Home Range of an Adult Female Peregrine Falcon (Falco peregrinus) during the Breeding and Non-breeding Seasons in Kentucky, USA

To measure the prevalence of senescence in southern elephant seals (Mirounga leonina Linn.) at Marion Island, changes in adult-female survival and breeding probabilities with age were quantified. Markrecapture data that had been collected over a 17-year period were analysed using recently developed software to obtain likelihood estimates of survival and capture probabilities. With recapture effort constant over the study period, capture probabilities during the breeding seasons were used as indices of breeding probabilities. Longevity in the population was assessed from the resighting of tagged and hence known-age individuals. Less than a 1% difference between prime-age survival and post prime age survival was found over 8 cohorts of marked females. In addition, no reduction in survival of very old individuals was detected, suggesting the absence of senescence in terms of reduced survival in southern elephant seals. No evidence of reproductive senescence in terms of reduced breeding probability with age was detected. Mortality throughout the population therefore resulted in no individuals surviving to the age where physiological decline would become a mortality agent or result in failure to breed. Five percent of female southern elephant seals survived to age 10 and 0.5% to age 17.

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Home range and activity of African goshawks Accipiter tachiro in relation to their predation on bats

Koedoe ◽

10.4102/koedoe.v33i2.437 ◽

1990 ◽

Vol 33 (2) ◽

Cited By ~ 4

Author(s):

I.L. Rautenbach ◽

M.B. Fenton ◽

A.C. Kemp ◽

S.J. Van Jaarsveld

Keyword(s):

Home Range ◽

Adult Female ◽

Sex Ratios ◽

Home Ranges ◽

Radio Tracking ◽

High Fecundity ◽

Previous Summer

Winter radio-tracking of three African goshawks Accipiter tachiro showed that they each occupied well-wooded home ranges of at least 28 hectares. They perched and roosted mainly within densely foliaged trees and an adult female changed perches on average 4,7 times per hour. No crepuscular predation of bats was recorded, in contrast to regular summer predation on colonies of little free-tailed bats, Tadarida pumila, but winter emergence rates of these bats at dusk had dropped to < 5 of the previous summer. We predict that many accipiters will be regular predators of bats and that skewed sex ratios and high fecundity may be two means by which bats counter this predation.

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Population trends and diversification of breeding habitats of Peregrine Falcon (Falco peregrinus) in the Czech Republic since 1990

Ornis Hungarica ◽

10.1515/orhu-2018-0020 ◽

2018 ◽

Vol 26 (2) ◽

pp. 121-129

Author(s):

Václav Beran ◽

Josef Vrána ◽

David Horal

Keyword(s):

Czech Republic ◽

Breeding Habitat ◽

Peregrine Falcon ◽

German Population ◽

Falco Peregrinus ◽

The Czech Republic ◽

Nest Boxes ◽

Industrial Buildings ◽

The 1960S ◽

Population Restoration

Abstract The population of the Peregrine Falcon (Falco peregrinus) in the Czech Republic recovered from a nearly total extinction during the 1960s and 1980s (03 breeding pairs) and the first successful breeding after this interval was confirmed in 1995. The increase of the population size accelerated after 2000 and it is still growing despite the limited amount of suitable natural breeding opportunities. There were 89 known pairs in 2016, 70 of them were proven to breed with altogether at least 121 reared young. Several breeding attempts on historical buildings in citycentres were recorded up to 2002 (in Prague and Pilsen), but this breeding habitat was abandoned later. More and more pairs are nowadays breeding on industrial buildings. The first breeding on a power plant chimney, 300m above the ground was discovered in 2010. Moreover, 16 breeding pairs were found on industrial buildings in 2016 (mainly tall chimneys or cooling towers and powerplant buildings), all of them breeding in nest boxes. The colonization of industrial buildings started in western part of the Czech Republic and continues eastwards every year. Currently, the easternmost colonized building is in Mladá Boleslav. We have no recent treebreeding pairs and all eight published historical cases are at least doubtful. Most of the observed Peregrines ringed abroad came from Germany, indicating a strong influence of German population on restoration of the population in the Czech Republic. Within these recoveries, some of Peregrines were released in the treebreeding population restoration project in Germany and Poland, but all these birds bred on rocks.

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Effects of adults on survival and recruitment of Peromyscus leucopus

Canadian Journal of Zoology ◽

10.1139/z87-380 ◽

1987 ◽

Vol 65 (10) ◽

pp. 2519-2523

Author(s):

Gregory H. Adler ◽

Mark L. Wilson ◽

Michael J. DeRosa

Keyword(s):

Adult Female ◽

Adult Male ◽

Peromyscus Leucopus ◽

Survival Rates ◽

Adult Males ◽

Control Grid ◽

Young Males ◽

Young Females ◽

Breeding Seasons ◽

And Control

A population of Peromyscus leucopus (white-footed mouse) in northeastern Massachusetts was manipulated for 3 years to determine the effects of adults on survival and recruitment. Two experimental grids were established, from which either all adult males or all adult females were removed continually. The effects of these two manipulations were compared with demography on a control grid. Manipulations had no apparent effect on breeding intensity of young, survival rates of adults, or residency rates of adults and young. Recruitment of adult males was higher on the adult male removal grid than on the control grid. Recruitment rates of adult males and of young males and young females were lower on the adult female removal grid than on the control grid. Survival rates of young males were higher on the adult female removal grid than on the control grid; this effect may have been due to either reduced adult female residency or adult male recruitment. All differences between experimental and control grids were noted only during breeding seasons. Adult males apparently limited recruitment of adult consexuals. The effects of manipulations on other measured parameters were inconclusive because of high immigration rates of adult males onto the adult male removal grid and reduced recruitment of adult males and decreased production of young on the adult female removal grid.

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