day length


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day length

the number of daylight hours per day, increasing towards midsummer and the reverse towards midwinter. The effective trigger in the commencement and cessation of the breeding seasons in those species that demonstrate seasonal breeding.
References in periodicals archive ?
It's triggered by day length and shifts in hormones, not just by a cold day here and there.
While the research did not indicate precisely when and where these future earthquakes will occur, it showed that most of the intense earthquakes that responded to changes in day length seemed to occur near the equator.
For the proposed research, accurate control of light intensity ( 0 to 1,000 mol(PAR)), far red/red ratio, day length, temperature (-10 to 45C), relative humidity (40 to 85 %), carbon dioxide level (0 to 2,000 ppm) and airflow is needed.
We tested using general linear models (GLM) with IBM SPSS Statistics 22 if 1) age of birds, 2) sex, 3) breeding method and 4) day length influenced daily ranges, distance travelled per hour and number of times capercaillies fed per h.
Birds such as blackbirds and blue tits are behaving much as normal, as day length is an important factor in when they breed, while sightings of insects including ladybirds and redtailed bumblebees are also around average.
But long-distance migratory birds, for example, time their migration based on day length in their winter range.
Some edible plants are referred to as "day-length sensitive," although day length is a misnomer because these plants are actually sensitive to the number of hours of darkness.
This gives Doha a change in day length of 3 hours 10 minutes between June and December, and the further away from the equator you travel, the greater this difference becomes.
Scientists can measure how fast the Earth spins by observing distant objects in space and timing how long they take to come back into view--that is one day length.
But usually the date with equal day and night lengths comes a few days before the equinox 6 plus, day length varies depending on how close you are located to the equator.
Changes in day length tell many organisms that the seasons are changing.