Homeland Security
Early on a cool overcast morning, there is an eerie lack of activity in the marshlands. The wind is nonexistent. Silence emanates from the fields of pickleweed that surround the marsh. The world appears to be at a standstill until a gull crosses high overhead.
An adult female American Avocet, well camouflaged in the shallow brown water, shouts an alarm. The call is loud, sharp and short. It sounds like a scout whistle that gets cut off abruptly. A slow response from her family members forces the mother to repeat the alarm. Her head pulses back and forth to the rhythm of her call, which is getting progressively louder. Her outstretched wings beat forcefully as she strives for her call to reach its maximum output. The urgency of her distress is unmistakable.
Ten feet away, two chicks, resembling balls of cotton on bendy straws, break into an awkward bobbling sprint toward their mother. Some 50 feet away, a male American Avocet stops fishing. After a quick glance toward the sky, he dismisses the threat and returns to fishing. The two chicks follow their father’s lead and lumber to their previous location. The mother stares at her mate.
This mother may be oversensitive to potential predators, but that sensitivity is understandable. This family started with four hatchlings. Now, after only three weeks, they are down to two.
When a great egret lazily glides over the marsh, the mother again repeats her alarm call. She again gesticulates wildly, and the chicks again come running toward her. This time, her mate notes the low elevation of the intruder’s approach and leaps from the water. The egret knows it’s in trouble.
The male avocet reaches top speed within only a few wingbeats. Vegetation becomes a blur as the bird speeds towards its target while emitting a warning call of its own. The vocalization is like that of his mate, but louder and more disorienting. His whistle has an echo, which disguises the origin of the sound.
The egret flaps its wings desperately trying to gain lift. Heavy wings that lack quick-twitch muscles are a reminder that this is a body made for quick strikes, not quick getaways. Falling and rising, the bird charts a comically erratic escape path.
A trilled squawk from the egret confirms a bite from the male avocet that has now caught up to the slower shorebird. Satisfied that the egret has received the message, the avocet slides by the egret feet first as if marking a territorial boundary. The avocet returns to its fishing spot while the frazzled egret rushes to the far end of the marsh. With the day started, silence will not return to the marsh until the evening hours.
