The Closest to a Desert that A Tropical Island Can Offer: Hiking at Cabo Rojo National Wildlife Refuge

Consolea moniliformis

Date: April 3, 2024

Place: Cabo Rojo National Wildlife Refuge, Cabo Rojo, Puerto Rico

Coordinates: 17.981184, -67.167123

Length: 1.7 miles

Level: easy 

When I chose Puerto Rico as the destination for the spring break trip for my chika and me, I had a very limited idea of what the country looked like. Having explored the northeastern region, where we hiked at El Yunque National Forest and got to see the tropical rain forest side of the island. Then we moved to Guanica, where it was considerably dryer, but still very green and lush. We stayed in Guanica for three days and did a lot of beach time but also one notable hike - at Cabo Rojo National Wildlife Refuge, at the southwestern side of the island. On our way to Cabo Rojo the scenery changed again - the southwestern tip of Puerto Rico is not quite a desert, but it is the most arid part of the island. The vegetation there, while too dense to indicate a real desert, was vegetation suitable for water-limited environment, such as cacti and acacia trees. 

The Google navigator app led us a bit astray. Thankfully, the road signs for Cabo Rojo NWR were clear so we arrived at the right place despite the navigator errors. The gate was partially closed, but there was no closure sign and the wind was strong, so I assumed the gate was swung in by the wind and I continued driving into the refuge. 

There was no human soul in the refuge and the small visitor center was closed. We parked, got our cameras and plenty of water, and looked for the trailhead. 

There were a number of trail options in the place. I consulted the map on the kiosk and selected an interpretive loop trail that seemed just right for the time we had. We located the trailhead  and headed in that direction. 

Our hike as captured by my GS

It was really hot there that day, feeling in the 90's. My understanding was that it could get much hotter there, but saying it didn't make it any cooler in our minds. It didn't take long before we were dripping sweat. 

Trail

My chika has little tolerance for heat. I saw her expression and thought she was trying really hard to bite back complaining about this hike. I was about to remind her that this refuge visit was on her list of 'wanna go there' when all of a sudden her demeanor changed a 180 degrees. She exclaimed 'Ani!' and started clicking her camera furiously. It was a lifer bird for her, and one that she really wanted to see. 

Smooth-billed Ani

A whole flock of ani birds joined the first one, and soon they were making a lot of noise with their shrill calls. While my chika was busy photographing them I paid attention to the surrounding vegetation. This was the first place in Puerto Rico where I've seen cacti as part of the natural landscape. I've seen many cacti in many a desert in the mainland's southwest, but never before have I seen vine-covered cacti. This must be a semi-desert area, where water is limited enough but not too much, and the heat is intense. 

Pilosocereus armatus

There were acacias and acacia-like trees with thin, composite leaves that evolved for minimizing water loss through transpiration, and shade very little underneath. 

Other than being a perch for the ani and other birds, the trees were the favorite sunning perches for the iguana lizards, of which we've seen many in the refuge and all over the southern region of Puerto Rico. 

Green Iguana, Iguana iguana

During the first three days in Puerto Rico we met the iguanas only as roadkill. In fact, iguanas made the overwhelming bulk of roadkill that we saw on the island. It was only after moving to Guanica that we started seeing these reptiles alive, and once seeing them, they were everywhere. I later learned that these iguanas were introduced to Puerto Rico as pets and at some point a few were negligently released in the wild and reproduced to populate the island to the point where they became a pest and a serious threat to agricultural crops. 

Green Iguana, Iguana iguana

We walked fairly slowly, absorbing the wild scenery around us.  The heat intensified, making me wish we had chosen to go to the beach today as well. 

We moved interchangeably between open areas and groves of trees that provided some shade. We paused frequently in the small, shaded patches to breathe and sip some water. 

Some of the trees looked very similar to Tamarind, a tree I was familiar with from my trip to Hawai'i in the winter of 2020. I wasn't far off - one of the common names for this tree is Manila tamarind, and its seeds are consumed in a very similar manner to the Indian tamarind. This too is an introduced species in Puerto Rico. 

Guamúchil (Manila Tamatind), Pithecellobium dulce

All the time I was admiring the trees and the other vegetation, my chika was busy trying to get a clear shot of the gray little birds in the trees. When it comes to birding, she has more patience than for anything else in her life.  

Eastern Wood Pewee

We lumbered on along the trail. The path was easy - flat, wide, and well taken care of. The heat however, was intense. I didn't have a proper map of the place but my navigator indicated some water bodies ahead and I was looking forward to seeing them. 

Trail

As of yet we have not seen any surface water on the hike, only vegetation indicative of water limitations. 

Pilosocereus armatus

I found a fasciated cactus (a condition where an abnormal meristem leads to a unusual plant shape) which was interesting to see.

We didn't linger at any point of the hike. While the heat made me want a break, it also prompted me to keep going until we were done. I had in mind to find a beach after that and chill in the water. In the meantime, we grabbed momentary relief whenever we walked under a tree that cast some real shade on the trail.

I couldn't help feeling a bit disappointed when we reached the first pond and found that it was almost dry. I think the few birds that were there felt similar.

Pond

I saw a great egret at the edge of the pond but as I pointed it out to my chika it took off and flew away. My chika shrugged - great  egrets are a common sight almost anywhere we go around California.

Great Egret

None of the birds we saw at that pond, or whatever was left of it, were new, or 'lifers' to us. It was still nice to see some feathered life in the water or by its edge.

Lesser (front) and Greater (back) Yellowlegs

The killdeer was so well camouflaged that we spotted it only when it sounded its signature call after which it was named.

Killdeer

We continued past the pond. The trail was well maintained - the grass was high on the sides but the trail was trimmed nice and wide. I didn't see thistles there, but there was other prickly vegetation I was happy to not have rubbed against.

Trail

One of the most impressive prickly plants we saw there was actually a tree, and the thorns were covering its bark. Yes, I did try touching, and yes, I regretted it.

The acacia trees also had thorns, needle-thin, nasty things that grew out of the stem knobs. The birds didn't mind the thorns at all, and my chika was happy encountering more Puerto Rican birds that were new to here.

Gray Kingbird

This trail was an interpretive trail, meaning here and there were signs with information about the place and its inhabitants. The signs were particularly useful when it was clear what was their object, such as the Quenepa tree.

Quenepa, Melicoccus bijugatus 

At the place where we were to loop back was another pond. This pond had more water but considerably fewer birds.

Pond

Not that we didn't see anything interesting there. In fact, one of my favorite sights from my trip to Puerto Rico was right there by that birdless pond - a cactus growing on top of another tree, as an epiphyte (a plant that grows on other plants, such as the bromiliads we've seen at El Yunque National Forest).  It was too high up for me to check out the groove in which it sprouted and thrived, but I cannot see another way in which it must have happened - cacti are not epiphytes in their nature. 

Epiphytic Cactus

We reached a trail junction - to continue would have taken us to the coastal road an a possible access to the beach. We bth wanted to go to the beach but we preferred driving there, so we took the curve around the pond, looping back to the parking area. We crossed a little bridge spanning a now dry creek, found a shaded place and sat down for a short break. 

Lizard on the bridge

The trail was easy and not very long but the heat was so intense that all I wanted by the half point was to finish it and go to the beach. My chika would have liked to hang there a bit longer - she listened to the birds in the trees but they were difficult to see and eventually she too was ready to move on. 

She got better luck once the trees opened up a bit - a flock of ani birds settled in the acacia trees, screaming loudly at one another. 

Smooth-billed Ani

The ani calls followed us for a good distance. Despite the heat I kept on the lookout for wildflowers. There weren't all that many of them. The doves that we saw a bit further away were silent, and only their movement revealed their location.

Common Ground Dove

 

Unlike the tropical rain forest of El Yunque that had so much bloom, the Cabo Rojo NWR had very little wildflower display. This area probably sees more seasonal change too, and we might have been to late for the bloom peak. Still, we so some flowers.

Brazilian Rosemallow, Hibiscus phoeniceus 

We reached another trail junction where the hikers trail joined what looked like a narrow dirt road. On the side near the junction was a patch of what looked like inverted pea blossoms. They were indeed of the pea family, but not the genus, and the flower was upside-down compared to its real pea relatives. The Latin name of this flower reveals what the person naming it was seeing in this shape.

Blue Pea, Clitoria ternatea 

The dirt road put us right back in he open, but the afternoon sun was already down enough for some shade to be cast on the trail from the trees on the side. The heat was still pretty intense though.

Trail

Although we were hiking in a small area of the preserve, still we saw more new things on the way back, such as this interesting tree in the photo below. which had fruit that looked like lemons but clearly wasn't a lemon, and not even a citrus of any kind.

Higuerito, Crescenia linearifolia

It didn't fool me, but it did fool some of the plant identification applications I've tried to  identify this tree. Unlike other trees in the refuge, this one didn't have an information sign next to it. It was other people on the iNaturalist platform that identified it for me.

Higuerito, Crescenia linearifolia

Something else I found interesting was another epiphyte plant that was growing on a branch of this Higuerito, mock lemon tree. At first I thought it might be a parasite plant such as the mistletoe. Later however, I saw it growing even on power lines, so it certainly didn't need its perch to be a living thing.

Ballmoss, Tillandsia recurvata

We moved on. From the beginning of the hike I had a feeling of familiarity - that I should know how the vegetation community there should be called. It was about two thirds into the hike that it finally struck me - this reminded me much of an African savanna, except that there were more trees and a lot more of medium size vegetation - the in-between layer that the African savanna didn't have. The reason for the difference was very clear - Puerto Rico didn't have native large grazers that would take care of eliminating this second story vegetation.

An information sign by the side of the trail told us about a unique little flycatcher that lived in this area. Shortly after reading the sign, the bird itself showed up to model for us.

Juí Blanco, Caribbean Elaenia

My chika was very excited about the little Elaenia, and I had to work a bit to convince her to take a photo of the turkey vulture that circled the sky above us. These vultures are native to the western USA and are very prevalent there. They were introduced to Puerto Rico and made their home in the southwest region of the island.

Turkey Vulture

One of the trees growing there I recognized immediately - that was the tamarind tree. It was introduced to Puerto Rico as it was in Hawai'i, where I last saw this species on the Captain Cook Monument hike.

Tamarind, Tamarindus indica

The dirt road connected with a hikers trail and once again we were walking on a narrower path of cut down grass.

Trail

The bushes and low trees were home to many little birds there. We could hear them all right, and some of them we could even see occasionally. 

Yellow-faced Grassquit (female)

Nearly all the little brown or gray birds we saw there that day were lifers to us, although the exact identification of their species was somewhat challenging.

Puerto Rican Flycatcher

The iguanas however, were no problem to identify, and they were everywhere there, sunning on the tallest of the trees in the refuge.

Green Iguana

Of the cacti I saw in the refuge that day was also a pad cactus that reminded me of the beavertail from California. It wasn't a beavertail though, and it had lovely, intensely red flowers. I asked my chika to take a close up photo with her birding camera and I selected that photo to head this post.

Consolea moniliformis

Size matters not, said Master Yoda, and at least when it comes to wildflowers he was right. Some of the prettiest and most delicate flowers I saw that day were also the smallest.

Bellyache Bush, Jatropha gossypiifolia

We completed the loop and continued on the in and out spur that connected it to the parking area. The parking area was a large circle with an 'island' of cut grass and some tall trees. A few hyperactive yellow butterflies swirled over the green blades without pausing even for a second. I took many photos and only one of them looks somewhat like a butterfly.

Grass Yellow Butterfly

My daughter yelped and I turned to see a large iguana sliding down a tree near us and running away at top speed. I snapped a quick photo but the iguana was already far away. These lizards can sure run fast.

They run very funny too. I was too far away to capture the details of the running iguana but my chika did get a nice series, each position looks more funny than the other. I chose the least weird one to post here.

Green Iguana

Hot and sweaty, my chika made her way quickly back to the car where we had to wait patiently while I snapped a few shots of a little flower blooming in the grass.

Three-lobed False Mallow, Malvastrum coromandelianum

The first thing we did in the car was to get the air conditioner on. While I punched in the next destination into my navigator app another car showed up, which turned out to be an official refuge park. The ranger inside rolled down the window and barraged us with a sharp speech in Spanish. It was too fast for me to catch even single words in that speech so I nudged my chika, who took three years of Spanish in high school and was putting her knowledge into good use during our trip. We didn't need my chika's Spanish this time, though. The moment the ranger realized we were tourists she changed her demeanor, and in perfect English told us that the refuge was closed to visitors that day. I guess that it wasn't the wind that pushed the gate was half-closed. I apologized and drove off, silently thankful that our mistake was seen at the end of the hike and not before it. 

 

This interesting hike was also the last one we did in Puerto Rico that trip. We did a number of cool nature explorations on the rest of our time there, but these were beach and ocean explorations rather than inland ones. There's much more of Puerto Rico that  I'd love to see in the future, especially of the mountains in the center of the main island, which we only had a glimpse of on our drive from Manatí to Guanica. At the end of our tip we also spent some time in Vieques, a small island southeast of the main Puerto Rico island, where we got to see the wonderful bioluminescence of Mosquito Bay, and to go on a private snorkeling tour with Crystal Clear Vieques, an amazing tour that was one of the best highlights of our time in Puerto Rico. I had only a week there, but I fell in love with Puerto Rico. I will go there again for sure, now it's only a matter of not waiting another 30 years before making that happen.