Recreational Birding

I headed down to St. Marks NWR this morning for a little recreational birding. It was a cool morning for mid-June. There was a fat crescent moon and, with no clouds to play with, a calm and muted sunrise.

I had chosen to watch the dawn flight from the Double Dikes at Lighthouse Road. Hundreds of Red-winged Blackbirds and Boat-tailed Grackles boiled out of the marshes, all heading out to the West to hunt for food. The heron rookery at the North end of East River Pool produced a single Anhinga. That rookery started declining prior to Hurricane Michael. It used to have herons, egrets and ibis in the low hundreds. 

Stony Bayou I had Roseate Spoonbills, Reddish Egrets and the usual dowitchers and plovers. I also noted fourteen Marbled Godwit and a single Whimbrel. There were Least Terns and a lone Black Tern.

I swung down to the Lighthouse, but didn’t find much. So, I decided to head for the Double Bridges.

I parked my car and began to walk slowly, watching and listening. By now most of the refuge’s Summer breeders have young out and are noticeably quieter. I found Northern Parula and Blue Gray Gnatcatchers and could hear an Acadian Flycatcher calling. Nearing the second bridge I followed the sound of a Yellow-Throated Vireo and saw a pair feeding low in the canopy.

Then I noticed a bird moving fast and low over the North Fork of the East River. I walked over to the edge of the bridge and saw a streak of yellow fly into the nest box sitting on top of a pole. It was a Prothonotary Warbler bringing nesting material into the box.

Prothonotary Warblers are one of two species of cavity-nesting warblers in the US. The other, Lucy’s Warbler, inhabits mesquite desert in the Southwest. One of the refuge volunteers, Michael Hill, built two nest boxes and set them up this Spring near the two bridges. Prothonotary Warblers are known to use nest boxes when they are available. 

Prothonotary Warblers return to St. Marks in March and are usually nesting by April. This late nesting attempt may be a renesting due to a failed first attempt, but Prothonotaries have been known to have second broods.

Male birds start the nest, but the female completes it. I watched as the drabber female made repeated trips to the nest box carrying bits of vegetation. The more brightly colored male sat on an overhanging branch. It will take a few more days for her to complete the nest, after which they’ll ignore it for a few days. Then, over several days the female will enter the nest box in the morning and lay an egg before leaving. Late nestings usually have four eggs. When the last egg is laid, she’ll start incubating and in about two weeks the young will hatch.

If you want to see Prothonotary Warblers, they should be starting to feed young in early July. Both parents will be coming in with insects for about ten days until the young birds fledge and leave the nest box. This will be a good opportunity to observe them and you should be able to do so without disturbing them. There is a six-foot alligator that hangs out there.. It will keep you from getting too close. Stay on the roadway and you and the warblers will both be fine.

The nest site is located at the Northmost of the two Double Bridges. After you pass the Visitors Center drive about 0.4 miles and park just before the first at-grade bridge. The nest box will be on the right side of the road. Please park safely and observe social distancing if other people are present.