An eye-catching non-native Venezuelan Troupial

Birding Southwest Puerto Rico: Laguna Cartagena

Puerto Rico is a brick-shaped island that is 100 miles wide and 35 miles tall. That’s big enough to provide a good amount of habitat and species diversity. It’s small enough that any spot can be reached in 2-3 hours (traffic permitting). One popular area for birding is the southwest corner of the island, where there are a couple of national wildlife refuges. During my one full day of birding in Puerto Rico, I spent part of it in the southwest. I headed first to Laguna Cartagena, a big lake in the middle of dry forest. You get there by driving down a short flat dirt road through some hay fields. If it wasn’t already noon, and muggy and hot, when I arrived, the roadside birding would probably have been quite good. But my target was the lake itself where I hoped to spot three or four lifers.

If you’re headed to the observation tower, which I was, park here. At the parking area, Venezuelan Troupial, an introduced exotic native to South America that likes dry scrub, and Puerto Rican Woodpeckers were moving around the tall trees. It’s a 10 or 15 minute walk to a big wooden observation tower that offers views of the lake. Despite the mid-day heat, the walk to the observation tower was quite full of birds. A group of Smooth-billed Ani were making some noise. Turkey Vultures, a Red-tailed Hawk, and a pair of Magnificent Frigatebirds were soaring above. Some Monk Parakeets went zooming past. And in the scrub along the path were Black-faced Grassquit and multiple super-bright Northern Red Bishops. 

The observation tower is pretty far from the lake, but it offers sweeping views of the area. I scanned the distant water looking for two target duck species. One was present – some West Indian Whistling Ducks. I struck out on White-cheeked Pintail. There were also some Ruddy Ducks and Coots out on the water as well. Next to the observation tower, there’s a wooden walkway that takes you out to the edge of the water. The water was mostly covered with lily-like vegetation. Walking around on those lilies were Green Heron, Common Gallinule, and a lifer Purple Gallinule.

The view from atop the observation tower at Laguna Cartagena

In some trees alongside the wooden path, a lifer Yellow-faced Grassquit appeared for a moment and then vanished. Some non-native Orange-cheeked Waxbill counted in eBird as a reluctant lifer, having established themselves in Puerto Rico. A Yellow-billed Cuckoo did some tail-lifting exercises. 


There is a lot of ground to cover at Laguna Cartagena. Just north of the path to the observation tower is an alternative path that gets you closer to the water. Had there been more ducks and whatnot around, I might’ve walked down it. Some mountain biking trails extended into the vegetation south of the lake. For the 90 minutes I was there on a Saturday at mid-day, I didn’t see anyone else.

Birding Southwest Puerto Rico: Cabo Rojo NWR

A main birding reason to go to southwest Puerto Rico is to find an endangered Yellow-Shouldered Blackbird. They live only on Puerto Rico and nearby tiny Mona Island. They favor coastal mangrove forests and scrub. EBird had reports from a few different spots in the southwest. I first tried to visit the Boqueron Wildlife Refuge (Refugio de Vida Silvestre de Boqueron), but I couldn’t find a way into the place. All I found were closed gates at a couple entrances. So I headed to Cabo Rojo NWR, which is a large area of coastal habitat, including some supposedly pink salt flats. Again, I was stymied here, finding first a closed gate and then a closed road between me and my destination.

I finally managed to find a way to a spot where Yellow-Shouldered Blackbirds had recently been reported. The eBird hotspot is a mouthful – “Salinas de Cabo Rojo NWR – camino villa pesquera Fraternidad.” It wasn’t clear that the spot was open to the public. But there was a road (called Short Road on google maps) that crossed a salt flat and led to some scruby bushes. It seemed like good habitat. As I walked, I spotted some Black-necked Stilts, Snowy Plovers, and a Ruddy Turnstone feeding in the shallow, stinky water. Then, I saw a half dozen black birds flying south towards me from the nearby residential area. I got one in my binoculars, and it was a Greater Antillean Grackle. They were flying right at me, and I enjoyed the views. After they passed, I lowered my binoculars and noticed another group of 3 blackbirds flying over the salt flat towards the coast. These birds had yellow patches on the wing!

Maybe if they weren’t so blurry, Yellow-Shouldered Blackbirds wouldn’t be endangered

I quickly snapped a record shot and walked to the patch of bushes where they’d flown. I couldn’t refind them. I did spot a lifer Caribbean Eleania while I wandered. There was also a pair of American Oystercatcher at water’s edge that my camera managed not to focus on.

I checked out a couple of other spots in the area, which is vast, often scenic, and occasionally stinky. The Interpretive Center for the Salt Flats was closed when I arrived at 4:30pm, so I didn’t get to wander there. Overall, though, it was pretty good birding in SW Puerto Rico. There are a bunch of different spots, all within 20 minutes or so of each other, with good species variety.