Filling the Gaps: Puerto Rico

Because I had visited Puerto Rico during winter, I knew I had left some Caribbean species on the table and would have to return during the summer months to add them to my Biggest Year list. The two most conspicuous species in this category were Antillean Nighthawk and Caribbean Martin. Both are migratory and disappear from the Isla del Encanto (“enchanted island”) in winter. There may be a few Martins that spend the winter (reported in eBird). But I was watching for them throughout my visit in late January-early February. They return to breed in April and remain common to abundant through the end of September, following a pattern that is similar for Antillean Nighthawk. 

As it turned out I added Antillean Nighthawk at the Marathon Airport in Florida in May so I wasn’t worried about that species. If the Caribbean Martin was the only species that could be added then a return trip to Puerto Rico would not be cost-effective. However there were several other rare species (Masked Duck, Yellow-breasted Crake, Scarlet Ibis, Lesser Antillean Bullfinch) and some uncommon exotic species (Pin-tailed Wydah, Indian Silverbill, Java Sparrow, Yellow-crowned Bishop, White Cockatoo, Orange-fronted Parakeet, Orange-winged Parrot, Saffron Finch) that could help get me to my goal of 900 species for the USA and Territories. To that end I scheduled a 5-day trip to Puerto Rico from Sep 26-30, reserving a full fare Frontier Airlines flight from and to Miami. I left the flights to and from Florida open in case I had an opportunity to chase a new vagrant in Florida. My friend Manuel Amador offered to host me during my visit and provide a vehicle for me!

I arrived in San Juan at 9:30 AM on Tuesday September 26, 2023, after spending a short night sleeping on the floor of the Miami airport. Manuel picked me up and we were soon heading toward the southwest corner of the Island, a three-hour drive. Our targets were Masked Duck and Yellow-breasted Crake at Laguna Cartagena National Wildlife Refuge. The plan was to arrive at the observation tower before dark to try to see these nocturnally active species. If we missed them or arrived too late to see them in the fading light of dusk, we would listen for them singing from the wetlands under cover of darkness. If we didn’t hear them we would spend the night in a hotel nearby and return in the morning before sunrise. 

We followed map directions to the eBird hotspot which was a mistake as the route left us a mile from the observation tower. The foot trail we then used was overgrown with dew-laden vegetation and we got thoroughly soaked with dew and sweat trying to reach our destination. When we finally arrived at the observation tower it was already too dark to see. And we could barely hear over the din of the cicadas, Coqui tree frogs and other noisy insects and amphibians. We did however hear a couple of nearby Puerto Rican Owl. 

On the hike in to the tower we had seen some birds flying silently in the fading light and asssumed they were Puerto Rican Nightjar which are common in the region. As we retreated back to our vehicle after straining to hear water birds over the amphibian din, we lit up our pathway with the lamps provided by our cell phones. Then we noticed one of the nightjars flying to within inches of our phones hawking insects attracted to the lights. By now I was exhausted (I had slept only a few hours the night before on the Miami airport floor), uncomfortably sopping wet, and unfocused. I did not pay too much attention to the nightjar because I had already audio-recorded the species in February. However, I had not seen the nightjar very well during my previous trip and didn’t have a photo so Manuel and I tried to photograph the bird when it came close to the light. Apparently I need some lessons in nocturnal photography as nothing came out but during this process I got a better look at the bird. It had long tapered wings, a short notched tail and no obvious white patches anywhere in the plumage. The lack of white and the short tail ruled out Antillean Nighthawk, Pauraque and the migratory North American nightjars (whip-poor-wills and Chuck-Wills-Widow) which all have long tails, and males have large white patches in their tails. I could not recall what Puerto Rican Nightjar looked like but I assumed that was this bird. “Funny,” I thought out loud, “the long wings and short tail recall Short-tailed Nighthawk,” a species I had seen in Brazil. Several days later I remembered to look up Puerto Rican Nightjar and was dumbfounded when I saw that it’s tail resembled that of the whip-poor-wills: long with large bright white patches. Now I was cursing myself that I did not have a photo. Manuel had noted a crook in the wing shape, giving the shape a bat like vibe (similar to Lesser Nighthawk). His description was also consistent with Short-tailed Nighthawk, which would be a new species record for Puerto Rico, if only we had some documentation. Without photographic or audio documentation, it would be considered a hypothetical sight record at best. In the spirit of caution in accepting rare or unsupported sightings of species, I decided not to count Short-tailed

Nighthawk for my Biggest Year list. Interestingly, I learned from my brother that Short-tailed Nighthawk has wandered to Belize and the Bay Islands off Honduras. Perusing the eBird database, I could not find any confirmed reports of extralimital Short-tailed Nighthawk in the Caribbean region. 

On Wednesday, September 27, 2023, we rose before sun up and this time approached the wetland from the appropriate side. On the entrance road (a private farm road), we stopped to assess an odd-looking long-legged wader that blocked our path. We could not make out plumage details in the darkness, despite illumination by our car headlights. As we approached, it would turn and run a short distance and then face us again, blocking our path. It’s large size, overall shape, behavior and habitat (dirt road with puddles in an arid or agricultural setting) reminded me of Double-striped Thick-knee, a large drab-plumaged plover of dry grasslands in Central and South America. I managed to get some poor images from a 1-2 second video of the bird as it flew away from us. Evaluating the fuzzy video frame by frame in my camera viewfinder I could see a black and white pattern in the wing which a thick-knee would exhibit. If it was a thick-knee it would again be a first record for Puerto Rico (there is a previous record for the USA in Texas). Thinking outside the box can be dangerous. Sometimes I forget to think inside the box.  I reported this large plover to eBird as a rare Double-striped Thick-knee only to discover later that one of the frozen video frames clearly shows the upper wing pattern of non-breeding Black-bellied Plover, a locally common wintering species of shorebird. As soon as I made this discovery, I retracted the identification but the damage had already been done. I now have a reputation of having a wild imagination and carelessness in my bird identification practices (at least in Puerto Rico). Given this reputation, how will anyone take my report of Short-tailed Nighthawk seriously? I would need to have rock solid documentary evidence. 

The morning visit to Laguna Cartagena was successful. I spotted and photographed a foraging Yellow-breasted Crake (Biggest Year-bird number 754) among the water lillies. I also spied a singing male Pin-tailed Wydah perched atop a shrub (755). Several swallows hunted insects over the marshy lake. I thought I had noticed a large one among these swallows, possibly a Caribbean Martin or a rare migrant Cuban Martin. However, all the swallows that I inspected closely were the smaller Cave Swallow. 

We made several stops along the route back to San Juan. At one spot along the three-hour drive I thought I heard the smack of a Connecticut Warbler’s chip note through my open window. Yes, Connecticut Warbler sometimes uses Puerto Rico as a migratory stopover en route to South America and has even spent the winter there so this visit was yet another opportunity to detect this rare warbler which had become another nemesis species for me. Manuel turned the car around and I investigated the chip note on foot. The habitat was an overgrown pasture with lots of weeds and shrubs, appropriate for Connecticut Warbler. Many birds were present. I played a taped call for Connecticut Warbler and spished. An Indian Silverbill (756) responded, perching briefly on a phone wire but not long enough for me to snap a photo. It was silent so I could not record audio. It quickly returned to its life of foraging among the weeds. This was a weak add to my Biggest Year list and I hoped to encounter another one that I could document. 

Another potential add for my Biggest Year list was Ruddy Quail-Dove. Julio Salgado, our guide in February, had told me that he feared that Hurricane Maria had extirpated the species from the island several years earlier. Checking BirdsEye for species I still needed to see, this one popped up, indicating several recent observations had been reported to eBird. One of these was close to our route so we headed in that direction. When we arrived, I noted that the habitat was appropriate for quail-dove — steep hillside covered in dense tropical forest. 

Manuel parked at the bottom of the hill and I began hiking uphill along a two track. Several Zenaida Dove caught my attention. This ruddy-colored dove does its best to imitate the appearance of the Ruddy Quail-Dove and theoretically could be the source of the recent report. My attention quickly turned to some smack-like chip notes from the dense understory. Could these be Connecticut Warbler? I spished and a Puerto Rican Tody popped into view. What a cutie! 

We followed another lead from the Birds Eye App to the mangrove-ringed mudflats near Salinas on the south coast where Caribbean Martin had been reported earlier in the week. No sign of martins but migrating shorebirds were everywhere on the mudflats. The sun was setting and I would not have time to identify them all. I quickly snapped some photos of some nearby Wilson’s Plover. An hour later we were home in the suburbs of San Juan.  

On Thursday, September 28, 2023, I dropped Manuel off at his embroidery shop in Rio Piedras, and drove an hour east to Ceiba. Here I hiked into the mangrove swamps of the Medio Mundo y Delgao National Wildlife Refuge in search of a resident Scarlet Ibis. The 100 degree heat combined with 100% humidity was almost unbearable. I could not drink enough water, and soon my stock was depleted. In the extreme heat I would not last long so after three hours of searching I surrendered. I had not found my target but I did see a loose flock of five adult American Flamingo! After a break to rehydrate and cool off, I visited the municipal beach at Ceiba. I was surprised to find several Brown Booby foraging close by, as well as a small group of Gull-billed Tern, which was flagged as rare in eBird. I drove back towards San Juan through the neighborhoods of Fajardo hoping to find Caribbean Martin in this coastal community. I only found Cave Swallow. The sun was setting as I drove into El Yunque National Forest. No martins but I did find several Puerto Rico Screech-Owl. 

Friday, September 29, 2023, I headed back to Laguna Cartagena to try to corroborate my earlier report of Double-striped Thick-knee and look through the swallow flock more carefully to find a Caribbean Martin. Manuel gave me the use of his car again. I left his driveway at 3 AM. I hoped to arrive early enough for a chance to refind the Short-tailed Nighthawk as well.  No sign of thick-knee or nighthawk. I could not conjure up a Masked Duck either despite perfect habitat (shallow, water-lilly choked lake). I found about 100 Cave Swallow but not a single martin. I returned to San Juan via Salinas again looking for martins without luck. 

My son Nick had been following my progress in Puerto Rico. He called me and said that I should look for the Caribbean Martin at Bayamon, a suburb of San Juan. He had done some digging on eBird.org and his research revealed that every checklist submitted from the Parque Lineal in Bayamon during the past week had a martin. I arrived there with an hour of daylight remaining. This was a beautifully manicured park that followed a canal for a couple of miles. The riparian habitat along the canal was ideal for swallows and martins. There was a ton of bird activity in the park. I stayed until dark but did not encounter any martins. I scrutinized over 100 Cave Swallow and hiked about three miles. 

Saturday, September 30, 2023, was my last morning in Puerto Rico. My flight was scheduled for 10:30 AM so I had a couple hours to kill in the morning. I decided to return to Parque Lineal in Bayamón in search of the elusive Caribbean Martin. I found a different trail that was even more productive for birds and after hiking two miles and spending a couple hours searching the fabulous habitat, it was time to go to catch my flight. As I arrived at my parked car, a bird flew through the periphery of my vision. I turned to view the flying object better and there it was: a female Caribbean Martin (757) was coursing over the canal right by the parking area. Go figure. I snapped off a couple of quick shots with my Nikon P950 point-and-shoot camera so that I would have the proof I needed to document the sighting. 

With the Caribbean Martin, I had added four new birds to my year list. But I had left a bunch of species off the list. I told Manuel that I hoped to return once more before the end of the year. Now I was off to Miami, Florida. I had seen a report of Thick-billed Vireo, an ABA Code 3+ species, from Boca Raton which is about an hour north of Miami. I hoped to arrive in time to find it before dark as my connection to Denver was scheduled for 6 AM Sunday morning.