Factors Influencing the Breeding Distribution of the Peregrine Falcon in Victoria, Australia

1997 ◽  
Vol 24 (4) ◽  
pp. 433 ◽  
Author(s):  
W. B. Emison ◽  
C. M. White ◽  
V. G. Hurley ◽  
D. J. Brimm
Keyword(s):  
Volcanic Activity ◽  
Human Activities ◽  
Peregrine Falcon ◽  
Factors Influencing ◽  
Tree Hollows ◽  
Peregrine Falcons ◽  
Large Trees ◽  
Breeding Distribution ◽  
Nesting Sites ◽  
Water Vegetation

Since 1950, 199 nesting sites of peregrine falcons (Falco peregrinus) have been found in Victoria. Over half (51%) are on natural cliffs, 37% in trees and 12% on human-made structures and stone quarry faces. Most eyries on natural cliffs occur in the uplands (>200 m elevation) or along the coast. Tree eyries are located in hollows and in stick nests of other birds; most of these are within the distributions of red gums and belahs. Human-made structures (other than quarries) supporting nests include dam walls, silos, electricity pylons and buildings. Factors believed to influence the breeding distribution of peregrine falcons in Victoria are discussed; these include volcanic activity, landform and elevation, water, vegetation, climate, other birds and humans. The influence of human activities on the distribution of nesting peregrine falcons appears to have been positive. However, the future of the population of peregrine falcons nesting in tree hollows is of concern: it is likely that large trees with nest hollows will be destroyed or will fall from decay long before sufficient numbers of replacement trees are available.

The Peregrine Falcon, Falco-Peregrinus-Macropus S, in Tasmania .1. Distribution, Abundance and Physical Characteristics of Nests

1987 ◽  
Vol 14 (1) ◽  
pp. 81 ◽  
Author(s):  
NJ Mooney ◽  
NP Brothers
Keyword(s):  
The State ◽  
Peregrine Falcon ◽  
Nearest Neighbour ◽  
Nest Sites ◽  
The North ◽  
Peregrine Falcons ◽  
North Eastern ◽  
Breeding Distribution ◽  
Altitudinal Limit ◽  
Eastern Half

Peregrine falcons occur throughout Tasmania, their breeding distribution being essentially a contraction of their sighting distribution. In a study lasting from 1973 to 1986, we came to know the exact location of 108 nesting territories and the approximate whereabouts of 25 more. During the first half of the study 60% of nesting territories were occupied and about 50% were active (eggs laid); by 1986 these values had increased to 75-80% and nearly 70% respectively. The number of breeding pairs rose from 59 to 92, averaging 72. Most occurred in high-density clumps of from five to ten pairs, within which active eyries were regularly and potential eyries randomly distributed (mean G-values 0.88 and 0.46). Densities varied considerably between clumps, from mean nearest-neighbour distances of 5.7 km, and 2.08 pairs per 100 km2, in a river gorge, to 18.4 km and 0.33 pairs per 100 km2 in a group of islands. Areas with the highest density tended to have the most regularly spaced active eyries. Of all pairs, 85% were in the north-eastern half of the State; the overall mean densities in the north-eastern and south-western halves was 0.18 and 0.032 pairs per 100 km2 respectively. All recent nestings were on natural cliffs, half of which were sandstone; half were in sheltered positions; 15% were on offshore islands, and coastal nests were usually associated with nearby islands. Most eyries and nest sites faced north and/or east. Cliff eyries averaged 48.6 m in height, and in most areas there were three or four times as many potential as active eyries; lack of suitable cliffs is the main limit to breeding in only 2.7% of Tasmania. The upper altitudinal limit to breeding is about 900 m, which excludes 2.5% of the State.

scholarly journals Biophysical factors influencing the choice of nesting sites by the green turtle (Chelonia mydas) on the Kenyan coast

2019 ◽  
Vol 18 (2) ◽  
pp. 45-55
Author(s):  
Fridah D. Obare ◽  
Robert Chira ◽  
Dorcus Sigana ◽  
Andrew Wamukota
Keyword(s):  
Human Activities ◽  
Vegetation Cover ◽  
Green Turtle ◽  
Chelonia Mydas ◽  
Management Tool ◽  
Factors Influencing ◽  
Biophysical Factors ◽  
Beach Width ◽  
Nesting Sites ◽  
Kenyan Coast

The green turtle (Chelonia mydas) is the most common sea turtle nesting along Kenya’s coastline. Varying biophysical factors influence choice of nesting sites where eggs are laid. This study was conducted between February and November 2016 and was designed to establish the relationship between numbers of C. mydas nests on the beach and biophysical variables such as vegetation cover, organic matter content (OMC), beach width, and beach slope. Multiple regression analysis was employed to assess the factors that contribute to the number of C. mydas nests on a beach. This analysis did not allow prediction of the number of nests in a statistically significant way (F (4, 26) = 0.094, p > 0.05, R = 0.120). However, there was a decrease in the number of nests with increased vegetation cover (b = - 0.013), OMC (b = - 8.114), beach width (b = - 0.089) and slope of the beach (b = - 0.352). Approximately 70% of nests occurred on beaches with medium and fine sand. Beaches with intense human activities were associated with high OMC which significantly affected the number of nests on the beach. It is therefore recommended that existing laws should be enforced to control beach development and human activities along the Kenyan coast to protect nest sites. Additionally, long term monitoring should be put in place to evaluate the impact of human disturbance on the favourable biophysical factors influencing the number of nests on a beach, as a management tool in the conservation of C. mydas. 

scholarly journals Mackenzie River Peregrine Falcon Surveys 1966–2018

2018 ◽  
Vol 26 (2) ◽  
pp. 134-142
Author(s):  
Keith Hodson
Keyword(s):  
Canadian Arctic ◽  
Peregrine Falcon ◽  
Eastern Slope ◽  
Occupied Site ◽  
Nest Sites ◽  
Lesser Scaup ◽  
Great Slave Lake ◽  
Peregrine Falcons ◽  
Breeding Distribution ◽  
Mackenzie River

Abstract The author with assistants monitored the breeding distribution of Peregrine Falcons (Falco peregrinus) along the length of the Mackenzie River, Northwest Territories, Canada from 1966 to 2018. This river traverses a thousand miles (1600 km) of the western Canadian Arctic from Great Slave Lake to the Beaufort Sea and roughly parallels the eastern slope of the Mackenzie Mountain cordillera between latitudes 61 degrees N and 68 degrees N. All potential nest sites have been checked on each survey and counts of nest sites occupied (at least one bird seen) decreased from the count of 12 sites in 1966 to the lowest count of 7 in 1972. In 1990 the count was 37 and up to 2018 the highest count was 75 in 2010. A count of nest sites successfully producing young was variable with a low of 5 in 1972 to a high of 58 in 2011. Production of young averaged 2.43/successful site from 1990 until 2018 (excluding 2012). Production of young averaged 1.4/occupied site over this period. Recent increases in availability of passerine prey because of widespread fires in the last decades are felt to be the latest phenomena affecting these birds (pers.obs.) Prey utilized by Peregrines was studied over a period of four years and passerines composed 20% of their diet. Two species Lesser Scaup (Athya affinis) and Lesser Yellowlegs (Tringa flavipes) formed 25% of their diet.

scholarly journals Changes in Diurnal Cliff-Nesting Raptor Occurrence on the Ungalik River in Western Alaska: 1977, 1979, and 2008

ARCTIC ◽  
2016 ◽  
Vol 69 (3) ◽  
pp. 225
Author(s):  
Tim Craig ◽  
Erica H. Craig
Keyword(s):  
Natural Variation ◽  
Small Population ◽  
Peregrine Falcon ◽  
The Past ◽  
Peregrine Falcons ◽  
Nesting Sites ◽  
Occupied Territories ◽  
Buteo Lagopus ◽  
Global Population ◽  
Nesting Season

Diurnal cliff-nesting raptors were inventoried on the Ungalik River, Alaska, in 1977 and 1979. In 2008 we resurveyed the drainage, replicating the techniques used in 1979. The density of nesting raptors during the late nesting season has doubled in the past three decades, from six occupied territories detected in 1977 and four in 1979 to 12 in 2008. A single Peregrine Falcon (Falco peregrinus) was sighted during aerial surveys in 1977, and a pair of Peregrine Falcons was detected during a boat survey in 1979; however, nesting by these birds was not confirmed. In contrast, we detected five occupied Peregrine Falcon territories along the Ungalik River in 2008. Other changes in cliff-nesting raptor occurrence included a decrease in occupied Gyrfalcon (Falco rusticolus) territories from four in 1977 to one in 1979 and two in 2008, a decrease in Rough-legged Hawk (Buteo lagopus) nests from one in 1979 (none in 1977) to none in 2008, and increases in Golden Eagle (Aquila chrysaetos) nests, from two in 1977 and 1979 to five in 2008. Changes in the number of nests of cliff-nesting raptors in this small population may have resulted, in part, from natural variation associated with changes in weather or prey abundance. However, it is likely that the increase in nesting Peregrine Falcons is related to global population recovery. Our data indicate that factors other than available nesting sites limit cliff-nesting raptor numbers along the Ungalik River. Spatial analysis indicated that cliff-nesting raptor nests were most often on hills or cliffs that face away from the coast, which is the source of most storms.

scholarly journals Nesting Preferences for Two Woodpecker Species (Dendrocopos Major and Dendrocopos Medius) in Comana Forest, Southern Romania/ Preferințele de cuibărit la două specii de ciocănitori (Dendrocopos Major şi Dendrocopos Medius), în Pădurea Comana, Sudul României

2015 ◽  
Vol 57 (1) ◽  
pp. 35-45 ◽  
Author(s):  
Ioana Damoc ◽  
Tiberiu Sahlean ◽  
Roxana Ion ◽  
Mihaela Ion ◽  
Lotus Elena Meşter
Keyword(s):  
Food Sources ◽  
Pedunculate Oak ◽  
Large Trees ◽  
Nesting Sites ◽  
Turkey Oak ◽  
Nest Height ◽  
Middle Spotted Woodpecker ◽  
Dendrocopos Major ◽  
Nesting Preferences

Abstract The main goal of this study is to get a better insight of the habitat requirements for the Great- and Middle Spotted Woodpeckers. Woodpeckers are forest specialists, threatened all over Europe mainly by the loss of forest habitats and also by the loss in quality of the habitat by reducing the food sources and nesting sites. Both species showed a strong preference for oaks, lime, large trees and dead wood for nesting, but Middle Spotted Woodpecker proved to be more selective in terms of tree species. Nest-height was influenced by tree diameter. Both species have the same nesting preferences for Turkey oak, lime and Pedunculate oak, in a Quercetum farnetto-cerris type of forest. The orientation of the nest hole on the tree was mainly NE-E-SE for Middle Spotted Woodpecker and N-NE-E for Great Spotted Woodpecker.

scholarly journals Denke as krisisterrein in die verskynsel van kerkkrimping by tradisioneel Afrikaanssprekende susterkerke

2013 ◽  
Vol 34 (1) ◽  
Author(s):  
Phia Van Helden
Keyword(s):  
Church Growth ◽  
Appreciative Inquiry ◽  
Human Activities ◽  
Great Commission ◽  
Factors Influencing ◽  
Human Thinking ◽  
Determining Factor ◽  
Sister Churches

Thinking as a crisis area in the phenomenon of the declining traditionally Afrikaans �sister churches�. Since little can be done, humanly speaking, to address the numerous factors influencing the decline of churches, it is obvious that everything humanly possible must be done. Thinking plays a major role in ecclesiology. This article focuses on human thinking as crisis area and as variable in ecclesiology. Because thinking is the determining factor controlling human activities, it is necessary to transform and change thinking when imbalances appear under the microscope of the last command of Jesus. Through the Great Commission, the Christocentric paradigm is revealed which serves as a corrective guideline for the imbalances created by the institutionalistic (I-paradigm) or the spiritualistic (S-paradigm) paradigms. Appreciative Inquiry (AI) is rediscovered as Scripture-based approach regarding change in thinking and the resulting change in the ecclesiastic crisis area, thus focussing on a more complete obedience to the Great Commission and promoting the possibility of natural church growth.

Direct and Indirect Estimates of Peregrine Falcon Population Size in Northern Eurasia

The Auk ◽  
2000 ◽  
Vol 117 (2) ◽  
pp. 455-464 ◽  
Author(s):  
J. L. Quinn ◽  
Y. Kokorev
Keyword(s):  
Population Size ◽  
Northern Eurasia ◽  
Published Data ◽  
Peregrine Falcon ◽  
Species Overlap ◽  
Peregrine Falcons ◽  
Nesting Association ◽  
The Common ◽  
Territory Density ◽  
Post Hoc

Abstract We used two different methods to estimate the density of nesting Peregrine Falcons (Falco peregrinus) across different parts of northern Eurasia. In the “territory-density” method, we extrapolated our density estimate of 406 km2 per territory (95% CI = 295 to 650 km2 per territory) in a high-density area, the Pyasina basin on the Taymyr Peninsula, to other similar areas across the range defined by published estimates. To estimate numbers in low-density areas, we used published data that suggested that Peregrine Falcon territories occur every 1,000 km2. Based on the nesting association between Peregrine Falcons and Red-breasted Geese (Branta ruficollis), we used a second, post hoc method to provide a comparative estimate where the ranges of the two species overlap. This model was based primarily on the population ecology of the Red-breasted Goose and included parameters such as the proportion of the goose population nesting with peregrines, the proportion of peregrine pairs associated with geese, goose population size, and three other variables. Some of these variables were already known, whereas others had been estimated as part of another study. The territory-density and nesting-association methods led to estimates of 1,586 (95% CI = 991 to 2,179) and 2,417 (95% CI = 1,306 to 3,528) falcon territories, respectively, across the common range of Peregrine Falcons and Red-breasted Geese; the first method suggested a population of 3,652 falcon territories (95% CI = 2,282 to 5,018) across the entire range F. p. calidus. Although both approaches entailed several major assumptions, together they provide the only quantitative estimate of this remote population of Peregrine Falcons.

Variation in Peregrine Falcon Eggs

The Auk ◽  
1984 ◽  
Vol 101 (3) ◽  
pp. 578-583 ◽  
Author(s):  
William A. Burnham ◽  
James H. Enderson ◽  
Thomas J. Boardman
Keyword(s):  
Embryonic Development ◽  
Representative Sample ◽  
Shell Thickness ◽  
Egg Size ◽  
Peregrine Falcon ◽  
Eggshell Thickness ◽  
Fresh Weight ◽  
Initial Weight ◽  
Future Studies ◽  
Peregrine Falcons

Abstract Eggs collected from captive and wild Peregrine Falcons (Falco peregrinus) were used to examine variation in eggshell thickness, length, breadth, and initial weight to resolve questions about eggshell data from wild falcons. For captive falcons, shell thickness of first clutches did not change over the years a falcon laid or with embryonic development. Eggshells in third clutches, but not second clutches, were significantly thinner than those from first clutches. Greatest variation in shell thickness existed between eggs within a clutch and did not differ significantly between wild and captive eggs. Entire clutches of wild falcons should be represented in future studies to maximize the chance of obtaining a representative sample in regard to shell thickness. Egg size (L, B, and fresh weight) decreased over the years a captive falcon laid. A significant decrease in size (B and fresh weight) also occurred in second and third clutches laid the same year. Ratcliffe's Index generally appeared to be a reliable indicator of shell thickness in captive-laid eggs.

Ecological factors influencing the breeding distribution and success of a nomadic, specialist predator

2012 ◽  
Vol 21 (7) ◽  
pp. 1835-1852 ◽  
Author(s):  
J. Terraube ◽  
B. E. Arroyo ◽  
A. Bragin ◽  
E. Bragin ◽  
F. Mougeot
Keyword(s):  
Ecological Factors ◽  
Factors Influencing ◽  
Specialist Predator ◽  
Breeding Distribution
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