By Alex Harper
May is arguably the most exciting month for birders in Southern Nevada. The first two weeks of the month in particular can be exceptionally dynamic in terms of bird activity and species diversity.
Leading up to May, there is a gradual progression of migratory activity. It started with waterfowl moving out of the area and shorebirds, swallows and blackbirds moving in. By the last two weeks of April and into May, the low-elevation trees have begun to leaf out, some flowering plants have produced blooms, and insect activity quickly followed. With the progressively longer and warmer days, more and more birds pour in from various areas from the south. Dozens of species of songbirds that have been absent from the area since they passed through Nevada the previous fall move show up at suitable stopover habitat. Stopover habitat may be yards, parks, golf courses, or natural areas; these birds are often looking to refuel, rest and find water. They must do these while avoiding native predators like hawks, nonnative predators like cats, and avoid obstacles such as windows, transmission lines, and buildings.
Songbirds typically migrate at night. They typically move when the conditions are most favorable: when they are flying with the wind instead of into a head wind and when the skies are clear. Migratory birds heavily rely on reading the stellar map of the night sky and pause their migration when the weather is adverse. Evidence-backed research strongly indicates that migratory birds can detect the magnetic activities concentrated at the poles and that birds use that ability is another navigational tool.
Well-equipped with internal navigation systems, these marathon fliers will often fly throughout the night, setting off on their journeys shortly after sunset. They may put down at dawn the following morning, but individuals that have stored up on fat can use the extra energy to continue for several hours after sunrise. This is a race to the best breeding location, after all. The ones to make it first to the breeding grounds may be the genetically fittest, having found enough food and energy to outcompete the less genetically fit birds to get to the best territories to successfully raise young. The last of the birds may take whatever is left over.
Amongst these songbirds are numerous flycatchers, vireos, Swainson’s Thrushes, wood-warblers, sparrows, tanagers, orioles, grosbeaks, buntings, and sparrows. Look for these birds anywhere at any time. You may find that on some days that songbirds are in your neighborhood. Palo Verde trees, with their abundant yellow flowers, can be especially enticing to some of these songbirds. The staple spring migration sites to visit amongst birders have been and continue to be Corn Creek Field Station, Floyd Lamb Park and Clark County Wetlands. Other artificial oases include the interstate community of Primm or the town of Indian Springs. These beacons of green amongst the desert landscape attract songbirds like moths are attracted to a porch light.
Songbirds are colorful, diverse, and often accessible to those living in the metropolitan area. One may not need to travel far from home to catch these birds as they pass through. But there is more to May than songbirds. Shorebirds continue to pass through the region. Anyone visiting the Las Vegas Wash, Henderson Bird Viewing Preserve, Bowman Reservoir and other sites may be able to catch members of this diverse order of birds that includes plovers, stilts, avocets and sandpipers. Shorebirds are often considered to be amongst the most difficult of groups of birds to learn if one focuses too much on their plumage or patterns, but pay attention to bill shape, bill size, leg length, and feeding behavior of these birds and you will start to get the swing of the identification process. Shorebirds are mystifying in that they may migrate at high altitudes and cover long distances between wintering and breeding grounds. Many of the shorebirds species passing through Southern Nevada may be coming from South America on their way towards the Arctic tundra of Alaska or Canada.
You will also notice that the neighborhood birds have begun to tend to young birds leaving the nests. The sounds of fledglings and nestlings may catch your ear amongst the sounds of passing planes, cars and other artificial sounds. Up in the nearby mountains, however, birds are a few weeks behind. At locations like Deer Creek and Fletcher Canyon in the Spring Mountains, birds may just be arriving to tending to territories. By the end of May, head into the mountains to observe the breeding bird activity in parks of Ponderosa Pines or stands of aspens.