Survival
In adult House Sparrows, annual survival is 45-65%. After fledging and leaving the care of their parents, young sparrows have a high mortality rate, which lessens as they grow older and more experienced. Only about 20–25% of birds hatched survive to their first breeding season. The oldest known wild House Sparrow lived for nearly two decades; it was found dead 19 years and 9 months after it was ringed in Denmark. The oldest recorded captive House Sparrow lived for 23 years. The typical ratio of males to females in a population is uncertain due to problems in collecting data, but a very slight preponderance of males at all ages is usual.
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Famous quotes containing the word survival:
“...I have a duty to speak the truth as I see it and to share not just my triumphs, not just the things that felt good, but the pain, the intense, often unmitigating pain. It is important to share how I know survival is survival and not just a walk through the rain.”
—Audre Lorde (1934–1992)
“Evolution is the law of policies: Darwin said it, Socrates endorsed it, Cuvier proved it and established it for all time in his paper on “The Survival of the Fittest.” These are illustrious names, this is a mighty doctrine: nothing can ever remove it from its firm base, nothing dissolve it, but evolution.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)
“The planet’s survival has become so uncertain that any effort, any thought that presupposes an assured future amounts to a mad gamble.”
—Elias Canetti (b. 1905)