DENDROCHRONOLOGY OF UNITED STATES IMMIGRATION
Information Design Journal
2019, volume 25, pages 6–20
Immigrants are central to the identity of the United States, the population of which has grown in number and diversity as a function of new arrivals from around the globe. This article describes a visualization project that uses the visual metaphor of tree rings to explore the contribution of immigrants to the country’s population. Immigrants and native-born persons are represented and differentiated as cells in trees, with layered annual rings capturing patterns of population growth. These rings register, in their shape and color, certain environmental conditions. In order to mimic the natural process by which growth rings are formed, we devised a computational system that simulates the growth of trees as if cells were data-units. Dendrochronology involves dating certain events by analyzing patterns of growth in trees. Analogously, in our visualizations the rings can be counted and dated, showing the chronological evolution of the population. The dendrochronology theme is a poetic take on the data, yet it is also a functional and conceptual space that is used to construct language and rationales on that data. The tree-growth process not only inspires the appearance of the visualizations but also informs the rules of the computational system that creates them.
THE ANIMAL HUMMINGBIRD
Taboo, Transgression, and Transcendence in Art & Science Proceedings
2019, volume 2, pages 77–85
Since antiquity, from east to west, birds are represented in various artistic interpretations, such as paintings, music, poems, and sculptures. The mysticism and the romanticism associated with these animals come from, among other characteristics, their colors, songs and behaviors. Hummingbirds are classic examples of this narrative, portrayed, most of the time, as small, colorful, affable, and delicate living beings. In the imaginary, these birds visit flowers with their almost supernatural flight, sharing in a friendly way the resources of the forest. However, what is the reality in a wild world where the human archetype loses its value? In this narrative, I deconstruct the humanized representation of hummingbirds, evidencing two scientific aspects that contradict the romanticism associated with this group. The first is based on disassociating the fragile and friendly image of this small bird, understanding its exhausting routine and the continuing need to maintain high metabolic rates, often with limited dietary resources. When it finds a flower full of nectar, the instinct will guide it to the most intense combats against any threat, revealing their intrinsic strength and aggression. The second aspect is perhaps one of the most expressive when we talk about birds: colors. In a diversely colored group, where even the black of the crows makes them chimeric figures, unraveling their true chromatic signs can reveal other perspectives. When looking at the paintings of Ernst Haeckel, portraying multicolored encounters between hummingbirds and orchids, it becomes unimaginable to think about what other tones can hide in the real rainforest. In fact, for the human vision, very little will change between the painting and the forest. However, evolution allows the hummingbird to see a spectrum inaccessible to us, the ultraviolet. Thus, with this advantage, these birds can see a world invisible to humans, which gives us the limitation of seeing the true colors that matter to hummingbirds. Evolution is inevitable, and we, as biological beings, are subject to it. Rationalization, which differentiates us as a species, gives us the freedom to mystify and romanticize what is wild, and this can be an evolutionary advantage. In the same way, with that same rationality, it is possible to rip the humanized filters put on wilderness.
ATLANTIC BIRD TRAITS: A DATA SET OF BIRD MORPHOLOGICAL TRAITS FROM THE ATLANTIC FORESTS OF SOUTH AMERICA
2019, volume 100, E02647
Scientists have long been trying to understand why the Neotropical region holds the highest diversity of birds on Earth. Recently, there has been increased interest in morphological variation between and within species, and in how climate, topography, and anthropogenic pressures may explain and affect phenotypic variation. Because morphological data are not always available for many species at the local or regional scale, we are limited in our understanding of intra- and interspecies spatial morphological variation. Here, we present the ATLANTIC BIRD TRAITS, a data set that includes measurements of up to 44 morphological traits in 67,197 bird records from 2,790 populations distributed throughout the Atlantic forests of South America. This data set comprises information, compiled over two centuries (1820–2018), for 711 bird species, which represent 80% of all known bird diversity in the Atlantic Forest. Among the most commonly reported traits are sex (n = 65,717), age (n = 63,852), body mass (n = 58,768), flight molt presence (n = 44,941), molt presence (n = 44,847), body molt presence (n = 44,606), tail length (n = 43,005), reproductive stage (n = 42,588), bill length (n = 37,409), body length (n = 28,394), right wing length (n = 21,950), tarsus length (n = 20,342), and wing length (n = 18,071). The most frequently recorded species are Chiroxiphia caudata (n = 1,837), Turdus albicollis (n = 1,658), Trichothraupis melanops (n = 1,468), Turdus leucomelas (n = 1,436), and Basileuterus culicivorus (n = 1,384). The species recorded in the greatest number of sampling localities are Basileuterus culicivorus (n = 243), Trichothraupis melanops (n = 242), Chiroxiphia caudata (n = 210), Platyrinchus mystaceus (n = 208), and Turdus rufiventris (n = 191). ATLANTIC BIRD TRAITS (ABT) is the most comprehensive data set on measurements of bird morphological traits found in a biodiversity hotspot; it provides data for basic and applied research at multiple scales, from individual to community, and from the local to the macroecological perspectives. No copyright or proprietary restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications or teaching and educational activities.
MOLECULAR SEX DETERMINATION IN NEOTROPICAL MONOCHROMATIC HUMMINGBIRDS
2018, volume 29, pages 225–228
Many species of hummingbirds are sexually monochromatic. This is surprising because in all hummingbird species parental care is carried out by females, while males are promiscuous, and this mating system is usually associated with some form of sexual dimorphism. To study sexual selection in monochromatic species, the identification of sex is a prerequisite. Using blood and feathers from live individuals we apply a simple method to identify sex. We amplified fragments of the CHD-1 gene through PCR, using P2 and P8 primers with fluorescence, followed by genotyping in an automatic sequencer. We sexed 110 individuals of five species: Versicolored Emerald (Amazilia versicolor), White-throated Hummingbird (Leucochloris albicollis), White-vented Violetear (Colibri serrirostris), Black Jacobin (Florisuga fusca), and Swallow-tailed Hummingbird (Eupetomena macroura). We found gene fragments of two sizes: 374 bp in both sexes (Z chromosome) and either 379 or 383 bp in females (W chromosome). Using this method for monochromatic species permits sexing in species with similar fragment sizes between sexes (i.e., hummingbirds). Sexing monochromatic birds will be very useful for field studies that require continuous monitoring of individuals in the wild.
THE RUFOUS HORNERO (FURNARIUS RUFUS) NEST AS AN INCUBATION CHAMBER
Journal of Thermal Biology
2014, volume 47, pages 7–12
Foraging and incubation are mutually exclusive activities for parent birds. A trade-off is generated when a combination of food availability and temperature regulation force birds to choose one and neglect the other, at least temporarily. The Rufous Hornero builds large, oven-like, mud nests, the evolutionary cause of which remains unknown. We tested that temperature variation inside the nest is that which is expected if one function of the nest were for temperate regulation. If so, this would suggest that the nest works as an incubation chamber (but which now may serve more than one function). We divided nests into two natural treatments: nests that received more continuous direct sunshine (sun), and those that received less direct sunshine, due to shade from trees or buildings (shade). Thermometer data loggers were placed in the nest cavity and outside, in the shade of the nest, and temperature was measured every 10 min. We predicted that temperatures would consistently be higher and less variable in nests than outside nests. Also, at higher ambient temperatures the nest would function better as an incubation chamber as a consequence of having evolved in a hotter climate. Thus, in Curitiba, where temperatures are lower than where the species (and nest) evolved, nests in greater sunshine should have thermal characteristics that support the incubation chamber hypothesis. Predictions were supported: with Repeated Measures ANOVA and t-tests, we found that temperatures were more constant and higher in nests, especially when in the sun, and as the season progressed (hotter ambient temperatures). We conclude that the large mud nest of the Rufous Hornero works as an incubation chamber that likely evolved to help resolve the incubation-foraging trade-off in the very seasonal and hot regions where the bird evolved. Thus, as an incubation chamber, the nest allows the bird to forage rather than incubate thereby resolving the foraging-incubation trade-off and potentially favoring survival of the adults and their foraging for, rather than incubating, their young. Counter intuitively, in the study area, where the Rufous Hornero is a recent arrival following deforestation, and where the climate is very different from where it evolved, there seems to be no clear thermal benefits for the birds from their energetically expensive mud nest.
AN IMPROVED METHOD FOR CAPTURING CAVITY-NESTING BIRDS TESTED WITH THE RUFOUS HORNERO (FURNARIUS RUFUS)
2014, volume 25, pages 389–396
Several methods are available to capture cavity-nesting birds but not all are equally easy to use. Here we propose an improved method, in which we use a modified fish basket placed over the opening to the nest using an extendible pole. When a bird enters the basket trap, the entrance to the trap is closed by pulling on a string that shuts the door securely with velcro. We used this method to capture the Rufous Hornero (Furnarius rufus), a Neotropical ovenbird that builds enclosed mud nests. Rufous Horneros, as other birds of open habitats, are often very difficult to capture with mist nets, apparently because in such habitats mist nets are relatively easy to recognize and avoided due to the windy and light conditions. In 2010, we captured 29 birds, none of which abandoned their nests. While similar to some traps, this trap is light-weight and easier to carry and mount in the field. Additionally, the trap door assures that the bird cannot escape once in the trap and it is impossible for the trap to entangle in nearby plants. It can be adapted for capturing a variety of species, such as Neotropical ovenbirds, that build enclosed nests, and cavity-nesting birds, such as woodpeckers, woodcreepers, and parrots.