Hi Alicia, After I posted i continued to search and found this JOURNAL ARTICLE Sexual Size Dimorphism and Assortative Mating in Carolina Wrens
Thomas M. Haggerty Journal of Field Ornithology Vol. 77, No. 3 (Summer, 2006), pp. 259-265 It states clearly that: "Analysis revealed that males were significantly larger than females in all body measurements." I had read that only males sing but it was not clear till I found this that males were larger. you suggest that females sing too. > On Feb 27, 2020, at 3:56 PM, Alicia <t...@ottcmail.com> wrote: > > Hi Bard, > > We have had C. Wrens in our yard since 1995, when we moved in, except for 15 > mos following the cruel February of 2015 which wiped out the majority of the > C. Wrens in this area. Have never noticed any size differential in any of > the pairs & have only been able to tell them apt by song: the male sings a > two or three part song and the female has a buzzier, irritated sounding > response - they duet. The young birds do take a month or so to get up to > size after they fledge, but that wouldn't explain a small one at your feeder > all winter. > > That great resource Wikipedia, however, says there is a size difference on > average & gives citations for that proposition: >> At 12.5 to 14 cm (4.9 to 5.5 in) long, with a 29 cm (11 in) wingspan and a >> weight of about 18 to 23 g (0.63 to 0.81 oz), the Carolina wren is a fairly >> large wren; the second largest in the United States species after the cactus >> wren. Among standard measurements, the wing chord is 5.4 to 6.4 cm (2.1 to >> 2.5 in), the tail is 4.5 to 5.6 cm (1.8 to 2.2 in), the culmen is 1.4 to 1.8 >> cm (0.55 to 0.71 in) and the tarsus is 2 to 2.3 cm (0.79 to 0.91 in).3 >> <https://books.google.com/books?id=-r35SXfm9BYC&pg=PA134> Sexual >> dimorphisma is slight with males being larger than their mates. A study >> indicated that out of 42 mated pairs, all but one of male was larger than >> the female of the pair. The males were on average 11 percent heavier along >> with having longer wing chords.13 >> <http://www.buildingthepride.com/faculty/tmhaggerty/Articles/dimorphism%20article.pdf>C. >> Wrens sing all year round, although I am not sure if females do except in >> response to male song. Did your small bird sing? The males also have a call >> that is somewhat similar to the female's buzzy song but I don't think the >> females ever sing anything melodic so if your small bird did sing >> melodically, I think that means it's a male. > > The idea of a small C. Wren seems so odd - for a wren, they seem massive to > me! Will be interested in hearing about whether they interbreed. > > Alicia > > P.S. This photo > <https://www.birds.cornell.edu/crows/images/CarWrenseriesthmb.jpg> (which > comes from a webpage Kevin McGowan posted to show much white can be in C. > Wren tail feathers) also shows a much greater size differential than I at > least would have expected! > > > On 2/27/2020 3:00 PM, Bard Prentiss wrote: >> Throughout the winter our feeders have been visited by a small c. Wren. >> Today it was joined by a notably larger one. Probably the other half of the >> pair that has nested here for several years. There is a clear size >> difference in that pair. If sex doesn’t account for size differentiation >> in this species what might explain it? >> Do sub species interbreed? >> Best, >> Bard >> >> Bard Prentiss >> >> (607)882-0504 >> >> >> Best, >> Bard >> >> Bard Prentiss >> (607)882-0504 >> -- >> >> Cayugabirds-L List Info: >> http://www.NortheastBirding.com/CayugabirdsWELCOME >> <http://www.northeastbirding.com/CayugabirdsWELCOME> >> http://www.NortheastBirding.com/CayugabirdsRULES >> <http://www.northeastbirding.com/CayugabirdsRULES> >> http://www.NortheastBirding.com/CayugabirdsSubscribeConfigurationLeave.htm >> <http://www.northeastbirding.com/CayugabirdsSubscribeConfigurationLeave.htm> >> >> ARCHIVES: >> 1) http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html >> <http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html> >> 2) http://www.surfbirds.com/birdingmail/Group/Cayugabirds >> <http://www.surfbirds.com/birdingmail/Group/Cayugabirds> >> 3) http://birdingonthe.net/mailinglists/CAYU.html >> <http://birdingonthe.net/mailinglists/CAYU.html> >> >> Please submit your observations to eBird: >> http://ebird.org/content/ebird/ <http://ebird.org/content/ebird/> >> >> -- >> > -- Cayugabirds-L List Info: http://www.NortheastBirding.com/CayugabirdsWELCOME http://www.NortheastBirding.com/CayugabirdsRULES http://www.NortheastBirding.com/CayugabirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/Cayugabirds 3) http://birdingonthe.net/mailinglists/CAYU.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
