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Conspecific broadcasts are effective to increase detection of owls. To determine the most appropriate time of the year to survey owls, we played conspecific owl vocalisations monthly in a temperate rainforest of southern Chile. From 12 broadcast points surveyed we recorded detections of Glaucidium nana, Strix rufipes and Tyto alba. Glaucidium nana presented a bimodal detection curve throughout the year and we recorded two regular vocalisations in response to broadcasting: contact pair call and territorial call. Strix rufipes and T. alba both showed a peak of detection between February and May. Strix rufipes presented three vocalisations: territorial call, contact pair call and female contact pair call while T. alba uttered two vocalisations: territorial call and twittering call. We recommend surveys during the end of the breeding season (austral summer–autumn) when detection is higher in most owls. Surveys should also take into consideration the variability of the vocalisations and include covariates in monitoring to evaluate occupancy/detection models.  相似文献   

3.
This study examined foliar nutrient dynamics and nutrient resorption (retranslocation) in three species of Chilean Nothofagus (Fagaceae) that differed in leaf lifespan and elevational distribution. In our central Chile study area the elevations at which these three species are most abundant increase from N. obliqua (deciduous) at low elevations to N. dombeyi at intermediate elevation and N. pumilio (deciduous) at higher elevations up to treeline. We sampled a single stand at 1680 m in which all three species co-occurred. Nothofagus dombeyi leaves were structurally heavier, with specific leaf mass approximately twice that of the two deciduous species. On a concentration basis, foliar N increased in the order N. dombeyi < N. pumilio < N. obliqua and foliar P increased in the order N. dombeyi < N. obliqua < N. pumilio. However, when the differences in specific leaf mass among species were taken into account by calculating N and P content on a leaf area basis, N. dombeyi had the greatest N and P content. N and P remained relatively constant throughout most of the 4-yr N. dombeyi leaf lifespan, then decreased prior to abscission. Nothofagus dombeyi resorbed significantly less N (44-50%) than did the two deciduous species (63-78%), both on proportional and absolute bases. In contrast, N. pumilio and N. dombeyi resorbed similar amounts of P prior to abscission (40-50%), whereas no significant resorption of P from leaves of N. obliqua was noted. We use these results to clarify the relative importance of environmental gradients associated with elevation vs. genetically fixed leaf lifespans in controlling the nutrient dynamics of these congeneric tree species.  相似文献   

4.
Morphological comparisons of long-clawed mice in southern South America reveal the existence of four genera, only three of which are named. The fourth genus is described and compared with Geoxus, Chelemys and Notiomys. External, cranial and dental characters indicate that the new mouse is most closely related to Geoxus , the raton topo or mole mouse. Geoxus and the new form may be distinguished using both qualitative and quantitative characters. The incipient specializations of the new mouse for fossorial life suggest that it represents an early offshoot along the line leading to the more highly specialized Geoxus. Discovery of a new mammalian genus in Chile, where naturalists have been active for more than two centuries, indicates the importance of continued biological surveys, even in ostensibly well-studied regions. The new mouse reinforces the strong differentiation of faunas inhabiting southern beech ( Nothofagus ) forests in South America, where generic endemism of rodents and marsupials reaches 67%.  相似文献   

5.
Accelerated climate change represents a major threat to the health of the planet's biodiversity. Particularly, lizards of the genus Xenosaurus might be negatively affected by this phenomenon because several of its species have restricted distributions, low vagility, and preference for low temperatures. No study, however, has examined the climatic niche of the species of this genus and how their distribution might be influenced by different climate change scenarios. In this project, we used a maximum entropy approach to model the climatic niche of 10 species of the genus Xenosaurus under present and future suitable habitat, considering a climatic niche conservatism context. Therefore, we performed a similarity analysis of the climatic niche between each species of the genus Xenosaurus. Our results suggest that a substantial decrease in suitable habitat for all species will occur by 2070. Among the most affected species, Xtzacualtipantecus will not have suitable conditions according to its climatic niche requirements and Xphalaroanthereon will lose 85.75% of its current suitable area. On the other hand, we found low values of conservatism of the climatic niche among species. Given the limited capacity of dispersion and the habitat specificity of these lizards, it seems unlikely that fast changes would occur in the distribution of these species facing climate change. The low conservatism in climatic niche we found in Xenosaurus suggests that these species might have the capacity to adapt to the new environmental conditions originated by climate change.  相似文献   

6.
The Glacidorbidae, a family restricted to the Gondwanan realm (Tasmania, southeastern and southwestern Australia, and southern Argentina and Chile), previously included five genera with 20 identified species; 19 of them are Australian, with one genus and species, Gondwanorbis magallanicus (Meier-Brook & Smith, 1976 Meier-Brook, K. & Smith, B.J. (1976) Glacidorbis Iredale, 1943, a genus of freshwater prosobranchs with a Tasmanian-Southeast Australian-South Andean distribution. Archive für Molluskenkunde 106, 191198. [Google Scholar]), from South America. Here we describe two new species of Gondwanorbis: Gondwanorbis fueguensis n. sp. from the freshwater gastropods province of Southern Patagonia (Argentina) and Gondwanorbis tricarinatus n. sp. from Chile, and a new genus and species from the freshwater gastropods province of northern Patagonia (Argentina), Patagonorbis nahuelhuapensis n. sp and n. gen.

http://www./zoobank.org/urn:lsid:zoobank.org:pub:62EA0972-3AEF-4188-8E6D-F10895CE2BEF  相似文献   

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Comerinia chuetolamina gen. & sp. nov. was collected from a cargo of dried Daphnia imported to Britain from Mexico. Females can be distinguished from all others described in the family Acaridae in that setae 14, 15 and d5 are flattened dorsoventrally over most of the basal half. This region appears blade-like, bearing numerous strong pectinations along the ventral side. Males may be recognized by a series of characters, some of which reflect a close relationship with Forcellinia Ouds., 1924 and others with Tyrophagus Ouds., 1924. The position of the new genus in a commonly used key to adults of the family Acaridae is indicated.  相似文献   

9.
A new genus of Metopiinae, Ojuelos Khalaim, gen. n., with a single species, Ojuelos juachicus Khalaim & Ruíz-Cancino, sp. n., is described from Jalisco Province in central Mexico. Ojuelos belongs to the group of three genera (Cubus Townes & Townes, Colpotrochia Holmgren and Triclistus Förster) having a high lamella separating the antennal sockets and reaching the median ocellus (this lamella possesses a dorsal groove in it, just below the median ocellus), but differs from these genera primarily by 1) face and clypeus not convex in lateral view, 2) face separated from clypeus by a shallow transverse impression, 3) mandible with lower tooth very strongly reduced, 4) flagellomeres of antenna strongly transverse, and 5) dorsal carinae of propodeum reduced. A portion of the key to the genera of Metopiinae is provided to distinguish the new genus.  相似文献   

10.
The effect of glaciation on the levels and patterns of genetic variation has been well studied in the Northern Hemisphere. However, although glaciation has undoubtedly shaped the genetic structure of plants in the Southern Hemisphere, fewer studies have characterized the effect, and almost none of them using microsatellites. Particularly, complex patterns of genetic structure might be expected in areas such as the Andes, where both latitudinal and altitudinal glacial advance and retreat have molded modern plant communities. We therefore studied the population genetics of three closely related, hybridizing species of Nothofagus (Nobliqua, N. alpina, and N. glauca, all of subgenus Lophozonia; Nothofagaceae) from Chile. To estimate population genetic parameters and infer the influence of the last ice age on the spatial and genetic distribution of these species, we examined and analyzed genetic variability at seven polymorphic microsatellite DNA loci in 640 individuals from 40 populations covering most of the ranges of these species in Chile. Populations showed no significant inbreeding and exhibited relatively high levels of genetic diversity (HE = 0.502–0.662) and slight, but significant, genetic structure (RST = 8.7–16.0%). However, in N. obliqua, the small amount of genetic structure was spatially organized into three well‐defined latitudinal groups. Our data may also suggest some introgression of N. alpina genes into N. obliqua in the northern populations. These results allowed us to reconstruct the influence of the last ice age on the genetic structure of these species, suggesting several centers of genetic diversity for N. obliqua and N. alpina, in agreement with the multiple refugia hypothesis.  相似文献   

11.
Dioon argenteum sp. nov. (Zamiaceae) is described from northern Oaxaca, México. Flat leaves, and persistently tomentose, slightly imbricate leaflets with marginal prickles characterize this species. The specific epithet argenteum was chosen to describe the silver appearance of the persistent tomentum covering the new leaves. D. argenteum appears to have affinities with D. purpusii and D. califanoi.   © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 471–476.  相似文献   

12.
From August 2011 to November 2013, 68 opossums (8 Didelphis sp., 40 Didelphis virginiana, 15 Didelphis marsupialis, and 5 Philander opossum) were collected in 18 localities from 12 Mexican states. A total of 12,188 helminths representing 21 taxa were identified (6 trematodes, 2 cestodes, 3 acanthocephalans and 10 nematodes). Sixty-six new locality records, 9 new host records, and one species, the trematode Brachylaima didelphus, is added to the composition of the helminth fauna of the opossums in Mexico. These data, in conjunction with previous records, bring the number of taxa parasitizing the Mexican terrestrial marsupials to 41. Among these species, we recognized a group of helminths typical of didelphids in other parts of the Americas. This group is constituted by the trematode Rhopalias coronatus, the acanthocephalan Oligacanthorhynchus microcephalus and the nematodes Cruzia tentaculata, Gnathostoma turgidum, and Turgida turgida. In general, the helminth fauna of each didelphid species showed a stable taxonomic composition with respect to previously sampled sites. This situation suggests that the rate of accumulation of helminth species in the inventory of these 3 species of terrestrial marsupials in the Neotropical portion of Mexico is decreasing; however, new samplings in the Nearctic portion of this country will probably increase the richness of the helminthological inventory of this group of mammals.  相似文献   

13.
A new species of frog, Alsodes australis, is described from the temperate Nothofagus forest of southern Chile and Argentina, based on adults and tadpoles. Up to now, no sympatric occurrence of another congeneric species is known from the type locality. The genus comprises three species groups. From a karyological point of view this species is included in the monticola group, whose species have 26 chromosomes.  相似文献   

14.
通过调查,对Araucaria cunninghamii和A.heterophylla的选模式和中国分类学文献(如<广州植物志>、<中国树木学>、<中国高等植物图鉴>、<中国植物志>、<中国树木志>、、<中国高等植物>)的A.cunninghamii和A.heterophylla(或A.excelsa)作比较,证实中国分类学文献中的A.cunninghamii和A.heterophylla(或A.excelsa)分别是A.heterophylla(Salisb.)Franco和A.cunninghamii Aiton ex A.Cunn..这两种植物的叶形变化较大,但有明显的区别:诺福克南洋杉A.heterophylla幼树的末级小枝的叶细长呈线形、叶尖急尖,牛长角小于45°,腹面无明显的脊,成龄株的末级小枝的叶扁平呈鳞片状;南洋杉A.cunninghamii幼树的末级小枝的叶呈两侧扁的钻形、叶尖短刺状,生长角45°-90°,腹背两面具明显的脊,成龄株的末级小枝的叶呈四棱状钻形.  相似文献   

15.
Chinch bugs are associated with several species of monocots, and species of Gramineae are the principal plants utilized. In Mexico, 24 species of Blissidae have been recorded. The immature stages of Ischnodemus sallei (Signoret), Toonglasa munda (Slater & Wilcox), and T. tumorosis (Slater & Wilcox) are described and illustrated. These species have been recorded from several species of bamboo. Distributional records in Mexico and the host plants of these chinch bugs are also included.  相似文献   

16.
Analysis of the gut contents of six syntopic Cyprinodon species from Laguna Chichancanab, Mexico, shows that the supposed basal form, C. beltrani , feeds on detritus and has the longest gut. All other species have significantly shorter guts. Whereas C. simus exclusively ingests detritus despite short gut length, all other species additionally rely on different benthic invertebrates. Each species has developed specific preferences: C. labiosus (amphipods), C. verecundus (bivalves), C. maya (ostracods and gastropods) and C. esconditus (ostracods and chironomid larvae). However, all of them ingest a minimum of c. 40% detritus. According to Schoener's index, pairwise niche overlap varies from c. 40% to over 95% in the species flock. Contrary to this, there is almost no overlap between the members of the flock and the only other native fish species, Gambusia sexradiata , which feeds nearly exclusively on terrestrial arthropods dropping on the water surface. Recently, the cichlid genus Oreochromis and the characid Astyanax fasciatus gained access to the lake. The cichlids show moderate to high niche overlap, whereas in A. fasciatus it is low. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 85 , 125–134.  相似文献   

17.
A new diatom (Bacillariophyceae) genus and two new species are described from the arid region of the North American southwest. The new genus, Playaensis, and new species, P. circumfimbria and P. furtiva, are distinguished by frustule morphology and autecology. Playaensis possesses unique, narrowly lunate longitudinal ribs bordering the raphe and spathulate spines, but their evolutionary relationship to known genera is unclear. In Payton Lake, New Mexico, P. circumfimbria and P. furtiva are rare in the diatom community, and their geographic and geological extent are not known, but they may be restricted to alkaline, slightly saline lakes of the region.  相似文献   

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Three new species of Isospora Schneider, 1881 are described from agamid lizards, Isospora cannoni n. sp. in Diporiphora australis from northern Queensland, Australia, I. choochotei n. sp. in Calotes mystaceus from northern Thailand, and I. deserti n. sp. in Agama pallida from Israel. I. cannoni oöcysts are subspherical, 20–25 × 22.5–27.5 m with two ovoid sporocysts, 14–15.5 × 10–11.5 m. I. choochotei oöcysts are spherical to subspherical, 24–32 × 28–32.5 m with two ovoid sporocysts, 11 × 15.5–18 m. I. deserti oöcysts are spherical, 25–28 m in diameter with two ovoid sporocysts, 10–11 × 14–17.5 m. All species had sporocysts with Stieda bodies and underwent endogenous development in the nucleus of the host gut epithelial cells. At completion of merogony and gamogony, the host nucleus was reduced to a thin envelope. The significance of endogenous stage characteristics in Isospora taxonomy is discussed.  相似文献   

20.
Diet and morphospace of larval stages of two sympatric lanternfish Diogenichthys atlanticus and D. laternatus from the south-east Pacific Ocean were compared and the covariance between both variables was assessed for each species. Diogenichthys atlanticus stomach contents consisted mainly of copepod nauplii and digested remains and this species had a broader niche than D. laternatus, in which stomach contents were highly digested. No dietary overlap was found between both species. The covariance between skull shape and diet for D. atlanticus was given by a wider mouth gape related to the presence of copepod nauplii, whilst for D. laternatus, a shorter snout and posteriorly displaced eye were related to the presence of highly digested stomach contents. Interspecific differences between diets and skull shapes suggest that both species may have undergone morphological or niche divergence to avoid competition, such as feeding at different hours or depth stratification.  相似文献   

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