By the middle of 2021, Bonaire was once again receiving visitors.  For birding, that meant that not only the island’s local birders were out finding rare birds, but visitors were as well!  And the list of special birds observed in the latter half of 2021 is truly astounding!

eBird and Observation reviewer, guest author Peter-Paul Schets provided a semi-annual summary of the rare bird sightings for the first half of 2021.  Today, he speaks about the many unusual Bonaire rare bird sightings in the latter six months of 2021.

Flycatchers, Martins, Purple Gallinules, Glossy Ibises, and an American Redstart.

Less rare, but always nice to observe, are Fork-tailed Flycatchers which were recorded from July 19th through September 19th, with one observation showing seven birds at the freshwater ponds of the wastewater treatment plant.

Another good find was two Brown-chested Martins by a visiting Dutch birder on July 29th.

Starting with the end of July, Purple Gallinules were recorded almost weekly from the freshwater ponds, with a maximum of three birds registered. They might have been breeding at that location since juveniles were observed.

After this spectacle in July, the month of August was more usual with a Glossy Ibis still present from earlier in the year and, sometimes, accompanied by a second bird.  At least one Glossy Ibis was present throughout the entire second half of the year at the freshwater ponds.

On August 14th, Sietse recorded an early American Redstart, only one of the two (another in September) observed this year. It appears this bird is becoming more scarce on Bonaire since the recent years have provided only a few records.

The month of September again brought several scarce and rare birds to Bonaire. On September 4th Steve and I did a Big Day, which resulted in a good number of 83 species recorded. Although no truly rare birds were spotted on this day, a Gull-billed Tern, a Roseate Tern, and Red-footed Boobies are birds I don’t see every day. The three Brown Noddies which I saw the day before didn’t show up at Willemstoren on our Big Day but six Common Bottlenose Dolphins provided a great alternative.

Global October Big Day 2021.

These semi-annual global bird counts which occur simultaneously around the world provide researchers with “snapshots” of  important avian data.  The bird counts provided by citizen scientists around the world can help ornithologists identify migration trends, population changes, or indicate other valuable data.

A Blue-black Grassquit, a Dickcissel, Buff-breasted Sandpipers, and American Golden Plovers.

By far, the rarest bird of this month was the male Blue-black Grassquit observed at the freshwater ponds on September 18th, 45 years after the last recorded observation on Bonaire. I was just able to get one picture of this bird in flight; it was not a great image, but it was enough to confirm its ID.

This day was very special with a (shy) Dickcissel at the freshwater ponds, as well as three Buff-breasted Sandpipers and three American Golden Plovers on the eastern coast near Washikemba. Susan wrote a special blog post about our birding adventures on that wonderful day.  Actually, the number of Buff-breasted Sandpipers at this location grew to 23 when Susan did another count on September 28th.

Earlier in September, I had already found an American Golden Plover at the freshwater ponds, and this species was seen at different locations by several birders for the balance of the year.

Other interesting birds this month were the first Bobolinks (20 at the freshwater ponds on September 13th; a maximum of 65 birds a few days later), the first Prothonotary Warbler at Lac (September 15th), a Hudsonian Godwit at the freshwater ponds on September 15th and it was probably the same individual that was also recorded again in October and again in November, and an Upland Sandpiper at the freshwater ponds on September 19th.

Blackpoll Warblers

Each year keen birders are looking forward to the month of October as this is the prime time for migrating warblers on their way from North America to South America. But, like last year, the numbers of individual birds and the number of species were not spectacular. Blackpoll Warblers–as to be expected as it is the most common warbler–were recorded starting October 22nd but only in small numbers. The last one was observed on November 21st.

Northern Waterthrushes, a Cape May Warbler, and a Black-and-white Warbler.

Northern Waterthrushes also arrived and stayed, but also in smaller numbers than usual. However, two much rarer species of warblers did show up. A very human-tolerant Cape May Warbler was found by Martijn Hickmann in his own garden on October 22nd, which stayed for several days, enabling local birders to see this rare one and to take pictures of it–a wonderful opportunity thanks to Martijn.  Further, on October 23rd, Lia Avis had the luck of discovering a Black-and-white Warbler at Seru Largu.

Another Dickcissel, Rose-breasted Grosbeaks, a Wilson’s Phalarope, and more Buff-breasted Sandpipers!

Apart from the warblers, more passerines visited Bonaire on their way to the south. On October 17th, Susan had a nice find with a very friendly Dickcissel in Washington-Slagbaai National Park. Beginning on October 20th, Martijn’s garden was visited several times by two Rose-breasted Grosbeaks, another bird from North America that is rather rare on the ABC islands. Other nice observations this month were that of a Wilson’s Phalarope at Red Beryl on October 15th by a visiting birder and that of two Buff-breasted Sandpipers by Steve at the freshwater ponds.  This was an unusual location for this sandpiper, which had only been observed on the open eastern coast in prior records. The list of species at the freshwater ponds grows longer and longer!

Comb Ducks are Bonaire rare birds!

The most spectacular finds in October were the two female Comb Ducks at the freshwater ponds on October 24th by Lia. These two ducks only stayed for the weekend, so they were gone when I visited the island again in November. But in that month some other nice ducks would appear…

A Veery and many, many Soras.

On this same date (October 24th), a birder found and photographed a Veery at Echo Dos Pos Conservation Area. This shy thrush-like bird, which breeds in North America, has only had a few prior sightings on Bonaire and the last record was in 2005. By the end of October, the Soras arrived, and, especially in November, they were present in unusually large numbers (up to 13 recorded at one time at the freshwater ponds, with very likely dozens actually present). And then the month of November began. Normally birding is more or less slowing down this month but not this year!

Indigo Buntings, a Blue Grosbeak, and another Baltimore Oriole!

For nearly all of November, four Indigo Buntings (one male and three females) were present at the freshwater ponds, mostly staying in the same area near to the main pond.  The last female moved onward in her migration when foliage in the area was cut back.

American Wigeon, Ring-necked Duck, a Lesser Scaup, and the new-for-Bonaire Green-winged Teal.

 And then it was duck time again! The first good November duck was a female American Wigeon which I found at Mona Passage on November 15th. This bird was also seen by a few local birders and visiting birders, each time in the company of a small flock of Blue-winged Teals.

On November 20th a female Ring-necked Duck appeared at the freshwater ponds, almost exactly two years after the famous 2019 bird which stayed for months together with a female Lesser Scaup. This year it had to wait six days before a Lesser Scaup appeared, which Susan recorded on November 26th. But unlike 2019, this year it was a male which decided to call the freshwater ponds “home” for several weeks.

In the meantime, a much rarer duck arrived at the freshwater ponds. On a late Sunday afternoon walk, I had the good fortune to find a female Green-winged Teal. Quite amazingly, this species had never been recorded on Bonaire before, so this meant species number 243 for the island of Bonaire. It stayed for several weeks and all local birders were able to see this small duck.

A Seedeater and Mangrove Cuckoo!

But the month was not over yet…. On November 27th, both Steve and Lia took images of an intriguing small bird at the freshwater ponds.  It was definitely a seedeater, but which one? As it was a female, identifying it is hard or impossible. The Lined Seedeater, which has been recorded only once before on Bonaire, is most likely, but other species, especially Lesson’s Seedeater, can’t be ruled out. So Steve or Lia had best find a male!

Even though the seedeater could not be positively identified, Steve got a great consolation prize–a Mangrove Cuckoo on November 26th in Washington-Slagbaai National Park. This species is very irregularly recorded on the ABC islands and is unpredictable in its occurrence.

Least Grebes are irregularly present and seldom breed on the island, but two of them were seen displaying courtship behaviors, mating, and nest building at the freshwater ponds starting in the middle of November.  Thus, a breeding situation does seem likely.

Further, separate from the Purple Gallinules encountered at the freshwater ponds, a few have shown up at other locations, such as an immature one at the Mona Passage. This one was often feeding right in the open, sometimes side-by-side with a Sora; quite an unusual view!