Relationships among Territory Size, Habitat, Song, and Nesting Success of Northern Cardinals

The Auk ◽  
1986 ◽  
Vol 103 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Richard N. Conner ◽  
Mary E. Anderson ◽  
James G. Dickson
Keyword(s):  
Tree Height ◽  
Ground Level ◽  
Nesting Success ◽  
Territory Size ◽  
Cardinalis Cardinalis ◽  
Young Males ◽  
Song Complexity ◽  
Breeding Seasons ◽  
Northern Cardinals

Abstract We collected data from 30 territories of Northern Cardinals (Cardinalis cardinalis) during 3 breeding seasons (1979-1981) in eastern Texas. Territory size was positively correlated with tree height and negatively correlated with the density of foliage at ground level and at 3 m above the ground, and with the density of shrubs. Nesting success was positively correlated with presence of patchy understory foliage and arthropod biomass in territories. Cardinals with low song complexity and shorter songs held better-quality territories and had better nesting success than cardinals with more complex songs. We suspect that young males may use long, complex songs to establish a territory initially, and in subsequent years put less time and effort into song and more into care and defense of young.

scholarly journals A multiscale assessment of Red-tailed Hawk reproductive success relative to urban density and habitat type

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Justin H White ◽  
Jessi L Brown ◽  
Zachary E Ormsby
Keyword(s):  
Urban Areas ◽  
Urban Expansion ◽  
Habitat Type ◽  
Nesting Success ◽  
Arid Environments ◽  
Hatch Date ◽  
Urban Density ◽  
Landscape Characteristics ◽  
Suburban Areas ◽  
Breeding Seasons

Abstract Despite the unique threats to wildlife in urban areas, many raptors have established successfully reproducing urban populations. To identify variations in raptor breeding ecology within an urban area, we compared metrics of Red-tailed Hawk reproductive attempts to landscape characteristics in Reno and Sparks, NV, USA during the 2015 and 2016 breeding seasons. We used the Apparent Nesting Success and logistic exposure methods to measure nesting success of the Red-tailed Hawks. We used generalized linear models to relate nesting success and fledge rate to habitat type, productivity to hatch date (Julian day) and hatch date to urban density. Nesting success was 86% and 83% for the respective years. Nesting success increased in grassland-agricultural and shrub habitats and decreased in riparian habitat within the urban landscape. Productivity was 2.23 and 2.03 per nest for the breeding seasons. Fledge rates were 72% and 77%, respectively, and decreased in riparian areas. Nestlings hatched earlier with increased urban density and earliest in suburban areas, following a negative quadratic curve. Nesting success and productivity for this population were high relative to others in North America. Productivity increased in habitats where ground prey was more accessible. We suggest that suburban areas, if not frequently disturbed, provide sufficient resources to sustain Red-tailed Hawks over extended periods. As urban expansion continues in arid environments globally, we stress that researchers monitor reproductive output across the urban predator guild to elucidate patterns in population dynamics and adaptation.

Snake behavior and seasonal variation in nest survival of northern cardinals Cardinalis cardinalis

2012 ◽  
Vol 43 (6) ◽  
pp. 496-502 ◽  
Author(s):  
Jinelle H. Sperry ◽  
Douglas G. Barron ◽  
Patrick J. Weatherhead
Keyword(s):  
Seasonal Variation ◽  
Nest Survival ◽  
Cardinalis Cardinalis ◽  
Northern Cardinals

Effects of adults on survival and recruitment of Peromyscus leucopus

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.

Annual Productivity and Its Measurement in a Multi-Brooded Passerine, the Eastern Bluebird

The Auk ◽  
1979 ◽  
Vol 96 (3) ◽  
pp. 562-572
Author(s):  
Benedict C. Pinkowski
Keyword(s):  
Success Rate ◽  
Age Groups ◽  
Nesting Success ◽  
Egg Laying ◽  
Success Rates ◽  
Sialia Sialis ◽  
Eastern Bluebird ◽  
Annual Productivity ◽  
Eastern Bluebirds ◽  
Breeding Seasons

Abstract Breeding and demographic parameters are examined for 434 Eastern Bluebirds (Sialia sialis) attempting 324 nests in southeastern Michigan during 1968-1977. Nesting birds spent an average of 10.4 weeks (63.9% of a 16.2-week season) in the study area. Only 154 (35.5%) of the nesting birds remained for entire breeding seasons; these season-long residents averaged 2.14 nests/season and had a higher success rate (68.4%) and presumably greater productivity (5.6 young · pair−1 · season −1) than other birds because site fidelity depends on nesting success. Although two seasonal peaks for egg-laying were observed, only 75 of 357 birds (21.0%) successfully raised two broods. Evidence is presented to suggest that birds observed for only part of a season initiated nests at the same rate while in and not in the study area, so that an average annual productivity value of 5.0 young · pair−1 · season −1 is calculated for all nesting birds from the observed success rate (57.1%) and mean length of stay in the area. Estimated average productivity of yearlings (4.3 young · pair−1 · season −1) was lower than that of adults (5.7 young · pair−1 · season −1) although nesting success rates were similar in the two age groups.

scholarly journals Demography of Bell's Vireos in Missouri Grassland-Shrub Habitats

The Auk ◽  
2000 ◽  
Vol 117 (4) ◽  
pp. 925-935 ◽  
Author(s):  
Joel M. Budnik ◽  
Mark R. Ryan ◽  
Frank R. Thompson III
Keyword(s):  
Nest Predation ◽  
Molothrus Ater ◽  
Nesting Success ◽  
Growth Potential ◽  
Population Declines ◽  
Annual Survival ◽  
Rate Of Increase ◽  
Study Population ◽  
Breeding Seasons ◽  
Seasonal Fecundity

Abstract Numbers of Bell's Vireos (Vireo bellii) have declined throughout much of the breeding range in recent years, yet little information exists to determine factors that are causing these declines. We studied Bell's Vireos nesting in grassland-shrub habitats at two study areas in central Missouri to determine reproductive performance, survival, and population growth potential. Birds were color banded and observed during the breeding seasons of 1996, 1997, and 1998 to determine seasonal fecundity. We monitored 124 breeding pairs (127 pair years) and 213 nests. Density declined from 1.00 to 0.80 territories per 10 ha at the first site and increased from 1.11 to 1.33 at the second site during the study. Mean nesting success was 31 ± SE of 0.03% overall and ranged from 13 to 42% among years and study areas; 57% of the pairs fledged at least one young. Low annual production was a function of high rates of nest predation (41% of all nests observed, accounting for 44 to 78% of daily nest mortality annually) and nest parasitism by Brown-headed Cowbirds (Molothrus ater; 29% of nests observed, 17 to 37% of daily nest mortality annually). Mean seasonal fecundity was 1.60 young fledged per pair per year (range 1.00 to 1.79). Annual survival of adults was 61 ± 0.04% and was higher than previously reported. We used our estimates of seasonal fecundity and annual survival of adults to determine the finite rate of increase (λ) for our study population. Our study areas seemingly comprised sink habitats (λ = 0.85). Thus, the vireos on our study areas likely were limited by low reproductive success. Population declines also may be caused by habitat loss, which highlights the need for investigation of historical and current rates of loss of grassland-shrub habitat.

Unexpected Changes in Reproductive Rates and Mean Age at First Birth during the Decline of the Pribilof Northern Fur Seal (Callorhinus ursinus)

1993 ◽  
Vol 50 (4) ◽  
pp. 858-864 ◽  
Author(s):  
Andrew W. Trites ◽  
Anne E. York
Keyword(s):  
Pregnancy Rates ◽  
Territory Size ◽  
Callorhinus Ursinus ◽  
Age At First Birth ◽  
First Birth ◽  
Young Males ◽  
Fur Seals ◽  
Northern Fur Seals ◽  
Reproductive Rates ◽  
Age And Sex

From 1956 to 1968, female northern fur seals (Callorhinus ursinus) were harvested on the Pribilof Islands, Alaska, in an effort to increase the productivity of the herd. In theory, pregnancy rates should have increased and the age at first birth should have declined as population density was reduced. Instead the opposite happened: pregnancy rates dropped and age of first birth increased. It is unlikely that these changes were caused by shortages of food or poor physical condition of the females, given that body size increased over this period. The most likely explanations for the changes observed between 1958 and 1974 are related to altered age and sex ratios of breeding animals caused by the depletion of females and/or the harvesting of young males. Changes in pregnancy rates and age at first birth are inconsistent with the density-dependence paradigm and suggest that relative densities of mature age and sex classes on the breeding beaches (a product of social interactions and territory size) may be more consequential than absolute population densities in affecting the reproductive biology of northern fur seals.

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