DOI: 10.5061/dryad.ngf1vhhzz
title: Data from: Temperature seasonality drives taxonomic and functional homogenization of tropical butterflies

description: To understand the potential impact of climate change on butterfly
 assemblages across a tropical island, we used thousands of museum records
 of diurnal Lepidoptera to model current (1970–2000) and forecast future
 (2061–2080) species distributions and combined these to test for taxonomic
 and functional homogenization. We then quantified climatic-mediated
 effects on current and forecasted taxonomic and functional composition
 and, specifically, whether temperature was a primary driver, as predicted
 by the temperature-size rule and the thermal melanism hypotheses. Finally,
 we measured wing traits important in thermoregulation (size and color) and
 determined trait-mediated changes in forecasted species distributions over
 time. Our models projected an increase in taxonomic and functional
 richness over time, and a decrease in taxonomic and functional turnover –
 a signature of biotic homogenization. Under future climate scenarios,
 models projected a decrease in wing length and an increase in wing
 brightness at higher elevations. One variable, temperature seasonality,
 was the strongest predicted driver of both the current spatial
 distribution and the projected percent change over time for not only wing
 traits, but also taxonomic and functional richness and turnover. This
 dataset contains wing trait data for 62 butterfly species of Puerto Rico,
 included in the study, measured on digitized museum specimens. Generally,
 10 individuals of each species were measured, allowing for measurements of
 inter- and intraspecific wing trait variation. Traits include: wing length
 and width, and color metrics: intensity, hue, saturation, and
 brightness. 
description: We used the Stuart J. Ramos
 Collection to measure wing traits because
 it was (and
 is) the only digitized
 collection of Puerto Rico butterflies. The
 Stuart J. Ramos Collection (SJRC; 3410 records; SJRC) was donated by the
 late S. J. Ramos to the McGuire Center for Lepidoptera and Biodiversity,
 Florida Museum of Natural History (MGCL) at the University of Florida, in
 Gainesville, Florida, USA. We used image analysis software
 to measure dorsal forewing
 length as the length between the forewing tip and the site of wing
 attachment on the thorax, and forewing width as the widest section of the
 forewing.
 We also measured hue,
 saturation, and brightness (HSB) on a 1 cm<sup>2</sup> region
 of the wing near the thorax, avoiding major veins and visible scale
 damage. Furthermore,
 we focused on females because
 1) their parental investment and, thus, energetic requirements are often
 greater than those of males, and 2) male coloration can be biased by
 sexual selection. Of the 62
 species, only four (all Nymphalidae) had visually noticeable size
 differences, with females being larger than males. In a few instances in
 which images of females were not available, or the sex could not be
 determined from visual characteristics such as markings or size
 differences, we selected individuals randomly within species for trait
 measurements (Female:Unknown = 48:14). We aimed for a maximum of ten
 individuals per species when possible (median = 10; mean = 8.1 individuals
 per species).
description: # Data from: Temperature seasonality drives taxonomic and functional
 homogenization of tropical butterflies ## Description of the Data and file
 structure We used the Stuart J. Ramos Collection to measure wing traits
 because it was (and is) the only digitized collection of Puerto Rico
 butterflies. The Stuart J. Ramos Collection (SJRC; 3410 records; SJRC) was
 donated by the late S. J. Ramos to the McGuire Center for Lepidoptera and
 Biodiversity, Florida Museum of Natural History (MGCL) at the University
 of Florida, in Gainesville, Florida, USA. We used image analysis software
 to measure dorsal forewing length as the length between the forewing tip
 and the site of wing attachment on the thorax, and forewing width as the
 widest section of the forewing. We also measured hue, saturation, and
 brightness (HSB) on a 1 cm<sup>2</sup> region of the wing near
 the thorax, avoiding major veins and visible scale damage. Furthermore, we
 focused on females because 1) their parental investment and, thus,
 energetic requirements are often greater than those of males, and 2) male
 coloration can be biased by sexual selection. Of the 62 species, only four
 species (all Nymphalidae) had visually noticeable size differences, with
 females being larger than males. In a few instances in which images of
 females were not available, or the sex could not be determined from visual
 characteristics such as markings or size differences, we selected
 individuals randomly within species for trait measurements (Female:Unknown
 = 48:14). We aimed for a maximum of ten individuals per species when
 possible (median = 10; mean = 8.1 individuals per species). The
 speciesTraits.csv file contains the family and species name for 62 species
 in addition to wing traits: wing length (cm), wing width(cm), intensity,
 hue, saturation, and brightness. Additional columns describe the number of
 images for which traits were measured (num_images) and the number of those
 images whose specimen was identified as female (num_images_females). A
 blank cell indicates that it was not possible to identify the sex of the
 specimen based on visual characteristics alone. The column
 'occurences_n' describes the number of occurrences for each
 species. The column 'percPoorAUC' describes the percentage of
 models per species exhibiting poor performance (using a mean AUC threshold
 greater than 0.6; Cheng & Bonebrake 2017). Finally, species range size
 in square kilometers is described in column 'rangeSize_km2'.
 Interestingly, the percentage of models exhibiting poor performance per
 species was positively correlated with species range size (Rsq = 0.58). ##
 Sharing/access Information The data are derived from digitized specimen
 images from the Stuart J. Ramos collection which are available in the
 Symbiota Collections of Arthropods Network (Gries et al., 2014; SCAN,
 2019). Gries, C., Gilbert, M. E. E., & Franz, N. M. (2014). Symbiota:
 A virtual platform for creating voucher-based biodiversity information
 communities. Biodiversity Data Journal, 2, e1114. SCAN. 2019. Biodiversity
 occurrence data accessed through SCAN Data Portal,
 http//:scan-bugs.org/portal/index.php, accessed on 2018-05-01.