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1.
We studied the reproductive characteristics of 2 syntopic lizard species, Sceloporus gadoviae and Sceloporus jalapae (Phrynosomatidae). Specimens of S. gadoviae ( N = 105) and S. jalapae ( N = 41) were collected in a tropical arid forest from Tehuacán Valley, Puebla, México. Males of S. gadoviae reached sexual maturity at the same snoutvent length (SVL; 45.0 mm) as S. jalapae , and a similar pattern occurred in females of both species (SVL; 41.0 and 42.0 mm, respectively). Males of S. gadoviae exhibited reproductive activity throughout the year, with a longer activity during the dry (November to May) and part of the wet season (June to September). In contrast, reproductive activity in S. jalapae males occurred during the wet season (July to September). Females of S. gadoviae showed continuous reproduction, whereas females of S. jalapae exhibited seasonal reproduction. Mean SVL of sexually mature females was higher for S. gadoviae ( ̄ x ± s ̄x = 50.4 ± 0.52) than for S. jalapae (46.0 ± 0.54, P S. gadoviae was lower (3.9 ± 0.14 eggs) than for S. jalapae (5.6 ± 0.43). There was no significant correlation between snout-vent length of females and clutch size of S. gadoviae ( r 2 = 0.22, P > 0.05) or S. jalapae ( r 2 = 0.48, P > 0.05). Our study suggests that although both species inhabit the same environment, they have different reproductive characteristics.  相似文献   

2.
Different insect trapping methods were compared weekly on recently burned and nearby unburned rangeland in the Great Basin of western Utah. Flight traps (or wing traps) collected the most specimens (total = 4,916 at burned site, 4,384 at unburned site) but represented the fewest species (no more than 11 spp./wk at either site); this method was not recommended because of difficulty in removing specimens from adhesive. Water traps amassed the next largest number of specimens ( ̄x ± SE/wk = 150.9 ± 75.3 at burned site, 158.0 ± 66.4 at unburned site) and the most species ( ̄x ± SE/wk = 21.6 ± 6.4 at burned site, 35. 1 ± 4.5 at unburned site). The weekly collections from pitfall traps between the sites were significantly different (P < .05) in number of specimens ( ̄x ± SE/wk = 8.1 ± 1.5 at burned site, 19.7 ± 4.8 at unburned site) and species ( ̄x ± SE/wk = 4.7 ± 0.6 at burned site, 9.5 ± 2.0 at unburned site). Malaise traps were the most convenient. Black Malaise traps collected more specimens ( ̄x ± SE/wk = 99.8 ± 19.4 at burned site, 90.6 ± 16.4 at unburned site) and species ( ̄x ± SE/wk = 22.9 ± 3.9 at burned site, 19.4 ± 6.5 at unburned site) than white malaise traps (specimens:  ̄x ± SE/wk = 72.1 ± 22.4 at burned site, 87.1 ± 31.2 at unburned site; species:  ̄x ± SE/ wk = 19.7 ± 6.6 at burned site, 16.4 ± 5.4 at unburned site), although this difference was not significant.  相似文献   

3.
Suwallia sierra and Sweltsa pisteri are described as new species in the family Chloroperlidae from California, USA. Illustrations of the male terminalia of both species and the female and egg of S. sierra are presented. In addition, detailed figures of the epiproct of 2 similar species, Sweltsa townsei and Sweltsa resima , are included. Diagnoses provided comparing the new taxa with related species. Observations indicate that S. sierra may belong to the same clade as the genus Neaviperla .  相似文献   

4.
Habitat use and selection by Merriam's Wild Turkeys ( Meleagris gallopavo merriami ) in Wasco County, Oregon, was studied during 1981-82. This turkey population selectively used forested cover types (such as ponderosa pine-Douglas-fir-oak, ponderosa pine-oak) characterized by a variety of structural features, species, and age classes. The population used single species forested cover types (oak, ponderosa pine) less than expected, used nonforested cover types in proportion to their availability, and avoided forested cover types with structure simplified by logging activities. The four age and sex classes had large seasonal home ranges ( ̄x = 1,615 ha); the smallest home ranges were exhibited by adult males in winter and the largest were shown by subadult males in fall. In most instances, turkeys used cover types as they were available. We suggest that structural complexity of vegetation, both within and among cover types, is an important component of habitat for Merriam's Wild Turkeys that should be considered in the evaluation of potential release sites and in habitat management plans.  相似文献   

5.
Western jumping mice, Zapus princeps, were live - trapped during the summer of 1975 in an aspen forest in the Front Range of the Colorado Rocky Mountains. Home range sizes were calculated using the exclusive boundary strip method, and it was discovered that males had larger home ranges (298 &ndash; 3315 m 2 , x = 1743 m 2 ) than females (680 &ndash; 1275 m 2 , x = 1041 m 2 ). Mean range length was 96.5 m for males and 78.5 m for females. Spatial relationships showed that females tended to be more territorial than males, based on the females' higher percentage of exclusive home ranges, greater distance between centers of activity, and more uniform spacing.  相似文献   

6.
Winter populations of raptors and scavengers were surveyed along 175 km of rural roads in Moffat County, northwestern Colorado. The survey began in 1988 and is currently continuing. Over the 7 yr of the survey reported here, we found Golden Eagles in high abundance ( ̄ x = 5.8 km/eagle) compared to most studies in similar habitat. Bald Eagles were less abundant, but increasing compared to 20 yr earlier. American Rough-legged Hawks were in low abundance, probably due to the predominance of sagebrush habitat along the route. Northern Ravens were seen in low numbers in 4 yr. American Crows were seen in 2 yr. Black-billed Magpies were nearly as abundant ( ̄ x = 6.5 km/magpie) as Golden Eagles and often scavenged with them. Magpie and Golden Eagle numbers were significantly correlated over the years of study. We conclude that northwestern Colorado is a significant overwintering area for Golden Eagles.  相似文献   

7.
《Journal of Natural History》2012,46(31-32):2095-2115
A comparative morphometric study was performed on two species of shrimps, Macrobrachium macrobrachion (Herklots, 1851) and Macrobrachium vollenhovenii (Herklots, 1857). In total, 714 specimens (563 males and 151 females) originating from four rivers in Ivory Coast were analysed. The morphometry was carried out on 33 measurements; seven meristic and four morphological characters and ratios were calculated from the measurements. Data were analysed using univariate, bivariate and multivariate statistics. Meristic and morphological characters did not allow separation of distinct species. However, metric variables and ratios clearly discriminated the two species. The characters (merus/palm, carpus/palm, palm width/palm length, carpus width/carpus length, palm width) related to the form and the size of second pereiopods could be used for the discrimination of both species. This study, by allowing accurate identification of these species, will facilitate future research.  相似文献   

8.
The effects of elk ( Cervus elaphus ), pronghorn ( Antilocapra americana ), and mule deer ( Odocoileus hemionus ) browsing on shrubs in big sagebrush ( Artemisia tridentata ) communities were monitored over a 31-year period in Yellowstone National Park. Ungulates were restricting Wyoming big sagebrush (spp. wyomingensis ) heights, size, and recruitment on the lower-elevation stratum only, while no such suppression was observed on the high-elevation stratum. Parallel increases in mountain big sagebrush (spp. vaseyana ) densities and cover occurred over the study period on both browsed and unbrowsed sites at the higher-elevation stratum, although big sagebrush, green rabbitbrush ( Chrysothamnus viscidiflorus ), and horsebrush ( Tetradymia canescens ) were slightly taller and crown sizes were slightly larger on unbrowsed than browsed sites. Wyoming big sagebrush utilization (percent leader use) was eight times higher ( ̄ x = 87 ± 7.2% by pronghorns, mule deer, and elk) on the low-elevation winter ranges stratum (the Boundary Line Area [BLA] portion of the winter range), while mostly mountain big sagebrush with leader use averaged only 11 ± 4.1% (nearly all by elk) on the high-elevation range stratum. In addition, annual aboveground biomass production of big sagebrush did not differ between browsed and unbrowsed study sites on the high-elevation stratum of the winter range. Population turnover was higher on browsed plots versus unbrowsed plots. No difference was observed in percent dieback of big sagebrush adult plants between browsed and unbrowsed plots at the higher stratum. Browsing did not influence the number of leaves or seedstalks per plant ( P > .05), but leaves averaged 45% longer and seedstalks 42% longer on browsed big sagebrush. Ungulate browsing, however, apparently suppressed production, germination, and survival of Wyoming big sagebrush on the low-elevation stratum. Numbers of Wyoming big sagebrush declined 43% and cover declined 29%, 1957-1990, on browsed sites on the BLA. Annual biomass production on browsed sites at the low-elevation stratum was only 6-35% that of unbrowsed sites, and big sagebrush recruitment was less on browsed sites. Percent leader use of big sagebrush did not differ between the period of ungulate reductions, 1962-1969, and the 1980s on the lower stratum ( ̄ x = 87% leader use), but utilization was less on higher portions of the winter range during the period of elk reductions ( ̄ x = 2%) than during the 1980s following cessation of elk controls ( ̄ x = 11%).  相似文献   

9.
《Journal of Natural History》2012,46(5-6):379-388
Scutovertex alpinus, a rare species, is redescribed in detail. This species is one of the smaller representatives of the genus with an average body length of 494 μm and a body width of 276 μm. Specific characters are a narrow, short, triangular median ridge between the narrow lamellae, sensillus clavate and spinose, distinct small cuticular foveae distributed over gastronotic region, and 10 pairs of short spiniform notogastral setae. Three pairs of notogastral saccules; a fourth saccule anterior notogastral seta h3 is developed asymmetrically in many cases. Leg chaetome: I (1-4-3-4-18), II (1-4-3-4-15), III (2-2-1-3-15), IV (1-2-2-3-12). Solenidia: I (1-2-2), II (1-1-2), III (1-1-0), IV (0-1-0). The comparison with several congeneric species points to a close relation to Scutovertex pileatus. Scutovertex alpinus inhabits mosses, cushion plants and tussocks in Alpine regions. The known geographic distribution is limited to Alpine regions of the eastern Alps and to one location in Germany (Harz).  相似文献   

10.
ABSTRACT

We describe a new species of rhacophorid frogs from Nghe An Province in northern Vietnam based on morphological and molecular evidences. Morphologically, Kurixalus gracilloides sp. nov. is distinguished from its congeners by a combination of the following diagnostic characters: body size small (snout–vent length 27.9–31.2 mm in males); head width subequal to head length; snout rounded with no dermal projection; canthus rostralis distinct, curved; vomerine teeth present; single internal vocal sac; iris golden-brown; small nuptial pad in finger I; dorsal surfaces golden-brown with a saddle-shaped dark marking; large dark spots on ventral surfaces absent; dermal fringes along outer edge of limbs; conical dermal appendage at the heel; skin on dorsum rough; skin on throat and chest granular; finger webbing rudimentary and toe webbing moderately developed, webbing formula I 2–2½ II 1½–3 III 1¾–3½ IV 3–1½ V. The new species is separated from all other congeners by uncorrected genetic distances ranging from 5.4% to 12.7% based on mitochondrial 16S rRNA gene. Phylogenetic analyses of mtDNA suggest that the new species is nested within a clade of Taiwanese and Yunnan Kurixalus with strong support values. The new species is currently known only from secondary bamboo forest in Pu Mat National Park, northern Vietnam, at elevations of 150 m asl. We suggest the new species should be considered as Near Threatened (NT) following the IUCN’s Red List categories.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:C1BF843F-2F31-4CED-B1F9-13A9035C77C9  相似文献   

11.
Semiweekly mark and recapture livetrapping was conducted July-October 1985 to determine the effectiveness of wheat treated with inomethacin, a prostaglandin synthetase inhibitor, to control the productivity of a wild population of montane voles ( Microtus montanus ) in southeastern Idaho. Before treatment, control (C) and experimental (E) groups, each on ca 0.3 ha, were statistically equal in population size ( ̄X ± SD; C = 50 ± 21, E = 45 ± 14), adult female: male ratio (C = 1:0.8, E = 1:0.7), juvenile:adult ratio (C =0.16:1, E = 0.13:1), number of juveniles per 100 females ( ̄X ± SD; C = 27 ± 8, E = 21 ± 18), and percentage of pregnant females ( ̄X ± SD; C = 44 ± 10, E = 46 ± 17). After the 15-week experiment all population categories were unchanged for the control group and significantly (P ≤ .05) lower for the experimental group, which ended with a final population of ( ̄X ± SD) 17 ± 6, with 7 ± 21 juveniles per 100 females and an 11 ± 14% pregnancy rate.  相似文献   

12.
《Journal of Natural History》2012,46(37-38):2339-2345
The morphological effects of nematode parasitism by Pheromermis myrmecophila were investigated in two species of ants, Lasius flavus and Lasius niger, collected on Clare Island, Ireland. Infected males and queens were found for L. flavus but only infected queens in L. niger. The numbers of nematodes present in each infected specimen were counted and their lengths were measured. Head width, femur length and wing measurements were made for infected and non-infected individuals of both species. In queens, the length of the nematodes decreased as the number per ant increased. When single nematodes were present their mean lengths were significantly greater in L. flavus than in L. niger. In addition to the reduction in wing size for all parasitized specimens, head widths and femur lengths of the queens were significantly different in both species. A log–log graph of radial cell length versus width suggested a linear reduction of wing size.  相似文献   

13.
《Journal of Natural History》2012,46(17-18):1303-1331
A morphometric study of 105 specimens of Synodontis schall, including most type specimens of all nominal species considered junior synonyms of S. schall has been undertaken. Two new species S. ouemeensis and S. kogonensis are described from the Ogun (Nigeria), Oueme (Benin) and Mono (Togo) basins, and the Kogon and Fatala (Guinea) basins, respectively. A neotype is designated for S. schall. The two new species differ from S. schall mainly by the width of the premaxillary toothplate (12.9–24.3% HL for S. schall vs. 21.6–32.7% HL), and can be distinguished one from the other by differences in orbit diameter (20.5–26.8% HL for S. ouemeensis vs. 19.4–21.0% HL for S. kogonensis) and prepectoral length (23.4–28.2% SL for S. ouemeensis vs. 21.6–23.3% SL for S. kogonensis).  相似文献   

14.
Summary

One hundred and eighty males and 23 female specimens of Geryon tridens from 60 to 110 miles west of Ireland were examined in July 1968.

The carapace length/width relationship was calculated as;

and

where y = carapace length and x = carapace width.

Eleven per cent of the males captured had moulted recently, and one female had recently carried eggs.

The average size of crabs was found to increase from east to west, and it is suggested that the present sample is taken from the western side of the main population. There was no relationship between average size and the depth of the water in which they were caught.  相似文献   

15.
《Journal of Natural History》2012,46(35):3217-3226
Animal mating systems are moulded by ecological factors, mainly the temporal patterns of reproduction. We report the reproductive period, use of microhabitats, clutch and egg sizes, reproductive efforts, occurrence of sexual size dimorphism, and the relation between body size and fecundity in the gravid females of Trachycephalus venulosus and Scinax fuscovarius at Serra da Bodoquena, Central Brazil. The reproduction of both species was correlated with the rainy season. Females of T. venulosus produced more eggs and their eggs were larger than those of S. fuscovarius. The females of both species were larger and heavier than males. The reproductive effort was measured as the ratio of gonad mass in relation to body mass. Females of both species presented similar reproductive efforts, but males of S. fuscovarius invested more in gonads compared to males of T. venulosus. Trachycephalus venulosus presented significant correlation between snout–vent length versus number of mature eggs and body mass versus number of mature eggs and ovarian mass. Scinax fuscovarius showed significant correlation between body mass versus ovarian mass. Trachycephalus venulosus is an explosive breeder, whereas S. fuscovarius has prolonged reproduction. These species are able to adapt to several types of habitat, due to behavioural and physiological plasticity.  相似文献   

16.
17.
The ecology of West African arid savannah snakes is still poorly known, especially in regard to the fossorial species. Here, field data on distribution, morphometrics, habitat use and diet are reported for the sand boa Eryx muelleri (Erycidae) from three different countries, i.e. Burkina Faso, Togo and Nigeria. This snake was observed in 21 distinct localities, and a total of 39 individuals was recorded. The species is likely fairly common and locally abundant. Mean body length of snakes was similar among countries and between sexes, but males had proportionately longer tails than females. Body length was significantly positively correlated with both tail length and head length. Adult sex ratio was close to parity. Most of the specimens were found in well-vegetated spots with low percentage of bare soil. There were apparently both ontogenetic and intersexual dietary variations: (1) a single analysed juvenile fed upon a small-sized lizard, whereas adults fed considerably upon young rodents; and (2) females fed exclusively upon young rodents and males upon both lizards and young rodents. In conservation terms, the species is actively exported from Togo for the pet trade, and additional individuals may also be illegally collected in other countries.  相似文献   

18.
Capnia caryi , a new species of Nearctic Capniidae, is described from adults collected from high-elevation locations in the Southern Rocky Mountains of southern New Mexico and Arizona. Males are distinguished by their rounded club-shaped epiproct and sclerotized knobs on abdominal terga 8 and 9. Females possess a darkly sclerotized subgenital plate that covers most of tergum 8 and is produced posteriorly as a pair of broadly rounded lobes.  相似文献   

19.
Blackbursh ( Coleogyne ramosissima Torr.) is a dominant desert shrub in a distinct mid-elevations vegetation belt between creosote bush-bursage ( Larrea tridentata-Ambrosia dumosa ) shrubland below and big sagebrush-pinyon pine- Utah juniper ( Artemisia tridentata-Pinus monophylla-Juniperus osteosperma ) woodland above in the Mojave Desert. Seed germination patterns of blackbrush seeds collected from 2 elevations (1200 and 1550 m) in 5 mountain ranges within the blackbrush shrublands were investigated. Morphological features of blackbrush seeds, including weight, length, and width, were not significantly different ( P > 0.05) among elevations and mountain ranges in the Mojave Desert. Germination of blackbrush seeds was optimal when preceded by a prechill period of 4-6 wk. Seeds incubated at room temperature germinated poorly. Seeds collected at warm, low-elevation sites appeared to be less dormant (required less prechill time), germinated faster, and showed a higher overall germination response; watering at 2-wk intervals revealed the greatest germination. Some ecotypic variation among populations establishing at different elevations was evident with regard to dormancy duration and germination response at certain constant temperatures.  相似文献   

20.
The population structure of 2 Great Basin odonate species was assessed using protein electrophoresis. Analyses included 7 populations of Sympetrum corruptum (suborder Anisoptera), a migratory and highly mobile dragonfly, and 8 populations of Enallagma carunculatum (suborder Zygoptera), a weak flier that is not known to migrate far from natal water sources. Though we expected the damselfly ( E. carunculatum ) to show greater genetic isolation than the dragonfly ( S. corruptum ), both species apparently had high levels of gene flow (theta = 0.0604 for S. corruptum , theta = 0.0485 for E. carunculatum ) and showed no evidence for isolation by distance. These results suggest that both species are highly vagile and that the most important factors affecting population structure of these odonates may be ecological conditions such as habitat patchiness and the ephemerality of water sources.  相似文献   

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