Home range of greater and lesser rhea in Argentina : relevance to conservation

In this work we report results of radiotracking studies on the movements and home range sizes of two near-threatened species, the greater rhea (Rhea americana) and the lesser rhea (Pterocnemia pennata pennata) in relation to different land use regimes. We radiomonitored greater and lesser rheas for 3 years in their respective habitats: the Pampas and the Patagonia regions. We chose two study areas in each habitat with similar agricultural activities and different hunting control. We did not find significant differences in movements and home range size between study areas of each species. This suggests that disturbance caused by human presence in the areas did not affect rhea spacing behaviors. Moreover, lesser rheas showed larger home range and movements than greater rheas, showing that the home range size is not an immutable property of body mass, and that abundance and distribution of food appears to be the main factor that influences the movements and home range size of these birds.     

Habitat preferences of ptarmigan hunters in Norway

Hunting for willow ptarmigan (Lagopus lagopus) is a popular recreational activity in Norway, but studies of the hunters are limited. While large game management in Norway is based on sound models and research, management of small game hunters and hunting have not been subject to the same rigour. Compared to the extensive body of knowledge about ptarmigan behaviour and habitat preferences, the knowledge base on ptarmigan hunters is very limited. We surveyed the habitat preferences of 3,056 hunters to identify preferred landscape categories using pictures covering a range of landscape types. We also examined to which extent residence types and forms of hunting were related to habitat preferences. Through factor analysis, we identified three categories of hunting habitat; mountain forest, low alpine and high alpine. Mode of hunting is more important than residence status in terms of preferred habitat. Hunters using dogs preferred mountain forest and low alpine habitats more than hunters without dogs. Hunters without dogs had a higher preference than dog hunters for high alpine habitats. Hunters with mixed modes of hunting have wider habitat preferences. Residence status only affects the perception of the mountain forest habitat. The results may have implications for management as land use and place-based meanings are currently changing in many natural and rural landscapes, and hunting needs to be integrated with other recreational uses.     

Reproductive success of wild Lesser Rheas (Pterocnemia -Rhea- pennata pennata) in north-western Patagonia, Argentina

We studied the reproductive success of a wild Lesser Rhea population (Pterocnemia -Rhea- pennata pennata) during two reproductive seasons (2004/2005 and 2005/2006) in north-western Patagonia, Argentina. The parameters recorded included population and nest density, clutch size, hatching success, chick survival (up to 3 months of age) and percentage of chicks that reached the juvenile stage after the winter. We also estimated the percentage of males that attempted to nest and of those that were successful (those producing at least one chick), daily nest mortality rates (DNMR) at different stages of the nesting cycle and the probability that an egg that has been recently laid will produce a chick. On average, both years pooled, the density of this population of Lesser Rheas was 1.55 ± 0.2 individuals/km² (SE), nest density was 0.17 ± 0.04 per km ² , clutch size was 20.8 ± 6.4 eggs, hatching success was 74.4% ± 11.3, Mayfield’s probability of an egg that will produce a chick was 0.64, chick survival was 65.4% ± 14.5 and percentage of chicks that reached the juvenile stage was 26.3%. Nearly a quarter of Lesser Rhea males in the population attempted to nest during a breeding season, and the DNMR was significantly higher during the laying stage (most nest failures were due to anthropogenic disturbances related to livestock raising activities). Nesting success, hatching success, and chick survival of Lesser Rheas were higher than those of their most closely related species, the Greater Rhea (Rhea americana), whereas the percentage of chicks that reached the juvenile stage was similar due to high winter mortalities of chicks. We suggest that the increase in reproductive effort is a strategy of this species to overcome environmental constraints.     

Nest-site habitat selection by Lesser Rheas ( Rhea pennata pennata ) in northwestern Patagonia, Argentina

Selection of nest-site habitat by a population of wild Lesser Rheas (Rhea pennata pennata) was studied in the northwestern Patagonia steppe, Argentina, during two reproductive seasons (2004/2005 and 2005/2006). Nest spatial distribution was compared with randomly selected points in the study area. Contrary to observations in other ratite species, nest distribution showed an aggregate pattern associated with “mallín” (meadow) areas, which are habitats of higher productivity in the Patagonia steppe. Moreover, similar to observations made on the Greater Rhea (Rhea americana), vegetation cover was higher in nest sites than in randomly selected sites, probably because higher vegetation provides concealment from predators and protection from the strong westerly winds that frequent in this region. Our results reinforce the importance of “mallín” areas for the reproduction and conservation of this threatened ratite species.     

Fossil cocoons associated with a dinosaur egg from Patagonia,Argentina

Abstract: Eight fossil (Cretaceous) insect cocoons were discovered within the infillings of a broken dinosaur egg of a clutch from a Patagonian locality. Cocoons are considered to be in situ based on detailed preservation of thin, delicate walls with surface texture, infillings that are similar to the surrounding rock matrix and the clustered distribution of cocoons in only one egg out of the clutch of five eggs. According to the shape, size, and thin wall with surface texture, the cocoons are interpreted as having been produced by wasps. The wasps may have been attracted to the egg because of the presence of scavenging insects feeding on the decaying organic matter, or they may have been attracted to spiders feeding on the scavenging insects. In either scenario, after attacking the insects or spiders inside the sand infillings of the egg, the wasp larvae produced the cocoons described herein. The presence of wasps, which are at the top of the scavenging food webs, suggests that a complex community of invertebrates would have developed around rotten dinosaur eggs.     

An articulated titanosaur from Patagonia (Argentina): New evidence of neosauropod pedal evolution

Most titanosaur dinosaurs are represented by incomplete skeletal elements lacking articulated pes. An exceptionally preserved specimen from the Late Campanian–Early Maastrichtian strata of Patagonia (Argentina) provides new data on pedal morphology and the evolutionary trends of these huge dinosaurs. This finding is one of the few articulated titanosaur pes known in the world, and shows a phalangeal formula of 2-2-2-2-0. The first three digits possess sickle-shaped claws and the articular facets of ungual phalanges, suggesting mobility in horizontal and vertical planes. A comparative analysis of available record suggests that titanosaurs had a progressive reduction of size and number of pedal phalanges in digits III and IV during the Late Cretaceous.     

Climatic influences on fire regimes along a rain forest-to-xeric woodland gradient in northern Patagonia, Argentina

ABSTRACT. Influences of annual climatic variation on fire occurrence were examined along a rainfall gradient from temperate rainforest to xeric woodlands in northern Patagonia, Argentina. Fire chronologies were derived from fire scars on trees and related to tree-ring proxy records of climate over the period 1820–1974. Similarly, fire records of four Patagonian national parks for the period 1940–1988 were compared to instrumental weather data. Finally, the influences of broad-scale synoptic weather patterns on fire occurrence in northern Patagonia were explored.
Fire in Nothofagus rainforests is highly dependent on drought during the spring and summer of the same year in which fires occur and is less strongly favoured by drought during the spring of the previous year. The occurrence of fire in dry vegetation types near the steppe ecotone is less dependent on drought because even during years of normal weather fuels are thoroughly desiccated during the dry summer. In xeric Austrocedrus woodlands, fire occurrence and spread are promoted by droughts during the fire season and also appear to be favoured by above-average moisture conditions during the preceding 1 to 2 growing seasons which enhances fuel production. Thus, in the xeric woodlands fire is not simply dependent on drought but is favoured by greater climatic variability over time scales of several years.
Fire activity in northern Patagonia is greatly influenced by the intensity and latitudinal position of the subtropical high pressure cell of the southeast Pacific. Greater fire activity is associated with a more intense and more southerly located high pressure cell which blocks the influx of Pacific moisture into the continent. Although long-term changes in fire occurrence along the rainforest-to-xeric woodland gradient have been greatly influenced by human activities, annual variation in fire frequency and extent is also strongly influenced by annual climatic variation.     

Ultrastructural study of Arcellites humilis Villar de Seoane and Archangelsky, 2008, from the Cretaceous of Patagonia,Argentina

A scanning and transmission electron microscopy-based ultrastructural study of Arcellites humilis Villar de Seoane and Archangelsky, 2008, from the Kachaike Formation and Piedra Clavada Formation (Albian-Cenomanian) from several localities in Patagonia (Argentina), is presented in this paper. TEM-photographs of thin-sectioned specimens show a thick spore body wall composed of three layers: a thin and dense exine, an inner granular perine sublayer with irregularly disposed small channels and lacunae, and an outer alveolate perine sublayer with channels perpendicular to the external surface. Transverse sections of the A. humilis wall are compared with fossil and extant species of Marsileaceae. We show that the wall ultrastructure is similar in A. humilis, A. santacrucensis, A. disciformis, A. stellatus and Regnellidium upatoiensis. However, the body wall and acrolamella of A. humilis are more similar to those of R. diphyllum Lindman than to those of the Marsilea L. or Pilularia L. species. Water ferns such as members of the Marsileaceae played an important role in aquatic or semi-aquatic niches in Patagonian Cretaceous floras, suggesting that high humidity and temperature prevailed during the Albian-Cenomanian in this region of Argentina.     

Same species,different population dynamics: Spatio-temporal differences of Undaria pinnatifida (Ochrophyta,Phaeophyceae) in the intertidal of North Patagonia,Argentina

Population dynamics can be influenced by physical and biological factors, particularly in stressful environments. Introduced species usually have great physiological plasticity, resulting in populations with different traits. Undaria pinnatifida, a macroalga originally described from northeast Asia, was introduced in Northern Patagonia, Argentina (San Matías Gulf) around 2010. To describe the spatio-temporal variability in population structure and morphometry of U. pinnatifida, we conducted monthly field samplings for 2 years at the intertidal area of two contrasting sites in the San Matías Gulf. Individuals of U. pinnatifida were classified by developmental stage, and their morpho-gravimetric variables were measured. In both intertidal sites juveniles were found in higher proportion during austral autumn and grew and matured during the autumn-winter months (from May onwards), and individuals senesced during early austral summer (December and January). Conversely, density and biomass were largely different between sites, and individuals showed slight morphological variability between sites. Environmental (e.g., nutrient concentration, available substrate) and biological factors (e.g., facilitation, competition) may explain the observed differences. Since there is not a macroalga with U. pinnatifida morphometrical characteristics in the intertidal environments of San Matías Gulf, studying this recent introduction gives us a better understanding of its potential ecological effects.     

Cultural transmission of ethnobotanical knowledge in a rural community of northwestern Patagonia, Argentina

In the present study we analyzed medicinal and edible plant utilization in Cuyin Manzano, a small rural population located near the Andean forests of Argentina. We also studied where and when plant knowledge was learned, who the principal transmitters were, and how people were taught. The participants were interviewed individually and at random, by means of a semi-structured questionnaire. Interviews were carried out in 16 families in order to examine the present use of wild plants. The inhabitants of Cuyin Manzano cited 87 plants: 63 medicinal and 24 edible species. They mentioned on average 31 ± 10 species per person. Similar patterns of plant use were found in young and old people alike, irrespective of gender. Learning about useful plants took place at an early age as a result of family tradition. This local knowledge is acquired and taught “by doing,” and is mostly transmitted vertically through family dissemination. Wild plant learning implies the acquisition of plants' physical and functional features as well as their environmental characteristics.     

A 3-year airborne pollen and fungal spores record in San Carlos de Bariloche, Patagonia, Argentina

Airborne pollen in San Carlos de Bariloche was sampled from September to March 2001–2004 with a Hirst-type volumetric spore trap placed at a height of 15 m in a city extending from the humid forests, through the mesic forests, to the steppe. The total amount of pollen recorded varied widely from year to year. The pollen index was 4,395 in the sampling period 2001/2002; 9,055 in 2002/2003 and 2,756 in 2003/2004. The main pollen period extended from October to January. In October, pollen concentration was the highest. Sixty-six pollen types were identified. Cupressaceae and Nothofagus were the major contributors. Betula, Prunus, Pinus and Populus, the most abundant ornamental taxa in the city, also contributed to the pollen record. Pollen of Maytenus and Lomatia was representative of the mesic forest, while pollen in the lower layers of the humid forest was present in trace amounts. Cupressaceae, Nothofagus and Betula prevailed during spring (September–December), and Plantago, Rumex and Poaceae during summer (December–March). The association of daily pollen concentration and meteorological variables, temperature (mean, maximum, minimum), dew point, rainfall and wind speed, was significant. Correlations showed to be negative, with the exception of that to wind speed. The total sum of fungi spores increased from 1,771 in 2001/2002; through 8,441 in 2002/2003 to 13,782 in 2003/2004. Relative concentration rose to 29%, 48% and 84% of the total number of pollen and fungal spores recorded during each sampling period.     

Patterns of coexistence between two mesocarnivores in northern Patagonia in the presence of invasive hares and anthropogenic disturbance

We analysed coexistence patterns between two mesocarnivores, Geoffroy's cat (Leopardus geoffroyi: Felidae) and culpeo fox (Pseudalopex culpaeus: Canidae), in northern Patagonia, Argentina. We examined spatial distribution influenced by land cover, anthropogenic disturbance and invasive hare presence, and analysed temporal activity patterns and dietary composition. If competitive exclusion accounts for carnivore coexistence in this system, we predicted segregation would occur in one or more of these aspects as a mechanism for coexistence. We performed camera trapping in Nahuel Huapi National Park, from February to May 2012 and January to April 2013. Using camera detections, we analysed spatial patterns with co‐occupancy modelling and temporal patterns by fitting kernel density estimates and measuring overlap. We performed a dietary meta‐analysis using available literature and performed a discriminant function analysis of diet categories between species. We observed high spatial and temporal overlap between Geoffroy's cats and culpeo foxes. We found no evidence of segregation in relation to land cover occupancy, anthropogenic disturbance, invasive hare occurrence or activity patterns. Though both species consumed predominantly small and medium mammals, Geoffroy's cats consumed more birds, reptiles and amphibians, and culpeo foxes consumed more large mammals, carrion and plant material; coexistence between these two carnivores in this Patagonian protected area appears to be facilitated by diet segregation.     

A new genus and species of darner dragonfl y (Aeshnidae: Odonata) from the lower Eocene of Laguna del Hunco,Patagonia, Argentina

A new genus of Aeshnidae, Huncoaeshna n. gen., based on Huncoaeshna corrugata n. gen., n. sp., is erected from Laguna del Hunco (Ypresian) in Patagonia Argentina. The specimen presents a special kind of preservation with the middle part of the wing wrinkled. The presence of only two fossil specimens of Aeshnidae in South America is surely due to the lack of paleontomologists and collections of fossil insects in the subcontinent.     

四川雉鹑的冬季夜栖地选择

四川雉鹑(Tetraophasis szechenyii)是中国特有物种,国家Ⅰ级重点保护野生动物,对其冬季夜栖地选择的了解,有助于理解物种的生存策略,为物种保护提供参考。利用徒步跟踪和无线电遥测的方法,我们于2006年9月到2007年4月在四川省雅江县帕姆岭进行了野外研究。采用卡方检验、配对样本t检验和二元逻辑斯缔回归等方法对数据进行分析。结果发现:(1)四川雉鹑利用鳞皮冷杉(Abies squamata)和大果红杉(Larix potaninii var.macrocarpa)两种树夜栖,卡方检验分析发现四川雉鹑对这两树种没有明显的选择偏好(χ2=0.745,df=1,P=0.388);(2)夜栖树的胸径为(25.8±1.3)cm,夜栖枝条离地高度为(6.3±0.3)m,直径为(3.3±0.1)cm;(3)与对照样地相比,夜栖地生境一般靠近林缘,乔木的平均胸径大、林下盖度小、倒木数量多,夜栖树胸径大、最近乔木胸径大和最近乔木距离远;(4)逻辑斯缔回归分析表明:夜栖树第一枝距地面高为冬季四川雉鹑夜栖地选择的关键因子;倒木数量、平均乔木胸径、最近林缘距离为次关键因子,该模型对夜栖地的预测正确率为80.9%。冬季四川雉鹑选择夜栖地是安全、能量和地点转移三个因素综合作用的结果,在不同的环境下,同一物种对环境会有不同的适应策略。     

Community assembly and inventory efficiency at a regional scale: the case of terrestrial Heteroptera (Insecta) in northern Patagonia,Argentina

The first step to understanding the species present in a particular area is to perform inventory and assemblage studies. To obtain a species inventory, it is important to determine parameters such as species richness and relative abundance. This information can be useful for future studies and decision-making purposes in the conservation area. Despite the fundamental role of the terrestrial Heteroptera in ecosystems, they remain poorly known. We expected that the terrestrial Heteroptera species assemblage would be strongly associated with plant communities. Presently, 840 samples were collected in northern Argentine Patagonia during two years, 2013 and 2014. A total of 1950 adults of terrestrial Heteroptera belonging to 12 families, 32 species, and 8 morphospecies were found. Various statistical techniques were applied to correct the observed data for undersampling bias. These suggested that the lower boundary of the summer Heteroptera species richness in northern Patagonia was about 44–54 species. We concluded that the high regional habitat heterogeneity along the west-to-east and south-to-north gradients was paralleled by the turnover of Heteroptera. However, the Patagonian steppe shared a high number of species with the Monte and Subantarctic provinces. The suction sampling technique is an efficient technique to collect Heteroptera in environments with different plant structure and should thus be used in a complementary way with the sweeping technique.     

First Record of Undaria Pinnatifida (Laminariales, Phaeophyta) in Southern Patagonia, Argentina

The Japanese kelp Undaria pinnatifida was found on 7th September 2005 in Ría Deseado (Santa Cruz, Argentina). This invasive algae was registered from the lower intertidal to the upper levels of the subtidal zone. The sporophytes were fixed to slabs, gravel and rocks of variable sizes and were also present as epibionts of tunicates. The sporophytes total length ranged between 3 and 88 cm, with a mean of 28.75 cm in the intertidal and 38.3 cm in the subtidal. The density and biomass increased from the intertidal to the subtidal. The kelp population showed a higher number of small immature individuals in the intertidal than␣subtidal where the organisms were bigger and with more individual biomass. This first record of U. pinnatifida in Southern Patagonia extends its southern distribution limit in Argentina, showing progressive expansion in the southwestern Atlantic. More surveys must be conducted to understand the evolution of U. pinnatifida invasion and its impact on the native benthic community.     

Using California Gnatcatcher to Test Underlying Models in Habitat Conservation Plans

Abstract: Habitat Conservation Plans are a widely used strategy to balance development and preservation of species of concern and have been used in southern California, USA, to protect the coastal California gnatcatcher (Polioptila californica). Few data exist on gnatcatcher abundance and distribution, and existing data have problems with issues of closure (i.e., sampling occurs in a short enough time period such that abundance or distribution are not changing), detectability, and proper attention to probability-based sampling schemes. Thus, a habitat model has been relied upon in reserve design. California gnatcatchers are the flagship and umbrella species of many plans and we provide the first estimates that incorporate probabilistic sampling and test predictions from the habitat model. Probability of occurrence was 26% (SĚ = 0.06); however, occupancy varied by modeled habitat quality with slopes <40%, warm, and wet sagebrush habitat having higher occupancy probabilities. Interpreting abundance and occupancy probabilities by vegetation type was complicated by error detected in Geographic Information System vegetation metadata files. The slope (1.08, SĚ = 0.66), temperature (0.79, SĚ = 0.70), and precipitation (—2.62, SĚ = 1.21) variables associated with habitat models were stronger influences on occupancy than was patch size (0.48, SĚ = 0.66). Previous models weight patch size equal to slope and climate. Our work demonstrates that probabilistic sampling can be carried out on a large scale and the results provide better information for managers to make decisions about their reserves.     

Wildlife in the life of local people of the semi-arid Argentine Chaco

The semi-arid Argentine Chaco is inhabited by mestizo people, who live on an economy of subsistence based on the use of natural resources and livestock ranching. I investigated the dietary and economic importance of wildlife for local people. Through interviews and participant observation, I found that wildlife is used primarily as food, providing about a third of the total meat consumed by local peasants. Local people use at least 26 species of wildlife although they concentrate on few species. Small species, Chacoan cavies and armadillos, are consumed most, representing 48% of the total wild meat consumed. Consumption of wild meat follows seasonal patterns determined by hunting methods, preferences for meat quality and species activity patterns. The consumptive value of wild meat is high in comparison with wages, but lower in comparison with forest exploitation. Illegal commercialization of wildlife is practiced mainly by villagers and by outsiders and it affects endangered species. Patterns of use of wildlife by local people differ from other Latin American groups in terms of the range of species hunted and the role that hunting plays in local people’ livelihoods. The first steps towards conservation of this increasingly threatened region should involve decreasing hunting by local people of the more vulnerable species and controlling all illegal commercial hunting.     

A new species of Grindelia (Asteraceae, Astereae) from the Meseta del Somuncura (Patagonia), Argentina

Grindelia coronensis, a new species from the Meseta del Somuncura, Prov. Río Negro, Argentina, is described and illustrated. It is similar toG. chiloensis (Cornel.) Cabrera but it is readily distinguished by its leaves which are conspicuosly differentiated into a obovate blade and a long petiole.     

Habitat Characteristics of the Cyprinidae in Small Rivers in Central Thailand

Cyprinids were sampled, by electrofishing, from 159 sites on small rivers in four major watersheds across central Thailand. Total abundance, estimated by the depletion method, varied directly with water velocity and, inversely with discharge while species richness varied inversely with habitat width and, directly with ambient oxygen and alkalinity. Numerical abundance of cyprinids was well above that for any of the other 27 families of fishes represented in the catches. Incidence of occurrence was high only for a few cyprinid species in each watershed with most species present in ≤10% of the sites. Across all sites, cyprinids represented approximately 35% of all species captured and were absent from only two sites. Species richness was highest in the Maeklong watershed. Canonical correspondence analysis identified five significant habitat variables, temperature, habitat width, discharge, ambient oxygen and alkalinity, and the extent to which each influenced the distribution of the 41 cyprinid species. The results are discussed in relation to environmental factors and ecological adaptations.