[TN-Bird] Re: Singing in female passerines

Female Scarlet Tanagers also sing, though their song is softer than the male's 
(see Sibley's Guide to Bird Life and Behavior, p 514).

Below I have pasted a link to a short article about singing female Northern 
Cardinals, and some information regarding bird song from the Birder's 
Handbook.

Benny Thatcher
Knoxville, TN

http://www.sciencenews.org/pages/sn_arc98/8_29_98/fob6.htm

Ornithologists differentiate, somewhat arbitrarily, between a call and a song 
by the length and complexity of the vocalization.  Calls tend to serve 
specific functions and are generally innate rather than learned.  For example, 
alarm calls serve to alert all within earshot that danger is present; they 
tend to be rather similar among groups of birds and often communicate their 
message across species.  Contact calls are used among members of a flock or 
between mates to indicate the location of the caller.  Many species in groups 
that lack song (such as gulls and parrots) have complex repertoires of calls 
that serve varied functions.

Song is a well-developed feature primarily of oscine passerines (hence, they 
are referred to as "songbirds"), and generally must be partly or entirely 
learned.  Songs identify the species of the singer.  In addition, the 
territorial or advertising song of males serves the dual function of 
territorial proclamation directed at other males and of mate attraction 
directed toward females.  Thus the song warns the former to keep out of the 
defended territory and invites the latter to join the singer.  There are 
other, more subtle functions and messages, as well.  The motivation of the 
singer can be conveyed by the amount that he sings; in order to attract a 
mate, unpaired males devote more time to singing than do paired males.  When 
excited, such as during and immediately following a territorial encounter with 
a rival male, the rapidity of singing often increases.  Song length also may 
increase or decrease when the bird is agitated.

Males of approximately three-quarters of all songbirds sing two or more 
different songs and are said to possess "song repertoires." Each song having a 
particular configuration of syllables and phrases repeated in a stereotyped 
fashion is referred to as a "song-type." At the extreme end of the range in 
repertoire size is the male Brown Thrasher, estimated to sing in excess of 
3,000 song-types.  The evolution of elaborate song repertoires is presumed to 
be the result of sexual selection arising from competition between males for 
females.  In selecting a male with which to pair, females may use size and 
complexity of the song repertoire to assess a male's overall potential 
"fitness" as a partner.  In some species, these characteristics are known to 
increase with age, and may serve as an indirect gauge of breeding experience 
and health.  Increased complexity and size of repertoire also have been shown 
to correlate with measures of territory quality in some species, thus 
providing further information to a female about to invest her immediate 
reproductive future on the basis of what she hears.

There is some experimental evidence that song is important in coordinating the 
reproductive cycle between mates in addition to its presumed role in 
maintaining the pair bond.  Male song is known to stimulate ovarian 
development and egg laying in Budgerigars and to accelerate nest-building 
activity in female Canaries.  In fact, ornithologist Don Kroodsma has shown 
that female Canaries exposed to large repertoires are more stimulated to build 
nests than are females exposed to impoverished repertoires.  Laboratory 
experiments with female Song Sparrows demonstrate that larger song repertoires 
elicit more copulation-soliciting displays; females prefer repertoires of 4 
song-types compared to 1, 8 compared to 4, and 16 compared to 8. Observations 
of pairing in the field, however, revealed no relationship between repertoire 
size and either date of initial pair formation or the speed with which a 
second mate was acquired following removal of the first female.  Thus, 
although larger song repertoires appear to serve as stronger stimuli in sexual 
and nesting behavior, there is little field evidence that they influence 
female choice of mates in species where song repertoire size is not correlated 
with male age (as in the Song Sparrow).

Individual males often can be identified by characteristic features of their 
songs, and birds of many species have been tested in the field for their 
ability to discriminate between the songs of neighbors (males that are already 
established on territories and pose no real threat) and strangers (males that 
are searching for a territory on which to establish themselves).  The ability 
to distinguish between neighbors and strangers without being able to see them 
should afford considerable energy savings to a territory holder.  The song of 
an established neighbor can be answered with a song or can be ignored; the 
song of a stranger, however, necessitates a vigorous physical as well as vocal 
rebuff.  Territorial males identify each other using both song features and 
location from which the song originates.  Interestingly, species with large 
repertoires show a somewhat reduced ability to discriminate between neighbors 
and strangers than do species with limited repertoires.  For example, Song 
Sparrows, with repertoires of 8 to 10 songs, show weaker discrimination than 
closely related Swamp Sparrows, with repertoires of 4 to 5 songs.

The ability to recognize neighbors by vocalizations alone has not been found 
in species that nest in dense colonies.  This is true even for species (such 
as the Northern Gannet, Laughing Gull, and Black-legged Kittiwake) that can 
recognize their young or their mates by vocalizations.  Presumably under 
conditions of unobstructed visual contact, natural selection has not favored 
vocal recognition of neighbors.

© 2001 Thayer Birding Software LLC. All rights reserved.





>===== Original Message From dfv@xxxxxxxxxx =====
>I have the impression that singing in passerines generally indicates males.
>However, I know that female Northern Cardinals do sing as well.  Is anyone
>out there aware of any literature that includes information about which
>species exhibit female singing and which do not?
>
>Thanks,
>Dave Vogt
>Chattanooga, TN
>=================NOTES TO SUBSCRIBER=====================
>
>The TN-Bird Net requires you to sign your messages with
>first and last name, city (town) and state abbreviation.
>-----------------------------------------------------
>----------------------------------------------------
>To post to this mailing list, simply send email to:
>tn-bird@xxxxxxxxxxxxxx
>-----------------------------------------------------
>To unsubscribe, send email to:
>tn-bird-request@xxxxxxxxxxxxx
>with 'unsubscribe' in the Subject field.
>* * * * * * * * * * * * * * * * * * * * * * * * * * * * *
>
>  TN-Bird Net is owned by the Tennessee Ornithological Society
>       Neither the society(TOS) nor its moderator(s)
>        endorse the views or opinions expressed
>        by the members of this discussion group.
>
>         Moderator: Wallace Coffey, Bristol, TN
>                 wallace@xxxxxxxxxxxxxxxxxxx
>
> * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
>     Visit the Tennessee Ornithological Society
>          web site at http://www.tnbirds.org
>* * * * * * * * * * * * * * * * * * * * * * * * * * * * *
>Topographical Maps located at http://topozone.com/find.asp
>* * * * * * * * * * * * * * * * * * * * * * * * * * * * *
>
>    ========================================================

=================NOTES TO SUBSCRIBER=====================

The TN-Bird Net requires you to sign your messages with
first and last name, city (town) and state abbreviation.
-----------------------------------------------------
----------------------------------------------------
To post to this mailing list, simply send email to:
tn-bird@xxxxxxxxxxxxxx
----------------------------------------------------- 
To unsubscribe, send email to:
tn-bird-request@xxxxxxxxxxxxx 
with 'unsubscribe' in the Subject field.
* * * * * * * * * * * * * * * * * * * * * * * * * * * * *

  TN-Bird Net is owned by the Tennessee Ornithological Society 
       Neither the society(TOS) nor its moderator(s)
        endorse the views or opinions expressed
        by the members of this discussion group.
 
         Moderator: Wallace Coffey, Bristol, TN
                 wallace@xxxxxxxxxxxxxxxxxxx

 * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     Visit the Tennessee Ornithological Society
          web site at http://www.tnbirds.org
* * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Topographical Maps located at http://topozone.com/find.asp
* * * * * * * * * * * * * * * * * * * * * * * * * * * * *

    ========================================================

Other related posts: