Under normal circumstances, in front of dense vegetation, the net is nearly invisible to a flying bird, but with a sky-blue background the net is easily seen. By having this tall net, we can place it just outside of an active martin nest cavity, giving us a higher probability of capture. The net is held up by two 30-foot poles (about the height of a two story house!) on either side that keep the net taut. We start by setting up a finely meshed, black mist net used to safely capture small birds. The project’s primary tasks in the summer of 2022 are to capture Desert Purple Martins, collect samples, and attach geolocators. Tucson Audubon’s Desert Purple Martin Project seeks to answer these questions. For example, where do they go during the winter? What is their migration pathway? Should they be classified as a subspecies or a species? When it comes to Desert Martins, these basic facts are unknown. Making a conservation plan for a species often starts with gaining an understanding of its complete life history. Purple Martin in saguaro nest cavity, Richard Fray As our climate changes and saguaros are pressured with increasing drought, freezes, and fire, Desert Martins will be affected. One of the most important facts we know about this understudied subspecies is that without saguaros, their nesting habitat would become extremely limited, and their populations would drastically decline. Our records show that they nest almost exclusively in cavities that are more than 15 feet off the ground and therefore have a strong reliance on mature saguaros. Active nests can be found in and around Tucson in areas such as Tucson Mountain Park, the Mason Center, and Saguaro National Park. These martins are assumed to have high site fidelity, meaning they will use the same nest cavity year after year. Many species use these cavities after the woodpeckers depart, most notably, our study subspecies, the Desert Purple Martin. These cavities, originally created by woodpeckers, are found only on saguaros that are at least 13 feet tall. A few soup-can-sized holes have been carefully carved into its sides. Prickly pear, cholla, and creosote are at our level, but above us towers a saguaro: a giant, columnar cactus at least 40 feet tall with six massive spiny arms. We are surrounded by a vast tract of Sonoran Desert as far as the eye can see. Dawn is breaking, signaling the best time for us to begin our research efforts. Illuminated by headlights, we do our best to quickly and quietly set up our first net. The Connecticut Audubon Society Coastal Center at Milford Point, Hammonasset State Park’s East Beach Nature Center in Madison, and Sherwood Island State Park in Westport all enjoy active martin colonies.Įach July we help the Connecticut Department of Energy and Environmental Protection band the martins at the Coastal Center, and last summer we produced a video that shows the process.Desert Purple Martin on saguaro, Scott Olmstead There are several around the state that are easily accessible. Where to find it: The best places to look for these birds is, of course, around their nest colonies.
When to look: Purple Martins are returning in good numbers to their breeding colonies now and will soon begin their reproductive cycle. The adult female has a dark bluish back but grey-brown underparts. Noticeably larger than other swallows, Purple Martins can be distinguished not only by size, but also by a slightly slower wing beat. What it looks like: The male Purple Martin is not purple, but entirely bluish black and is the only North American swallow with a dark belly. They are very tolerant and sociable birds, and respond well to husbandry of the colony, which involves regular checking of the nest cavities for parasites, mortality, and unwanted intruders such as House Sparrows and Starlings. Purple Martins are not easy to attract, requiring certain habitat and landscape conditions, usually open areas near water, but once a colony is established, they will return every year to breed and raise their young. Connecticut Audubon Society photo by Jennifer Prat
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