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.     

Pollution and developmental abnormalities of Atlantic fishes

Synopsis Planktonic eggs of Atlantic mackerel,Scomber scombrus, provide evidence that pollution is associated with mortality, malformation, and abnormal chromosome division of fish embryos developing about the surface of the U.S. Atlantic coast. Embryo data are substantiated by the finding that adults of mackerel, windowpane flounder,Scophthalmus acquosus, and winter flounder,Pseudopleuronectes americanus, from more polluted coastal areas also have higher frequencies of mitotic abnormality than those from less polluted regions of the Mid- and North Atlantic. No ontogenetic interval escapes contamination. All are likely to be adversely influenced, resulting in considerable direct and indirect cumulative effect on total early-life survival. Development of genetic and epigenetic resistance to reproductively harmful influences of contaminants may interfere with other modifications in structure and function necessitated by natural environmental fluctuations, changes in climate, and by fishing itself.     

Reproductive ecology of Vipera latastei, in the Iberian Peninsula: implications for the conservation of a Mediterranean viper

Eurosiberian vipers have been considered model organisms, and studies on their reproductive ecology have afforded much of the current knowledge concerning viviparity in snakes. However, such studies are biased towards northern species and there is little information on Mediterranean species and/or populations. The reproductive ecology of Vipera latastei in the Iberian Peninsula was studied by analysing a large sample of specimens from collections, to better understand the conservation status of this Mediterranean viper. Males and females matured at small and similar body sizes (240 and 265 mm snout-vent length, respectively) and reproductive cycles in both sexes were seasonal. Spermatogenesis peaked in August, vitellogenesis developed in spring and the timing of the mating period was puzzling, with populations mating in autumn, spring, or in both seasons. The most striking finding was that adult females reproduced triennially on average. Lataste's viper is currently in continuous decline in the IP, and most of its populations are isolated in Mediterranean mountains. We hypothesize that prey scarcity and the brevity of the activity period in mountain habitats diminishes the ability of vipers to recover over the short term the energy expended in reproduction. The species needs 2 years for the acquisition and storage of energy ("capital breeder"), and a third year for the expenditure of this energy (in vitellogenesis and embryogenesis), a year during which females feed consistently ("income breeder"). Thus, this viper combines both strategies to supply the reproductive energy cost. Current decline in population and distribution, together with a poor capacity to renew populations, renders Lataste's viper vulnerable to environmental stochasticity.     

Annual pattern of fecal corticoid excretion in captive Red-tailed parrots (<Emphasis Type="Italic">Amazona brasiliensis</Emphasis>)

Annual patterns of fecal corticoid excretion were analyzed in the threatened Red-tailed parrot (Amazona brasiliensis) in captivity. Corticoid concentration over the 15 months of the study (mean ± standard error, 12.6 ± 0.32 ng g⁻¹, n = 585) was lowest around May (the southern Fall), and greatest around September (late winter), just prior to their normal breeding period. Corticoid excretion follows a seasonal pattern best explained by reproductive cycles rather than climate, although climate may be involved in the timing of corticoid excretion. Fecal corticoids also show promise as a tool to measure stress levels. We demonstrate that fecal corticoid measurement is a simple, yet efficient method for monitoring adrenocortical activity in captive, and perhaps wild, parrots. Monitoring adrenocortical activity can inform researchers about imposed stress in captivity, whether pair-bonds are forming in captive birds, and of the timing of breeding both in captivity and in nature.     

What factors influence the occurrence of the genus Degelia (a threatened lichen) in central Spain?

The main factors determining the occurrence, abundance, growth and reproductive capacity of threatened lichens need to be known in order to implement conservation initiatives. The main objective of the present study was to evaluate which factors affect the conservation status of Degelia species-complex in central Spain. We undertook a non-parametric analysis to evaluate whether population sizes are larger in protected areas. We fitted generalized linear models (GLM) and mixed models (GLMMs) to analyze which variables are driving occurrence and abundance of Degelia, the thallus size and reproduction capacity. Results show that population sizes of Degelia are very variable, being larger in broad-leaved evergreen forests and inside protected areas. Tree characteristics play an important role in its local dynamics.     

Assessment of multiple paternity in single litters from three species of carcharhinid sharks in Hawaii

We tested for presence or absence of multiple paternity in single litters from each of three congeneric shark species in Hawaii: the sandbar shark, Carcharhinus plumbeus, bignose shark, Carcharhinus altimus, and Galapagos shark, Carcharhinus galapagensis. Based on eight polymorphic microsatellite loci, we excluded paternity by a single sire in sandbar and bignose sharks, but could not exclude a single sire for the litter from the Galapagos shark. This study doubles the number of shark species tested for multiple paternity, and is the first demonstration of multiple paternity in sandbar and bignose sharks.     

Habitat preferences of lesser rheas in Argentine Patagonia

This work reports the first results of a 3-year study (1998–2001) on habitat use and preferences by wild lesser rheas (Rhea pennata pennata) in the ecotone Monte–Patagonian steppe of Argentina. Ponds and four different habitat alternatives for lesser rheas were determined using satellite images and different structural vegetation characteristics: steppe, shrubland, shrub steppe, and mallines. Lesser rheas (adults, juveniles and chicks) used all habitats available to feed, although they showed preference for mallines, open areas that offer good visibility and abundant food resource. Rheas used shrub steppe and steppe for nesting, but they did not show preference for either habitat type. Nest site had a higher percentage of vegetation cover than control sites. Lesser rheas apparently preferred concealed sites for nesting since they offer protection from severe climate conditions and from predators. Our results suggest that habitat preference by lesser rheas counterbalances profitability of feeding to the corresponding cost of predation.     

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.     

Host mussel utilization of the Itasenpara bitterling (<Emphasis Type="Italic">Acheilognathus longipinnis</Emphasis>) in the Moo River in Himi,Japan

Bitterling are fishes that use freshwater mussels for oviposition. The pattern of mussel utilization of an endangered bitterling species, Acheilognathus longipinnis, which spawned in autumn, was investigated in a lowland river. Six Unio douglasiae nipponensis (1.5% of total 388 individuals) hosted A. longipinnis embryos consistently in their outer gills, and they inhabited areas along the river bank where mussel density was relatively high on a less compacted mud substrate. Unexpectedly low rates of host utilization and the rare occurrence of juvenile (shell length, <40 mm) hosts (<0.8% of total individuals) suggest the need for greater attention to the conservation of A. longipinnis.     

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.     

巴西植物遗传资源保护与对外交流管理

巴西拥有高等植物55000种,居世界第一。植被分为6个区系,即亚马逊雨林、塞拉多(Cerrado)稀树草原、卡廷加(Caatinga)旱生植被、大西洋雨林、南方森林草原和潘塔纳尔(Pantanal)湿地植被。已建立554个原生境保护区和126个基因库,保存植物遗传资源25万份。对外交流由巴西农业科学院(EMBRAPA)遗传资源与生物技术中心(CENARGEN)统一管理。     

广州市场近10年的龟鳖贸易状况调查研究

为了掌握近年来广州市场龟鳖贸易状况及变化趋势,本研究对中国龟鳖贸易需求大、非法贸易严重的广州地区进行了10年的市场调研,结合2010至2019年广州地区查处龟鳖非法贸易案件的物证鉴定信息进行了统计分析。结果显示,2010年8月至2011年7月的专项调查记录到市场出售的龟鳖74种,其中,野生龟鳖41种,野生龟鳖个体市场占比2.01%,养殖龟鳖33种,个体市场占比97.99%,非法贸易龟鳖40种,个体市场占比3.74%;专项调查之后的8年内的不定期抽查记录到市场出售的龟鳖45种,其中,野生龟鳖18种,野生龟鳖个体市场占比1.13%,养殖龟鳖27种,个体市场占比98.87%,非法贸易龟鳖21种,个体市场占比2.29%;10年的物证鉴定案件信息统计显示,广州市场非法贸易龟鳖19种,共638只个体,其中17种龟鳖在市场调查有记录,包括养殖龟鳖7种,野生龟鳖12种,野生个体339只,占个体总数53.13%。自2010年以来,广州市场龟鳖贸易的种类及规模均呈下降趋势,龟鳖种类减少明显;宠物市场记录数据分析,养殖来源的龟鳖种类及数量市场占比上升,非法贸易龟鳖种类及数量市场占比下降,野生龟鳖种类及数量市...     

Wetland classification and inventory: A summary

Regional, national and local wetland classifications have been developed and successfully applied. These have invariably been orientated towards conservation and management goals, and the information used to assess wetland loss or to assign management priorities. Existing national and regional classification systems have not only been useful, but they provide an essential base for developing an international system. At the international level, differences among existing systems in the definition of a wetland and how wetland types are defined assume great importance and need to be resolved. Classification is an essential prerequisite for wetland inventory. A number of international inventories have been undertaken, although these have not generally utilized the available high technology and data storage systems available through remote sensing and geographic information systems. More extensive international inventories will require standardization of techniques for data collection, storage and dissemination. A minimum data set needs to be defined with standards for data accuracy. An international committee under the auspices of an international agency (e.g. IWRB, Ramsar Bureau, IUCN) needs to be established to develop an international classification system and guidelines for carrying out a complete inventory of the world's wetlands.     

Growth, summer cohort output, and observations on the reproduction of brook silverside, Labidesthes sicculus (Cope) in the Kawartha Lakes, Ontario

The brook silverside, Labidesthes sicculus (Cope), is unique in Canadian waters, as it completes its life cycle in 1 year. Previous studies based on scale ageing had suggested the species was an “annual,” but we confirmed this for the first time by otolith analysis. Growth rates from both back-calculation, and the Gompertz model, indicated an asymptote near the end of the summer, and average summer growth rates of 0.77 and 0.70 mm/day, respectively. The Gompertz model gave the best fit (n = 201, r = 0.744) with an L∞ of 85.4 mm TL, and instantaneous growth rate, g, of 0.0264. Back-counting daily growth increments allowed us to show that broods of young fish were produced throughout the summer, from late May to mid August, with maximum hatch taking place in mid-July. The species is a “batch” (serial) spawner, with only a fraction of the eggs ripening in the ovary and being released at as yet undetermined intervals. Eggs of the larger immature fish in the first summer developed from 0.05 to 0.21 mm in diameter (preserved) by fall, and in mature fish of the following spring and summer, developed to 1.2 mm in diameter (preserved), 1.4 mm fresh, at spawning. Attached to each egg was a filament averaging 2.0 cm in length, adhesive in nature, and presumably for attachment to vegetation. The egg also had microscopic hairs on its surface. No evidence was found to support temperature-dependant sex determination, nor were embryos or sperm found in the ovaries of spawning females, unlike Labidesthes sicculus vanhyningi, (the southern subspecies) which has internal fertilization. The Canadian species possesses a genital papilla through which the eggs were released, and an apparently much smaller male genital papilla than the southern subspecies.