scholarly journals Effect of Fall Hatch Date and Length of Light Restriction on the Photoperiodic Response of Turkey Females

1962 ◽  
Vol 41 (2) ◽  
pp. 493-497 ◽  
Author(s):  
J.A. Harper ◽  
J.E. Parker
Keyword(s):  
Photoperiodic Response ◽  
Hatch Date

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.

Photoperiodic Response of Flowering in Two-Branched Soybean Plants

1979 ◽  
Vol 140 (4) ◽  
pp. 414-417 ◽  
Author(s):  
S. Shanmugasundaram ◽  
Wang Chao-Chin ◽  
T. S. Toung
Keyword(s):  
Photoperiodic Response ◽  
Soybean Plants

Effects of carbon dioxide on Pharbitis, Xanthium, and Silene in short days

1974 ◽  
Vol 52 (6) ◽  
pp. 1283-1291 ◽  
Author(s):  
A. N. Purohit ◽  
E. B. Tregunna
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Concentration ◽  
Dry Weight ◽  
Morphological Characters ◽  
Photoperiodic Response ◽  
Pharbitis Nil ◽  
Light Sources ◽  
Short Day ◽  
Unit Leaf ◽  
Silene Armeria

The flowering response and other morphological characters of Pharbitis nil, Xanthium pennsylvanicum, and Silene armeria were studied in environments with different levels of carbon dioxide and oxygen under short-day conditions. Different light sources and intensities were also tested. Irrespective of the light source and intensity used, higher levels of carbon dioxide delayed or inhibited flowering as well as other morphological characters of the short-day plants but induced flowering in the long-day plant. Dry weight per unit leaf area as well as total chlorophyll increased with carbon dioxide concentration. The results are discussed in relation to some other recent reports, and it is proposed that large variations in photosynthetic rates of plants probably alter their photoperiodic response.

Responses of Some Turkish Wheat Cultivars to Vernalization and Photoperiod

1988 ◽  
Vol 24 (2) ◽  
pp. 237-245
Author(s):  
Serpil Terzioğlu
Keyword(s):  
Bread Wheat ◽  
Normal Development ◽  
Photoperiodic Response ◽  
Reliable Information ◽  
Floral Initiation ◽  
Wheat Cultivars ◽  
Primary Shoot ◽  
Time Of Year ◽  
Short Days

SUMMARYThe vernalization and photoperiodic response of six locally adapted bread wheat cultivars grown under natural daylength conditions during the summer or winter months was examined in glasshouse experiments. The wheat was vernalized by chilling imbibed grains at 2 ± 1°C for 0, 15 or 45 days. Vernalization for 45 days followed by long summer days led to floral initiation in all cultivars within 28 days but vernalization for 0 or 15 days only led to floral initiation in one cultivar. Vernalization followed by long days reduced the time from transplanting to anthesis, resulting in early ear emergence. Vernalization followed by short days accelerated the development of all the cultivars, but normal development could also occur without vernalization at this time of year. Apical differentiation of the primary shoot and its length and development gave the most reliable information on the period of vernalization required.

Sign in / Sign up

Export Citation Format

Share Document