Birding in Colombia #12: A Neotropical Lake

Greater Ani

Our next birding adventure was a decidedly different ecosystem than the mid-to-high Andes spots that had dominated our tour so far. We were headed the Laguna de Sonso Nature Reserve.

It contains the last extensive remnant of natural wetland the Cauca River Valley

It comprises a series of marshes and lagoons on the east bank of the Cauca River, between the municipalities of Buga, Yotoco and Guacari. With an area of almost eight square miles, it sits at 3,068 feet and was sunny and decidedly sticky.

Looking very Jurassic

Sonso is home to more than 160 species of birds, including lots of water species we hadn’t seen in a few days.

When we arrived, we discovered that we could not actually enter Nature Reserve because of recent flooding. So, we regrouped and birded around the wetlands just outside the locked gates.

We could see in; I doubt that we missed anything

Our route included some dry paths through lakeside trees and beside reed-filled ponds plus some areas that looked as though they had recently been underwater.

It had dried sufficiently for walking

We started with a trifecta of Whistling Ducks …

Black-bellied Whistling Duck

White-faced Whistling Ducks

Fulvous Whistling Duck

There are eight species of Whistling Ducks, or Tree Ducks. I had seen the White-faced and Black-bellied, but the Fulvous were new. 

Fulvous is a color described as a tawny brownish-yellow, beige or caramel-brown

Found in the tropics and subtropics, they have long legs and necks, a hunched appearance, black underwings in flight and are very gregarious, flying to and from night-time roosts in large flocks. Oh, and, of course, they have distinctive whistling calls.

Black-bellied Whistling Ducks

Both sexes have the same plumage. Males, especially within the Fulvous species, will often help with the construction of nests and take turns with the female incubating eggs.

The area around us had a lot of other water birds – Great Egrets, Cattle Egrets, Bare-faced Ibises, a Blue-winged Teal, Common and Purple Gallinules, Southern Lapwings, a Wattled Jacana, a Solitary Sandpiper, Neotropic Cormorants, Cocoi Herons, a Black-crowned Night Heron and a Ringed Kingfisher – but I was concentrating on the Ducks and didn’t pay much attention. Except when this Black-necked Stilt’s chick briefly appeared. 

The chick is somewhere behind those reeds

And, I saw a new lifer – a Buff-necked Ibis – that was flying too fast into the sun for my camera.

I saw them multiple times and never got a photo; Drawing: Birds of the World

The group kept saying that they saw a Snail Kite. I thought I missed it until I looked closely at the photo I took of some of Black-bellied Whistling Ducks flying away. There’s a Snail Kite right in the tree!

Pretty obvious when you zoom in

We left the front lake and walked down a path through some trees to a vista of the River. 

Birds like cecropia trees

Along the way, we had quite a few sightings ...

Black-crowned Night Heron

Black-billed Thrush in a fruit tree

Streak-headed Woodcreeper and Tropical Kingbird

Ruddy Ground Dove

Great Kiskadee and its cousin, a Rusty-margined Flycatcher

Yellow-Olive Flatbill

I saw a bird and clicked a pic before I could even get the attention of my fellow travelers who were searching another tree for a Chivi Vireo. I showed the photo to Alejandro and he deemed it a Southern Beardless Tyrannulet. A Lifer! Super.

But, later, eBird challenged that and I looked closely at both birds. 

It was a Yellow-bellied Elaenia; not a new bird, but a cute one

And, I missed the Chivi Vireo, which would have been a new bird. This was truly a bird-in-hand-versus-bird-in bush situation. 

I did manage to see an Acadian flycatcher – one that has evaded me in the U.S. – but I didn’t get a photo. 

And, I photographed some Northern Warrior Wasps on their papery nest.

That nest is a work of art

Looking out toward the River, we saw lots of birds perched in dead trees. Finally, after missing them several time, I saw and photographed some Spectacled Parrotlets (lifer!) ...

After chasing these birds all over!

Plus there were ...

Blue-headed Parrots

Lineated Woodpeckers and an Oriole Blackbird

The yellow and black bird fooled me at first; I thought it was a Yellow-hooded Blackbird, but it was an Oriole Blackbird, another lifer.

We had been noting, but largely ignoring, Black Vultures for the past few days. But, Sonso had some very impressive ones.

 

They were all enjoying the sunshine

Later, we encountered quite a few Black Vultures walking in the dried mud among Capybara footprints. I really hoped we'd see one of the giant rodents, but we never saw more than the prints.

Way on the other side of the river, a Green Iguana lazing way up in a tree branch caught our eye. 

They are green only as juveniles, then they turn brown

On closer inspection, we also saw Spectacled Parrotlets, a Great Kiskadee, a Tropical Kingbird and a Yellow Oriole (another lifer) in the tree above the Iguana.

Can you find them? Are there ones I missed?

We had some nice looks at a perching female Snail Kite, which, along with the Broad-winged and Roadside Hawk, seemed to be one of the most common raptors in this part of Colombia.

The Kite was calm and collected

she moved once to a palm at bit farther out

And, then again, to a tree adjacent to a pasture

Off beyond the Kite was a Red-breasted Meadowlark, a gorgeous bird I had seen in 2022 in Costa Rica. It was too far for a photo and almost too far for binoculars. We never saw another.

My Costa Rican sighting

As we rounded the end of the wetlands, we saw more of many of the water birds we had seen when we first arrived at Sonso Lake. Here were even more that I didn’t snap – Limpkin, Osprey, Spotted Sandpiper, Glossy Ibis, Snowy Egret, Striated Heron and Pied Water-Tyrant – all that I had seen and photographed before, either in Colombia or elsewhere.

I did get a photo of Wattled Jacana

Back at Guarinocito Lake, we had been thrilled to encounter a couple of Northern Screamers. Sonso delivered with that bird’s cousin, the Horned Screamer, which was, obviously, another lifer for me.

Screamer #2 (sounds like a horror movie title)

One of just three Screamer species (I guess I’ll have to go to Bolivia, northern Argentina, Paraguay, southwestern Brazil or Uruguay to see the Southern Screamer), the Horned Screamer stands about three feet tall and has long, heavy legs, a small chicken-like bill and a long spiny structure projecting forward from its crown. 

This “horn” is unique among birds because it is not a feather, but is a cornified structure loosely attached to the skull that grows continuously while often breaking at the tip.

Left: We saw two; Right: Close up of the horn

Horned Screamers tend to group together, but are, for the most part, semi-social. They are rather sedentary, living in well-vegetated marshes and feeding on water plants. We saw two that were hanging out with a couple of Black Vultures.

A macabre group

Later, one flew further away into the sunlight.

Warming up

We swung around and walked along a canal and saw many more birds. This was a great spot. We had two lifer Cuckoos …

Dwarf Cuckoo (not the best angle)

Striped Cuckoo, singing and singing

Then, two different Woodpeckers ...

A Spot-breasted Woodpecker (lifer) and a Red-crowned Woodpecker (old friend)

The Spot-breasted was working diligently on its nest

We saw a much closer-range pair of Yellow Orioles also hard at work building a nest ...

I think it has a long way to go

... another Oriole Blackbird ...

This one was much closer

... and a very close Greater Ani, shining in the sun ...

They usually look black – until you get some light

Looking towards the reedy wetlands, we saw a distant Great Egret ...

Standing tall

Not far away is where I saw my first Bittern – a Pinnated Bittern that briefly raised its head above the reeds. Cool but I wish I could have gotten a photo. As it was, I barely saw it through a scope.

The final lifer of the day was a Jet Antbird deep in some thick foliage ...

The spotted wings are beautiful

Then, we had visits from two other lovely birds ...

A curious Palm Tanager

A regal Yellow-headed Caracara

On that side of the lake, we came upon an Azteca Ant nest and another Northern Warrior Wasp nest, this one a long, pointed affair. 

It’s hard to tell the Ants, left, from the Wasps, right, or even the Termites

To make these interesting nests, the Wasps gather fibers from dead wood and plant stems, that they mix with saliva to create a gray or brown material similar to handmade paper. Some Warrior Wasp nests are shaped like Armadillos, giving the Wasp the name “Armadillo Wasp.”

Colombia has 3,642 documented species of Butterfly and I only captured a few. 

Right is a Menapis Tigerwing; I haven't ID'd the one on the left yet

We were mystified by what looked like bubblegum stuck to some of the trees at the edge of the water.

This pink is NOT enhanced

After-the-fact research and a closer look at the photos revealed that they were Apple Snail eggs (with baby Snails hatching).

You can actually see baby Snails hatching

These large freshwater snails have both gill and lung respiratory structures, separated by a division of the mantle cavity, making them amphibious. This makes them exceptionally well adapted to tropical regions characterized by periods of drought alternating with periods of high rainfall. They also an operculum that can seal the shell entrance to prevent drying out while the Snail is buried in the mud during dry periods.

Apple Snails; Photo: Nemesis

Since they can’t seem to make up their minds, they are also gonochoristic, meaning that each individual can be either male or female.

The pink color protects eggs against predation by fish and other aquatic inhabitants (I guess fish don’t like bubblegum).

Apple Snails are the number one food for Snail Kites, so that makes sense.

Maybe that's what the male Snail Kite we saw soaring was looking for

As we walked to the van that Hernan had moved to a shaded spot by the locked gates, Enid casually asked Alejandro if he could find a Potoo. Minutes later, he did! 

Just a Common Potoo sleeping in a tree

I had seen this unusual bird in Costa Rica (I have also seen the Great Potoo in Costa Rica and the Northern Potoo in Mexico and Roatan). I have written about Potoos here. 

In another tree nearby we saw another Streaked Woodcreeper working his way up the branches. 

An industrious bird

Sonso Lake was a success. A hot, sticky, swampy success. But, full of great birds.

Next, things will get colorful.

A female Red-headed Barbet

Tour dates: March 7-28, 2026