Water balance and fluid consumption in the southern grasshopper mouse, Onychomys torridus

Weight loss was rapid and fluid consumption decreased sharply when Onychomys torridus were exposed to salinities greater than 0.3 Molar. The southern grasshopper mouse is physiologically unspecialized for maintaining water balance in its xeric habitat. The southern grasshopper mouse is capable of weight maintenance on smaller daily water rations than is the northern grasshopper mouse ( Onychomys leucogaster ) . Differences in the water balance of O. torridus and O. leucogaster may influence their local distributions in areas of sympatry.     

Records of the northern grasshopper mouse ( Onychomys leucogaster ) in western Iowa

In Iowa, the northern grasshopper mouse ( Onychomys leucogaster ) previously was known only from the northwestern part of the state. Herein, we report records of O. leucogaster from the 1970s and 1980s that extend its distribution into west-central and southwestern Iowa. These records may represent dispersal movements into these parts of Iowa by southward movements from populations in northwestern Iowa or they may represent eastward movements of individuals from Nebraska prior to channelization of the Missouri River.     

Plague in pine martens and the fleas associated with its occurrence

Thirteen pine martens ( Martes Americana ) were sampled periodically from July 1979 to September 1980 for plague ( Yersinia pestis ) antibodies and their fleas collected and identified. Four individuals were positive for plague antibodies on 8 of 24 sampling occasions. Titer peaks in these individuals occurred simultaneously in early winter but fell to undetectable levels by late spring. A chipmunk flea ( Monopsyllus ciliatus ) was the most common ectoparasite constituting 55% of all individuals collected. Thirty-one percent of all fleas belonged to Chaetopsylla floridensis, a species previously unreported in California. The remains of ground-dwelling sciurids (chipmunks, Eutamias spp., and ground squirrels, Spermophilus spp.) were very common in marten scats during the period preceding elevated titers. For this reason, and the fact that 92% of all fleas collected from martens during this same period were found more commonly on chipmunks and ground squirrels, these rodents were implicated as the source of the martens’ exposure to plague.     

New record and southern range extension for the Mearn's grasshopper mouse ( Onychomys arenicola Mearns, 1896) in Veracruz, Mexico

Mearn’s grasshopper mouse ( Onychomys arenicola ) in Mexico is found primarily in the central and northern states. This is the first report of the genus Onychomys in the state of Veracruz, based on 7 captured specimens (3 collected). This finding extends the species’ known distribution by approximately 470 km east-southeast. In addition, this record increases the alpha diversity of terrestrial mammals for the state of Veracruz to 192 species.     

Pleioxenous host-restriction in fleas

A review of the pleioxenous genera of fleas, those genera whose species are confined to hosts of a single family, indicates that such a restriction results from one of several situations. Genera of 10 or more taxa (species and subspecies) were considered, so as to exclude very small genera that might be relicts. Polyxenous genera, whose species occur regularly on two or more families (and frequently on two or more orders) of hosts are far more numerous than pleioxenous genera.

Bat fleas (Ischnopsyllidae) are unique in that all genera are pleioxenous. This seems to reflect the fact that most bat fleas occur on cave-dwelling bats, and that the cave provides for larval development of bat fleas. Five pleioxenous genera occur on rodents in deserts or semiarid regions. The extreme climatic changes that have been concomitant with desertification from the Mid-Cenozoic, and especially in the Pleistocene, are paralleled by the proliferation of the mammalian hosts themselves in deserts. Three pleioxenous genera are found on fossorial rodents (Geomyidae). These rodents appear to have been isolated and rejoined during climatic changes in western North America; and rapid speciation of their fleas followed speciation of the hosts. One pleioxenous genus, and others that are nearly pleioxenous, parasitize cricetine mice in Central America. It is suggested that the Cenozoic archipelago which occupied this region provided an environment for rapid speciation of both hosts and their fleas. Two pleioxenous genera are found on tree squirrels in the tropics. Although fleas of mice occasionally make permanent transfers to squirrels, as the former occupy squirrel nests, reverse transfers (from tree squirrels to mice) are rare. Two genera of fleas are restricted to murid mice in Africa south of the Sahara; this is a region in which murid mice usually outnumber species of other rodent families. One pleioxenous genus occurs on Arvicolidae, possibly a result of rapid speciation of hosts during the extreme climatic changes in boreal habitats during late Cenozoic and Pleistocene.

There is a tendency for the apparently more ancient families of fleas (e.g. Stephanocircidae, Pygiopsyllidae and Hystrichopsyllidae) to have very few pleioxenous genera but many polyxenous genera. The more modern families of fleas (e.g. Leptopsyllidae and Ceratophyllidae) contain a higher percentage of pleioxenous genera.     

Ectoparasites of the occult bat, Myotis occultus (Chiroptera: Vespertilionidae)

Only a single previous study has examined ectoparasites of the occult bat ( Myotis occultus ), from which only 2 species of fleas were identified. For our study, we examined 202 individuals, 52 fresh hosts and 150 museum specimens, from New Mexico and southern Colorado for ectoparasites. We recorded 2158 ectoparasites, 634 from fresh hosts and 1524 from museum specimens. Ectoparasites belonged to 10 families and 13 genera of insect or acari and represent new host and locality records. In general, ectoparasites collected from fresh hosts and museum specimens were represented by 4 major species of mite: Macronyssus crosbyi, Alabidocarpus calcaratus, Acanthophthirius lucifugus, and Alabidocarpus nr. eptesicus. From our study, we found fresh hosts to have significantly greater prevalence values for Myodopsylla gentilis (flea), Chiroptonyssus robustipes (mite), and Leptotrombidium myotis (chigger), whereas museum specimens had significantly greater prevalence values for A. calcaratus (mite) and A. nr. eptesicus (mite). There were no significant differences between prevalence values for 4 mites including M. crosbyi, A. lucifugus, Pteracarus nr. minutus, and Cryptonyssus sp. Our study represents the only extensive study of ectoparasites on M. occultus and provides evidence for the importance of examining fresh hosts and museum specimens in future ectoparasite studies.     

Fleas associated with the northern pocket gopher ( Thomomys talpoides ) in Elbert County, Colorado

We collected 532 fleas, 526 of which were Foxella ignota ignota , from 247 northern pocket gophers, Thomomys talpoides , in Elbert County, Colorado, over 13 months. Other fleas included 1 Hystrichopsylla dippiei ssp., 3 Spicata rara , 1 Oropsylla idahoensis , and 1 female flea tentatively identified as Oropsylla (Opisocrostis ) sp. These are new records for H. dippiei ssp. and S. rara in Elbert County. Fleas were cleared using standard methods and were placed on microscope slides in Canada balsam. The number of fleas per host ranged from 0 to 26. The highest median number of fleas per host ( n = 5) was in May with a low median ( n = 0) in August. Mean intensity and relative density of fleas peaked in April and May, respectively. Total flea abundance peaked from April through July. Approximately 72% of the male gophers ( N = 99) were infested with fleas, whereas 57% of the females ( N = 148) had fleas. Flea abundance on influenced by hormones of the host. We suggest further randomized studies of fleas on T. talpoides to investigate parasite abundance throughout the year.     

Distribution records and comments on fleas in southwestern South Dakota

From October 2003 through April 2006, we collected 565 fleas incidental to a distribution survey of mammals in southwestern South Dakota. Sixty-one specimens, representing 18 species of mammals, possessed 20 species of fleas. The geographic distributions of these flea species revealed 8 new records for the Black Hills and its adjacent grasslands. Four species— Megarthroglossus divisus, Stenoponia americana, Odontopsyllus dentatus, and Amaradix euphorbi —constitute new records for South Dakota, thus increasing the state’s known flea fauna to 42 species. Hunters, trappers, and field biologists should be aware that serosurveillance during the 1990s revealed the presence of sylvatic plague and tularemia in the Black Hills area. Desde octubre de 2003 hasta abril de 2006, colectamos 565 pulgas de manera incidental durante un estudio de la distribución de mamíferos en el suroeste del estado de Dakota del Sur. Los 61 especímenes, que representaban 18 especies de mamíferos, albergaban 20 especies de pulgas. Sus distribuciones geográficas revelaron 8 nuevos registros para las Colinas Negras (Black Hills) y las praderas adyacentes. Cuatro de estas especies ( Megarthroglossus divisus, Stenoponia americana, Odontopsyllus dentatus y Amaradix euphorbi ) constituyen nuevos registros para Dakota del Sur. Esto aumenta el número de especies de pulgas conocidas del estado a 42 especies. Los cazadores, tramperos y biólogos de campo deben estar conscientes de que la vigilancia serológica durante la década de los 1990 reveló la presencia de la plaga silvática y la tularemia en el área de las Colinas Negras.     

Two new species of fleas of the genus Meringis (Siphonaptera: Hystrichopsyllidae)

Two new species of Meringis are described. Meringis disparalis, n. sp., has been most commonly taken from Dipodomys merriami but has also been taken from D. ordii and Onychomys leucogaster. Collection localities include the counties of Dona Ana, Eddy, and Luna in southern New Mexico. Meringis facilis, n. sp., has been taken from D. ordii, several other rodents, and Sylvilagus audubonii. Collection localities include Crowley County, Colorado, and Bernalillo, Chaves, and Valencia counties in New Mexico. A key to the species of ♂ Meringis is given.     

Fleas (Siphonaptera) in nests of boles ( Microtus spp.) in montane habitats of three regions of Utah

As a parallel study of a survey of fleas of trapped small mammals in montane southern Utah, we removed 77 adult fleas from 12 of 13 nests of voles ( Microtus longicaudus, M. montanus and M. richardsoni ) collected from montane meadows in the Abajo and La Sal Mountains, the Markagunt Plateau and Pine Valley Mountains, and the Uinta Mountains, May 1991-July 2002. Six species and subspecies of fleas parasitic on Microtus spp. were found, 1-3 species in each nest. Three specimens of the ubiquitous deer mouse ( Peromyscus spp.) flea Aetheca wagneri (Baker) were also found. We collected the following 7 taxa from the locations indicated: Catallagia decipiens Rothschild in 5 nests: Abajo and Pine Valley Mountains and Markagunt Plateau; Hystrichopsylla dippiei truncata Holland in 2 nests: La Sal and Uinta Mountains; H. occidentalis sylvaticus Campos & Stark in 5 nests: Pine Valley Mountains; Peromyscopsylla selenis (Rothschild) in 1 nest: Markagunt Plateau; A. wagneri in 2 nests: Abajo and Pine Valley Mountains; Megabothris abantis (Rothschild) in 5 nests: Abajo and Uinta Mountains and Markagunt Plateau; Malaraeus telchinus (Rothschild) in 2 nests: Abajo and Pine Valley Mountains. One preserved larva was identified as Hystrichopsylla prob. occidentalis sylvaticus , and 2 dead larvae, the only specimens found in nest 13, were identified as probably the same. Kane County is a new record for C. decipiens and P. selenis ; Kane and Summit Counties are new for M. abantis . Nest surveys can generally supplement rather than replace trapped-host surveys. Their main value is in population studies. They are also a source of larvae for morphology and taxonomy research.     

Density, biomass, and diversity of grasshoppers (Orthoptera: Acrididae) in a California native grassland

A native California perennial grassland was sampled for grasshopper populations. The grassland is managed for the preservation of the native perennial bunchgrass, Nassella pulchra Hitch. Grasshopper density, biomass, diversity, and richness were measured from July 1993 to October 1994. Average density of all grasshoppers was 2.30 hoppers/m 2 (0.66 s ) for 1994 (June through August). Overall forage consumed for 1994 was 140 kg/ha, suggesting that grasshopper populations exist at economically damaging levels. Grasshoppers do not appear in the grasslands until late spring, after annual grasses have set seed. Biomass of grasshoppers peaks in July when adults are predominant. Both grasshopper density and biomass were higher in 1993 than in 1994, and a total of 5 species were found throughout the study. Melanoplus sanguinipes Fabricus dominated the acridid communities and accounted for more than 95% of the individuals.     

Mites (excluding chiggers) of mammals of Oregon

New information on the ectoparasitic mites of the following species of mammals from Oregon is presented: (1) pika — Ochotona ; (2) squirrels — Eutamias, Spermophilus, Tamiasciurus; (3) grasshopper mouse — Onychomys; (4) woodrats — Neotoma; (5) muskrat — Ondatra; (6) jumping mice — Zapus; and (7) weasels — Mustela, Spilogale. New records of species for the state and new host records are also given. Finally, a cross - referenced list of all known mites of wild mammals from Oregon is presented.      

Noteworthy flea records from Utah, Nevada, and Oregon

Collections from several scattered western localities have (1) extended the ranges in Nevada of two sagebrush vole fleas, Oropsylla bacchi johnsoni and Megabothris clantoni prince , (2) provided a second record for Utah of the rarely collected flea, Delotelis telegoni , and (3) included additional examples of unusual and seldom reported host-flea relationships for the area.     

Consumption of diffuse knapweed by two species of polyphagous grasshoppers (Orthoptera: Acrididae) in southern Idaho

Consumption of diffuse knapweed ( Centaurea diffusa Lam.) by 2 polyphagous grasshopper species, Melanoplus sanguinipes (F.) and Oedaleonotus enigma (Scudder), was studied using microhistological analysis of grasshopper crop contents. Grasshoppers were confined to cages containing C. diffusa and Sisymbrium altissimum L., a member of the mustard family known to be readily eaten by these 2 grasshopper species. Preference indices for knapweed were lower than for S. altissimum in 4 of 5 trials. An uncaged population of M. sanguinipes on a knapweed-infested site consumed only small amounts of knapweed until late summer when most other plants were senescent. Results suggested that diffuse knapweed s low palatability to generalist herbivores may confer to it a competitive advantage over other rangeland plants.     

Flea exchange between deer mice and some associated small mammals in western Utah

Collections from several scattered western localities have (1) extended the ranges in Nevada of two sagebrush vole fleas, Oropsylla bacchi johnsoni and Megabothris clantoni prince , (2) provided a second record for Utah of the rarely collected flea, Delotelis telegoni , and (3) included additional examples of unusual and seldom reported host-flea relationships for the area.     

New data on bats from Dire Dawa region,eastern Ethiopia,with the first record of Rhinopoma microphyllum in the country

ABSTRACT

A small collection of bats composed of six species from Dire Dawa area, eastern Ethiopia, is presented. Besides three species previously known in the region, Rousettus aegyptiacus, Epomophorus minimus and Chaerephon pumilus, three bats were newly documented from the area, Rhinopoma microphyllum, R. cystops and Scotophilus leucogaster. R. microphyllum is here reported for the first time in Ethiopia. From molecular genetic comparisons Ethiopian R. cystops belongs to the Arabian subspecies lineage R. c. arabium, previously unknown from the African continent, raising interesting biogeographic questions.     

Deer mouse, Peromyscus maniculatus, and associated rodent fleas (Siphonaptera) in the arctic-alpine life zone of Rocky Mountain National Park, Colorado

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Peromyscus maniculatus and related small rodents have been examined for ectoparasites in the tundra region of the Rocky Mountain National Park 1974–1979. One hundred and ninety-four P. maniculatus were examined from two tundra sites. Flea infestation rates were 1.9 fleas per mouse examined and 4.1 fleas per infested mouse. Species taken in significant numbers were Monopsyllus thambus (51 percent), Peromyscopsylla hesperomys (34 percent), Malaraeus euphorbi (9 percent), and Catallagia calisheri (4 percent). Peromyscus maniculatus host/flea relationships in the tundra are compared with those in other life zones in the park.       

Fleas (Siphonaptera: Ceratophyllidae, Ctenophthalmidae) from rodents in five southwestern states

Nine species of fleas were collected incidental to a survey of rodents for molecular studies in Arizona, Colorado, New Mexico, Texas, and Utah, south of latitude 38° N. Three species were parasites of woodrats, Neotoma spp.: Orchopeas neotomae Augustson was confirmed for Texas, and the distribution patterns of O. agilis (Rothschild) and O. schisintus (Jordan) were more clearly defined. Four species were parasites of mice, Peromyscus spp.: Aetheca wagneri (Baker) was a new flea for P. gratus Merriam, the distribution of O. leucopus (Baker) was extended to far west Texas, Plusaetis sibynus (Jordan) was new for Utah and N. lepida , and the range of Stenoponia americana (Baker) was extended west of the Continental Divide in New Mexico. Other species included Foxella ignota (Baker) and Meringis dipodomys Kohls.     

LIX.—Description of a species of Palæmon from near Sydney,probably either a new species or the adult form of Palæmon (Eupalæmon) danæ, Heller

Summary

Plagues of small mammals in Australia are nearly confined to rodents, both native and introduced. Only in the arid regions do small marsupials reach plague numbers.

Records of plagues have been found as early as 1845, but in many of them there is insufficient information to identify the species involved.

Plagues can develop under three main conditions, namely (a) when species are introduced into new environments, (b) in the artificial environment of crop plants, and (c) in the natural environment.

There are records of the introduced Rattus rattus forming plagues. On colonizing Lord Howe Island in 1918 the species built up to plague numbers in two years. On other islands the species is likely to have built up large populations also. Of various reported plagues on the Australian mainland, Rattus rattus has been identified definitely on only one occasion, in western New South Wales in 1887. There are earlier reports of the introduced rats and mice occurring in large numbers in unsettled areas, but it seems more likely that the animals were native species, wrongly identified, than introduced species which had spread into the areas concerned.

Two groups of species build up to plague numbers in the artificial environment of crop plants. These are Rattus conatus and some other native species which infest sugar-cane in Queensland, and Mus musculus which often infests wheatfields but also forms plagues in other habitats. Both groups infect the crop from a neighbouring natural habitat. Detailed ecological studies have been carried out on both these types of infestation. Reports of dispersal of plagues of Mus musculus need investigation.

Mus musculus can form plagues over a wide range of habitats, from the arid regions of central Australia to the high rainfall areas of tropical Queensland. The status of the form inhabiting the arid regions needs study.

The arid regions of Australia provide a special environment in which live a number of species of small mammals, both eutherians (rodents) and marsupials. In this habitat breeding occurs when there is a sufficient rainfall, and is not regulated at its extremes by an annual climatic cycle. Some of the riverine lands within the region receive drainage from outside, and this modifies the relationship with rainfall in the Lake Eyre Basin particularly. Under favourable conditions several species of the small mammals can build up to plague numbers. In this they appear to differ markedly from the small mammals of other deserts of the world. The special features of the Australian arid environment which allow this are unknown.

Plagues of Rattus villosissimus are generated in the tablelands to the south of the Gulf of Carpentaria, and hordes of the rodents disperse in large numbers, mostly moving out of the home territory along the course of rivers draining it to the south, and sometimes also to the north. The little information available concerning the populations suggests similarities with the cyclic changes which take place in populations of voles and lemmings in the northern hemisphere. There is no good information about the period of recurrence of the plagues, present records showing a range from three to seventeen years.

The little information available about the plagues of small mammals in Australia suggests parallels with such plagues elsewhere. The common factors are a small size, an herbivorous (? or insectivorous) diet, a high reproductive potential and a polymorphism which permits quick adaptation to the different population structures found under different population densities.     

Importance of migrating salmon smolt in Ring-Billed ( Larus delawarensis ) and California Gull ( L. californicus ) diets near Priest Rapids Dam, Washington

Ring-billed ( Larus delawarensis ) and California Gulls ( L. californicus ) have been implicated in depredations on migrating salmon smolt in the Columbia River. As part of a gull management program conducted in 1995 and 1996, we collected L. delawarensis (n = 120) and L. californicus (n = 45) near Priest Rapids Dam, Washington, and analyzed stomach contents to determine food habits and thus the importance of fish in gull diets. Percent volume measurements and index of relative importance rankings suggested a greater reliance on fish by L. californicus than by L. delawarensis . Peak percent consumption of fish by both species occurred in May, coinciding with peak salmon outmigration through Priest Rapids Dam; and for both species number of fish consumed by gulls was higher below Priest Rapids Dam. Gulls collected prior to, and after, peak smolt migration indicated low importance rankings for fish in both L. delawarensis and L. californicus diets. However, the importance ranking of fish in gull diets changed over time and was higher for both species as the smolt migration peaked in May.