|Posted by Brian on July 19, 2019 at 1:05 PM|
It's been a while since I've updated you all on my research progress, so I thought I would do so now.
First, my first paper, from my undergraduate research at Cal Poly Pomona, titled "Trends in bird species richness in the midst of drought", was recently published in the June 2019 edition of Western Birds! This one is based on my work as an undergraduate, and investigates the effects of drought on coastal sage scrub bird communities using long-term data. The big takeaway from this paper is that resident, non-migratory birds seem to struggle during drought, and either become more cryptic and/or experience increased mortality. However, this effect disappears when a supplemental water source was provided. Further, migratory species richness remained the same with and without drought without supplementental water, while the number of migratory bird species detected increased during drought when a supplemental water source was provided. The main message coming from this paper is that supplemental water sources might be an important consideration for maintaining the diversity of bird species in some regions as climate change and drought become intensified over time.
The first paper regarding the hybrid zone between Allen's and Rufous Hummingbird, titled "Behavioral and morphological evidence of an Allen’s × Rufous Hummingbird (Selasphorus sasin × S. rufus) hybrid zone in southern Oregon and northern California" was recently accepted by The Auk: Ornithological Advances. This paper should be out in either the July or October issue. In this paper, we map out the hybrid zone, which spans (phenotypically) from northern California (Humboldt County) to central Oregon (Lane County) along the coast, and inland from Humboldt County through Horse Creek in Siskiyou County, CA (although inland transect data was not completed at the time this paper was submitted). In this paper, we identify several new characters that differentiate Allen's and Rufous Hummingbird, and find, via geographic cline analysis, that sexual selection seems to be a dominant force in maintaining species boudnaries between Allen's and Rufous.
I'm also working on three additional papers, and hope to get at least two of them submitted this year. These include behavioral sequence analysis of Allen's and Rufous Hummingbird and their hybrids, where we identify novel behavioral characters across the hybrid zone and address how evolutionary novelty might evolve, a phylogeographic study of Allen's Hummingbird using whole-genome data and ecological niche modeling, and a comparison of the genomes of Allen's and Rufous Hummingbird, especially on the Z chromosome (the sex chromosome in birds), where most species differences are found.
I'll have an update regarding the 2019 field season, which was very brief (only two weeks this time out!) but successful, soon!. This field season closed out sampling for my dissertation, which I am completing in December 2019.