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Cassin’s, Botteri’s, and Grasshopper sparrows – the songs of these grassland specialists are emblematic of summers on the Research Ranch where they nest within dense, native grass, feast upon hordes of grasshoppers, and give birders looking to get a good look a run for their money. While the range maps for these species show them as year-round residents, living and working on the Research Ranch has revealed a much more complicated story. 

Each May, the ranch comes alive with Botteri’s Sparrows, and their bouncy, bubbling song echoes from every corner of the ranch until things turn conspicuously silent mid-September. They are hard to get a good look at even when abundant, known to run around like mice below the grass, and there are a handful of winter records each year within suitable southeastern Arizona habitat. This leaves us wondering: do Botteri’s Sparrows migrate away from the ranch each fall, or are they just extremely hard to detect outside of the breeding season? 

Cassin’s Sparrows are equally confounding. They don’t arrive on a fixed schedule like Botteri’s, instead miraculously showing up after our first serious monsoon storm. It’s like clockwork – first comes the rain, then come the Cassin’s Sparrow. In a good year, they can be so abundant that their White-throated Sparrow-like song can drown out even the boisterous Botteri’s. In a dry year, they might not show up at all. The ability of these sparrows to seemingly materialize on the Research Ranch at exactly the right time is nothing short of astounding, and how they pull it off remains a mystery. 

Grasshopper Sparrows are the most reliable of the bunch with a truly year-round presence. You can walk the grasslands of the Research Ranch on any day of the year and hear their insect-like calls and tinkling songs but depending upon if you’re here during the breeding or wintering seasons, you may be listening to different birds. It’s suspected that our breeding birds head south for the winter, replaced by birds that breed further north. So, while Grasshopper Sparrows do appear to be a year-round resident at the species level on the Research Ranch, it may not be so at the level of individual birds. 

Unraveling these mysteries is key to the conservation of these birds and their habitats on and off the Research Ranch. Fortunately, we have the tools and partners to make it happen.  

Installed in 2022 and managed by Bird Conservancy of the Rockies as part of their Great Plains-Chihuahuan Desert Motus Network, our on-site Motus (Latin for “movement”) station is equipped to pick up signals sent from tiny, radio-emitting tags that can be affixed to small wildlife. With more than 2,000 stations scattered across 34 countries, our station is just a small part of the broader Motus network, a program of Birds Canada, aimed at advancing research on the ecology and conservation of birds, bats, and large insects. Our station was first put to work in 2024 when, with the help of the Arizona Game and Fish Department, Sonoran Joint Venture, Arizona State University, and Tucson Bird Alliance, our first Research Ranch sparrows were equipped with Motus tags. This marked the start of our Research Ranch Grassland Sparrow Motus Project, and as of this summer, more than 25 birds have been tagged.  

The value of these tagged birds goes beyond what they’ll help us learn about their species. They’re also helping us better understand Motus as a tool, leaving us more able to decide when Motus is or isn’t the right fit for a study. Through our work, we’ve found that topography (like the rolling hills of the Research Ranch) and individual species behavior (like that of a ground-dwelling Botteri’s vs. a high-flying migrant), both play a role in the efficacy of Motus technology. Also, these tagged birds are providing countless research opportunities for the next generation of conservation scientists. First to engage with the project was Arizona State University’s Heaven Sanchez, one of our 2025 Appleton-Whittell Research Ranch Fellows, and most recently was a group of Prescott College ornithology students who helped us tag this year’s batch of birds. 

With three years of field work behind us, this is just the beginning for the Research Ranch Grassland Sparrow Motus Project. Our work so far has revealed new questions, new tracking technologies continue to offer new methods of research, and there is no shortage of students looking to launch a career in conservation science to help find answers. Stay tuned for forthcoming scientific publications and next steps in the project, and until then, keep an eye on our tagged birds and visitors from other projects through our !