A warm southerly breeze in mid-March brings with it loose, granular conditions on the ski slopes, a layer of mud on dirt roads, and the return of the first seasonal avian residents – among these are the red-winged blackbirds.
This jet black bird with the red and yellow patch on its upper wing, known as an epaulet, is quick to return to its breeding grounds when air currents become favorable for migration. Despite the presence of snow on the ground, ice on many of our waterways, and periodic outbreaks of bitter cold, these birds exhibit an eagerness to get back to their breeding areas.
Immediately upon their arrival, the males begin to lay claim to favored sections of marsh and the weedy shorelines of rivers, ponds, and lakes, especially those that are covered by cattails. It is in such areas of tall aquatic grasses, shrubs, sedges and weeds that the females will be looking to establish a nesting territory when they arrive during the first few weeks of April.
Unlike many birds, the red-winged blackbird does not form a pair bond with a single individual, rather the male services the reproductive needs of all of the females that happen to set up a nesting territory within the boundaries of their section of real estate. It is not uncommon for a prime chunk of marsh, held by a single male, to encompass up to three female nesting territories.
Those individuals that arrive first tend to gain control of the best parcels of marsh. These are the older and more experienced males that average from 3 to 6 years of age. They have learned what areas are likely to attract the strongest and hardiest females, as well as what settings are most likely to allow for a successful nesting season. In this way, these males can best ensure that their genetic information will be passed on to future generations of red-wings.
Once a male selects a territory, he will defend it by loudly announcing his presence with a distinct vocalization. The phrase, “O-Ka-TEE” is often used to describe this call. Additionally, the male opens its wings slightly to expose its epaulets. This visual cue is given to alert other nearby males that he is dead serious about defending his area. It is akin to a human brandishing some type of weapon while standing on his front porch when confronting an unwelcome visitor. Finally, the male is quick to attack any other male that fails to heed the warnings.
Over a several day period, regular skirmishes with neighboring males over the exact boundaries ensue until ownership claims become established. Because most wetlands are still covered in snow and ice, these birds are forced to find food outside their breeding territories. It is not uncommon in mid to late March to note small flocks of male red-wings in poplar trees that border open, south-facing hillsides where foraging conditions are better. Also, when the wind comes up from the north, preventing other migrants from arriving and creating bitter cold conditions, the males congregate in more sheltered locations rather than guard a breeding territory that is currently devoid of any rivals.
Yet, as soon as the weather turns more spring like, these birds quickly return to their patch of marsh to immediately challenge any intruder that has just arrived from the south. Since the first birds back have had a chance to recover from their bout of long distance flight, they are generally at an advantage when they confront recent arrivals that are more physically drained.
During years when frequent spells of unseasonably cold and snowy weather hinder this birds ability to forage, these early migrants may experience significant nutritional stress. This is why birds are careful not to return too early in March.
Read more stories about birds in New York here.
Photo of Red-winged Blackbird courtesy Wikimedia user Walter Siegmund.