Food habits of prairie mink during the waterfowl breeding season

1987 ◽  
Vol 65 (9) ◽  
pp. 2322-2324 ◽  
Author(s):  
Todd W. Arnold ◽  
Erik K. Fritzell
Keyword(s):  
Breeding Season ◽  
Food Habits ◽  
Mustela Vison ◽  
Ground Squirrels ◽  
Total Diet

We studied the food habits of radio-marked male mink (Mustela vison) in southwestern Manitoba from April through July of 1984 and 1985. Mammals were the major prey during April (99% of diet) and, to a lesser extent, May through July (44–21%). Muskrats, ground squirrels, and voles were the most important mammalian prey. Avian prey comprised from 55 to 75% of the diet during May, June, and July. Waterfowl (adults, ducklings, and eggs) accounted for 23% of the total diet. Other important avian prey included coots, grebes, and marsh-nesting blackbirds. We estimated total prey requirements for our radio-marked male mink and concluded that their predation had little impact on populations of prairie waterfowl during this study.

Food Habits of the Ural Owl (Strix uralensis) During the Breeding Season in Central Japan

2013 ◽  
Vol 47 (3) ◽  
pp. 304-310 ◽  
Author(s):  
Taishi Suzuki ◽  
Seiki Takatsuku ◽  
Aki Higuchi ◽  
Ikki Saito
Keyword(s):  
Breeding Season ◽  
Food Habits ◽  
Central Japan ◽  
Ural Owl

scholarly journals Seasonal expressions of androgen receptor, estrogen receptors and cytochrome P450 aromatase in the uteri of the wild Daurian ground squirrels (Spermophilus dauricus)

2018 ◽  
Author(s):  
Yu Wang ◽  
Ziyi Wang ◽  
Wenyang Yu ◽  
Xia Sheng ◽  
Haolin Zhang ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Androgen Receptor ◽  
Breeding Season ◽  
Stromal Cells ◽  
Seasonal Changes ◽  
Ground Squirrels ◽  
Sex Steroid ◽  
Expression Levels ◽  
Cytochrome P450 Aromatase ◽  
Glandular Cells

The reproductive tissues including the uterus undergo dramatic changes in seasonal breeders from the breeding to non-breeding seasons. Classically, sex steroid hormones play important roles in the uterine morphology and functions. To clarify the relationship between sex steroid hormones and seasonal changes in the uterine morphology and functions, the wild Daurian ground squirrels (Spermophilus dauricus) were used as seasonal breeder model. And the immunolocalizations and expression levels of androgen receptor (AR), estrogen receptors α and β (ERα and ERβ) and cytochrome P450 aromatase (P450arom) were investigated in the uteri of the wild Daurian ground squirrels in the breeding (April) and the non-breeding (June) seasons via immunohistochemistry, Western blot and RT-PCR. Histologically, the uterine weight, the thickness of endometrium and the glandular density were significantly higher in the uteri of the breeding season than those of the non-breeding season. In both seasons, the immunostaining of AR was only presented in stromal cells of the uteri; the positive staining of ERα and ERβ were localized in stromal cells and glandular cells; P450arom was merely immunolocalized in glandular cells. The protein and mRNA expression levels of ERα, ERβ and P450arom were higher in the uteri of the breeding season than those of the non-breeding season; conversely, the expressions of AR were higher in the uteri of the non-breeding season comparing with those of the breeding season in both protein and mRNA levels. The AR: ER ratio in the uteri of the non-breeding season exceeded the AR: ER ratio in the uteri of the breeding season in the wild Daurian ground squirrels. These results suggested that seasonal changes in the expression levels of AR, ERs and P450arom might be correlated with the uterine morphology and histology changes, and estrogen may play an important autocrine/paracrine role in regulating the uterine functions of the wild Daurian ground squirrels.

scholarly journals Seasonal expressions of SPAG11A and androgen receptor in the epididymis of the wild ground squirrels (Citellus dauricus Brandt)

2020 ◽  
Vol 64 (2) ◽  
Author(s):  
Wenyang Yu ◽  
Ziwen Zhang ◽  
Pei Liu ◽  
Xiaoying Yang ◽  
Haolin Zhang ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Androgen Receptor ◽  
Luteinizing Hormone ◽  
Epithelial Cells ◽  
Breeding Season ◽  
Seasonal Changes ◽  
Follicle Stimulating Hormone ◽  
Ground Squirrels ◽  
Mrna Levels ◽  
Real Time Quantitative Pcr

Sperm-associated antigen 11A (SPAG11A) is expressed exclusively in the epididymis, which can specifically regulate sperm maturation. The aim of this study was to investigate the seasonal expressions of beta-defensin (SPAG11A) and androgen receptor (AR) in the epididymis of the wild ground squirrels (Citellus dauricus Brandt). Morphologically, the results showed that epididymis length and weight in the breeding season were significantly higher than those of the non-breeding season. Histologically, the results revealed that enlarged lumen diameters, thickened epithelial and abundant sperm in the breeding season while reduced lumen diameters and epithelial with no sperm in the non-breeding season. SPAG11A was intensely expressed in cytoplasm and nucleus of epithelial cells in the breeding season, and weaker staining in the non-breeding season. The immunostaining of AR was only presented in nucleus of smooth muscle cells and epithelial cells in the whole epididymis with stronger staining in the breeding season. The results of real-time quantitative PCR also showed that the mRNA levels of SPAG11A and AR in the epididymis during the breeding season were significantly higher than those of the non-breeding season. In addition, the levels of testosterone (T), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in the serum were higher during the breeding season. Taken together, these results suggested that SPAG11A might play an important role to regulate seasonal changes in epididymal function of the wild ground squirrels.

scholarly journals Seasonal expressions of VEGF and its receptors VEGFR1 and VEGFR2 in the prostate of the wild ground squirrels (Spermophilus dauricus)

2021 ◽  
Vol 65 (2) ◽  
Author(s):  
Yuchen Yao ◽  
Wenqian Xie ◽  
Di Chen ◽  
Yingying Han ◽  
Zhengrong Yuan ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Breeding Season ◽  
Stromal Cells ◽  
Seasonal Changes ◽  
Ground Squirrels ◽  
Vascular Endothelial ◽  
Expression Levels ◽  
Breeding Seasons ◽  
Endothelial Growth Factor ◽  
Endothelial Growth Factors

As a vital male accessory reproductive gonad, the prostate requires vascular endothelial growth factors for promoting its growth and development. In this study, we investigated the localizations and expressions of vascular endothelial growth factor (VEGF) and its receptors including VEGF-receptor1 (VEFGR1) and VEGF-receptor2 (VEGFR2) in the prostate of the wild ground squirrels during the breeding and the non-breeding seasons. The values of total prostate weight and volume in the breeding season were higher than those in the non-breeding season. Histological observations showed that the exocrine lumens of the prostate expanded in the breeding season and contracted in the non-breeding season. The mRNA expression levels of VEGF and VEGFR2 in the prostate were higher in the breeding season than those in the non-breeding season, but the mRNA expression level of VEGFR1 had no significant change between the breeding and non-breeding seasons. Immunohistochemical results revealed that VEGF, VEGFR1 and VEGFR2 were presented in epithelial and stromal cells during the breeding and non-breeding seasons. In addition, the microvessels of the prostate were widely distributed and the number of microvessels increased obviously in the breeding season, while decreased sharply in the non-breeding season. These results suggested that expression levels of VEGF and VEGFR2 might be correlated with seasonal changes in morphology and functions of the prostate, and VEGF might serve as pivotal regulators to affect seasonal changes in the prostate functions of the wild male ground squirrels via an autocrine/paracrine pathway.

Food Habits of the Mink, Mustela vison Schreb., in Sweden

Oikos ◽  
1969 ◽  
Vol 20 (1) ◽  
pp. 182
Author(s):  
R. Gerell
Keyword(s):  
Food Habits ◽  
Mustela Vison

Proliferation and apoptosis processes in the seasonal testicular development of the wild Daurian ground squirrel (Citellus dauricus Brandt, 1844)

2017 ◽  
Vol 29 (9) ◽  
pp. 1680 ◽  
Author(s):  
Yingying Han ◽  
Jinqi Zhan ◽  
Ying Xu ◽  
Fengwei Zhang ◽  
Zhengrong Yuan ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Breeding Season ◽  
Caspase 3 ◽  
Nuclear Translocation ◽  
Ground Squirrels ◽  
Nuclear Antigen ◽  
Plasma Testosterone ◽  
Testicular Development ◽  
Cyclin D2 ◽  
Proliferation And Apoptosis

The aim of the present study was to elucidate the regulatory role of cell proliferation and apoptosis in testicular development of wild Daurian ground squirrels during the breeding season (April), the non-breeding season (June) and before hibernation (September). Gross mass and hormonal analysis showed that the testis : body mass ratio and plasma testosterone concentration fluctuated seasonally, with a peak in April and lowest values in June. Similarly, spermatogenesis was fully developed in April but suppressed in June and September. Testicular decellularisation and vacuolisation was seen during the transition from the breeding to the non-breeding season. Furthermore, testicular levels of proliferating cell nuclear antigen, cyclin D2 and caspase-3 protein were significantly increased in June and September. Intriguingly, positive terminal deoxyribonucleotidyl transferase-mediated dUTP–digoxigenin nick end-labelling staining and nuclear translocation of caspase-3 in testicular germ cells appeared only during the prehibernation period, whereas accumulation of cyclin D2 in spermatocyte nuclei occurred in September. These findings demonstrate, for the first time, that both cell proliferation and apoptosis are stimulated during the prehibernation period, indicating that a hormonal-regulated balance of testicular germ cell proliferation and apoptosis may play a pivotal role in preparing for testicular recrudescence of wild Daurian ground squirrels.

scholarly journals The Indispensable Role of Androgen in Follicular Development of Wild Female Ground Squirrels (Citellus dauricus Brandt) During Non-Breeding Season.

2011 ◽  
Vol 85 (Suppl_1) ◽  
pp. 656-656
Author(s):  
Xiaonan Li ◽  
Ji Weng ◽  
Shuqiang Liu ◽  
Meiyu Xu ◽  
Qiang Weng ◽  
...  
Keyword(s):  
Breeding Season ◽  
Follicular Development ◽  
Ground Squirrels ◽  
Wild Female
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