Conservation // 5 min Read

In the Field: September Eye to the Sky

Written by Aaron Palmieri, Conservancy Educator

Sep 7, 2021


August was the definition of “the dog days of summer.” Between the heat and rain, many of us grimaced anytime we had to leave the comfort of our air conditioning. Nonetheless, people were still out birdwatching and observing the seasonal shifts in activity. Tree swallows began popping up in the area, though it will be later in the migration that we witness their feathered storm. Hummingbird abundance also increased as the northern individuals started making their way through. Make sure to keep your hummingbird feeders clean and the nectar fresh! Meanwhile, immature raptors, such as Cooper’s and red-tailed hawks, were seen flying around flaunting their newfound independence.

Cooper's Hawk
Cooper's Hawk

We also received word of a leucistic bluebird that was spotted flying around Longfield stables. This bird is likely either Blanca or the fledgling from this past summer, but it is great to hear of any sightings of this fascinating mutation! And finally, the rattling calls of belted kingfishers, which are here year-round, returned to the marsh as they dispersed from their neighboring breeding habitat.

Leucistic bluebird [Photo provided by Sharon Pepe]
Leucistic bluebird [Photo provided by Sharon Pepe]

As we made our way through August, I was concerned that we may not see many of the early migrating warblers mentioned in last month’s post. Conservancy staff witnessed one yellow warbler, but the other species had gone undocumented. However, that all changed when we had a wonderful conversation with Dr. Ballance and Mrs. Watkins who were visiting Palmetto Bluff to relax and photograph wildlife. They had taken amazing photos of black-and-white warblers, yellow warblers, American redstarts, prairie warblers, and northern parulas along with many of our more common species seen around the Bluff. Among their collection of photographs, they also shared the first documentation of a blue-winged warbler at Palmetto Bluff, which made it our 213th bird species! To say this bird is rarely seen in Beaufort or Jasper County is an understatement. There are only 34 eBird records in our area, with some dating back as far as 1986, and most were documented in April or September. We hope the abundance of warblers the couple saw is a sign that we will have a fantastic migration!

Moving away from unique bird sightings, let us talk about breeding activity in August. The bluebird nesting season finished earlier in the month, and we thought that was the end of summer breeding activity for 2021… That is, until we checked the cavity nest boxes! The August cavity box check is normally one of the quieter months, with a few sightings of squirrels, cockroaches, and spiders hiding out in the wooden abodes. This changed when we encountered a nesting black-bellied whistling-duck!

Black-bellied Whistling-Duck
Black-bellied Whistling-Duck

Black-bellied whistling-ducks are cavity-nesting waterfowl like wood ducks and may lay eggs from April to September, but they primarily nest between mid-May and mid-July. The nest box contained a dozen eggs, and after doing a follow-up check a few days later, there were still twelve eggs. This meant we knew that the female had finished her clutch and was incubating!

The fun part, for me, is we can now make a rough estimate on when these eggs should hatch. To form this estimate, there are a few pieces of information to know about breeding birds and black-bellied whistling ducks:

  1. Most birds lay one egg a day
  2. Whistling-ducks lay eggs in the evening
  3. Whistling-ducks begin incubating 2-3 days before the last egg is laid
  4. Whistling-duck eggs hatch in roughly 28 days
  5. The ducklings are mobile shortly after hatching and will leave the nest after about a day.

Time to do some math!

There was an old squirrel nest in the box during the July 12th survey, and the clutch of eggs was first seen on August 16th. Black-bellied whistling-ducks are hands-off with their nest construction. Unlike wood ducks, they forgo lining their nest with downy feathers and they do minimal nest preparation before laying their eggs. At most, they may form a shallow bowl in material already present within the cavity. This lack of nest building behavior could mean that the female may have already selected the box for nesting but had not yet laid eggs during the July nest box check. We are going to start our estimate based on if she laid her first egg the following evening. If we account for one egg being laid each day and factor in the start of incubation with the time it takes for the eggs to hatch, we have a rough time frame of August 18th to September 10th! I know August 18th was not the hatch day because that was when I did my second check to confirm the clutch size, and there were no signs of an oncoming hatch. The signs for whistling-ducks include pecking from inside the egg and peeping calls up to 2 days before they emerge. Knowing this, the estimated time frame has shrunk to between August 21st and September 10th.

We were ecstatic to have the opportunity to witness this nesting activity, but we still needed to be respectful of the nesting birds. We did not want to continuously disturb the adults during incubation as this may cause them to abandon the nest. Thankfully, we have trail cameras to help with the task! We placed two cameras around the nest box; one camera below to capture footage of the chicks leaving, and the other camera is on a nearby tree to document the adults coming and going. We plan to leave the box alone until the September cavity nest box check, which will likely be the week after they leave the nest. This means we won’t have any new information until October’s Eye to the Sky, but we are excited to share this journey with you!

Even though August was an unexpectedly surprising month, it is time to look at September and the excitement it will bring. The fall migration officially kicks off this month, along with Conservancy bird walks! We hope to see a variety of migratory species at the Bluff as these birds take a quick reprieve from their southward flights.

Pied-billed grebes will slowly appear around Palmetto Bluff’s lagoons in September. Grebes are often mistaken for ducks, and this tends to be related to the fact that they float on the water like ducks, and they are sometimes intermixed with waterfowl. However, the grebe’s short, narrow beak compared to the flat bills of ducks is a good indicator that the bird you are looking at is not a duck. Grebes also have lobed toes instead of webbed feet, but this characteristic is rarely observed as they seldom leave the water due to the awkward positioning of their legs. Their legs are closer to their posterior, which makes it difficult to balance on land, but improves their ability to swim underwater. Grebes are so water-bound that they even nest on floating vegetation!

Revisiting the flycatchers mentioned in August, Acadian and great crested flycatchers will join the eastern kingbirds and eastern wood-pewees that have already begun their southern migration. It may feel like we lose all of the flycatchers during the winter, but there is one species that migrates to the southern United States to wait out the colder months: the eastern phoebe. Phoebes will trickle into coastal South Carolina throughout September and can be identified by their namesake calls and consistent tail pumping.

Baltimore orioles are a bird watcher’s favorite that will begin migrating south in September. They are always seen in low numbers in our area, even though they can be quite prevalent just north of us in Charleston County. I wish I knew the reason behind the low abundance, but I can at least recommend ways to increase your chances of seeing them. These tropical birds are normally attracted to nectar feeders, orange halves, grapes, and sunflower seeds, but they will also visit suet feeders in their winter range here in the South. Most of my observations of orioles in Beaufort County are actually of these birds visiting suet. Another way to increase your chances of oriole visitors is to plant native trees and shrubs that produce fruit in the fall and winter. Native dogwoods, hawthorns, and viburnums are great examples of fall fruit-bearing plants that birds love, and they also provide seasonal variation for your yard!

Lastly, the rest of the warblers are on the move! While many of the early migrants from August will still be migrating through, we will see additional colorful characters embark on their journey south. Chestnut-sided warblers were seen last September bouncing through the canopy of Sandhill Loop and they will hopefully make another appearance this year! Cape May and magnolia warblers join the chestnut-sided warblers as some of our rare warbler sightings during the migration. All three of them have only been documented once at Palmetto Bluff, but I hope to continue seeing these warblers!

Cape May Warbler
Cape May Warbler

Black-throated blue warblers are one of our more common migratory species to appear at the Bluff. We see at least one each migration and we recommend you keep an eye out for them in River Road Preserve or along the Sandhill Loop. A warbler to certainly be on the lookout for is the Blackburnian warbler. Blackburnians almost never migrate along the coast during the spring migration, so fall is when to look out for them. Blackburnian warblers are another species that has yet to be documented at Palmetto Bluff.

September does not need to be all about the migratory birds that come and go from Beaufort County. The resident bluebirds, cardinals, and other year-round species have shifts in their behavior as well. Chickadees and titmice will form foraging flocks throughout the fall and winter as they search for food. Pine warblers will begin visiting feeders more regularly instead of spending most of their time in the pine canopies. Meanwhile, species such as the white-eyed vireo, which seems overly abundant during the summer may seem more reclusive as they become less vocal during the winter. The migration often steals the spotlight from the birds we see all the time, but I wanted to make sure to show some appreciation for the cardinals, chickadees, wrens, and other common birds that are often responsible for starting our love of bird watching. I love hearing of any migratory bird sightings throughout the year, but please let me know when you see our residential friends that provide Palmetto Bluff with year-round beauty.

Northern Cardinal
Northern Cardinal

The fall migration has officially begun, and we hope you have a lot of luck spotting migratory warblers! If you see or photograph something you wish to share, you can submit your sightings to Aaron Palmieri at apalmieri@pbconservancy.org and they may appear in next month’s update.

August’s Unique Sightings:

  • Roseate spoonbills (Moreland Ponds)
  • Belted Kingfisher (Marsh around Moreland)
  • Cooper’s Hawks (Managed Forest)
  • Yellow Warblers (Conservancy Classroom, River Road Preserve)
  • Leucistic Bluebird (Longfield Stables)
  • American Redstarts (River Road Preserve)
  • Prairie Warblers (River Road Preserve)
  • Blue-winged Warbler (River Road Preserve)
  • Black-and-white Warblers (River Road Preserve)

August Contributors:

Tish Ballance & Melissa Watkins (Instagram: movingwildphotography), David Miller, Sharon Pepe, Joe Brackin & Roberta Marcantonio, Brian Byrne

Photos below were provided by Dr. Tish Ballance and Melissa Watkins.

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