Monday 27 March 2023

Heading East Into The Atlantic Forest

The Atlantic Forest (Mata Atlântica in Portuguese) stretches across the southeastern coastal region of Brazil, reaching inland as far as southeastern Paraguay and northeastern Argentina. In broad terms, the Atlantic Forest is formed and continues to be maintained by moisture-laden trade winds reaching the low mountains along the coast of this part of South America. Rainfall in this region leads to proliferation of vegetation, and with that comes high biodiversity. A number of different forest types compose this region including restinga on stable coastal dunes, tropical moist forest, montane forest, and montane savanna at the highest elevations. 

Much of the original vegetation cover in the Atlantic Forest has been removed. Estimates of forest cover lost usually range from 88-95 percent, and it is ongoing today. In some areas, only the steepest slopes are spared from the effects of the relentless human machine. 

Laura and I have plans to explore as much of the Atlantic Forest region as we can over several months and that began with just over a week in Argentina. Though Argentina only holds a small fraction of the total area of the Atlantic forest, it has some high quality areas full of unique species. 


February 3, 2023

We left the town of Ituzaingó at dawn and watched the landscape change as we headed east. By the time that we had crossed over into Misiones Province - the gateway to the Atlantic forest, as far as we were concerned - the marshes, grasslands and pastures had started to give way to small patches of woodland and occasional well-vegetated river valleys. We were still a good distance from "proper" Atlantic forest, but the species composition was undoubtedly changing already. 

Reserva Urutaú, Misiones, Argentina

Our first stop was in search of the Streamer-tailed Tyrant at a site called Reserva Urutaú. While the flycatcher was our main quarry, we would undoubtedly see many other species here in the scrubby, riverine vegetation and shrubby grassland. Lucky for us, a thick layer of cloud cover prolonged the bird activity, and we enjoyed a productive few hours. 

Unidentified seedeater (Sporophila sp.) - Reserva Urutaú, Misiones, Argentina

Long-winged Harrier - Reserva Urutaú, Misiones, Argentina

Road works needed...

The Streamer-tailed Tyrants eluded us but we enjoyed over 70 other species of birds. Two of these were lifers: the crisp Pearly-bellied Seedeater, and the skulky Spix's Spinetail. 

Pearly-bellied Seedeater - Reserva Urutaú, Misiones, Argentina

Spix's Spinetail - Reserva Urutaú, Misiones, Argentina

The wetland edges, as expected, held a nice variety of species including a Black-collared Hawk, the first Anhinga and Purple Gallinule for our Argentina lists, and Laura's lifer Tawny-headed Swallow. 

Anhinga - Reserva Urutaú, Misiones, Argentina

Tawny-headed Swallow - Reserva Urutaú, Misiones, Argentina

Quite a few Yellow-chinned Spinetails were rattling away from the rank grasses at the edges of the marsh.

Yellow-chinned Spinetail - Reserva Urutaú, Misiones, Argentina

Even with the overcast conditions, the warm temperatures and rapidly thinning cloud layer promoted the appearances of insects. Here are a few that I photographed at various points during the walk. 

Eighty Butterfly (Callicore sorana) - Reserva Urutaú, Misiones, Argentina

Flame-tailed Pondhawk (Erythemis peruviana) - Reserva Urutaú, Misiones, Argentina

Blurry-striped Longtail (Chioides catillus) - Reserva Urutaú, Misiones, Argentina

Royal Firetip (Mysoria barcastus) - Reserva Urutaú, Misiones, Argentina

Traumatomutilla vidua - Reserva Urutaú, Misiones, Argentina

Still Streamer-tailed Tyrant-less, Laura and I left Urutaú and ventured over to the next site called Parque Federal Campo San Juan. In birding circles, it is famous as being the location where the first Ocellated Crakes for Argentina were discovered, while it also holds a population of rare Sickle-winged Nightjars. Laura and I weren't there for the nightjars - after all, we had just seen them two nights earlier - but a high percentage of eBird checklists from here contained the Streamer-tailed Tyrant. Even though our visit was around midday, we were hoping for the best. 

Parque Federal Campo San Juan, Misiones, Argentina

We signed in with the friendly staff manning the entrance gate (no fee required!) and worked our way down the road. The conditions were still overcast but the temperatures were warming and a breeze was stirring. We had to work quickly to find birds before the suitable conditions got away on us. 

Luckily, we found the tyrants without much trouble; they were in the field behind the carpark at the end of the entrance road. And they were spectacular! I was not prepared for how large they were either - much larger than, say, a Fork-tailed Flycatcher. 

Streamer-tailed Tyrants - Parque Federal Campo San Juan, Misiones, Argentina

Streamer-tailed Tyrants - Parque Federal Campo San Juan, Misiones, Argentina

With our target acquired, Laura and I went for a walk a little bit further down the road, past the orange traffic cone placed in the middle of the road. We could see forest beyond and despite the time of day, we were sure that we could find a handful of new species. This was our first patch of Atlantic Forest, after all. A distant singing Spot-backed Antshrike, our first, provided all the incentive that we needed as we set off on foot. 

Parque Federal Campo San Juan, Misiones, Argentina

The birding was slow but we were on high alert. Surely a large percentage of the birds inhabiting these woods would be new for us. But most of what we found were ones we were familiar with, such as this Yellow Tyrannulet. Still, it was a bird worth admiring as it had been several months since our last. 

Yellow Tyrannulet - Parque Federal Campo San Juan, Misiones, Argentina

As someone who is interested in all things found in nature, not just those with feathers, there is rarely a dull moment when in a forest. I marveled at the abundant insect life during the slow birding periods, taking hundreds of photos of the kaleidoscope of colours laid out in front of me. 

Polydamas Swallowtail (Battus polydamas) - Parque Federal Campo San Juan, Misiones, Argentina

Staleochlora viridicata - Parque Federal Campo San Juan, Misiones, Argentina

Triorla sp. - Parque Federal Campo San Juan, Misiones, Argentina

Variegated Skipper (Gorgythion begga) - Parque Federal Campo San Juan, Misiones, Argentina

Diastatops intensa - Parque Federal Campo San Juan, Misiones, Argentina

Four-spotted Sailor (Dynamine postverta) - Parque Federal Campo San Juan, Misiones, Argentina

The road terminated at the Paraná River, giving us another look at Paraguay. My brief vigil added another ten species to my Paraguay list including a smart-looking Snail Kite on the far bank. 

Scanning into Paraguay from Parque Federal Campo San Juan, Misiones, Argentina

These lizards were basking on one of the decrepit buildings nearby. This is the widespread species called Tropidurus catalanensis, the Western Collared Spiny Lizard. 

Western Collared Spiny Lizard (Tropidurus catalanensis) - Parque Federal Campo San Juan, Misiones, Argentina

The return walk up the road was surprisingly birdless at first, giving me another crack at photographing insects. 

Flame-tailed Pondhawk (Erythemis peruviana) - Parque Federal Campo San Juan, Misiones, Argentina

Soldier Grasshopper (Chromacris speciosa) - Parque Federal Campo San Juan, Misiones, Argentina

Manuel's Skipper (Polygonus savigny) - Parque Federal Campo San Juan, Misiones, Argentina

Thoas Swallowtail (Heraclides thoas) - Parque Federal Campo San Juan, Misiones, Argentina

Heliopetes libra - Parque Federal Campo San Juan, Misiones, Argentina

But then we struck gold, in the form of a small mixed flock. In hindsight, none of these species were particularly unusual, and we would see many more in the upcoming weeks, but you never forget your first. 

Rufous-margined Antbird - Parque Federal Campo San Juan, Misiones, Argentina

Southern Antpipit - Parque Federal Campo San Juan, Misiones, Argentina

In addition to the above two species, we also saw our first Eared Pygmy-Tyrant and Ruby-crowned Tanagers. Two mammals also appeared on the road - an Azara's Agouti and a South American Coati. 

Azara's Agouti (Dasyprocta azarae) - Parque Federal Campo San Juan, Misiones, Argentina

South American Coati (Nasua nasua) - Parque Federal Campo San Juan, Misiones, Argentina

Before leaving the area behind, Laura and I made a quick check of the grasslands to search of the Ocellated Crakes. The winds had picked up and the sun had broken through, giving me little hope of actually finding them. And while we did not see any, an individual easily responded to my playback. During this time, I also photographed a small group of Cliff Swallows which constitued the first report of this species for the eBird hotspot. 

Cliff Swallow - Parque Federal Campo San Juan, Misiones, Argentina

On our way out we pulled over to admire these Pearly-breasted Seedeaters, a great improvement over the morning's experience. And with that, we called it a day and headed back to the town of Posadas to spend the night. Our first day in Misiones province had been a success. 

Pearly-bellied Seedeater - Parque Federal Campo San Juan, Misiones, Argentina

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