Nesting Density and Breeding Success of Golden Eagles in Relation to Food Supply in Scotland

Watson, J.; Rae, Stuart; Stillman, R. C.

doi:10.2307/5609

Cited by 59 publications

(41 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Such species may prefer territories allowing year-round availability of all major prey, rather than focusing on one or two prey-types and their associated habitats in particular (see Southern and Lowe, 1968, for a similar argument). Overall, the tight relationship between golden eagle individuals or populations and food availability has been demonstrated in many previous studies (e.g., Watson et al, 1988Watson et al, , 1992Jenny, 1992;Marzluff et al, 1997).…”

Section: Discussionsupporting

confidence: 52%

Adaptive range selection by golden eagles in a changing landscape: A multiple modelling approach

Pedrini

Rizzolli

Marchesi

2006

Biological Conservation

View full text Add to dashboard Cite

Land abandonmentNest-site selection Woodland expansion A B S T R A C T and abandonment is causing considerable woodland expansion in many mountainous areas of Europe, with potential repercussions on conservation-sensitive species typical of open habitats. We examined the potential impact of such changes on an alpine golden eagle population, by estimating the ranges potentially used by the eagles for foraging through different techniques (concentric circles of different radii and a tessellationmethod based on telemetry data). Compared to randomly located territories, eagles selected ranges farther away from conspecifics, characterised by a rugged topography and rich in main prey species and in open habitats favoured by their main prey species, such as grassland, shrubs, xerophytic vegetation and rocky outcrops. Similarly, nest spacing and breeding success were related to the availability of optimal foraging habitats, also favoured by the main prey species of the eagles. Even though woodland-variables did not enter any of the stepwise models, eagles were dependent on grassland habitats, currently lost to woodland at a rate of about 0.5-1% per year, and on shrub vegetation rapidly evolving into woodland, which accounted on average for almost 10% of the eagle ranges. Longterm loss of such habitat may imply up to a 66% woodland increase for some eagle ranges.Given the complexity of the uncovered relationships and difficulty to make firm predictions, subsidies to halt the abandonment of traditional agro-pastoral practices seem urgently needed.

show abstract

Section: Discussionsupporting

confidence: 52%

Adaptive range selection by golden eagles in a changing landscape: A multiple modelling approach

Pedrini

Rizzolli

Marchesi

2006

Biological Conservation

View full text Add to dashboard Cite

show abstract

“…In the western United States, eagles inhabit mountains and foothills, desert plateaus, and arid basins. In Scotland, eagles live in open mountains and moorlands, characterized by short vegetation, and avoid closed canopy woodland, open water, and improved farmland close to habitation (Watson et al 1992a). Large open areas created by clearcuts in historically forested western Washington were recently colonized by nesting golden eagles (Elruce er al.…”

Section: Natural History Of Golden Eaglesmentioning

confidence: 99%

A pilot golden eagle population study in the Altamont Pass Wind Resource Area, California

Hunt

1995

View full text Add to dashboard Cite

NREL/TP-44 1 -7821 UC Category: 1 2 1 0 DE95009220This pilblici~Iioll wus reproduced from the best iivaili\ble camera-ready copy submilled by the subcontractor and received no editorial review at NREL. NOTICEThis report was prepared as an account of work sponsored by an agency of the United States government.Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof GOLDEN EAGLE POPULATION PROJECT i EXECUTIVE SUMMARYDuring 1994, the Predatory Bird Research Group, University of California, Santa Cruz, conducted a preliminary field investigation of the ecology of golden eagles (Aquila chrymem) in the vicinity of the Altamont Pass Wind Resource Area (WRA). The facility contains about 6,500 wind turbines on 189 km2 just east of San Francisco Bay in California. Grassland and oak savanna habitats surrounding the WRA support a substantial population of golden eagles. Each year, the U.S. Fish and Wildlife Service receives reports from the wind industry of about 30 golden eagle casualties occurring at the WRA, with over 90 percent attributed to collisions with wind turbines. The purpose of this pilot study was to clarify and set in motion a research program that will identify (1) the effect of turbine-related mortality on the golden eagle population, (2) factors attracting eagles to the WRA, and (3) conditions that increase the risk of turbine strikes.To show the distribution of the population potentially impacted and to obtain survival data, we radio-tagged 31 adult and subadult eagles in the WRA vicinity during January and February 1994 and an additional 25 juveniles from nests surrounding the WRA in spring. Each transmitter contained a mortality sensor and was expected to last five years. Throughout 1994, we determined the location and status of each eagle in twice-weekly airplane roll-call surveys.Of the 31 winter-tagged eagles, 5 were members of pairs breeding near the WRA. Of the remaining 26 birds, 19 were subadults and seven were non-breeding adults (floaters). Over the course of the year, four (15 %) of the 26 non-breeders either departed the region or their radios failed. The remainder traveled within the northern Diablo Range which extends from the Qakland Hills southeast to San Luis Reservoir, an area of about 3,500 km2, for which we developed a digitized (GIS) vegetation map from satellite photographs. Our findings suggest that at least three-quarters of the golden eagles frequenting the WRA vicinity in winter are yearround residents of the Diablo Range.T...

show abstract

“…Although some reports indicate that the number of occupied Golden Eagle territories is relatively stable in the UK (Gibbons et al 1993, Green 1996 it seems likely that the population could expand if persecution and disturbance were reduced (Dennis et al 1984, Watson & Whitfield 2002, Whitfield et al 2003, 2004a, 2004b. However, land-use changes, including conifer afforestation (Watson 1992, Marquiss et al 1985, Whitfield et al 2001, wind farm developments (Walker et al 2005), modification of deer and sheep management regimes (Watson et al 1992b), local increases in recreation and tourism activity (Watson & Dennis 1992) and the reintroduction of White-Tailed Eagles Haliaeetus albicilla (Watson et al 1992a, although see Whitfield et al 2002) could all have additional adverse impacts upon Golden Eagles in Scotland.…”

mentioning

confidence: 99%

“…The abundance and distribution of live prey is said to be an important determinant of density and reproductive success of Scottish Golden Eagles (Watson et al 1992b). Consequently, conservation of such a wideranging and dispersed species, whose food resources depend on large-scale land-use policies, is unlikely to be achieved by statutory site designation alone (Pienkowski 1991).…”

mentioning

confidence: 99%

Ranging distance of resident Golden EaglesAquila chrysaetosin western Scotland according to season and breeding status

Haworth¹,

McGrady²,

Whitfield³

et al. 2006

Bird Study

View full text Add to dashboard Cite

Nesting Density and Breeding Success of Golden Eagles in Relation to Food Supply in Scotland

Cited by 59 publications

References 12 publications

Adaptive range selection by golden eagles in a changing landscape: A multiple modelling approach

Adaptive range selection by golden eagles in a changing landscape: A multiple modelling approach

A pilot golden eagle population study in the Altamont Pass Wind Resource Area, California

Ranging distance of resident Golden EaglesAquila chrysaetosin western Scotland according to season and breeding status

Contact Info

Product

Resources

About