PURPLE MARTINS IN THE DESERT...!
Unexpected residents of the Sonoran Desert.
During my childhood in Pennsylvania, many people had “Martin houses” - large bird nesting boxes built like an apartment complex, since that species communal. Martins, actually a species of swallow - the largest - were prized for farms and yards because of the prodigious quantities of various insects (including mosquitos) that the birds eat, as they are insectivorous. Although their range does not completely cover the continent, they are also summer residents (and welcome ones!) along the west coast, and in the Puget Sound area where we lived for many years before moving to the desert. Sadly, as with many species, their numbers have declined over the years. And for whatever reason, in the Pacific NW, they preferred nesting in gourd-like nest boxes that were over water - often installed on pilings in salt water, for example. One speculation for the reason is that starlings, which compete with all native cavity-nesting birds, don’t like being over water and so the Martins don’t have as many problems with them. So all my experience with their nesting locations were with Martin houses in the east or gourds over water in the west. Since many insects are near water or fields, I never thought we would have resident Purple Martins in the desert. I was happily wrong!
On one of my first hikes in the desert during the summer after moving here, I heard the distinctive call of multiple Purple Martins and looked up to see a number of them flying around over the area. At first I thought they might be birds migrating through to another location. Then it became apparent there was a large group of Martins using a huge, mature Saguaro as a staging locations. So I closer and the birds were clearly using cavities in the Saguaro to roost or nest. A little research indicated that yes, the desert has resident Purple Martins, and that their favored nesting/roosting locations are mature Saguaros with plenty of nest holes previously excavated by woodpeckers. Some more recent hikes in the desert surrounding our house yielded two more colonies, both in huge Saguaros. Tucson Audubon is actually doing a program focusing on Purple Martins in the desert, which we’re going to find out more about later this week.
Although we get other swallow species migrating through the area, they are more water-oriented and so except near the few permanent ponds and lakes in the desert, we don’t see them as residents. It’s nice to have the beautiful Purple Martins in the area.