scholarly journals Bird-window collisions in the summer breeding season

2014 ◽  
Author(s):  
Stephen B. Hager ◽  
Matthew E. Craig
Keyword(s):  
Breeding Season ◽  
Passer Domesticus ◽  
Abundant Species ◽  
Dispersal Patterns ◽  
Long Distance ◽  
American Robin ◽  
Vireo Olivaceus ◽  
A Site ◽  
Breeding Seasons ◽  
Permanent Residents

Birds that reside in urban settings face numerous human-related threats to survival, including mortality from bird-window collisions (BWCs). Our current understanding of this issue has largely been driven by data collected during spring and fall migration, and patterns of collision mortality during the summer breeding season remain relatively unexplored. We assessed BWCs during four breeding seasons (2009- 2012) at a site in northwestern Illinois, USA, by comparing the abundance, richness, migratory class, and age of the species living around buildings to species mortally wounded by window collisions. We also systematically assessed the daily timing of BWCs throughout the breeding season. We documented BWCs in 4 of 25 (16%) species and 7 of 21 (33%) species in 2009 and 2010, respectively. The relationship between BWCs and abundance depended on age. For adults, BWCs were highest in the least abundant species, e.g., Red-eyed Vireo (Vireo olivaceus), and lowest in species with high abundance values, e.g., House Sparrow (Passer domesticus). For juveniles, mortality was greatest for the most abundant species, and the American Robin (Turdus migratorius) accounted for 62% of all juvenile carcasses. Early in the breeding season, collision mortality was restricted to adults of Long- distance Migrants, whereas juveniles of all three migratory guilds (Long-distance and Short-distance Migrants and Permanent Residents) died at windows from late June through early August. Daily mortality for all species was highest between sunrise - 1600 h and lowest from 1600 h - sunrise the next day. Generally, the species observed as carcasses matched birds considered a ‘high risk’ for BWCs, e.g., Ruby-throated Hummingbird (Archilochus colubris), and those considered ‘low risk’ were not observed as carcasses, e.g., Blue-gray Gnatcatcher (Polioptila caerulea). Our results suggest that the number of BWCs during the breeding season does not necessarily increase with abundance, but rather appears related to variation among species and age classes, which may have important implications on the population health of affected species. The mechanisms driving these differences are unknown, but may be related reproductive behavior, flight speed, distance movements, and dispersal patterns.

scholarly journals Bird-window collisions in the summer breeding season

2014 ◽  
Author(s):  
Stephen B. Hager ◽  
Matthew E. Craig
Keyword(s):  
Breeding Season ◽  
Passer Domesticus ◽  
Abundant Species ◽  
Dispersal Patterns ◽  
Long Distance ◽  
American Robin ◽  
Vireo Olivaceus ◽  
A Site ◽  
Breeding Seasons ◽  
Permanent Residents

Birds that reside in urban settings face numerous human-related threats to survival, including mortality from bird-window collisions (BWCs). Our current understanding of this issue has largely been driven by data collected during spring and fall migration, and patterns of collision mortality during the summer breeding season remain relatively unexplored. We assessed BWCs during four breeding seasons (2009- 2012) at a site in northwestern Illinois, USA, by comparing the abundance, richness, migratory class, and age of the species living around buildings to species mortally wounded by window collisions. We also systematically assessed the daily timing of BWCs throughout the breeding season. We documented BWCs in 4 of 25 (16%) species and 7 of 21 (33%) species in 2009 and 2010, respectively. The relationship between BWCs and abundance depended on age. For adults, BWCs were highest in the least abundant species, e.g., Red-eyed Vireo (Vireo olivaceus), and lowest in species with high abundance values, e.g., House Sparrow (Passer domesticus). For juveniles, mortality was greatest for the most abundant species, and the American Robin (Turdus migratorius) accounted for 62% of all juvenile carcasses. Early in the breeding season, collision mortality was restricted to adults of Long- distance Migrants, whereas juveniles of all three migratory guilds (Long-distance and Short-distance Migrants and Permanent Residents) died at windows from late June through early August. Daily mortality for all species was highest between sunrise - 1600 h and lowest from 1600 h - sunrise the next day. Generally, the species observed as carcasses matched birds considered a ‘high risk’ for BWCs, e.g., Ruby-throated Hummingbird (Archilochus colubris), and those considered ‘low risk’ were not observed as carcasses, e.g., Blue-gray Gnatcatcher (Polioptila caerulea). Our results suggest that the number of BWCs during the breeding season does not necessarily increase with abundance, but rather appears related to variation among species and age classes, which may have important implications on the population health of affected species. The mechanisms driving these differences are unknown, but may be related reproductive behavior, flight speed, distance movements, and dispersal patterns.

Foraging movements of female bushy-tailed wood rats (Neotoma cinerea)

1996 ◽  
Vol 74 (5) ◽  
pp. 798-801 ◽  
Author(s):  
Michael G. Topping ◽  
John S. Millar
Keyword(s):  
Breeding Season ◽  
Rocky Mountains ◽  
Food Supply ◽  
Canadian Rocky Mountains ◽  
Long Distance ◽  
Neotoma Cinerea ◽  
Nocturnal Foraging ◽  
Breeding Seasons ◽  
Foraging Movements ◽  
Foraging Radius

Nocturnal foraging movements of female bushy-tailed wood rats (Neotoma cinerea) in the Canadian Rocky Mountains, Alberta, were monitored using radiotelemetry over two breeding seasons (1993–1994). Total distance moved and maximum foraging radius from the nest per night were calculated for individual females throughout the breeding season. Movements during pregnancy, lactation, and the postreproductive period did not differ significantly. Females moved much farther (up to 470 m) from the nest than previously reported for this species (60 m). Such long-distance movements may be related to the availability of an appropriate food supply.

Population ecology of the Australian frog Crinia signifera: adults and juveniles

1996 ◽  
Vol 23 (3) ◽  
pp. 249 ◽  
Author(s):  
CM Bull ◽  
I Williamson
Keyword(s):  
Breeding Season ◽  
Population Ecology ◽  
South Australia ◽  
Adult Mortality ◽  
Large Size ◽  
Early Emergence ◽  
The Common ◽  
Males And Females ◽  
A Site ◽  
Breeding Seasons

A population of the common Australian frog Crinia signifera Girard, 1853 was studied over a 3.5 year period at a site near Bridgewater in South Australia. In this population, C. signifera are long lived and iteroparous, with some individual males and females participating in at least four consecutive breeding seasons. Adult survivorship was high (up to about 70% per annum) for both males and females. Metamorphosis occurred from October to January and some individuals reached maturity within a year. However, most individuals reached maturity in the second breeding season following metamorphosis. Survival of juveniles ranged from 5 to 72% per annum, with individuals emerging early having higher survival than those that metamorphosed late. However, it was not clear whether increased survival was associated with early emergence or large size at emergence. The data support the argument that iteroparity is favoured in situations in which preadult mortality is higher and less predictable than adult mortality.

scholarly journals Evidence for use of both capital and income breeding strategies in the mangrove tree crab, Aratus pisonii

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jade Carver ◽  
Morgan Meidell ◽  
Zachary J. Cannizzo ◽  
Blaine D. Griffen
Keyword(s):  
Breeding Season ◽  
Breeding Strategy ◽  
Reproductive Period ◽  
Breeding Strategies ◽  
Mangrove Tree ◽  
Income Breeding ◽  
Aratus Pisonii ◽  
Breeding Seasons ◽  
And Storage ◽  
Capital And Income Breeding

AbstractTwo common strategies organisms use to finance reproduction are capital breeding (using energy stored prior to reproduction) and income breeding (using energy gathered during the reproductive period). Understanding which of these two strategies a species uses can help in predicting its population dynamics and how it will respond to environmental change. Brachyuran crabs have historically been considered capital breeders as a group, but recent evidence has challenged this assumption. Here, we focus on the mangrove tree crab, Aratus pisonii, and examine its breeding strategy on the Atlantic Florida coast. We collected crabs during and after their breeding season (March–October) and dissected them to discern how energy was stored and utilized for reproduction. We found patterns of reproduction and energy storage that are consistent with both the use of stored energy (capital) and energy acquired (income) during the breeding season. We also found that energy acquisition and storage patterns that supported reproduction were influenced by unequal tidal patterns associated with the syzygy tide inequality cycle. Contrary to previous assumptions for crabs, we suggest that species of crab that produce multiple clutches of eggs during long breeding seasons (many tropical and subtropical species) may commonly use income breeding strategies.

Episodic ovarian inhibin secretion is not due to LH pulses in anoestrous ewes

1989 ◽  
Vol 123 (2) ◽  
pp. 173-179 ◽  
Author(s):  
B. K. Campbell ◽  
A. S. McNeilly ◽  
D. T. Baird
Keyword(s):  
Breeding Season ◽  
Plasma Levels ◽  
Single Injection ◽  
Venous Blood ◽  
Follicular Development ◽  
Blood Samples ◽  
A Site ◽  
Ovarian Inhibin ◽  
Secretion Rates

ABSTRACT In sheep, secretion of oestradiol by the ovary is stimulated by pulses of LH but the factors controlling ovarian inhibin secretion are not well understood. We have investigated the effect of a single injection of LH on the ovarian secretion of inhibin. Six anoestrous Finn–Merino ewes which had one ovary autotransplanted to a site in the neck had jugular and timed ovarian venous blood samples collected at 10-min intervals for a total of 5 h. The secretion rates of both inhibin (1–3 ng/min) and oestradiol (0·5–8 ng/min) were similar to those observed during the breeding season indicating significant follicular development in these animals. After injection of 2·5 μg NIH-LH-S25 intravenously the concentration of LH in plasma rose from a baseline of 1·8 ±0·1 (s.e.m.) μg/l to a peak of 3·9 ±0·3 μg/l (P<0·01). This LH pulse stimulated a corresponding increase (P<0·01) in oestradiol secretion from a basal level of 0·9±0·2 ng/min to a peak of 4·6±0·6 ng/min that occurred within 30 min of injection. Although inhibin secretion was episodic in nature, increases were not related to either exogenous or endogenous LH pulses. We conclude that, in contrast to oestradiol, the secretion of inhibin by the ovary is not controlled acutely by changes in plasma levels of LH during anoestrus. Journal of Endocrinology (1989) 123, 173–179

scholarly journals Density and Flock Size of the Raven (Corvus corax) In the Orawa - Nowy Targ Basin During Non-Breeding Season

Ring ◽  
2006 ◽  
Vol 28 (2) ◽  
pp. 119-125
Author(s):  
Michał Ciach ◽  
Dominik Wikar ◽  
Małgorzata Bylicka
Keyword(s):  
Breeding Season ◽  
Early Spring ◽  
Food Resources ◽  
High Density ◽  
Line Transect ◽  
Flock Size ◽  
Early Winter ◽  
Corvus Corax ◽  
Line Transect Method ◽  
Breeding Seasons

Density and Flock Size of the Raven (Corvus corax) In the Orawa - Nowy Targ Basin During Non-Breeding Season During the 2002/2003-2004/2005 non-breeding seasons the density of the Raven in the open habitats of the Orawa - Nowy Targ Basin was studied by line transect method. The results were analysed in four periods (autumn, early winter, winter and early spring). The median density of Ravens did not differ significantly between individual periods and was respectively: 3.5, 3.8, 4.8 and 3.8 indiv. / 10 km. Number of birds during particular controls varied from 1.0 to 24.8 indiv. / 10 km. However, while excluding flocks, the median density of single individuals and pairs of the Raven was considerably lower and in subsequent periods reached respectively: 2.2, 2.4, 2.2 and 1.7 indiv. / 10 km. Flock size did not differ significantly between individual periods. Single individuals and, less often, groups of two birds were recorded mostly. Small (3-5 indiv.) and medium (6-15 indiv.) flocks were recorded rarely and large flocks (16 indiv. and above) - only exceptionally. The high density and strong fluctuations of abundance of Ravens were determined by flocks presence, which was probably linked to irregular occurrence of food resources.

scholarly journals Genetic structure and dispersal patterns of the invasive psocid Liposcelis decolor (Pearman) in Australian grain storage systems

2010 ◽  
Vol 100 (5) ◽  
pp. 521-527 ◽  
Author(s):  
K.M. Mikac ◽  
N.N. FitzSimmons
Keyword(s):  
Genetic Structure ◽  
Isolation By Distance ◽  
Geographic Distance ◽  
Allelic Diversity ◽  
Mantel Test ◽  
Null Alleles ◽  
Dispersal Patterns ◽  
Long Distance ◽  
Population Comparisons ◽  
Low Levels

AbstractMicrosatellite markers were used to investigate the genetic structure among invasive L. decolor populations from Australia and a single international population from Kansas, USA to determine patterns of dispersal. Six variable microsatellites displayed an average of 2.5–4.2 alleles per locus per population. Observed (HO) heterozygosity ranged from 0.12–0.65 per locus within populations; but, in 13 of 36 tests, HO was less than expected. Despite low levels of allelic diversity, genetic structure estimated as θ was significant for all pairwise comparisons between populations (θ=0.05–0.23). Due to suspected null alleles at four loci, ENA (excluding null alleles) corrected FST estimates were calculated overall and for pairwise population comparisons. The ENA-corrected FST values (0.02–0.10) revealed significant overall genetic structure, but none of the pairwise values were significantly different from zero. A Mantel test of isolation by distance indicated no relationship between genetic structure and geographic distance among all populations (r2=0.12, P=0.18) and for Australian populations only (r2=0.19, P=0.44), suggesting that IBD does not describe the pattern of gene flow among populations. This study supports a hypothesis of long distance dispersal by L. decolor at moderate to potentially high levels.

Phenotypic plasticity of the montane vole (Microtus montanus) in unpredictable environments

1992 ◽  
Vol 70 (11) ◽  
pp. 2121-2124 ◽  
Author(s):  
Norman C. Negus ◽  
Patricia J. Berger ◽  
Aelita J. Pinter
Keyword(s):  
Phenotypic Plasticity ◽  
Breeding Season ◽  
Growth Rates ◽  
Adaptive Strategy ◽  
Severe Drought ◽  
Microtus Montanus ◽  
Age Cohort ◽  
Montane Meadow ◽  
Study Sites ◽  
Breeding Seasons

From 1987 to 1989, the cohort dynamics of Microtus montanus populations were studied at two montane meadow sites approximately 160 km apart, in northwestern Wyoming. The 1987 and 1988 breeding seasons differed markedly from each other. In 1987, melt off occurred in April, and the first cohort was born in May (cohort 1). The entire breeding season was favorable owing to frequent rainfall throughout the summer. Cohort 1 animals grew rapidly and females began breeding at 4–5 weeks of age. Likewise, cohort 2 (June) animals exhibited rapid growth and females were breeding at 7–8 weeks of age. Cohort 3 (July and August) animals grew more slowly and most entered the winter as prepubertal animals of subadult size. At the end of the summer, cohort 3 animals represented >70% of the voles recruited during the breeding season. In 1988, following melt off in late April, precipitation was below normal and the situation intensified to severe drought through the summer. The growth rates of cohort 1 and 2 animals were significantly lower than 1987 growth rates, and very few females attained sexual maturity. At the end of the summer, cohort 3 animals represented <25% of the total recruitment at both study sites. Such apparent phenotypic plasticity of growth and maturation appears to be an evolved adaptive strategy that is responsive to several environmental cues. Both study sites, although widely separated, exhibited virtually identical patterns throughout the study.

Flexibility of nuptial colouration in a unique ecotype of Threespine Stickleback (Gasterosteus aculeatus)

2021 ◽  
Author(s):  
Rachel Corney ◽  
Anne Haley ◽  
Laura Weir
Keyword(s):  
Breeding Season ◽  
Gasterosteus Aculeatus ◽  
Colour Change ◽  
Threespine Stickleback ◽  
Relative Role ◽  
Mate Quality ◽  
Breeding Seasons ◽  
Potential Signal ◽  
Intersexual Competition

Nuptial colouration in animals may serve as a signal of competitor and/or mate quality during breeding. In many temperate fishes, nuptial colouration develops during discrete breeding seasons and is a target of sexual selection. We examine nuptial colouration and behaviour of a unique ecotype of Threespine Stickleback (Gasterosteus aculeatus Linnaeus, 1758), wherein males turn from dull brown-grey to pearlescent white during the breeding season. The main goal of this work was to determine the relative role of white colouration in intersexual competition and mate choice. In a combination of a field and laboratory work, we found that males are brightest white when engaging in courtship activities in the presence of a female; this indicates that white colouration may be primarily related to enhancing signalling during mate attraction. White colouration intensity increased as the breeding season progressed and may be related to an influx of conspecifics. Colour change from cryptic grey to bright white occurred rapidly (< 90 seconds) and may be deployed to enhance behavioural signals. We conclude that bright white colouration in the white ecotype is a potential signal of mate quality and may have evolved from a previously existing capacity for colour plasticity in common Threespine Stickleback.

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