Observing Spoonbills and Ibises

He was born when I was six and was, from the outset, a disappointment.―James Hurst, The Scarlet Ibis: The Collection of Wonder

White Ibis Nest with Nestlings, Pilant Lake, Brazos Bend State Park, Texas
White Ibis Nest with Nestlings, Pilant Lake, Brazos Bend State Park, Texas. This nest contains two nestlings: The one on the left is much larger. In this image, the parent is feeding the smaller of the two, and the larger chick is plotting to knock the smaller one from the nest, “accidentally,” of course. Note that this ibis nest, like the spoonbill nest below, is in an invasive Chinese tallow tree. Canon EOS 7D/600mm f/4L IS (+1.4x TC).

After a photo-birder friend (LM) told me about the White Ibises nesting on the the south edge of Pilant Lake, I recently spent a few hours trying to photograph nestlings. Only one nest can currently be photographed (above), but there are many others back in the swamp—and the air is filled with the weird gurgling noises ibises make.

The one nest that can be seen is still rather difficult to photograph given its distance from the trail and the profusion of vegetation. But I could see that the nest contains two nestlings, one much larger than the other. Likely the smaller chick simply hatched later, the size disparity exacerbated by the bigger chick receiving more than its fair share of food along the way. Such a disparity in nestling size often spells doom for the littlest birds. In this case, though, the little bird is a real fighter and chased mom’s beak around relentlessly hoping for a morsel or two of regurgitated crawfish. I hope it makes it, although the odds may be against.

White Ibis with Crawfish, Pilant Lake, Brazos Bend Sstate Park, Texas
White Ibis with Crawfish, Pilant Lake, Brazos Bend State Park, Texas. Ibises are enthusiastic consumers of aquatic arthropods. White Ibises nesting in salty environments will travel to freshwater environments to collect crawfish for their young. Baby ibises have poorly developed salt glands and can’t handle the high salt content of marine and brackish arthropods. Canon EOS 7D/600mm f/4L IS (+1.4x TC). High-speed synchronized fill-flash.

The long, curved beak of ibises is used to probe into burrows and crevices occupied by a variety of prey. The rapid up-and-down motion of the beak reminds me of a sewing machine. At BBSP, it’s common to see White and White-faced Ibises grabbing a variety of aquatic arthropods including predaceous diving beetles (larval and adult) and crawfish. Frogs and small fish are taken, too, as are the bulbs of some aquatic plants.

Spoonbill Nest with Nestlings, Smith Oaks Rookery, High Island, Texas
Roseate Spoonbill Nest with Nestlings, Smith Oaks Rookery, High Island, Texas. The chick on the far left is much smaller than the others. In Roseate Spoonbill nests that I have photographed, the smallest sibling is usually listless and helpless seeming, clearly not long for this world. The little bird above was consistently left out of the feeding frenzy initiated by the return of an adult bird. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

Spoonbills and ibises constitute the Family Threskiornithidae, the former being close relatives of the Old World Ibises. I tend to think of spoonbills simply as ibises with a specialized feeding strategy: Typically the bill is waved back and forth through the water to capture prey, vertebrate and invertebrate, which is then flipped up into the air and ingested (below).

Feeding Spoonbill, Myakka Rivefr State Park, Florida
Feeding Roseate Spoonbill, Myakka River State Park, Florida. Canon EOS 7D/600mm f/4L IS (+1.4x TC). Natural light.

We have seen all U.S. species of ibises, including the Scarlet Ibis, an exotic South American and Caribbean native that was introduced into Florida in 1961. We saw this species on Sanibel Island at the J.N. Ding Darling National Wildlife Refuge on the the west coast of Florida about seven years ago. A small group of these birds was walking along the strand line of this famously shelly beach. This sighting, dear reader, was before we were serious photo-birders, so you’ll just have to take my word that it occurred! We hope to return one day and document the behavior of these spectacular, brilliantly-colored Tropical birds.

White-faced Ibis with Predaceous Diving Beetle, Pilant Lake, Brazos Bend State Park, Texas
White-faced Ibis (Non-breeding) with Predaceous Diving Beetle, Pilant Lake, Brazos Bend State Park, Texas. Canon EOS 7D/500mm f/4L IS (+1.4x TC). Natural light.

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