Comparison of categorical color perception in two estrildid finches

This is the final version. Available from the University of Chicago Press via the DOI in this recordData and Code Availability: Data and code supporting the results are archived in the Dryad Data Repository (https://doi.org/10.5061/dryad.stqjq2c1z; Caves et al. 2020).Sensory systems are predicted to be adapted to the perception of important stimuli, such as signals used in communication. Prior work has shown that female zebra finches perceive the carotenoid-based orange-red coloration of male beaks—a mate choice signal—categorically. Specifically, females exhibited an increased ability to discriminate between colors from opposite sides of a perceptual category boundary than equally different colors from the same side of the boundary. The Bengalese finch, an estrildid finch related to the zebra finch, is black, brown, and white, lacking carotenoid coloration. To explore the relationship between categorical color perception and signal use, we tested Bengalese finches using the same orange-red continuum as in zebra finches, and we also tested how both species discriminated among colors differing systematically in hue and brightness. Unlike in zebra finches, we found no evidence of categorical perception of an orange-red continuum in Bengalese finches. Instead, we found that the combination of chromatic distance (hue difference) and Michelson contrast (difference in brightness) strongly correlated with color discrimination ability on all tested color pairs in Bengalese finches. The pattern was different in zebra finches: this strong correlation held when discriminating between colors from different categories but not when discriminating between colors from within the same category. These experiments suggest that categorical perception is not a universal feature of avian—or even estrildid finch—vision. Our findings also provide further insights into the mechanism underlying categorical perception and are consistent with the hypothesis that categorical perception is adapted for signal perception.Duke University Office of the Provos

Variation in carotenoid-containing retinal oil droplets correlates with variation in perception of carotenoid coloration

This is the final version. Available on open access from Springer via the DOI in this recordData availability: Data have been provided as supplementary material and have been archived on the Duke University Data Repository: https://doi.org/10.7924/r4jw8dj9hCode availability: Codes have been provided as supplementary material and have been archived on the Duke University Data Repository: https://doi.org/10.7924/r4jw8dj9hIn the context of mate choice, males may vary continuously in their expression of assessment signals, typically reflecting information about variation in mate quality. Similarly, females may exhibit variation in mate preference, which could be due to differences in how individual females perceive signals. The extent to which perception varies across individuals, however, and whether differences in sensory physiology underlie perceptual differences is poorly understood. Carotenoid pigments create the orange-red coloration of many assessment signals, and they also play a role in color discrimination in many vertebrates via their presence in retinal oil droplets. Here, we link variation in oil droplet carotenoid concentration with the ability of female zebra finches (Taeniopygia guttata) to discriminate an orange-red color continuum that parallels variation in male beak color, a mate assessment signal. We have shown previously that zebra finch females perceive this color range categorically, meaning they label color stimuli from this continuum as belonging to two categories and exhibit better discrimination between colors from different categories as compared with equally different colors from within a category. We quantified behavioral color discrimination and R-type (red) cone oil droplet spectral absorption, a proxy for carotenoid concentration. Oil droplet absorption was strongly predictive of variation in behavioral color discrimination ability. In particular, higher carotenoid concentration in oil droplets correlated with increased discrimination of colors from different sides of the previously identified category boundary. These data show that differences in the sensory periphery can correlate with individual variation in perception of a signal-relevant color range.Duke University Office of the ProvostHuman Frontier Science Progra

Did Dad Lick the Kids Today? Transmission of Microbes Through Parental Care in a Teleost Fish (Archocentrus nigrofaciatus)

Males and females may make distinctly different contributions to parental care. In cichlid fishes, females typically care for embryos while males guard territories. Parent-offspring contact may enhance transmission of beneficial microbes. Microbial sharing between group members is a potential mechanism for the evolution of social behavior (Lombardo 2007). Parental care is unusual among teleost (bony) fishes, but is ubiquitous among the cichlid fishes, and convict cichlids (Archocentrus nigrofaciatus) exhibit biparental care. We (1) quantified the parental behavior of males and females to determine whether they differed in amount or type of physical contact with their offspring; (2) collected samples of parental slime coats, embryos, and fry to compare the microbes associated with each, comparing samples from subsets of broods receiving parental care to others where parental contact was prevented. Females touched embryos significantly more often than males, but physical contact with fry is much less common and initiated by fry rather than parents. To date, molecular data support our prediction that fry receiving parental care bear microbes more similar to female vs. male parents, and to parents vs. siblings that did not receive care. Assuming this trend continues in subsequent samples, we conclude that parents are an important source of microbial inocula and that female contact during immobile developmental stages is especially important for microbial transmission

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Senior Thesis Proposal

Senior Thesis Proposa

Spea multiplicata Mating Calls as Indicators of Male Condition

The purpose of this experiment was to explore how female preferences affect the condition of males in allopatric and sympatric ponds. This investigation was carried out by attempting to determine what information mating call characteristics, especially call rate, might provide females in allopatric and sympatric populations.Bachelor of Art

Did Dad Lick the Kids Today? Transmission of Microbes Through Parental Care in a Teleost Fish (Cichlosoma nigrofasciatum).

Social behavior evolves by natural selection only if benefits outweigh costs. A little-studied benefit of group living is transmission of beneficial microbes. Unlike most fishes, convict cichlids have biparental care and contact with offspring that might promote microbial transmission. If parents exhibit division of labor, one may be more likely to transmit microbes. We (1) quantified parental behaviors of males and females to determine whether they differed in amount or type of contact with offspring; (2) collected samples of parental slime coats, embryos and fry to compare the microbes associated with each, comparing samples from subsets of broods receiving parental care to others where parental contact was prevented. Females touched offspring more often than males. Fry receiving parental care bear microbes similar to female vs. male parents, and to parents vs. siblings that did not receive care; thus, parental care is an important source of microbial transmission

Senior Thesis Proposal

Senior Thesis Proposa

Data and Script from: Reducing childhood mortality extends mothers’ lives

Please cite as: Matthew Zipple. (2024) Data and Script from: Reducing childhood mortality extends mothers’ lives. [dataset] Cornell University eCommons Repository. https://doi.org/10.7298/1r0d-tc78During the 20th century, childhood mortality was dramatically reduced globally, falling by more than 90% in the United States and much of Europe. Total fertility also fell, with the combined result that many parents who otherwise would have experienced the loss of a child were spared the trauma and negative health consequences that accompany such a loss. Here I use mathematical modeling to argue that the reduction in the frequency of child death that occurred in the 20th century indirectly led to a substantial reduction in female mortality, resulting in an extension of female lifespan. I estimate that the reduction in maternal bereavement in the US during the 20th century indirectly increased mean female lifespan after age 15 by approximately 1 year. I discuss implications for our understanding of the persistence of the sex gap in longevity and approaches to improving maternal health outcomes in countries that still face high levels of childhood mortality.Cornell University Klarman Postdoctoral Fellowship NSF Postdoctoral Research Fellowship in Biology (grant # 2109636