Article and photo by Joel Gilb, Bosque del Apache Park Ranger. Tropical Kingbird photographed on the refuge.
Many birders keep a “life list”—a document which catalogs all the different bird species an observer has encountered during their lifetime. Similarly, Bosque del Apache maintains a checklist detailing the many birds which have been recorded throughout the refuge’s history. Through the efforts of visitors, volunteers and staff, Bosque del Apache has documented an astonishing 413 different species of birds on the official refuge checklist. For perspective, more species of birds have been found on this roughly 57,000-acre refuge than in the entire state of Kentucky!
So why does Bosque del Apache have so many different birds? A few key factors come together to make it possible, with the most important being habitat diversity. Many distinct habitat types are present on site, from the rocky slopes of the Chupadera Mountains, to the scrubby Chihuahuan Desert, to the lush floodplain of the Rio Grande, all of which host their own array of birds. The wetland habitats are particularly valuable for birds, especially in our arid climate, and refuge staff work hard to maintain this unique and fragile oasis through careful water management. Additionally, the refuge’s unique geographic placement means that it can host birds associated with the western US, the Mexican border region, and even some eastern species on occasion. Not all of the 413 birds are regulars here; many have only shown up once or twice.
The Bosque del Apache bird checklist hasn’t always been so impressive. Back in 1948, when the refuge was not quite a decade old, our checklist numbered only 191 species. Habitat quality was still quite poor, with much restoration being needed to help bring back the wetlands and cottonwood forests that once were a crucial part of the region’s ecosystem. Over time, sightings started to add up. A long-tailed jaeger, which normally can be found at sea or on nesting grounds in the arctic, was documented here in 1956. Another marine species, the brown pelican, was recorded in 1963. Two highlights were a sungrebe in 2008 and a rufous-necked wood-rail in 2013— neither of these Latin American birds had been seen in the US before! As time went on the sightings added up, all while habitat was being restored through invasive plant removal and wetland management.
I had the pleasure of finding bird #413 on our checklist— a tropical kingbird which was hanging around the Flight Deck in late May of this year. Traditionally, you would’ve needed to visit southeast Arizona or the Lower Rio Grande Valley of Texas to spot this bird in the United States. However, tropical kingbirds have been expanding their range in the southwest during recent years and have even nested a few times in New Mexico. This year a pair nested near Caballo Lake, only about 60 miles to the south of Bosque del Apache. Other species which have been observed on the refuge in recent years, such as white-tailed kite, crested caracara, and gray hawk are also known to be expanding their presence in our state. No one is quite sure what is driving these birds into new areas. Some of the most likely influences are warmer weather, changes in habitat composition, and prey availability. Keeping tabs on these new arrivals could help us to better understand the changing environmental conditions in the southwest.
So, what’s next for the Bosque del Apache bird checklist? A few of the more likely possibilities for bird #414 include Anna’s hummingbird, Vaux’s swift, or rufous-backed robin. Citizen science platforms such as eBird have made it easier than ever for birders of all skill levels to share their sightings with fellow enthusiasts, as well as with research professionals who can put this data to use in their studies. Visitors who encounter a rare bird on the refuge are encouraged to post their sightings (with supporting details) to platforms such as eBird or iNaturalist, or to contact the refuge directly through email at BosqueDelApacheNWR@fws.gov.
Those interested in the refuge checklist can pick up a copy from the Bosque Nature Store.