نتایج جستجو برای: seasonal reproductive
تعداد نتایج: 158986 فیلتر نتایج به سال:
Correction: Spawning Site Selection and Contingent Behavior in Common Snook, Centropomus undecimalis
Reproductive behavior affects spatial population structure and our ability to manage for sustainability in marine and diadromous fishes. In this study, we used fishery independent capture-based sampling to evaluate where Common Snook occurred in Tampa Bay and if it changed with spawning season, and passive acoustic telemetry to assess fine scale behavior at an inlet spawning site (2007-2009). S...
Seasonal fluctuations in water availability cause predictable changes in the profitability of habitats in tropical ecosystems, and animals evolve adaptive behavioural and spatial responses to these fluctuations. However, stochastic changes in the distribution and abundance of surface water between years can alter resource availability at a landscape scale, causing shifts in animal behaviour. In...
the reproductive activity is influenced by environmental conditions in most animal species. the aim of the present study was to determine the seasonal changes of seminiferous tubules structure and spermatogenic activity in khouzestan arabian rams. for this propose 30 adult rams were reared under closed grazing conditions. four rams were randomly selected in each season and their live weight, te...
We searched for correlations between water level, rainfall, temperature, and reproductive activity of fishes in a lotic stretch of the Grande River below the Volta Grande Dam. Gillnets were used to catch the fish on six field journeys made bimonthly between April 1998 and February 1999. Fish gonads were classified according to maturation grade and the amount of mature or spent gonads was correl...
The most documented response of organisms to climate warming is a change in the average timing of seasonal activities (phenology). Although we know that these average changes can differ among species and populations, we do not know whether climate warming impacts within-population variation in phenology. Using data from five study sites collected during a 13-year survey, we found that the incre...
Investigations were made into the body condition, energy metabolite and endocrinal changes of male green turtles Chelonia mydas prior to and during their vernal breeding period in the southern Great Barrier Reef. Prior to migration, breeding males exhibited a higher body condition index than non-breeding males. However, during the migratory reproductive period, breeding males lost significant b...
Efficient reproductive performance of lactating dairy cattle in tropical/subtropical and arid environments throughout the world is impacted by a multiplicity of factors such as: the physical environment, socialeconomic status of producers, available nutrients, adaptability and genetic composition of cattle, intensive or extensive management systems, and available reproductive technology. Season...
I assessed the reproductive patterns of captive-born and wild-caught Asian elephants managed by the Myanmar Timber Enterprise. Calving among all female elephants was seasonal with higher births in cool months (October to February) and late monsoon (September). Captive-born mothers have significantly higher fecundity rates with lower inter-birth intervals than wild-caught mothers, likely due to ...
Vertebrates exhibit varied behavioural and physiological tactics to promote reproductive success. We examined mechanisms that could enable female loggerhead turtles to undertake nesting activities and maintain seasonal reproduction despite recent shark injuries of varying severity. We proposed that endocrinal mechanisms that regulate both a turtle's stress response and reproductive ability are ...
Shark tourism has become increasingly popular, but remains controversial because of major concerns originating from the need of tour operators to use bait or chum to reliably attract sharks. We used direct underwater sampling to document changes in bull shark Carcharhinus leucas relative abundance at the Shark Reef Marine Reserve, a shark feeding site in Fiji, and the reproductive cycle of the ...
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