Song Dialects and Colonization in the House Finch, Carpodacus mexicanus, on the East Coast

The Condor ◽  
1975 ◽  
Vol 77 (4) ◽  
pp. 407 ◽  
Author(s):  
Paul Mundinger
1986 ◽  
Vol 22 (3) ◽  
pp. 420-422 ◽  
Author(s):  
Douglas E. Docherty ◽  
Renee I. Romaine Long

The Auk ◽  
1983 ◽  
Vol 100 (1) ◽  
pp. 180-187 ◽  
Author(s):  
Dennis M. Power

Abstract Coefficients of variation and generalized variances are compared for nine morphological characters from five mainland and four island populations of the House Finch (Carpodacus mexicanus). The purpose is to test the idea that variability is reduced in isolated populations and that there is a "population variation parameter" that determines the level of variation in most characters. Variability is greater in bill characters for Guadalupe and San Benito Islands than for mainland and other island populations. There are no consistent differences among samples in variability of wing, tail, or hind-limb characters, except for a tendency toward increased tarsus-length variability in a southern Baja California population and reduced variability in this character in San Clemente Island and Guadalupe Island populations. In bill characters, increased variability is found in the most divergent populations. The results do not support the generalization that geographic (= genetic) isolation per se causes much of a change in variability in island populations of birds, nor is there support for the idea of a pervasive quality of the gene pool that determines the level of variability in most characters.


The Auk ◽  
2001 ◽  
Vol 118 (2) ◽  
pp. 327-333 ◽  
Author(s):  
Barry K. Hartup ◽  
Jean M. Bickal ◽  
Andre A. Dhondt ◽  
David H. Ley ◽  
George V. Kollias

Abstract Conjunctivitis, an infectious disease caused by Mycoplasma gallisepticum (MG), has produced a significant decline in eastern House Finches (Carpodacus mexicanus) of North America. In this paper, we present findings from two complementary studies designed to clarify annual and seasonal trends of MG infections in House Finches from the northeastern United States. The first was a field study of House Finches common to urban and residential habitat from Mercer County, New Jersey. We documented conjunctivitis in 11% (188/1,651) of the birds examined. Conjunctivitis prevalence in House Finches ranged from 0 to 43% per month, and exhibited marked seasonal fluctuation (elevations during fall and winter months and lower disease prevalence during the breeding season). There was excellent intermethod agreement on disease prevalence when measured by either presence of physical signs (conjunctivitis) or MG infection (kappa = 0.75). During the peak of the breeding season (April through June), conjunctivitis was present in a greater proportion of males lacking a cloacal protuberance than males with a cloacal protuberance (P < 0.01), but was similar between breeding and nonbreeding females. The second study, a volunteer survey, revealed the proportion of northeastern U.S. monitoring sites with at least one diseased House Finch each month ranged from a peak of 59% (August 1995) to a minimum of 12% (July 1999). Subsequent to the epidemic peak of disease in 1995, a series of recurring cycles occurred, with elevations in those proportions noted in late fall and winter and minima during the breeding season. Mycoplasmal conjunctivitis now appears endemic among House Finches of that region and demonstrates dynamics consistent with annual variation in host density.


Sign in / Sign up

Export Citation Format

Share Document