Data from: Do male fish prefer them big and colourful? Non-random male courtship effort in a viviparous fish with negligible paternal investment

In the majority of sexual species, there are asymmetries in reproductive effort, with males typically investing more in securing matings and females investing more in producing offspring. This causes males to mate less discriminately than females. Yet males may also become choosy if the following conditions are met: (a) that females vary in their reproductive value, (b) that males can perceive this variation, and (c) that mating with one female reduces the possibility of mating with another. These conditions may be met in the livebearing Goodeidae, a clade of Mexican fish whose females are often brightly coloured and whose males display costly ornaments and courtship as the only means to obtain matings. Males of the black-finned goodeid (Girardinichthys viviparus) have relatively simple, yet costly courtship behaviour, with mating probability depending on the duration of one-to-one courtship episodes, thus by courting one female they must ignore others. We evaluated whether the decision to court a female depends on her phenotype. Three variables of female phenotype were positively linked to the duration of male visits and to the frequency of displays performed by males: belly area, hue (“orangeness”) and size. Since fecundity and offspring survival were also a positive function of female size, we conclude that male G. viviparus evaluate the potential female reproductive value and allocate their courtship effort accordingly. Since male courtship effort is also influenced by female colouration, we suggest that our findings may help explaining the recurrent evolution of sexually dimorphic female colouration in this clade

Mendez Janovitz and Macias Garcia data

This is an Excel file containing data in three spreadsheet (Male choice trial, Brood size, Offspring survival). The top row from all the spreadsheets contains the label of each column with the variable name and the units. The first spreadsheet named “Male choice trial” contains the phenotypic data from 40 females (standard body length, belly area, dorsal fin area, hue, saturation and brightness) and the response of 10 males (Visit duration and Display frequency). The second spreadsheet named “Brood size” have the phenotypic data from 27 females (standard body length, belly area, dorsal fin area, hue, saturation and brightness) and the number of offspring they gave birth. The third spreadsheet named “Offspring survival” contains the phenotypic data from 11 females (standard body length, belly area, dorsal fin area, hue, saturation and brightness) as well as the number of offspring born, the number of offspring alive at sex weeks of age and the survival measured as the proportion of offspring with six weeks of age from those who were born

This town ain't big enough for both of us…or is it? Spatial co-occurrence between exotic and native species in an urban reserve.

Exotic species pose a threat to most ecosystems because of their potential to establish negative interactions with native biota. However, exotic species can also offer resources to native species, especially within highly modified environments such as urban ecosystems. We studied 17 exotic-native pairs of species with the potential to compete with one another, or in which one of the species could offer resources to the other, in an urban ecological reserve located within Mexico City. We used two-species occupancy models to analyze the potential association between the presence of the exotic species and the spatial distribution of the native species, as well as to assess if these species tend to avoid each other (negative spatial interaction) or to co-occur more often than expected under the hypothesis of independent occurrences (positive spatial interaction). Our results revealed few cases in which the exotic species influenced occupancy of the native species, and these spatial interactions were mainly positive, indicated by the fact that the occupancy of the native species was usually higher when the exotic species was also present. Seven of the eight observed non-independent patterns of co-occurrence were evident during the dry months of the year, when resources become scarce for most species. Our results also demonstrate that the observed patterns of species co-occurrence depend on the distance to the nearest urban structure and the amount of herb, shrub, and tree cover, indicating that these habitat features influence whether native species avoid or co-occur with exotic species. Our study represents an important contribution to the understanding of temporal dynamics in the co-occurrence between exotic and native species within urban ecological reserves