Biology subjects

Kittelberger, K. D.

Publications and source records attributed to Kittelberger, K. D..

3 recordsLinked to original sources

bioRxiv2026

Intraspecific trait variation shapes macro-scale patterns ofniche breadth and range size

Morphological variation within species may promote adaptation across ecological and geographic space, perhaps reflecting evolutionary plasticity and adaptability. Based on this concept, species with greater intraspecific variation in morphological traits may be expected to occupy broader ecological niches and larger geographic ranges. However, even in the age of global trait datasets, intraspecific morphological variation remains poorly quantified at broad taxonomic and geographic scales, limiting our understanding of how trait flexibility shapes ecological and biogeographic patterns. Focusing on 161 species of bulbuls, a widespread avian family containing some of the most abundant bird species in the world, along with some of the rarest and most restricted in range, we conducted global-scale sampling of morphological traits. These included beak shape, tarsus length and wing length, associated with dietary niche, foraging strategy and dispersal, respectively. Using phylogenetic models, we tested whether ecological niche breadth and geographical range size are predicted by intraspecific morphological variation quantified from 8,251 museum specimens and 5,627 live captures. Our results demonstrate that morphological trait variation predicts both ecological niche breadth and geographic range size. Furthermore, widespread species exhibit greater morphological variation than restricted-range species even when comparisons are constrained to equivalent geographic extents, consistent with the hypothesis that intraspecific trait variation facilitates range expansion rather than simply accumulating as a consequence of occupying a larger range. These results identify intraspecific morphological variation as a potentially important, yet largely overlooked, predictor of ecological traits and biogeographic distributions in birds.

ecology↗

bioRxiv2026

Wildfires during fall migration affect bird movements, avian health, and migration timing in western North America: Insights from bird banding and feather isotopes

With the peak of the wildfire season in North America typically occurring during the core part of fall bird migration, migratory birds are likely to be increasingly impacted by worsening wildfire seasons during their southerly movements. In this study, we combined two approaches to assess the impact of wildfires on migratory birds captured in southern Utah. First, we used five years of bird banding data to assess how bird movement and physical condition patterns are impacted. Second, we used stable hydrogen isotopes from collected feathers to identify the geographic origin of the individuals of several migratory species in order to better understand how fires may be influencing migration. We found that when there were more wildfires active in western North America, there were more captures of birds at our banding station, likely a result of birds shifting their movements to avoid areas of fire and smoke, and that birds had worse body condition and overall health as shown from lower body masses. We also found that during periods when wildfires are especially active and severe, wildfire activity has the most significant influence on bird movements and health compared to other prominent environmental variables. Our isotopic results provide evidence that two species migration patterns varied across the year in both migration timing and likely summer origin, and show how fire activity could have affected the migratory window for some species. More broadly, our isotope data improves our knowledge of the likely geographic origins of migratory birds in this particular flyway, adds to the literature on feather-based hydrogen isotope analyses, provides some of the first published isotope data for two species, and streamlines a workflow that can aid future researchers working with feather hydrogen isotope data.

ecology↗

bioRxiv2023

Solar Bird Banding: Notes on Changes in Avian Behavior While Mist-netting During an Eclipse

Solar eclipses present rare celestial events that can elicit unique behavioral responses in animals, yet comprehensive studies on these phenomena, particularly concerning bird behavior, remain limited. This study, conducted at the Red Butte Canyon Research Natural Area in Utah during the annular solar eclipse on October 14, 2023, aimed to document and analyze avian activity using bird banding data. Leveraging 11 years of banding records, we observed a surprising positive peak in bird captures, indicating increased activity during the eclipse, challenging conventional expectations of decreased activity during peak totality. The unexpected, record-breaking captures on the eclipse day at this location, which also surpassed the average trend in captures over time for 18 other banding days in mid-October, highlights the complexity of bird behavior during celestial events. This study marks the first known published effort to conduct bird banding during a solar eclipse. Quantitative analyses, including species composition and capture trends, contribute to a nuanced understanding of avian responses to the eclipse. This study underscores the importance of empirical research in unraveling the intricacies of how birds navigate and adapt to unique environmental conditions created by solar eclipses.

zoology↗