Iguazu National Park Research Articles

Description of Saccocoelioides miguelmontesi n. sp. (Digenea: Haploporidae) from characid fishes in the Iguazu River Basin based on morphological and molecular evidence.

Here we describe a new species of the genus Saccocoelioides found parasitizing Astyanax dissimilis Garavello & Sampaio, Psalidodon bifasciatus (Garavello and Sampaio) and Bryconamericus ikaa Casciotta, Almirón & Azpelicueta from the Iguazu National Park, Misiones province, Argentina. Saccocoelioides miguelmontesi n. sp. was studied based on morphological and molecular (28S rDNA and COI mtDNA sequences) data. The COI mtDNA tree indicated that the specimens collected from the three fish hosts are conspecific, with an intragroup p-distance of 0%. The new species shows an intermediate morphological configuration between the diminutive and robust forms described for Saccocoelioides by Curran (2018). Although, in the 28S rDNA tree, it is placed in a well-supported clade with the two robust species analysed (S. elongatus and S. magnus; p-distance of 1 and 2%, respectively), it differs from the robust group by the range of body size, mature egg size, oral and ventral sucker size, sucker ratio, oral sucker to pharynx ratio, and post-cecal or post-testis/body length percentage. Our results led us to redefine the robust group as having eggs shorter or equal in length to the pharynx. Saccocoelioides miguelmontesi n. sp. the 10th species reported from Argentina and the 7th species within the robust group.

Detecting Deforestation Using Logistic Analysis and Sentinel-1 Multitemporal Backscatter Data

This paper presents a new approach for detecting deforestation using Sentinel-1 C-band backscattering data. It is based on the temporal analysis of the backscatter intensity and its correlation with the scattering behavior of deforested plots. The backscatter intensity temporal variability is modeled with a logistic function, whose lower and upper boundaries are, respectively, set based on the representative backscatter values for forest and deforested plots. The approach also enables the identification of the date of each deforestation event, corresponding to the inflection point of the logistic curve that best fits the backscatter intensity time series. The methodology was applied to two forest biomes, a tropical forest at Iguazu National Park in Argentina and a temperate forest in the Brăila region in Romania. The optimal flattening parameter was 0.12 for both sites, with an F1-score of 0.93 and 0.71 for the tropical and temperate forests, respectively. The temporal accuracy shows a bias on the estimated date, with a slight delay of 2 months. The results reveal that the Sentinel C-band data can be successfully used for deforestation detection over tropical forests; however, the accuracy for temperate forests might be 20 pp lower, depending on the environmental conditions, such as rainfall, snow and management after logging.

Description of a new species of Auriculostoma (Digenea: Allocreadiidae) from Characidium heirmostigmata (Characiformes: Crenuchidae) from Argentina, using morphological and molecular data.

During a parasitological survey of fishes at Iguazu National Park, Argentina, specimens belonging to the allocreadiid genus Auriculostoma were collected from the intestine of Characidium heirmostigmata. The erection of the new species is based on a unique combination of morphological traits as well as on phylogenetic analysis. Auriculostoma guacurarii n. sp. resembles four congeneric species - Auriculostoma diagonale, Auriculostoma platense, Auriculostoma tica and Auriculostoma totonacapanensis - in having smooth and oblique testes, but can be distinguished by a combination of several morphological features, hosts association and geographic distribution. Morphologically, the new species can be distinguished from both A. diagonale and A. platense by the egg size (bigger in the first and smaller in the last); from A. tica by a shorter body length, the genital pore position and the extension of the caeca; and from A. totonacapanensis by the size of the oral and ventral sucker and the post-testicular space. Additionally, one specimen of Auriculostoma cf. stenopteri from the characid Charax stenopterus (Characiformes) from La Plata River, Argentina, was sampled and the partial 28S rRNA gene was sequenced. The phylogenetic analysis revealed that A. guacurarii n. sp. clustered with A. tica and these two as sister taxa to A. cf. stenopteri. The new species described herein is the tenth species in the genus and the first one parasitizing a member of the family Crenuchidae.

Assessment of the potential toxicological hazard of the Green Parrot Snake (Leptophis ahaetulla marginatus): Characterization of its venom and venom-delivery system

Snakes are the major group of venomous vertebrates, and the rear-fanged snakes represent the vast majority of species and occur worldwide; however, relatively few studies have characterized their venoms and evaluated their potential hazards for humans. Herein we explore the protein composition and properties of the venom of the rear-fanged Green Parrot Snake, Leptophis ahaetulla marginatus, the most common snake found in the Iguazu National Park (Argentina), as well as the main features of its venom delivery system. This species has venom reminiscent of elapid venoms, composed mainly of components such as 3FTxs, CRiSPs and AChE, but it shows low toxicity toward mammals (LD50 > 20 μg/g mouse). The histology of its Duvernoy's venom gland is similar to that of other colubrids, with serous secretory cells arranged in densely packed secretory tubules. The posterior end of its maxilla exhibits 1–3 blade-shaped and slightly recurved fangs but without grooves. This study provides an initial analysis of the biological role of venom in Leptophis, with implications for potential symptoms that might be anticipated from bites by this species.

Conflitos no processo de constituição e regularização do Parque Nacional do Iguaçu - PR

No presente artigo o objetivo é analisar a problemática associada à regularização fundiária de áreas protegidas, tendo como estudo de caso a situação do Parque Nacional do Iguaçu (PNI). As adversidades para a regularização fundiária representam um grave problema que acompanha a criação das unidades de conservação por todo o país e que, não raro, permanece sem solução por décadas. Para além das dificuldades orçamentárias para a regularização das áreas protegidas brasileiras, o que é um problema crônico, a questão torna-se mais complexa quando essas áreas - no caso da categoria de proteção integral - apresentam ocupação humana. O estudo apresenta, na primeira parte do artigo, os problemas relacionados ao financiamento da regularização das áreas protegidas. Na segunda parte, o intuito é discorrer sobre a importância do PNI no conjunto paranaense de áreas protegidas. Por último, é analisado o processo de regularização fundiária do PNI e os seus conflitos.

Mind the gap! Integrating taxonomic approaches to assess ant diversity at the southern extreme of the Atlantic Forest.

Understanding patterns of species diversity relies on accurate taxonomy which can only be achieved by long‐term natural history research and the use of complementary information to establish species boundaries among cryptic taxa. We used DNA barcoding to characterize the ant diversity of Iguazú National Park (INP), a protected area of the Upper Paraná Atlantic Forest ecoregion, located at the southernmost extent of this forest. We assessed ant diversity using both cytochrome c oxidase subunit 1 (COI) sequences and traditional morphological approaches, and compared the results of these two methods. We successfully obtained COI sequences for 312 specimens belonging to 124 species, providing a DNA barcode reference library for nearly 50% of the currently known ant fauna of INP. Our results support a clear barcode gap for all but two species, with a mean intraspecific divergence of 0.72%, and an average congeneric distance of 17.25%. Congruently, the library assembled here was useful for the discrimination of the ants of INP and allowed us to link unidentified males and queens to their worker castes. To detect overlooked diversity, we classified the DNA barcodes into Molecular Operational Taxonomic Units (MOTUs) using three different clustering algorithms, and compared their number and composition to that of reference species identified based on morphology. The MOTU count was always higher than that of reference species regardless of the method, suggesting that the diversity of ants at INP could be between 6% and 10% higher than currently recognized. Lastly, our survey contributed with 78 new barcode clusters to the global DNA barcode reference library, and added 36 new records of ant species for the INP, being 23 of them new citations for Argentina.

O turismo como integrador regional em cidades trigêmeas: Foz do Iguaçu (Brasil), Ciudad del Este Paraguai) e Puerto Iguazú (Argentina)

Este artículo tiene como objetivo analizar las dinámicas territoriales generadas por la actividad turística en las ciudades gemelas de Foz do Iguaçu (Brasil), Ciudad del Este (Paraguay) y Puerto Iguazú (Argentina). Por el número de visitantes, proporcionado por los organismos de estadística, se observó esta dinámica en cuatro principales lugares de interés turístico: el Parque Nacional do Iguaçu, el Parque Nacional del Iguazú, Itaipú Binacional y las ruinas jesuíticas. La actividad turística ha sido un vínculo de integración entre estas tres ciudades, que forman una región transfronteriza; sin embargo, hay que destacar el papel centralizador de Foz do Iguaçu por los servicios que ofrece y la cantidad de objetos existentes.

Male resource defence during intergroup aggression among tufted capuchin monkeys

In group-living species, conflicts between groups frequently involve multiple individuals participating in aggression towards the opposing group. Although defence is a collective action, individuals differ in their motivations. For males, the spatiotemporal distribution of resources should determine whether they defend food or mates. Although resource defence as a male mating strategy has been demonstrated primarily in unimale social systems, males in multimale groups generally directly defend access to females. I examined the factors affecting individual assessment of the costs and benefits of participation in aggressive intergroup encounters among tufted capuchin monkeys, Sapajus (Cebus apella) nigritus, at Iguazu National Park, Argentina. Through provisioning and playback experiments I show that male aggression during intergroup encounters in tufted capuchin monkeys is directly related to the presence of a high-quality food resource, whereas behaviours more consistent with direct mate defence were not apparent. Although males and females demonstrated concordant strategies, male responses were stronger than those of females, but no differences were observed between dominant and subordinate males in the presence of a defendable food resource. Resident females may be manipulating male–male competition within groups, using males as ‘hired guns’ to increase access to food resources, thereby increasing infant survivorship and decreasing interbirth intervals. In this population, intersexual conflict, which is often associated with infanticide and sexual coercion in nonhuman primates, has promoted cooperation between the sexes.

<p><strong><em>Ixodes schulzei</em> Aragão & Fonseca, 1951 in Argentina </strong></p>

Fil: Lamattina, Daniela. Ministerio de Salud. Instituto Nacional de Medicina Tropical; Argentina

First report of parasitism by Hexametra boddaertii (Nematoda: Ascaridae) in Oxyrhopus guibei (Serpentes: Colubridae)

The current study summarizes the postmortem examination of a specimen of Oxyrhopus guibei (Serpentes, Colubridae) collected in Iguazu National Park (Argentina), and found deceased a week following arrival to the serpentarium of the National Institute of Tropical Medicine (Argentina). Although the snake appeared to be in good health, a necropsy performed following its death identified the presence of a large number of roundworms in the coelomic cavity, with indications of peritonitis and serosal adherence. Additional observations from the necropsy revealed small calcifications in the mesothelium of the coelomic cavity; solid and expressive content in the gallbladder; massive gastrointestinal obstruction due to nematodes; and lung edema and congestion. Histopathological analyses of lung sections also showed proliferative heterophilic and histiocytic pneumonia. Parasites isolated from both the intestine and coelomic cavity were identified as Hexametra boddaertii by a combination of light and scanning electron microscopic examination. Results from this necropsy identify O. guibei as a new host for H. boddaertii, and is the first report of a natural infection by Hexametra in Argentina. Since Hexametra parasites may contribute to several pathological conditions in humans, and with the recent availability of O. guibei specimens through the illegal pet trade, it is necessary to consider the possibility of zoonotic helminth transmission of Hexametra from snake to human.

Check list of ground-dwelling ant diversity (Hymenoptera: Formicidae) of the Iguazú National Park with a comparison at regional scale.

We describe the ant fauna of Iguazu National Park (INP), a region of high biodiversity and endemism in northeastern Argentina that includes the southernmost protected area of the Atlantic Forest (AF). Ants were sampled over seven periods from 1998 to 2011 using a variety of techniques. We also surveyed museum collections and the scientific literature to obtain additional records of ants from INP. In addition to providing a species list, we compare ant composition of INP to other sites in the Upper Parana, Serra do Mar Coastal Forest and Araucaria eco-regions. A total of 165 ant species belonging to 57 genera are reported; 67 species are new records for Misiones Province and 48 species are reported from Argentina for the first time. Alto Parana and Canindeyu departments in Paraguay present the most similar ant fauna to INP. Serra da Bodoquena in Brazil showed higher similarity with the Upper Parana AF eco-region, despite that Serra da Bodoquena is composed of a mix of eco-regions. Ant diversity was lower in Upper Parana than in Serra do Mar Coastal Forest eco-region. This difference may result from higher primary productivity and a greater altitudinal variation in the coastal region.

Competition-induced stress does not explain deceptive alarm calling in tufted capuchin monkeys

Tactical deception has long attracted interest because it is often assumed to entail complex cognitive mechanisms. However, systematic evidence of tactical deception is rare and no study has attempted to determine whether such behaviours may be underpinned by relatively simple mechanisms. This study examined whether deceptive alarm calling among wild tufted capuchin monkeys, Cebus apella nigritus, feeding on contestable food resources can be potentially explained by a physiological mechanism, namely increased activation in the adrenocortex and the resulting production of glucocorticoids (GCs; ‘stress hormones’). This was tested experimentally in Iguazu National Park, Argentina, by manipulating the potential for contest competition over food and noninvasively monitoring GC production through analysis of faecal hormone metabolites. If deceptive false alarms are indeed associated with adrenocortical activity, it was predicted that the patterns of production of these calls would match the patterns of GC output, generally being higher in callers than noncallers in cases in which food is most contestable, and specifically being higher in callers on those occasions when a deceptive false alarm was produced. This hypothesis was not supported, as (1) GC output was significantly lower in association with the experimental introduction of contestable resources than in natural contexts wherein the potential for contest is lower, (2) within experimental contexts, there was a nonsignificant tendency for noncallers to show higher GC output than callers when food was most contestable, and (3) individuals did not show higher GC levels in cases in which they produced deceptive alarms relative to cases in which they did not. A learned association between the production of alarms and increased access to food may be the most likely cognitive explanation for this case of tactical deception, although unexplored physiological mechanisms also remain possible.

Ant mimicry in the spiderMyrmecotypus iguazu(Araneae: Corinnidae), with notes about myrmecomorphy in spiders

Abstract We describe the mimetic relationship between the ant-like spider Myrmecotypus iguazu Rubio & Arbino 2009 (Araneae: Corinnidae) and the carpenter ant Camponotus sericeiventris Guerin (Hymenoptera: Formicidae), studied in a subtropical rainforest in Iguazu National Park, Argentina. The morphological adaptations, aspects of coloration, and behavior responsible for the ant-like appearance in M. iguazu (the mimic) provide strong evidence that its model is C. sericeiventris. Both field observations and field and laboratory experiments suggest that this spider is a Batesian mimic.

Anancylus Rosanae(Gastropoda: Pulmonata), New Genus and New Species, from Iguazú National Park, Argentina

Seventeen species of ancylids occur in southern South America, seven in Argentina. Anancylus rosanae, n. gen. et sp., is described based on characters of the shell, radula, jaw and reproductive system. This new genus, found in the upper Iguazu River rapids, Iguazu National Park, Misiones Province, Argentina, has the following distinctive features: patelliform shell, usually low, with a circular apex located at the anterior end of the shell; three adductor muscles: large posterior (twice the length of the anterior muscles) and two tear-shaped anterior; adhesive epithelium between the two anterior muscular insertions; no difference between the plates of the jaw.

Seed Dispersal of the Palm Syagrus romanzoffiana by Tapirs in the Semi‐deciduous Atlantic Forest of Argentina

ABSTRACTVertebrates play a fundamental role in the dispersal of Neotropical trees, generating different seed shadows according to their physical and behavioral features. Tapirs are capable of consuming great quantities of large fruits, and they defecate seeds far from parent trees. For instance, intact seeds of the palm Syagrus romanzoffiana have been found in tapir dung piles in the Atlantic Forest of southeastern Brazil, suggesting that tapirs effectively disperse this species. However, recruitment was not examined therein. We studied tapir endozoochory of large and medium seeds in the semi‐deciduous Atlantic Forest of Argentina by examining dung piles found within Iguazu National Park. We recorded dung‐pile positions to evaluate the spatial distribution. We also counted the number of juveniles in 2 × 2 m quadrats placed on old dung piles in latrines, beneath adults and in random sites to estimate recruitment levels. Syagrus romanzoffiana seeds were present in 98 percent of dung piles, averaging >200 seeds/dung pile, indicating that this species constitutes the main fruit component in the tapir's diet. Dung piles showed a clumped deposition pattern reflecting the use of latrines. Juvenile recruitment in latrines was 21 times higher than that of under‐adult sites and 500 times greater than in random sites, and correlated with the frequency of use of the areas. We concluded that the lowland tapir is a major disperser of S. romanzoffiana. Given that this palm can be considered a keystone species, a disruption of this interaction might affect the entire community of frugivores in the long term.

Jaguar Panthera onca population decline in the Upper Paraná Atlantic Forest of Argentina and Brazil

The Green Corridor of Argentina and Brazil is the largest forest remnant of the Upper ParanaAtlantic Forest. The jaguar population of this region is highly fragmented and reduced. To assess the status of the subpopulation of jaguars of the Green Corridor we con- ducted four camera-trap surveys in three sites with different levels of protection. At Urugua-i ´ (34 stations, 1,495 trap-days) we recorded one individual (minimum density 5 0.12-0.33 per 100 km 2 ). At YabotiBiosphere Reserve (42 stations, 1,871 trap-days) we recorded two individuals (minimum density 5 0.11-0.25 per 100 km 2 ). At IguazuNational Park we conducted two surveys. In 2004 (39 stations, 1,839 trap-days) we recorded four adult individuals, estimating a density of between 0.49 - 0.16 and 1.07 - 0.33 per 100 km 2 . In 2006, we increased the area sampled (47 stations, 2,059 trap-days) and recorded 11 adult individuals, estimating a density of 0.93 - 0.2 to 1.74 - 0.34 per 100 km 2 . These density estimates are the lowest recorded for the species. Estimates for Iguazuare between 2-7.5 times lower than those reported in the early 1990s. This population decline probably results from the in- teraction of several factors, including lack of prey as a result of poaching and persecution. We estimate that there is currently a population of 25-53 adult jaguars in the Green Corridor. In spite of having sufficient potential habitat available this population is threatened and urgent conser- vation action is required.

Spoiled Brats: Is Extreme Juvenile Agonism in Ring‐Tailed Coatis (Nasua nasua) Dominance or Tolerated Aggression?

AbstractRing‐tailed coatis exhibit an extreme form of juvenile agonism not found in other social mammals. Two groups of habituated, individually recognized, coatis were studied over a 2.5‐yr period in Iguazu National Park, Argentina. Dominance matrices were divided by year and group, resulting in four dominance hierarchies which were analyzed using the Matman computer program. Strong general patterns were seen in both groups during both years. Adult males (one per group) were the highest ranking individuals, followed by male juveniles, female juveniles, adult females, and male and female subadults. The pattern in which young, physically inferior individuals were able to outrank larger adults is different from other social mammal species in that the juvenile coatis aggressively defended food resources and directed aggression towards older individuals. These agonistic interactions may not reflect ‘dominance’ in the traditional sense, and appear to be a form of ‘tolerated aggression.’ This tolerated aggression leads to increased access to food, and should help juveniles during a period in which they need to rapidly gain weight and grow. Because this tolerance of juvenile aggression is reinforced through coalitionary support of juveniles by adult females, agonistic patterns are also consistent with the hypothesis that juvenile rank is being influenced by high degrees of relatedness within coati groups. Although some interesting parallels exist, there is little evidence indicating that these dominance patterns are the same as those found in other social mammals such as hyenas, lions, meerkats, or Cercopithicine primates.

Efecto de la explotación forestal sobre la estructura, diversidad y composición florística de los palmitales de la Selva Atlántica en Misiones, Argentina

The effect of forest exploitation--timber and palmito (Euterpe edulis, Palmae) extraction--on structure, diversity, and floristic composition of forests known as palmitals of the Atlantic Forest of Argentina was analyzed. These palmitals are located in Misiones (54 degrees 13' W and 25 degrees 41' S). Three 1 ha permanent plots were established: two in the "intangible" zone of the Iguazu National Park (PNI), and another in an exploited forest site bordering the PNI. Three 0.2 ha non-permanent plots were also measured. One was located in the PNI reserve zone where illegal palmito extraction occurs. The other two were in logged forest. All trees and palmitos with DBH >10 cm were identified and DBH and height were measured. For each of the six sites, richness and diversity of tree species, floristic composition, number of endemic species, and density of harvestable tree species were estimated. The harvest of E. edulis increases density of other tree species, diminishing palmito density. Forest explotation (logging and palmito harvest) is accompanied by an increase in diversity and density of heliophilic species, which have greater timber value in the region. However, this explotation also diminishes the density of palmito, of endemic species which normally grow in low densities, and of species found on the IUCN Red List. Results suggest that forest structure may be managed for timber and palmito production. The "intangible" zone of the PNI has the greatest conservation value in the Atlantic Forest, since a greater number of endemisms and endangered species are found here.

Determinants of vigilance behavior in the ring-tailed coati (Nasua nasua): the importance of within-group spatial position

Individuals living in social groups are predicted to live under unequal predation risk due to their spatial location within the group. Previous work has indicated that individuals located at the edge of groups have higher “domains of danger”, thus are more likely to engage in vigilance or antipredator behavior. We studied the determinants of vigilance behavior in two groups of ring-tailed coatis in Iguazu National Park, Argentina. In addition to the expected pattern that coatis were more vigilant at the edge of the group, we found that individuals were particularly vigilant at the front edge of the group. This pattern conforms to predictions of differing predation risk caused by sit-and-wait predators with respect to mobile animal groups. In addition, coatis exhibited less vigilance when the number of neighbors within 5 m and group size increased. Of the three spatial variables tested, within-group spatial position was the most important predictor variable determining vigilance levels. These results confirm that spatial position has major effects on vigilance behavior, and that group directionality is an important factor which should be taken into account when measuring vigilance behavior. Coatis were more vigilant when juveniles less than 6 months old were in the groups. The presence of these young juveniles also affected the relationship between alarm response and vigilance levels. Coatis were more vigilant after strong alarm reactions, but only when young juveniles were not present in the groups. This may indicate that coatis give differential responses to alarm calls depending on the age of the caller. A comparison of antipredator vigilance between coatis and sympatric capuchin monkeys is consistent with the hypothesis that terrestriality leads to higher perceive predation risk for coatis.

Social influences on the acquisition of sex-typical foraging patterns by juveniles in a group of wild tufted capuchin monkeys (Cebus nigritus)

Foraging traditions in primates are becoming the subject of increasing debate. Recent evidence for such a phenomenon was recently provided for wild Cebus capucinus [Fragaszy & Perry, 2003]. To better understand the bases of animal traditions, one should examine intrapopulation behavioral variability and the influence of social context on within-group transmission of specific foraging patterns. We studied the variability of foraging patterns across age and sex classes, and the proximity patterns of juveniles to adults of both sexes in a group of wild tufted capuchin monkeys (Cebus nigritus) living in the Iguazu National Park, Argentina. Foraging activity was examined for a period of 9 months in terms of proportions of focal samples devoted to foraging on certain food targets, microhabitats, and supports, and using specific foraging patterns. Proximity analyses were performed to reveal patterns of association between juveniles and adults. Sex differences in foraging behavior were present and overrode age differences. Overall, males ate more animal foods, foraged more for invertebrates on woody microhabitats (especially large branches), palms, and epiphytes, and used lower and larger supports than females. Females ate more fruits, foraged more on leaves and bamboo microhabitats, and used smaller supports than males. Juveniles were similar to adults of the same sex in terms of food targets, foraging substrates, and choice of supports, but were less efficient than adults. Proximity patterns indicated that juvenile males stayed in close spatial association with adult males and preferentially focused their "food interest" on them. This phenomenon was less evident in juvenile females. The degree to which juveniles, especially males, showed some of the sex-typical foraging patterns correlated positively with their proximity to adults of the same sex. These findings suggest that the acquisition of foraging behaviors by juvenile males is socially biased by their closeness to adults of the same sex.