نتایج جستجو برای: breeding seasons
تعداد نتایج: 80998 فیلتر نتایج به سال:
Female aggregation and male territoriality are considered to be hallmarks of polygynous mating systems. The development of genetic parentage assignment has called into question the accuracy of behavioral traits in predicting true mating systems. In this study we use 14 microsatellite markers to explore the mating system of one of the most behaviorally polygynous species, the California sea lion...
The relationship between individual fitness and antioxidants and oxidative stress has come under increasing scrutiny of late. In particular, associations between oxidative balance indicators and reproductive success in the wild have been inconsistent in the limited prior work on this topic. Studies spanningmultiple seasons and antioxidant types are particularly lacking. Here, we examined associ...
A biological control strategy relying on a self-disseminating agent may provide the only affordable long-term technique for reducing brushtail possum (Trichosurus vulpecula) numbers throughout New Zealand. The objective of this study was to determine the frequency and patterns of social interactions in single and mixed-sex groups of possums, in order to identify interactions that may assist in ...
The semen quality during the low (May-July) and the peak (September-November) breeding seasons in 18 Nili-Ravi buffalo bulls varying in age from 3 to 15 years was studied. Ejaculatory volume was higher (P < 0.05) in adult (3.03 ± 0.13 ml) and old (2.86 ± 0.13 ml) than young (2.51 ± 0.11 ml) bulls and during the low (3.44 ± 0.11 ml) than the peak (2.57 ± 0.90 ml) breeding season. Mass activity o...
A 5-yr study was conducted beginning in 1983 with 460 cows to evaluate the effects of three breeding seasons (30, 45, and 70 d in length) and two times of spring calving, March (early) and April (late), on cattle production under Nebraska Sandhills range conditions. Criteria evaluated included pregnancy and weaning percentages, calving date and distribution, cow weights and body condition at fo...
We studied North Island robins over 7 breeding seasons following their reintroduction to Tiritiri Matangi Island. All robins bred in their first year if a mate was available. They usually retained pair bonds for life but some females switched mates within or between breeding seasons. There were 2 instances of sequential polyandry, where a female laid a clutch with a new male while her previous ...
The platelet-derived growth factor (PDGF) system is expressed and can exert its biological role in the male reproductive system including the maintenance of morphological structure and function of the epididymis. The aim of this study was to clarify the relationship between the PDGF system and seasonal changes in morphology of the wild ground squirrel epididymis during the breeding and nonbreed...
Prey species must balance predator avoidance behavior with other essential activities including foraging, breeding, and social interactions. Anti-predator behaviors such as vigilance can impede resource acquisition rates by altering foraging behavior. However, in addition to predation risk, foraging behavior may also be affected by socio-sexual factors including breeding chronology and social i...
Introduction: Dengue is a serious public health problem worldwide, with cases reported annually in tropical and subtropical regions. Aedes aegypti (Linnaeus, 1762), the main vector of dengue, is a domiciliary species with high dispersal and survival capacities and can use various artificial containers as breeding sites. We assessed potential container breeding sites of A. aegypti in the municip...
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