold, is embossed into the leather cover of the book. The medallion was sculpted by the noted artist, Mark Rossi, especially for the book. Because of the painted feather and the painted eagle head (both by Dr. Ellis), each numbered copy will be unique.
I recommend this book highly to persons fascinated with raptors or in the work of those who professionally study raptors. It is one of the most interesting I have ever read.

No comments:

Post a comment