[rec.birds] Lifespans

rising@zoo.toronto.edu (Jim Rising) (06/18/91)

In 1983a,b, and 1987 there were a series of articles published in the
Journal of Field Ornithology giving maximum known ages for N.A. passerine
birds based on bird-banding data.  Here are some of the ones you requested
(5-3 means five years, three months).  Note that these would tend to be
conservative because if a bird is banded as an adult, I think that they
generally assume the minimum possible age (i.e. 1 year old for an
Red-eyed Viero first caught in the spring, but it may be older).

    Anna's Hummingbird		6-00
    Red-shafted Flicker		6-08
    Yellow-shafted Flicker	9-02
    Scrub Jay (Cal.)		15-09
    Cedar Wawsing		7-00
    Rufous-sided Towhee (SC)	12-03
    Rufous-sided Towhee (Cal)	10-08
    Brown Towhee (San Jose, CA)	12-10
    Golden-crowned Sparrow	10-06
    Gambel's Wht-cr. Sparrow	13-04
    Brown-headed Cowbird	15-10
    House Finch			11-07
    American Goldfinch		8-10
    House Sparrow		13-04
The refs. are JFO 54(2):123-137,1983; 54(3) 287-294,1983; 58(3):318-
333,1987.  Of course, very few wild dickey-birds live this long; most
die within the first year, indeed first few months, and the probability
that a bird will live is also influenced by the population density
(i.e. much lower if the habitat is crowded with conspecifics; thus
hunting, e.g., may have no effect on local population sizes because
the loss to hunting is compensated for by a reduction in natural
mortality.  N.B., I said MAY have no effect...  It must be regulated
carefully).
-- 
Name:     Jim Rising
Mail:     Dept. Zoology, Univ. Toronto, Toronto, Ontario, Canada    M5S 1A1
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