Ribera Norte... Virtual walkaround

How about going now for a walk around the reserve?

Please refer to the map of the reserve. The trail is shown in red and some points mentioned along our walk are shown in white numbers.

Ready... Steady ... Wait! Just before we start, how about a quick introduction?

The various habitats we'll come across are the following:
Marshes - in which many species of tall rushes grow.
Lagoon - often covered with floating vegetation, including "camalote" water lilies.
Ceibal - clumps of forest of the fairly small "ceibo" trees (also written as "seibo") grow near the water. The Ceibo is the official national flower of Argentina.
Riverside bushes - where many characteristic plants grow.
Willow forest - There are various types, as introduced willow species have hybridized with the native form.
Río de la Plata coastline - with ample reedbeds. At low tide a large brown sandy beach is exposed.
Aliso forest - the return path winds through a small clump of these trees.

Of course, one cannot always define exactly where the boundaries are between each habitat. Plant colonies do not always form "pure stands", and many invasive exotic species add to the confusion. So don't be too concerned if you cannot immediatelly identify each habitat as you walk the trail! You'll find more information about this in the page on Aerial Views.

Most of the photos have been taken in spring or summer, when the vegetation is at its best, but remember that each season has its own worthy highlights. In winter some migrant birds arrive from Patagonia, and a keen eye will always be able to locate flowers and butterflies, even in winter.

One word about the rubbish we'll see on the way. You may think at first that the torn plastic bags hanging on low braches may have been discarded by a party visiting ahead of you. But in fact it is the result of the high tides of the Rio de la Plata which, several times a month, completely flood the reserve. Then, as the waters subside, many plastic bags and other unsightly (but essentially inert and harmless) trash is left clinging to branches and trapped at the base of trees and bushes. It is an unavoidable reminder that we are close to a large city that has rubbish-disposal problems. The best is not to take any notice of it. As you go only look out for the nice things! The lush spring growth succeeds in hiding much of it from sight, but in winter the trash may be a lttle more obvious.

1 - Arrival / Start of trail

OK, we've made it to Ribera Norte. We've come in through the main gates and have said "Hello!" to the warden or persons in charge. Next to the hut we may find a volunteer eager to give us a handout. If you need a nature guide-book you may find it useful to first visit the small stall. If it is about teatime on a weekend or bank holiday, and you can understand Spanish, ask about the free guided tour that normally runs once a day. Otherwise just set off on the trail. It is about 400m long and takes under an hour to do - or more if you stop often along the way. You'll now penetrate a mysterious world of wild plants and animals. You should see many birds, though the House Sparrow, so common in parks and gardens in Buenos Aires, tends to stay out of the reserve. This European species has colonized the whole country and is always found close to human habitation, while nostly keeping away from wilder habitats like this one.

The thatched hut at the entrance. The trail starts to the right of the picture Sadly the hut is no longer here - it was set alight one night by vandals

2 - Reeds and marshes on the left, swamps on the right

The narrow, elevated trail keeps us clear of the drenched land on either side of it. We come out of the shade and have many kinds of plants around us. On the left are tall stands of various species of rushes. Further afield some reddish Sarandi bushes host a colony of nesting egrets and herons during spring and summer. You'll hear their strange human-like gargles as they defend their nests. Further ahead you'll pass one of the largest Ceibo trees in the reserve, boasting large clumps of red flowers from spring through autumn. This is the National Flower of Argentina. On the right are willows. Look out for nests of Rufus Hornero, shaped like football-sized mud ovens. Many other bird are to be found here too: Hummingbirds, gnatcatchers, woodpeckers, etc.

Colony of egrets nesting in Sarandí (Cephalanthus glabratus - Rubiaceae)

Evidently we are not alone along this trail... Here is a curious Gray-necked Woodrail (Aramides cajanea). Make sure you do not scare it away intentionally. The quieter we are along the trail the more chances we'll have of seeing this and other birds that are naturally shy and wary of humans. Just like on any outing into the wilderness, there are no certainties here. Unlike visiting a zoo, there is no way to be sure you will see a particular kind of wild animal. But discovering them in the wild is so much more rewarding and exciting, even if the full list of resident species is only partly checked off...

3 - The Lagoon

We've made it to the quiet lagoon, perhaps the place where you'll see the most number of birds and maybe also coipus (large rodents) and tortoises as well. I suggest you stay here for a while, as this is where things DO happen! If you see a nice green lawn don't try to walk on it: it's only floating vegetation (mainly Areaceae: Pistia stratiotes). On the far side of the lagoon you'll most likely see wild duck, Jacanas, Gallinules and other herons. Many other bird species are sure to fly above the lagoon. Among the reeds look out for Plumbeous Rails, Rufous-sided Crakes and the Curve-billed Reedhaunter, three species that are a trademark of Ribera Norte! Keep an eye open for large apple snails, or their bright pink-coloured clumps of eggs laid on reeds near water. Most importantly: listen for bird calls. Once heard, look in the direction of the sound. You may be treated with a "new species"!

Perched on a distant ceibo tree is a White-necked Heron. On the floating vegetation is a lovely Rufescent Tiger-Heron (Tigrisoma lineatum)

4 - Back into the shade
We turn a couple of times and enter a shady "jungle". This is pretty much a ceibo forest ("ceibal" in Spanish). Lean down a little to try and spot 2 species of woodrail among the vegetation and in the swamps.

5 - The metal bridge

This is an important milestone. The bridge spans a muddy section where the elevated trail has in the past been repeatedly washed away. Look out for birds crossing underneath and hiding in the thick bushes. It is also a good vantage point to see the coastline and larger birds such as lapwings, gulls, raptors and reedbirds. And a nice place to bask in the sun! One foggy autumn morning I witnessed a marvellous migration of Fork-tailed Flycatchers. They were flying up north along the coast, and hidden by the dense fog, would come into view only 2 or 3 at a time. It was certainly surreal!

The coast of the Río de la Plata as seen from the metal bridge

6 - Riverside bushes

We are now walking parallel to the coast. In some parts here it is virtually a jungle, and certain bird species are found here more often, such as the Black-and-rufous Warbling- Finch or the Red-rumped Warbling-Finch. In summer and autumn I have also seen many rare butterflies here. A typical plant along this stretch is the Ludwigia elegans (see photo)

Ludwigia elegans

7 - Willow forest

We follow the trail and eventually enter a forest of tall willow trees. It is the realm of woodpeckers, woodcreepers and other shy birds that may stay quite high up in the canopy. Listen for the curious "jungle-like" calls of the Solitary Black Cacique. Wait a moment to see what surprises lie in store for us today! In summer one of the most beautiful Heliconium butterflies, with black, red and yellow can be seen flying here - distinctly amazonian!. In February you may see the largest of them all: the incredible white Morphos (Morpho epistrophus) that in flight seems to resemble an A4-sized sheet of paper animated by some invisible muscle. Photo on the right shoes the Green-barred (previously Golden-breasted) Woodpecker (Colapets melanolaimus).

8 - Detour to the coast

At the junction we take a short detour to the beach. If the tide is low we'll see a wide dull-brown sandy beach. Though not at first visible, some animals live here too, including various freshwater bivalves introduced from Asia and now thriving. They are potentially-serious newcomers that are invading the whole of the Parana-Uruguay system. The negative effects on the native biodiversity will be felt all the way up to Bolivia. It is to be seen just how serious this will become. A biological invasion is therefore taking place here and now, and sadly there is not much that can be done about it other than witness it from these shores. One windy day in autumn I noted here a solitary butterfly begin a feeble and erratic "flutter" above rather unsettled waters. I followed it with my binoculars as it continued undeterred away from the shore. It was simply migrating to Uruguay, far beyond the horizon!

The photo shows a Limpkin (Aramus guarauna), possibly feeding on exotic snails.

9 - Return leg

ROAD CLOSED! Due to the rest of the trail being watrerlogged and muddy, it is likely you will find it closed to the public. For the time being then, the return path is to go back the way you came. It is a pity for it means you may miss some nice parts. However, in my experience I seldom add any new bird species along the section that is now closed. Once back at the Visitor's Centre find your way to do in reverse direction the last part of the tail, which should normally be open. (See Part 12 below) Appeal: If you are able to contribute funds to the reserve, it will help to resolve this issue sooner than later. Thank you!

We're back on the trail around the reserve and there is still plenty to explore! We continue under tall willows and then walk close to the swamps and over a narrow bridge. If you are here in September you would be treated to a wonderful display of Yellow Irises in full bloom. Sadly these are not native plants but rather are a serious invader that is expanding unchecked and destroying the native habitats. It is definitely not good news here! However, many local birds seem to make a home in it: Curve-billed Reedhaunters, Wren-like Rushbirds, crakes and rails are often seen in them.

10 - Aliso forest

We continue along this straight stretch, with reeds on the left and a drainage ditch on the right. Further to the right is a yachting club. Look out for turtles resting on some floating plank. Dead "apple snails" are often found. But how did they arrive here? Many birds hunt them. Limpkins find them in the swamps and take them to their favourite perch above the trail to eat the soft parts inside - and then discard the shell. Woodrails possibly eat them too. We soon enter a fairly recent stand of Aliso trees (COMPOSITAE: Tessaria integrifolia). In the photo the tree in the foreground is a willow, and behind is the multitude of Alisos, a nice native tree with purple flowers, that is rapidly expanding. Alisos are the first trees to grow on new land formations of the Parana river delta.
Apple snail Scientific name: Pomacea caniculata It is the favourite food of the Limpkin and a raptor accurately called the Snail Kite. This fairly large snail lives in freshwater rivers, lakes and swamps.

11 - Winding through the reeds

We walk over another small bridge, out of the forest and again have tall stands of rushes and irises on either side. This is a good place to note the difference between the plants of Yellow Iris and the taller native rushes which include Totora (Typha latifolia) and Cortadera (Scirpus giganteus). We come close to the road bordering the reserve and then turn left. Here is another beautiful part with many plants and trees. As we climb to a higher level we come to a shady spot where you may see the lovely purple flowers of the Salvia guaranitica. This is often visited by hummingbirds such as the Glittering-bellied Emerald (Chlorostilbon aureoventris), which takes little notice of the mechanical device inside the flower that dabs pollen on its forehead as it inserts its long beak. What an outstanding adaptation to favour cross-fertilization!

Glittering-bellied Emerald (Chlorostilbon aureoventris) feeding from Salvia guaranitica.

12 - Elevated trail

We now walk along an elevated walkway that runs parallel to the road outside, made with old Quebracho sleepers recycled from the railway. Here is another chance to see gallinules, rails, distant herons or a reedhaunter. This is the spot from which you should be especially on the lookout for Scarlet-headed Blackbirds, normally seen at a fair distance. The call is a series of short clear high-pitched whistles. A sighting of this magnificent bird will certainly be the unforgettable big prize of the day! And to see it in the wild is so much nicer than restrained in a cage, where it will soon discolour and eventually die! It still nests at Ribera Norte, and you may see it caring for its chicks, as it roams free in the few and small wild spaces that we humans now allow it to survive in.

Elevated trail

Scarlet-headed Blackbird

13 - Back to starting point...
¿Did you like this "virtual walk" then? OK, so now come and see it with your own eyes. Your visit is certain to be different in one way or another. It may be a cloudy day, or it could be quite hot. But you'll be hearing the birds singing. You probably won't see every bird you were hoping for, but you'll take back many memories that you cannot experience by simply reading this.

As you leave remember to say "bye" to the warden: he'll like to know you enjoyed your visit, and will be interested in hearing any suggestions you might want to make.

If you are able to make any sort of contribution towards the upkeep of the reserve, you can be sure its inhabitants - the animals and plants that make it their home - will be forever grateful! It will also contribute to greatly increase the number of primary-school students that will come to the reserve to comply with part of their syllabus, most of who have here their very-first "hands-on" contact with nature. Many of them are from low-income areas. The Ribera Norte Association provides trained guides to show them the place and teach them about the importance of knowing - and conserving - our native plants and animals.
There is a small box near the entrance hut where you can leave your donation.

And if you are able to provide funding for more important projects, then please contact the Asociación Ribera Norte. Some of the plans that are on hold - pending adequate funding - are: the construction of a new trail through the higher land that does not flood and additional development of the nursery for native plants.