Genetic variation in male Yellow-headed Blackbirds from the northern Great Plains

1992 ◽  
Vol 70 (11) ◽  
pp. 2280-2282 ◽  
Author(s):  
Daniel J. Twedt ◽  
William J. Bleier ◽  
George M. Linz

Electrophoretic differences at 15 presumptive loci were used to assess allelic frequencies, heterozygosities, and polymorphism for male Yellow-headed Blackbirds (Xanthocephalus xanthocephalus) collected in east-central Alberta, north-central North Dakota, and east-central South Dakota. Five loci were polymorphic and mean heterozygosities ranged from 0.119 to 0.133. Significant differences were detected among these geographic populations of Yellow-headed Blackbirds, primarily due to differences in the allelic frequencies of isocitrate dehydrogenase and glucose-6-phosphate dehydrogenase. Differences detected were not sufficient to uniquely identify the geographic origin of Yellow-headed Blackbrids.

2020 ◽  
Vol 21 (7) ◽  
pp. 1469-1484
Author(s):  
Yafang Zhong ◽  
Jason A. Otkin ◽  
Martha C. Anderson ◽  
Christopher Hain

AbstractDespite the key importance of soil moisture–evapotranspiration (ET) coupling in the climate system, limited availability of soil moisture and ET observations poses a major impediment for investigation of this coupling regarding spatiotemporal characteristics and potential modifications under climate change. To better understand and quantify soil moisture–ET coupling and relevant processes, this study takes advantage of in situ soil moisture observations from the U.S. Climate Reference Network (USCRN) for the time period of 2010–17 and a satellite-derived version of the evapotranspiration stress index (ESI), which represents anomalies in a normalized ratio of actual to reference ET. The analyses reveal strong seasonality and regional characteristics of the ESI–land surface interactions across the United States, with the strongest control of soil moisture on the ESI found in the southern Great Plains during spring, and in the north-central United States, the northern Great Plains, and the Pacific Northwest during summer. In drier climate regions such as the northern Great Plains and north-central United States, soil moisture control on the ESI is confined to surface soil layers, with subsurface soil moisture passively responding to changes in the ESI. The soil moisture–ESI interaction is more uniform between surface and subsurface soils in wetter regions with higher vegetation cover. These results provide a benchmark for simulation of soil moisture–ET coupling and are useful for projection of associated climate processes in the future.


1986 ◽  
Vol 66 (1) ◽  
pp. 11-17 ◽  
Author(s):  
D. E. PARFITT ◽  
G. J. FOX ◽  
J. D. BROSZ

Blackbird feeding on sunflower is a significant problem in parts of the Northern Great Plains. Therefore, experiments were initiated to determine the relationship of chlorogenic acid (CA) in sunflower achenes to bird predation and the amount of variability for CA in sunflower genotypes. Eight inbred sunflower (Helianthus annuus L.) genotypes with variable levels of resistance to blackbird (Agelaius phoeniceus L. and Xanthocephalus xanthocephalus Bonaparte) and house sparrow (Passer domesticus L.) predation were evaluated at two locations in 1979 and 1980 for seed and hull CA. Differences were observed among inbred sunflower genotypes for CA concentration in both hull and seed. However, no significant correlation between percent CA in seed and mean percent bird damage over the four tested environments was observed. An unexpected positive correlation for hull CA and bird damage was found, however. Achene samples were taken from three positions within the sunflower head (outside, middle and inside) from seven inbred lines at three sampling dates. Genotype influenced CA level in both achene components while sampling date influenced CA level in the seed only. Position of achenes within the sunflower head did not influence CA concentration of either hull or seed. Thus, it is unlikely that the CA concentration of physiologically mature sunflower achenes (hull or seed) causes the observed bird predation pattern (edge to center) on sunflower heads. CA concentration is not apparently related to bird damage.Key words: Sunflower, bird feeding, chlorogenic acid, Helianthus annus L., blackbird


Rangelands ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 23-29 ◽  
Author(s):  
John R. Hendrickson ◽  
Kevin K. Sedivec ◽  
David Toledo ◽  
Jeffrey Printz

1973 ◽  
Vol 51 (12) ◽  
pp. 1267-1273 ◽  
Author(s):  
James D. Rising

The phenetic affinities of 56 specimens of the orioles Icterus galbula and I. bullockii, and specimens intermediate between them, from the northern Great Plains, are discussed. Phenetically intermediate individuals appear there in lower proportion than they do at most localities in the southern plains, suggesting that there is selection against such individuals in the north. The range of I. galbula seems to be extending southward m the northern plains at the expense of I. bullockii; this is possibly correlated with changes in the climatic environment. I. bullockii and I. abeillei both are uncommon in north-central Durango, Mexico, the only place where they are known to be sympatric.


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