Reserva Ecologia Costanera Sur, Buenos Aires, 9/12/23

It's been a long time coming but I finally took the plunge and scheduled a trip to Argentina.  September is not a great time to come as it's early spring in the north, winter in the south and summer birds are still off where it's warm.  But air fare and lodging were a lot cheaper than the warmer season and I knew I would find plenty to keep me busy and I was itching to go somewhere.

The overnight flight from McAllen, Tx to Dallas and then to Buenos Aires took about fifteen hours and wasn't that bad.  Took a while to get into town and get settled into my Air B&B condo in Puerto Madero.  But by 2pm I was ready to go birding and just a few blocks from the famous Reserva Ecologia Costanera Sur.  This huge park is a favorite for the locals where they can escape the urban intesity of Buenos Aires and walk, jog, bike or kick back with a cup of yerba mate.  A few even go birding and the cummulative eBird list for the park is an impressive 347 species.  There are large wetland areas and lots of mish mash introduced tree species tha makes a scrubby woodland that the local bird species have adapted to and and even a rough shoreline where the Rio de la Plata enters the Atlantic Ocean.

As I approached the park, the wetlands on the west side held plenty of new species and a lot of familiar ones.  At home we only have one species of coot but in Argentina there are a half dozen.  Here's the Red-fronted Coot with its maroon frontal shield and yellow bill.

The Red-gartered Coot has a yellow frontal shield bordered below by a rusty band.

The White-winged Coot has a plain yellow bill and frontal shield.

The entrance trail held what would prove to be common Rufous-bellied Thrushes.  But the first one is always exciting.

And the uber common Rufous-collared Sparrow.  In the Andes these guys act more like their Zonotrichia congeners up north, like regular sparrows.  But down here they are fearless city birds tirelessly singing throughout the day.

New to me was another noisy tame species, the Rufous Hornero.  I had seen Pacific Hornero in Ecuador so these were easy to ID.  They wandered around the trails looking for insects and occasionally collecting mud for their nest which looks like and old earthern Spanish oven known as an "horno".

Another wetland opened along the trail and a harsh scream drew my attention to my first Southern Screamers.  I've seen these turkey sized duck relatives in zoos so I knew the huge birds by sight.  The surprise was this pair was watching over their eggs.

Silver Teal was a new species for me.  And often a pair would be accompanied by a White-tufted Grebe.  I think this is an example of commensalism where the teal are doing the work stirring up food for the opportunistic grebe.

I've seen quite a few Masked Ducks though the years.  Apparently the they are uncommon at Costanera  Sur.

Black-necked Swan was a new species for me.

Another lifer that proved to be common was the Picazuro Pigeon.

All thoughout the Americas are various species of gnatcatchers.  Here in northern Argentina occurs the Masked Gnatcatcher.  They are just as difficult to photograph as our Blue-grays are.

Tropical tyrannulets can be difficult to identify but his one showed well for me.  The black streaking in the crown separates this Straneck's Tryrannulet from the very similar White-crested Tyrannulet.

It was getting late as I returned to the interpretive center near the entrance.  I was excited to find this cooperative Rufous-and-black Warbling-Finch.  Turns out they are pretty common in the park.

Walking back to the entrance I found a striking Yellow-billed Cardinal.

Argentina has a diverse Icterid fauna.  Unfortunately I did not find many of the varied blackbird species that occur hear.  I did find Grayish Baywings near the entrance.

I think this is a female Shiny Cowbird which lays it's eggs in the nest of Grayish Baywings.

In the Rio Grande Valley there is an introduced population of Monk Parakeets near the Hidalgo Pumphouse.  Other populations occur near Houston and Austin.  Down here they are a native species.

I fishished my first run through Costanera del Sur with afternoon sunlight illuminating lovely Rosy-billed Pochards.  The female looks very different as is the case of all members of the genus Netta which is similar to our genus Aythya.