Two martin fledgelings wait for their parents to bring some food. A fledgeling is a young bird which has left the nest. It is feathered but is still cared for by the parents. An evident characteristic is the enlarged oral flanges at the base of the bill. This structure is enlarged integumentary tissue which passerine chicks have when they hatch and decreases as the young grows. It is normally yellow and it will be more or less bright depending on how well lit the nest is. It is believed to arouse parents to feed the young and to serve as a food target to place it properly. The other detail is the colour of these juveniles. They are grayish compared to the adult which is brown.
CR

New Butterfly species: Ivory Eunica eburnea
© Silvia Vitale	© Silvia Vitale

Many-colored Rush-Tyrant Tachuris rubigastra

© J. Simón Tagtachian

White-lined Tanager Tachyphonus rufus

Juvenile male © Paula Milano y Juan Pablo Muszkats

Camponotus mus Camponotus mus is black and has short, erect hairs covering all the body. Its abdomen has longer and flattened hairs, which give it a golden colouring. Carpenter ants do not consume wood. They collet sucrose solutions from plants and aphids.

The mound of sawdust was not fortuitous. This was part of the material removed by these ants which were hollowing out the trunk of this live tree. The rest was scattered on the ground. As long as we stayed there they kept dumping material continuously. They emerged out of the hole, reached the edge, emptied the load and went back. Sawdust was of different sizes, sometimes as long as the ant itself. We put a finger near one of them to have a size reference point. It stayed montionless and showed no aggressiveness. Neither were they aggressive when the earwing passed by. Nevertheless the visit of a wasp did not pass unnoticed. Unluckily the action was not filmed, but the ants near the scene attacked the wasp in unison. The day before a wasp had been laying eggs in the surroundings. Video © Roberto Ares – Texto: Cora Rimoldi

New Butterfly species: Arawacus ellida
© Roberto Ares	© Roberto Ares

New Butterfly species: Big Lazy Actinote pyrrha
© J. Simón Tagtachian	© J. Simón Tagtachian

Burst of butterflies at RECS

1 – Southern Buckeye Junonia genoveva hilaris 2 – Fiery Skipper Hylephila phyleus 3 – Claudina Crescent Tegosa claudina 4 – Bella Mapwing Hypanartia bella 5 – Southern Fritillary Euptoieta hortensia 6 – Gulf Fritillary Agraulis vanillae maculosa 7 – Common Lazy Actinote pellenea 8 – Common White-milk Tatochila autodice 9 – Big Lazy Actinote pyrrha 10 – American White-milk Tatochila mercedis vanvolxemii 11 – Southern Monarch Danaus plexippus erippus 12 – Lesbia Sulfur var. heliceoides Colias lesbia 13 – Lyssipoides Metalmark Riodina lyssipoides 14 – Lesbia Sulfur Colias lesbia 15 – Celmis Satyr Ypthimoides celmis 16 – Caulonia Groundstreak Calycopis caulonia 17 – Argentine Checkered Skipper Pyrgus orcynoides © JST (J. Simón Tagtachian) – © RU (Rosana Ursino)

Limpkin Aramus guarauna

© Pablo Serur

American Kestrel Falco sparverius

© Pablo Serur

Many-colored Rush-Tyrant Tachuris rubigastra

Juvenile © Pablo Serur

Black-capped Warbling-Finch Poospiza melanoleuca

© Pablo Mosto

Blue-billed Black-Tyrant Knipolegus cyanirostris

Female (photo taken in February) © Paula Milano – Juan Pablo Muszkats

Camuati Wasp Polybia scutellaris There is an action between two camuatis which is solved by means of circular figures accompanied by vigorous wing beating. Communicational or confrontational act? Video © Roberto Ares – Text: Cora Rimoldi Read article

White-faced Ibis Plegadis chihi

© Pablo Serur

More juveniles
Harris’s Hawk Parabuteo unicinctus
© Pablo Serur
Rusty-collared Seedeater Sporophila collaris
© Pablo Serur	© Pablo Serur

Checkered Woodpecker Veniliornis mixtus

Nest currently under construction © Rosana Ursino

Fawn-breasted Tanager Pipraeidea melanonota

And now an adult © Pablo Mosto

Getting ready to leave
Brown-chested Martin Progne tapera
© J. Simón Tagtachian
White-winged Becard Pachyramphus polychopterusFemale © J. Simón Tagtachian	White-winged Becard Pachyramphus polychopterusMale © J. Simón Tagtachian

Juveniles
Blue-and-yellow Tanager Thraupis bonariensis© J. Simón Tagtachian	Roadside Hawk Buteo magnirostris© J. Simón Tagtachian
Glittering-bellied Emerald Chlorostilbon aureoventris© J. Simón Tagtachian	Rufescent Tiger-Heron Tigrisoma lineatum© J. Simón Tagtachian

]]> http://www.reservacostanera.com.ar/en/2012/03/08/novedades-marzo-2012/feed/ 0 http://www.reservacostanera.com.ar/en/2012/02/03/novedades-febrero-2012/ http://www.reservacostanera.com.ar/en/2012/02/03/novedades-febrero-2012/#comments Fri, 03 Feb 2012 02:43:22 +0000 cora.rimoldi http://www.reservacostanera.com.ar/?p=12455 Wood Storki
Mycteria americanaI saw this group of 7 individuals making a big turn above us
© J. Simón Tagtachian Roadside Hawk
Buteo magnirostris© J. Simón Tagtachian Hooded Siskin
Carduelis magellanicaA small flock having a bath accompanied by a Creamy-bellied Thrush
© J. Simón Tagtachian Fork-tailed Flycatcher
Tyrannus savanaOne of the several juveniles that migrated on the 20th
© J. Simón Tagtachian Yellow-winged Blackbird
Agelasticus thilius© J. Simón Tagtachian Masked Yellowthroat
Geothlypis aequinoctialisFemale
© J. Simón Tagtachian

Solitary Cacique Cacicus solitarius

© Oscar Melo

Rufescent Tiger-Heron Tigrisoma lineatum

© Roberto Ares

Green-winged Saltator Saltator similis

© Mariano Ordoñez

Fawn-breasted Tanager Pipraeidea melanonota

Off-season sighting. This tanager visits us in winter © Pablo Mosto

Grayish Saltator Saltator coerulescens

© Pablo Mosto

Some more insects

Go to Invertebrates

For-tailed Flycatcher Tyrannus savana Video © Roberto Ares Migración (See in full screen. First right icon on tool bar) We were reaching the cement pitch when a first group of six Fork-tailed Flycatchers, which I could not see, flew past over our heads. They were heading north. A bit later a front of several flycatchers emerged out of the top of the trees which flank the path. Flying low they dodged and mixed with pigeons, martins and other birds that are normally there. In a more or less disorderly way they progressed in a northerly direction and we lost sight of them. And a new wave appeared and so went on the bouts with dozens of flycatchers each. We were amazed at the number of individuals thay flew past. It was a feast. Some sat for a while on a branch and resumed flight with the same group or with the following one. Juvenile and female tails (18cm) outnumbered male tails (34 cm), a considerable difference in size. Several males had one of their rectrices broken. One of them was filmed during a stop. Such a flow of individuals could be nothing else but migration. In their migration route to the south the groups which spread out from the principal trunk aggregate again on their return trip gathering at roosting sites. Now in bigger quantities since juveniles born here also join the group. Is Costanera one of these favoured sites? For my part, this is the first time I have seen the migration of Fork-tailed Flycatchers. Of course, this is so short a time window that one must be at the right time and place to witness it. There are four subspecies of Fork-tailed Flycatchers having different migratory behaviour. The one that migrates to Argentina (Tyrannus savana savana) comes from the northern extreme of South America and is highly migratory. There is a transient species and the other two are resident. Tyrannus savana savana arrives in September-October to spend summer. Here it breeds and returns in February-March to winter in the north. Last year’s first photographic record was in October. Today, the 20th of February we saw them leave. Text: Cora Rimoldi

Campo Troupial Icterus jamacaiiThe “cousins”… © Carlos Gonzalez Ledo	Orange-backed Troupial Icterus croconotusare still together © Carlos Gonzalez Ledo
Red-eyed Vireo Vireo olivaceous© Carlos Gonzalez Ledo	Narrow-billed Woodcreeper Lepidocolaptes angustirostrisParticular position of the legs to grasp onto this smooth light pole. © Carlos Gonzalez Ledo
Cigüeña americana Ciconia maguariIt flew around the reserve trying to land. But finally it did not. © Carlos Gonzalez Ledo	Monk Parakeet Myiopsitta monachusEating the flower of Silk Floss Tree Ceiba speciosa © Carlos Gonzalez Ledo

Glittering-bellied Emerald in trouble
© Javier Ubiría	© Javier Ubiría
Norberto heard the desperate screamings of the juvenile Emerald. It was caught in the resistent spider of the nephila (one of the most resistent among the arachnids). The web was big. The hummingbird very small and light. It could not have freed by its own means. When we detected the presence of the spider (unluckily out of frame) 20 cm away, Norberto rushed to rescue the hummingbird. His prompt action lasted a few seconds. He swiped it off and released it. The Emerald was exhausted and shocked. It stayed in his hand till it recovered and flew off. The “bad” spider was about to kill the “good” hummingbird. I did not intend to interfere in a natural process. In a phenomenon which is apparently cruel and merciless. The observer must watch without interfering. Again the eternal game between life and death. The prey’s death which means the predator’s life. The web got destroyed during the realease of the Emerald and the spider was dragged to the ground. As we all know, there are species which are ill-famed: spiders, snakes, owls, sharks and the list goes on. Javier Ubiría

New bird species: Dark-throated Seedeater Sporophila ruficollis

Juvenile photographed in october 2011 10-2011© Pablo Mosto

Scissor-tailed Nightjar Hydropsalis torquata

Photo taken in 2011. But it is worth watching the details of this female Scissor-tailed Nightjar so exposed in broad daylight. The Nightjar becomes active at dusk so poor light prevents us from having a good look at it. 2-2011 © Rosana Ursino

Chotoy Spinetail Schoeniophylax phryganophilus

© Pablo Mosto

The Chotoy Spinetail appeared from time to time at Costanera. Last October it popped up and stayed to breed. During that time it was difficult to capture images since it moved surreptitiously so as not to be discovered. Here, instead, we can fully appreciate this relative of the Rufous Hornero. Long tail with two spines. Rufous crown and shoulders. Yellow chin and black throat flanked white. CR

Ferruginous Pygmy-Owl Glaucidium brasilianum
© Pablo Mosto	© Pablo Mosto
These two photos were taken a bit before the video. Pablo told us about the pygmy-owl. The prey is a juvenile of Small Elaenia
Caburé chico Glaucidium brasilianum Aves non gratae Among the bird species present at Costanera the Southern Caracara and the Ferruginous Pygmy-Owl are considered unwanted because they prey on birds, among other things. The birds know the risk they run when either of them are close. So they take courses of action that differ from one another. The Southern Caracara is stalked either solitarily or in pairs by the Chalk-browed Mockingbird (25 cm) and the Fork-tailed Flycatcher (38 cm) among other birds. They mob on the Caracara till it is driven away. It is chased and even pecked at on the wing. It seems funny to see how the big Caracara is driven away by a much smaller bird. Unlike the Caracara, the Ferruginous Pygmy-Owl is small in size (15 cm) and is harrassed by several bird species. The owl’s attitude is “I won´t move”. It stays undaunted in its place. There is a disconcerted flight around it screaming insistently. A sort of public protest so noisy that it is a useful signal for us to spot the owl. Otherwise, this small and cryptic bird is easily skipped in a tree. In this case there was a Red-eyed Vireo, a male Masked Yellowthroat, a Small-billed Elaenia, a Streaked Flycatcher (not appearing in the video), three Masked Gnatcatchers and several Emeralds (definitely some females). All of them sounded very altered. The feathered ball which appears under the branch is the juvenile Small-billed Elaenia of the above photos. It held it tightly with the claws and stood motionless only moving its head to keep visual contact with the birds flying by. None of them attacked the owl. They only put pressure by flying very close to it. At a point it moved to another branch and stood there for a while till it left. Video © Roberto Ares – Texto Cora Rimoldi

Blue-billed Black-Tyrant Knipolegus cyanirostris
Female © Pablo Serur	Female © Pablo Serur

South American Snipe Gallinago paraguaie© J. Simón Tagtachian	Ringed Teal Callonetta leucophrysPair © J. Simón Tagtachian
Ringed Teal Callonetta leucophrysIn flight circular white patch is seen © J. Simón Tagtachian
Brazilian Teal Amazonetta brasiliensisIn flight white triangular patch and blue speculum are seen © J. Simón Tagtachian

Glittering-bellied Emerald and Gilded Sapphire Chlorostilbon aureoventris – Hylocharis chrysura If in flower is the silk floss tree hummingbirds around you’ll see The Silk Floss tree Ceiba speciosa at the Viamonte Access is loaded with flowers. Joy to our eyes and a nutritious food source for the hummingbirds. There were a Gilded Sapphire (bronze colour) and a female Glittering-bellied Emerald (with grayish underparts), some time later a male showed up, too. The Gilded Sapphire defended from the competitors what it considered its tree. As the Sapphire identified an intruder it pounced on it to drive it away. The intruder reacted by escaping and the Sapphire escorted it to make sure it left the grounds. But success was temporary since the Emerald was back in no time and the sequence was repeated. When the male Glittering-bellied Emerald showed up things got worse for the Sapphire, now there were two intruders to be expelled from its territory. The movement of hummingbirds is so fast that only these scenes could be rescued. Among them, two chases © Roberto Ares – Text: Cora Rimoldi

February 2nd – World Wetlands Day

This day in 1971 in Ramsar, Iran, a treaty on wetlands was signed. It provides a framework for the conservation and sustainable use of their resources. Wetlands are defined as extensions where water is a crucial element and its regime (permanent or temporal water, tides, etc.) defines the structure and ecological functions of the place, be it lakes, rivers, swamps, marshes, marine areas, man-made sites, etc. Argentina joined the Convention on 4th of September 1992. The first site was the Monumento Natural Laguna de los Pozuelos in Jujuy. Reserva Costanera is the 14th site and was included on the list on 22nd of March 2005. Nowadays Argentina has 20 sites on the list. Joining the Convention implies a commitment on the part of the National Government to actively work to secure conservation and sustainable use of the area in question.

]]> http://www.reservacostanera.com.ar/en/2012/02/03/novedades-febrero-2012/feed/ 0 http://www.reservacostanera.com.ar/en/2012/01/04/novedades-enero-2012/ http://www.reservacostanera.com.ar/en/2012/01/04/novedades-enero-2012/#comments Wed, 04 Jan 2012 01:53:49 +0000 cora.rimoldi http://www.reservacostanera.com.ar/?p=12288 Great Egret
Ardea alba© J. Simón Tagtachian Cocoi Heron
Ardea cocoi© J. Simón Tagtachian Herons on the coast
Great and Snowy Egrets and Cocoi Heron
© J. Simón Tagtachian

Chotoy Spinetail Schoeniophylax prhyganophilus © Roberto Ares Today we met the Chotoy Spinetail again. The sound announced its presence and we stayed to watch it. But there were two different voices, one sounded like that of the adult. Is the other one another voice between adults or a juvenile’s voice? Almost a month ago food was taken to the nest to feed the chicks. CR

Masked Yellowthroat parasitized by Shiny Cowbird Geothlypis aequinoctialis – Molothrus bonariensis
© J. Simón Tagtachian	© J. Simón Tagtachian
Another case of parasitism. A male Masked Yellowthroat is feeding a Shiny Cowbird chick. Will it take the Masked Yellowthroat a greater effort to feed a cowbird taking into account the difference in size between these two species? Or is the effort balanced by the smaller number of chicks to be fed?

Harris’s Hawk Parabuteo unicinctusAdult © J. Simón Tagtachian	Harris’s Hawk Parabuteo unicinctusJuvenile © J. Simón Tagtachian
Rusty-collared Seedeater Sporophila collarisMale © J. Simón Tagtachian	Neotropic Cormorant Phalacrocorax brasilianus© J. Simón Tagtachian
Cocoi Heron Ardea cocoi© J. Simón Tagtachian	Black-capped Warbling-Finch Poospiza melanoleuca© J. Simón Tagtachian

Kelp Gull Larus dominicanus© J. Simón Tagtachian	Night-crowned Night-Heron Nycticorax nycticoraxTwo herons on the wing © J. Simón Tagtachian
White-winged Becard Pachyramphus polychopterusFemale © J. Simón Tagtachian	Vermilion Flycatcher Pyrocephalus rubinusMale © J. Simón Tagtachian
Fork-tailed Flycatcher Tyrannus savanaMale © J. Simón Tagtachian	Streaked Flycatcher Myiodynastes maculatus© J. Simón Tagtachian

Recreating the history of Costanera This goal of this section is to recover the history of the reserve in photos.I invite you to send photos of the beginnings of the reserve to recreate its history. See more photos in History in photos
Fuente: Municipalidad de Buenos Aires	Fuente: Lic. Sergio Recio
Fuente: Lic. Sergio Recio	Fuente: Lic. Sergio Recio

White-browed Blackbird Sturnella superciliaris

A male very far away. Since the last few years it has popped up regularly © J. Simón Tagtachian

Again at Costanera; Ringed Kingfisher Megaceryle torquata
© J. Simón Tagtachian	© J. Simón Tagtachian
© J. Simón Tagtachian	© J. Simón Tagtachian
Male. Lacks blue grey breast separated by white line. It has white underwing and undertail coverts

More Made at Costanera
Gray-necked Wood-Rail Aramides cajanea© J. Simón Tagtachian	Checkered Woodpecker Veniliornis mixtus© J. Simón Tagtachian

Red-eyed Vireo Vireo olivaceus© J. Simón Tagtachian

Golden-billed Saltator Saltator aurantiirostrisWith a Leucanella viridescens in the bill © J. Simón Tagtachian

Made at Costanera
Chalk-browed Mockingbird Mimus saturninus© J. Simón Tagtachian	Rufous-collared Sparrow Zonotrichia capensis© J. Simón Tagtachian
Black-and-rufous Warbling-Finch Poospiza nigrorufa© J. Simón Tagtachian	Great Kiskadee Pitangus sulphuratus© J. Simón Tagtachian
Double-collared Seedeater Sporophila caerulescens© J. Simón Tagtachian	Creamy-bellied Thrush Turdus amaurochalinus© J. Simón Tagtachian
Rufous-bellied Thrush Turdus rufiventris© J. Simón Tagtachian	Shiny Cowbird Molothrus bonariensis© J. Simón Tagtachian

Dark-billed Cuckoo Coccyzus melacoryphus© J. Simón Tagtachian	Masked Yellowthroat Geothlypis aequinoctialisFemale © J. Simón Tagtachian
Great Pampa-Finch Embernagra platensis© J. Simón Tagtachian	Tropical Kingbird Tyrannus melancholicus© J. Simón Tagtachian

]]> http://www.reservacostanera.com.ar/en/2012/01/04/novedades-enero-2012/feed/ 0 http://www.reservacostanera.com.ar/en/2011/12/16/novedades-diciembre-2011/ http://www.reservacostanera.com.ar/en/2011/12/16/novedades-diciembre-2011/#comments Fri, 16 Dec 2011 12:34:47 +0000 cora.rimoldi http://www.reservacostanera.com.ar/?p=12174 Happy 2012!

Cora

Chotoy Spinetail Schoeniophylax phryganophila A species rarely seen at Costanera. This year the chotoy visited us and stayed to breed. The nest was very well camouflaged among the branches of an Acacia caven and covered with climbing plants on top. This “I want to be invisible” behaviour did not let us see much. Its brownish color and its distracting behaviour to go into or out of the nest made the follow up even more difficult. We did not see it leave and, all of a sudden, in it went. The movement of its long tail let us spot it. Some jumps from one branch to another and it got lost in the denseness. It moved so quickly that the video was slowed down to a quarter of the velocity and the bird encircled to be easily visualized. How many chicks? We do not know, but it made several trips to get food. Video © Roberto Ares – Text: Cora Rimoldi

Solitary Black Cacique Cacicus solitariusThe nest on the left already has chicks, but at the back there is another nest… © Carlos Gonzalez Ledo

Red-eyed Vireo Vireo olivaceus© Carlos Gonzalez Ledo

Glittering-bellied Emerald Chlorostilbon aureoventris

Male © Pablo Serur

Más registros viejos, especies nuevas para el sitio Individuos liberados o escapados

Eurasian Collared Dove Streptopelia decaocto circa 2000 © Roberto Güller

Zebra Finch Taeniopygia guttata circa 2000 © Roberto Güller

Rufous Hornero parasitized by Shiny Cowbird Furnarius rufus – Molothrus bonariensis Every year we find Shiny cowbird chicks being fed by foster parents. This video shows the Rufous Hornero, but other eight species have been recorded photographically at Costanera. See Species parasitized by Shiny Cowbird 11-2011 © Javier Menendez

White-winged Becard Pachyramphus polychopetrus

Male © Pablo Serur

Scarlet-headed Blackbird Amblyramphus holosericeus
10-10-11 © J. S. Tagtachian	10-10-11 © J. S. Tagtachian
The nest in two stages. Halfway during construction the blackbird is tightening fibres and in the nest 15-10-11 © J. S. Tagtachian

Sayaca Tanager Thraupis sayaca © J. Simón Tagtachian

Scissor-tailed Nightjar Hydropsalis torquata © J. Simón Tagtachian

On the evening outing of 17th organized by RECS we saw the Scissor-tailed Nightjar and the Sayaca Tanager among other birds. As soon as we went in a heterogeneous group of birds were enjoying a bath in some pools of water on the Lizards Path. By the time we watched the nightjar it was almost dark and flash was not allowed to be used. Anyway the pair of nightjars did not seem to be worried by our presence and we stayed long watching them. They performed acrobatic raids in the air to engulf insects. But the male (bottom) exhibited a curious behaviour. It positioned parallel and head to head to the female, jumped and fell in the same place but looking backwards, then again to the head-to-head poisition. It repeated this figure another couple of times and they both flew away. Courtshipping?

Old records, new bird species to the site Released or escaped individuals

Tropical Pewee Contopus cinereus circa 2000 © Roberto Güller

Many-colored Chaco-Finch Saltatricula multicolor circa 2000 © Roberto Güller

Orange-backed Troupial Icterus croconotus© J. Simón Tagtachian	Small-billed Elaenia Elaenia parvirostris© Carlos Gonzalez Ledo
Rufous Hornero Furnarius rufusAlmost caught © Carlos Gonzalez Ledo	Solitary Cacique Procacicus solitariusNest © Carlos Gonzalez Ledo
Chalk-browed Mockingbird Mimus saturninusVery little chicks © Carlos Gonzalez Ledo	Red-crested Cardinal Paroaria coronataJuvenile © Carlos Gonzalez Ledo

Grayish Baywing Agelaioides badiusFeeding chick © Carlos Gonzalez Ledo	Checkered Woodpecker Veniliornis mixtusFeeding chick © Roberto Ares
Great Kiskadee Pitangus sulphuratusWaiting for a bit © Roberto Ares	Golden-billed Saltator Saltator aurantiirostrisThis juvenile already feeds by itself © Roberto Ares
Scarlet-headed Blackbird Amblyramphus holosericeus© Carlos Gonzalez Ledo	Bran-colored Flycatcher Myiophobus fasciatus© Roberto Ares
Eared Dove Zenaida auriculataSome are still courtshiping © Carlos Gonzalez Ledo	Eared Dove Zenaida auriculataReusing a mockingbird’s nest © Cora Rimoldi

]]> http://www.reservacostanera.com.ar/en/2011/12/16/novedades-diciembre-2011/feed/ 0 http://www.reservacostanera.com.ar/en/2011/11/07/novedades-noviembre-2011/ http://www.reservacostanera.com.ar/en/2011/11/07/novedades-noviembre-2011/#comments Mon, 07 Nov 2011 17:00:22 +0000 cora.rimoldi http://www.reservacostanera.com.ar/?p=11901 Gilded Sapphire – Cockspur Coral Tree
Hylocharis chrysura – Erythrina crista-galli


Nectar for a free ride
Pollination is an example of how organisms interrelate and need among each other to prosper. Pollination is the transference of polen from the stamens (masculine reproductive apparatus) to the stigma (terminal part of the femenine reproductive apparatus). The Cockspur Coral Tree like many other plants con not do this by itself and must resort to pollinators. Among birds hummingbirds play this role efficiently. And our example is the Gilded Sapphire.

The striking red colour of the flower attracts the sapphire and the nectar, the sapphire’s basic source of food, becomes a reward. With its specialized bill it reaches the nectaries at the base of the corolla. As it is lapping up nectar its head touches both the stamens and the stigma.

The anthers (teminal part of the stamens) will release pollen on the head of the sapphire to be transported to other flowers. The receptive stigma will receive pollen and if it is compatible fertilization will begin.

And I add an interesting detail. Look how the sapphire clasps with its minute legs. Flowers with a big petal like the Cockpur’s are used as a platform. Nevertheless, the sapphire keeps hovering as it feeds on nectar.

Video © Roberto Ares – Texto: Cora Rimoldi

Thoas Swallowtail Heraclides thoas thoantiades

Adult feeding on nectar of Lantana © J. Simón Tagtachian

Chestnut-capped Blackbird Chrysomus ruficapillus Source: www.laculturadelasaves.com.ar. There you can find a collection of 40 videos of 8 minutes each which were processed during 2011. Many of them were captured at this reserve and included on this site. © Roberto Ares

Snail Kite Rostrhamus sociabilis

Female. Two-tone tail © J. Simón Tagtachian

White-winged Becard Pachyramphus polychopterusMale © J. Simón Tagtachian	Masked Yellowthroat Geothlypis aequinoctialisMale © J. Simón Tagtachian
White-tipped Dove Leptotila verreauxi© J. Simón Tagtachian	Gilded Sapphire Hylocharis chrysura© J. Simón Tagtachian

Black and White Tegu Tupinambis merianaeHot days are coming and lizards are more frequently seen. Amira and Abel tell us: “It was approximately 0.80 to 0.90 m long. We sat on a bench facing the sea in front of the electric power plant. In fact we were only 3 m away from the lizard during approximately 20 minutes till we left. The lizard moved into and out of the brushes. It seemed not to be afraid of us and we indulged ourselves taking pictures of it.” © Amira Hesain

Scarlet-headed Blackbird Amblyramphus holosericeus© J. Simón Tagtachian

Bran-colored Flycatcher Myiophobus fasciatus© J. Simón Tagtachian

Chiguanco Thrush Turdus chiguanco

A bird rarely seen at Costanera. Thanks to José Luis we can add another record of this thrush. The only photos available date back to 2005. (Source: www.ecoregistros.com.ar) © José Luis Fernández Guaraz

Scarlet-headed Blackbird Amblyramphus holosericeus © Roberto Ares

Wrongly identified: Not a Parypthimoides phronius but a Celmis Satyr Ypthimoides celmis

This Celmis Satyr (Ypthimoides celmis) has been wrongly identified as a Parypthimoides phronius. Ezequiel, our butterfly consultant, always on the alert, has corrected our mistake and explains to us that: “The diagnostic characteristics are the eyespots, the lines of the ventral side and the general tone.” © Claudia Furman

Yellow-browed Tyrant Satrapa icterophrys© Claudia Furman	American Wood Stork Mycteria americanaY los tuyuyúes también volvieron © J. Simón Tagtachian
Streaked Flycatcher Myiodynastes maculatus© J. Simón Tagtachian	Rufescent Tiger-Heron Rufescent Tiger-HeronOne of the juveniles © J. Simón Tagtachian

Scissor-tailed Nightjar Hydropsalis torquata Male vocalizing. Video taken during the night outing on Saturday 12th © C. y D. Bastías

New butterfly species: European Peacock Inachis io An amazing finding: an exotic species at Costanera

© Javier Ubiría Ezequiel Núñez Bustos tells us: “This is very interesting. This is an Inachis io, a common butterfly in Europe !! There are no exotic diurnal butterflies in the country. This is the first record confirmed in situ.”

Dark-billed Cuckoo Coccyzus melacoryphus

© Pablo Serur

]]> http://www.reservacostanera.com.ar/en/2011/11/07/novedades-noviembre-2011/feed/ 0 http://www.reservacostanera.com.ar/en/2011/10/02/novedades-octubre-2011/ http://www.reservacostanera.com.ar/en/2011/10/02/novedades-octubre-2011/#comments Sun, 02 Oct 2011 20:19:36 +0000 cora.rimoldi http://www.reservacostanera.com.ar/?p=11358 Urutu Pit Viper
Bothrops alternatus

© Marcelo Gavensky

Red-eyed Vireo Vireo olivaceusAnother summer vistior © Pablo Serur

Harris’s Hawk Parabuteo unicinctus© Fernando Prado

New bird species: Green-backed Becard Pachyramphus viridis

Female. Seen on the Middle Path 50 metres far from the coast © Pablo Serur

Ash-colored Cuckoo Coccyzus cinereus© Pablo Serur

Bran-colored Flycatcher Myiophobus fasciatus© Pablo Serur

Streaked Flycatcher Myiodynastes maculatusAnother summer visitor arrived © C. y D. Bastías	European Starling Sturnus vulgarisAtypical © C. y D. Bastías
Grayish Baywing Agelaioides badius© Carlos Gonzalez Ledo	Whistling Heron Syrigma sibilatrix© C. y D. Bastías

White-tipped Plantcutter Phytotoma rutilaFemale © Fernando Prado

Golden-billed Saltator Saltator aurantiirostrisIncomplete black ring around buff throat © Carlos Gonzalez Ledo

Rufescent Tiger-Heron Tigrisoma lineatum
10-10-11 © Carlos Gonzalez L.	15-10-11 © C. y T. Di Mauro	17-10-11 © Carlos Gonzalez L.

Fork-tailed Flycatcher Tyrannus savanaAnother summer visitor has arrived at Costanera © C. y T. Di Mauro

White-barred Piculet Picumnus cirratusThe female is always spotted. Is there a male? © C. y D. Bastías

Feeding on the wing
Gray-breasted Martin Progne chalybea© Fernando Prado	Great Kiskadee Pitangus sulphuratus© Carlos Gonzalez Ledo
Two birds representative of two families which feed in flight The Gray-breasted Martin (Family Hirundinidae) and the Great Kiskadee (Family Tyrannidae) catch insects in flight but show behavioural and morphological differences. The Great Kiskadee sits still on a perch till it sees the prey, flies out to catch it and flies back to the same or a nearby place to eat it. Its bill is strong and has a hooked tip. Swallows feed on the wing. They are moving and so are insects, so a huge mouth is more appropriate to engulf preys. Their bills are short, broad and gape widely.

Green-barred Woodpecker Colaptes melanochlorosBuilding a nest © C. y D. Bastías	Scarlet-headed Blackbird Amblyramphus holosericeus© J. Simón Tagtachian
Southern Caracara Caracara plancusWith a rat © C. y D. Bastías	Ultramarine Grosbeak Cyanocompsa brissoniiEating Morus alba‘s fruit © Fernando Prado
Glittering-bellied Emerald Chlorostilbon aureoventrisMale © C. y T. Di Mauro	Sooty-fronted Spinetail Synallaxis frontalis© Carlos Gonzalez Ledo

Southern Caracara Caracara plancus
Photos by José Luis Merlo A typical scene during the breeding season. The Southern Caracara, a very terrestrial raptor, chooses material for the nest. It pulls the piece, tears it off and curls it to carry it more easily. With the branch held tightly in the bill it takes off and flies straight to the nest.

Tropical Kingbird Tyrannus melancholicusThe first to arrive © J. Simón Tagtachian	Small-billed Elaenia Elaenia parvirostris© Pablo Serur
White-banded Mockingbird Mimus triurusRarely seen at this time of the year © J. Simón Tagtachian	Sayaca Tanager Thraupis sayaca© J. Simón Tagtachian

Glaucous-blue Grosbeak Cyanoloxia glaucocaerulea

This is a last year’s photo, but it is worth adding it to the list. © Pablo Serur

Ringed Kingfisher Megaceryle torquata

It is true this male is flying away but we hope it will come back soon © Pablo Serur

Long-winged Harrier Circus buffoni

Adult (Dark Morph) © Pablo Serur

Chotoy Spinetail Schoeniophylax prhyganophilus
More photos of the Chotoy Spinetail © C. y D. Bastías	which seems to be staying with us for a while © C. y D. Bastías

Rufous-sided Crake Laterallus melanophaius© Carlos Gonzalez Ledo	Masked Yellowthroat Geothlypis aequinoctialisMale © J. Simón Tagtachian
Great Pampa-Finch Embernagra platensis© J. Simón Tagtachian	Yellow-browed Tyrant Satrapa icterophrys© J. Simón Tagtachian

Yellow-winged Blackbird Agelasticus thilius

At Coipos a flock of many individuals. In the photo: Top, an adult male and a juvenile male, bottom, a female © Carlos Gonzalez Ledo

Vermilion Flycatcher Pyrocephalus rubinusMale © Fernando Prado	Long-winged Harrier Circus buffoniFemale (Light Morph) 9-11 © Carlos Gonzalez Ledo
White-faced Ibis Plegadis chihiIn V formation 9-11 © Carlos Gonzalez Ledo	Maguari Stork Ciconia maguariA group of more than forty individuals was seen moving in south-north direction 9-11 © Carlos Gonzalez Ledo

Chotoy Spinetail Schoeniophylax phryganophilus © Roberto Ares

]]> http://www.reservacostanera.com.ar/en/2011/10/02/novedades-octubre-2011/feed/ 0 http://www.reservacostanera.com.ar/en/2011/09/05/novedades-setiembre-2011/ http://www.reservacostanera.com.ar/en/2011/09/05/novedades-setiembre-2011/#comments Mon, 05 Sep 2011 02:06:20 +0000 cora.rimoldi http://www.reservacostanera.com.ar/?p=11244 Stripe-backed Bittern
Ixobrychus involucris See more photos
© Pablo Serur

New Moth Species: Rush Veneer Nomophila noctuella

© Claudia Furman

Signs of Spring
Prunus in blossom, © C. y T. Di Mauro	butterflies, © C. y T. Di Mauro
first sprouts © Cora Rimoldi	and the song of birds. Clic to hear the Chalk-browed Mockingbird’s voice. © C. y T. Di Mauro – © José L. Merlo (voice)

Bare-faced Ibis Phimosus infuscatus © J. Simón Tagtachian	Thick-tailed Opposum Lutreolina crassicaudataOn a tour at the Visitors’ Center © Claudia Furman
Rufescent Tiger-Heron Tigrisoma lineatumIn this photo the two little Tiger-herons on 20th of september. On the right, on 24th. No third chick this year. © José L. Merlo	Rufescent Tiger-Heron Tigrisoma lineatum© J. Simón Tagtachian

Ferruginous Pygmy-Owl Glaucidium brasilianum
What beautiful eyes you have under those eye brows © J. Simón Tagtachian	How tricky these eyes look like When you turn your head around! Adapted from a Spanish song “Malagueña salerosa” © J. Simón Tagtachian

Grassland YellowFinch Sicalis luteola© J. Simón Tagtachian	Vermilion Flycatcher Pyrocephalus rubinusJuvenile © J. Simón Tagtachian
Scarlet-headed Blackbird Amblyramphus holosericeus© J. Simón Tagtachian	Narrow-billed Woodcreeper Lepidocolaptes angustirostris© J. Simón Tagtachian

Mourning Sierra-Finch Phrygilus fruticeti © Roberto Ares Juvenile male of Mourning Sierra-Finch eating and singing This Sierra-Finch lives in Patagonia and along the Andes. During the winter these southern birds move to the north reaching Buenos Aires. It was last seen some years ago. And funny enough only females have been registered at Costanera. Wrongly classified as a female Germán explains the morphological and behavioural aspects that account for a juvenile male. “The plumage of this individual is mainly grey and black in the lower belly and lacks the female’s typically speckled flanks. The cinnamon colour of the cheeks is darker. The individual still has light lines on both sides of the throat, which seems to be getting darker downwards. This is the typical “fresh” plumage of males, in which the black colour becomes even darker as feathers wear off. Besides, there are black areas on the rest of the face from the bill base to the loral area. Males’ bill is yellow in the breeding season, but darker outside this time. This may be because it is still young. And last but not least… it is singing beautifully! This is typical among oscine passerines during the breeding season, perched on a branch and claiming territory!

Rufescent Tigr-Heron Tigrisoma lineatum

Yesterday, 17, we already supposed a chick had already been born due to the adult’s posture. With the wings kept in an eaves-like manner to give shelter and heat to the newly born chicks. We stayed a long while but were not lucky. Today, instead, we had the chance to meet them. It was difficult since the adult was oriented to the canal and its big body blocked the view. One was pecking at a piece of fish when another bill appeared from one side. So, there are at least two. Will there still be an unhatched egg? © Roberto Ares

White-rumped Swallow Tachycineta leucorrhoa© José L. Merlo	Brown-chested Martin Progne tapera© J. Simón Tagtachian
Blue-and-Yellow Tanager Thraupis bonariensisMale © José L. Merlo	Neotropic Cormorant Phalacrocorax brasilianus© José L. Merlo

Field Flicker Colaptes campestris
Male © José L. Merlo	Female © J. S. Tagtachian

Red-crested Finch Coryphospingus cucullatusMale © J. Simón Tagtachian	Vermilion Flycatcher Pyrocephalus rubinusMale © C. y T. Di Mauro
Freckle-breasted Thornbird Phacellodomus striaticollis© J. Simón Tagtachian	Harris’s Hawk Parabuteo unicinctusJuvenile © J. Simón Tagtachian
Gray-breasted Martin Progne chalybea© C. y T. Di Mauro	White-browed Blackbird Sturnella superciliaris© C. y T. Di Mauro
Saffron Yellow-Finch Sicalis flaveolaReusing former Hornero’s nest © C. y T. Di Mauro	Sooty Tyrannulet Serpophaga nigricans© Claudia Furman

New bird species: Brown-and-Yellow Marshbird Pseudoleistes virescens

© Diego Bastías

Ferruginous Pygmy-Owl Glaucidium brasilianumWith a Rufous Hornero (?) © Claudia Furman

Spectacled Tyrant Hymenops perspicillatusJuvenile © Claudia Furman

]]> http://www.reservacostanera.com.ar/en/2011/09/05/novedades-setiembre-2011/feed/ 0 http://www.reservacostanera.com.ar/en/2011/08/08/novedades-agosto-2011/ http://www.reservacostanera.com.ar/en/2011/08/08/novedades-agosto-2011/#comments Mon, 08 Aug 2011 13:52:30 +0000 cora.rimoldi http://www.reservacostanera.com.ar/?p=11032 Lesser Canastero
Asthenes pyrrholeucaSeen near the coast
© Claudia Furman Orange-backed and Campo Troupials
Icterus croconotus – I. jamacaiiTop: Orange-backed Troupial. Bottom: Campo Troupial
© Guadalupe Coll Ferruginous Pygmy-Owl
Glaucidium brasilianumLight Morph
© J. Simón Tagtachian Great Pampa-Finch
Embernagra platensis© Carlos Gonzalez Ledo Yellow-browed Tyrant
Satrapa icterophrys© J. Simón Tagtachian Yellow-chevroned Parakeet
Brotogeris chiririIn search for Ceiba speciosa fruit
© Carlos Gonzalez Ledo Scarlet-headed Blackbird
Amblyramphus holosericeusAdult and juvenile. Seen from the brand new observatory
© J. Simón Tagtachian Green-winged Saltator
Saltator similis© J. Simón Tagtachian White-tipped Dove
Leptotila verreauxi© J. Simón Tagtachian Picui Ground-Dove
Columbina picui© J. Simón Tagtachian

Yellow Cardinal Gubernatirx cristataSeen on Av. Antartida Argentina on 15th, August. © J. Simón Tagtachian	Fawn-breasted Tanager Pipraeidea melanonotaStill moving around the reserve © J. Simón Tagtachian
Rusty-collared Seedeater Sporophila collarisSmall flock of 5 individuals © J. Simón Tagtachian	Southern-crested Caracara Caracara plancusWith a Cat Fish © J. Simón Tagtachian
Picazuro Pigeon Columba picazuro© J. Simón Tagtachian	Yellow-winged Blackbird Agelaius thiliusMale © J. Simón Tagtachian
Maguari Stork Ciconia maguari© C y T Di Mauro	Black-capped Warbling-Finch Poospiza melanoleucaSubadult © Carlos Gonzalez Ledo

Green-barred Woodpecker Colaptes melanochloros
7-2011 © J. Simón Tagtachian	© 7-2011 © J. Simón Tagtachian
Carpintero real Colaptes melanochloros © Roberto Ares
The photos and the video were taken at the Viamonte Access. The Gree-barred Woodpecker spontaneously started to play on the car windscreen. It spent there quite a while. Then came a Great Kiskadee and another Green-barred Woodpecker. Playing with the meaning of having fun is a concept difficult to prove when it is applied to birds in their natural environment. (Read the whole article)

Yellow Cardinal Gubernatrix cristata Watch out! Yellow Cardinal near Costanera This spectacular shot was taken on the 8th of August by Sergio Sánchez, a Bariloche dweller who comes to Buenos Aires for work reasons. Walking to the reserve along Antártida Argentina Av he spotted this cardinal. Though it was not made on the premises of the reserve this sighting is worth mentioning since this is a threatened species. We hope it will pop in at the reserve. © Sergio Sánchez

White-barred Piculet Picumnus cirratus Drumming and singing (and more photos) © J. Simón Tagtachian

White-barred Piculet Picumnus cirratus Drumming and singing (and more photos) © J. Simón Tagtachian

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