| the evolution of sexual size dimorphism in the house finch. ii. population divergence in relation to local selection. | recent colonization of ecologically distinct areas in north america by the house finch (carpodacus mexicanus) was accompanied by strong population divergence in sexual size dimorphism. here we examined whether this divergence was produced by population differences in local selection pressures acting on each sex. in a long-term study of recently established populations in alabama, michigan, and montana, we examined three selection episodes for each sex: selection for pairing success, overwinter s ... | 2000 | 11209788 |
| characterization of the mycoplasmal conjunctivitis epizootic in a house finch population in the southeastern usa. | an epidemiological study of the prevalence of mycoplasmal conjunctivitis in the house finch (carpodacus mexicanus) was conducted in auburn (alabama, usa) between march 1998 and february 1999. clinical disease was observed in 4% of the 1,214 finches trapped and examined. this rate is comparable to the average annual prevalence observed in this population since 1996, although the prevalence of clinical disease observed in the peak months of september through november was lower than in previous yea ... | 2001 | 11272508 |
| characterization of mycoplasma gallisepticum infection in captive house finches (carpodacus mexicanus) in 1998. | since 1995, the epidemic of mycoplasmal conjunctivitis in eastern house finches has affected the auburn, al, house finch population. to better characterize the current status of this host-parasite interaction, we established a captive flock of 38 seronegative, healthy finches in fall 1998. after a minimum quarantine period of 4 wk, two mycoplasma gallisepticum (mg)-infected house finches were introduced into this flock. over a 12-wk period, the flock was captured every 2 wk and each bird was obs ... | 2001 | 11332501 |
| sex-biased hatching order and adaptive population divergence in a passerine bird. | most species of birds can lay only one egg per day until a clutch is complete, and the order in which eggs are laid often has strong and sex-specific effects on offspring growth and survival. in two recently established populations of the house finch (carpodacus mexicanus) in montana and alabama, breeding females simultaneously adjusted the sex and growth of offspring in relation to their position in the laying order, thereby reducing the mortality of sons and daughters by 10 to 20% in both envi ... | 2002 | 11786641 |
| the evolution of sexual size dimorphism in the house finch. iv. population divergence in ontogeny. | differences among taxa in sexual size dimorphism of adults can be produced by changes in distinct developmental processes and thus may reflect different evolutionary histories. here we examine whether divergence in sexual dimorphism of adults between recently established montana and alabama populations of the house finch (carpodacus mexicanus) can be attributed to population differences in growth of males and females. in both populations, males and females were similar at hatching, but as a resu ... | 2001 | 11831668 |
| susceptibility of a naïve population of house finches to mycoplasma gallisepticum. | since 1994 an epidemic of mycoplasmal conjunctivitis has spread throughout the eastern house finch (carpodacus mexicanus) population leading to a significant decline in this population. the infection has not yet been reported from house finch populations west of the great plains. we hypothesized that the western population, like the eastern population, is susceptible to infection, and we tested this hypothesis by experimentally infecting house finches from missoula, montana (usa) with the house ... | 2002 | 12038126 |
| the effect of mycoplasmosis on carotenoid plumage coloration in male house finches. | parasites are widely assumed to cause reduced expression of ornamental plumage coloration, but few experimental studies have tested this hypothesis. we captured young male house finches carpodacus mexicanus in alabama before fall molt and randomly divided them into two groups. one group was infected with the bacterial pathogen mycoplasma gallicepticum (mg) and the other group was maintained free of mg infection. all birds were maintained through molt on a diet of seeds with tangerine juice added ... | 2004 | 15143143 |
| prevalence of blood parasites in eastern versus western house finches: are eastern birds resistant to infection? | the rapid spread of the bacterial disease, mycoplasma gallisepticum (mg), throughout the introduced range of house finches (carpodacus mexicanus) in eastern north america, compared to its slower spread through the native western range, has puzzled researchers and highlights the need to understand the relative differences in health state of finches from both populations. we conducted a light-microscope survey of hemoparasites in populations of finches from arizona (within the western range) and f ... | 2013 | 23807632 |
| house finch populations differ in early inflammatory signaling and pathogen tolerance at the peak of mycoplasma gallisepticum infection. | host individuals and populations often vary in their responses to infection, with direct consequences for pathogen spread and evolution. while considerable work has focused on the mechanisms underlying differences in resistance-the ability to kill pathogens-we know little about the mechanisms underlying tolerance-the ability to minimize fitness losses per unit pathogen. here, we examine patterns and mechanisms of tolerance between two populations of house finches (haemorhous [formerly carpodacus ... | 2013 | 23594550 |