Rodent Fauna Research Articles

Predation of Range Caterpillar, Hemileuca oliviae (Lepidoptera: Saturniidae) at Various Stages of Development by Different Species of Rodents in New Mexico During 1980 1

The hypothesis that differences in woodland and grassland rodent fauna were responsible for the absence of range caterpillar, Hemileuca oliviae Cockerell, in woodlands adjacent to infested grasslands was tested by field and laboratory experiments. There was little predation by any species on range caterpillar larvae. Three species exhibited active predation on eggs and pupae. Two of these species, Peromyscus maniculatus (Wagner) and Onychomys leucogaster (Wied-Neuwied), were found in grasslands inhabited by the range caterpillar. The third species, Peromyscus truei (Schufelt), was common in woodlands and showed particularly avid predation of range caterpillar pupae. The greater density and predation rate of this species over the grassland species was probably an important factor limiting the survival of range caterpillar in woodlands even when favorable host plants were present.

Effects of changing environments on Siwalik rodent faunas of northern Pakistan

Fossil assemblages from the Siwalik Group collected over the past six years reveal the development of the modern rodent fauna of the Potwar Plateau, Pakistan. The history of the Potwar rodent fauna proceeds through four stages: (1) extinction of archaic elements by 9 Ma; (2) faunal turnover around 7 Ma by phyletic evolution, immigration, and local extinction; (3) attainment of modern grade at about the Pliocene—Pleistocene boundary; and (4) increase in abundance of desert forms and agricultural pests probably associated with man and overgrazing

Zoogeographic implications of early Miocene rodentsfrom the Bugti beds, Baluchistan, Pakistan

Abstract Fossils from the Bugti beds, Baluchistan, Pakistan, suggest that the rodent fauna of the Indo-Pakistan subcontinent evolved in relative isolation from Europe between the middle Eocene and middle Miocene. Cricetid rodents entered South Asia after the time of the Bugti beds but before the Muree rodent fauna, which is similar to the lower Siwaliks.

Species diversity patterns in some present and prehistoric rodent communities.

Comparisons of prehistoric (A.D. 1100-1400) and extant cricetine-dominated rodent faunas from two locations in New Mexico and one in Arizona reveal temporal changes in both species diversity and taxonomic composition. The archaeological context of the prehistoric faunas permitted them to be dated rather accurately; paleoenvironmental inferences generated from other materials recovered in the excavations such as pollen samples, agricultural remains, and tree-ring specimens provided evidence about prehistoric environmental conditions in the study areas. Both richness and evenness components of diversity are lower in the present day faunas than in their prehistoric counterparts. At the beta (between-habitat or valley-wide) level of diversity the increased prehistoric species richness as well as the nature of the differences in present and prehistoric taxonomic composition can be accounted for by small climatic shifts which were occurring between A.D. 1100 and 1300 in the Southwest and the resultant biogeogrphic responses of certain rodent species. Alpha (or within-habitat) diversity is similar for all analyzed faunas. This suggests basic similarities in very local species packing despite observed spatial and temporal variation in valley-wide diversities. Environmental changes stemming from climatic shifts provide a reasonable explanation of the observed patterns of rodent species occurrence and diversity. Habitat destruction resulting from agricultural practies of prehistoric human populations appears to have had only a limited impact on these rodent communities.

Les gisements continentaux de Plaissan et de la Nouvelle Faculté de Médecine (Hérault) leur position stratigraphique

The study of Plaissan rodent fauna and the discoveryof a new fossiliferous locality, 〈Nouvelle Faculté Médecine〉, allow us to contribute to a more accurate biochronological mammalian scale, for the Bas-Languedoc Lower Miocene. Nouvelle Faculté Médecine, contemporaneous of La Paillade or slighthy older has a Aquitanian age; Plaissan, equivalent to Paulhiac, ist older than the oldest known interbedded marine level in the Languedocian marine Aquitanian (Les Cévennes); it should be contemporaneous with the ante-stratotypic Aquitanian of Carry-le-Rouet.

Food Relationships of a Rodent Fauna in a California Coastal Sage Scrub Community

During a 13 month live-trapping study on a 2.3 ha grid located in upland coastal sage scrub near Irvine, California, the food habits of seven species of rodents were determined using fecal analysis. These included four cricetids, Reithrodontomys megalotis , Peromyscus maniculatus , P. eremicus , and P. calif omicus , and three heteromyids, Dipodomys agilis , Perognathus fallax , and P. longimembris . Laboratory feeding experiments using the cafeteria method in autumn 1971 indicated different patterns of food preference from wide acceptance of shrubs, forbs, and grasses ( Dipodomys ) to lower preferences for shrubs and high preferences for grasses (all cricetids except P. maniculatus ) to relatively narrow acceptance of only grasses ( P. longimembris ). Comparison of diet composition by weight with volumetric percentages using fecal analysis of animals in feeding experiments indicated highest correlations for shrubs and forbs in cricetids and shrubs and grasses in heteromyids. Food habit trends revealed a high utilization of insects and Eriogonum fasciculatum by Reithrodontomys , a generalized diet for P. maniculatus , and a specialization on various seeds, flowers, and fruits by P. californicus and to a lesser degree by P. eremicus . The three heteromyids ate large amounts of annual and grass seeds during most months with the most opportunistic feeding shown by Dipodomys on grasses and forbs during winter-spring months. Food habits were most similar among the heteromyids, and P. eremicus-P. californicus . Of these, P. longimembris utilized winter torpor, whereas P. californicus was a seasonal resident. Food habit responses of subordinate cricetids to the spring immigration of P. californicus suggest the presence of both flexible feeding strategies and seasonally abundant resources in spring. These conditions may explain the continued coexistence of the diverse rodent fauna during this period.

Small Mammal Energetics in Grassland Ecosystems

Results of quantitative sampling of small mammal populations at different grassland sites for a 3—yr period are compared to evaluate the energy requirements and consumption, according to trophic levels, for total small mammal communities at all seasons in different years. The purpose was to search for patterns of food utilization by these consumers at the different sites. This picture of the bioenergetics of small mammal populations over a wide range of grassland sites was constructed from extensive US/IBP Grassland Biome diet and population data and from physiological information out of the literature. The work represents one step in the process of understanding the role of consumers in the ecosystem. No species occurs at all sites and different trophic strategies predominate among the small mammals at each site: Microtines (herbivores) dominate the tallgrass prairie, sciurids (omnivores) dominate the northern shortgrass prairie, and heteromyids (granivores) dominate the bunchgrass and desert grasslands. Other groups occur at these sites and vary in their importance. At the tallgrass and midgrass sites the small mammal populations are largely dependent on herbage consumption, while at the northern and southern shortgrass prairie sites the rodent fauna is largely dependent on invertebrates. The most uniform distribution of resource utilization by this component of the consumer community occurs at the desert grassland site, where herbage, seeds, and animal matter are all utilized. Relative to the total amount of consumable herbage available (that actually utilized by the small mammal population), this resource is only slightly utilized (from a fraction to a few percent of available). Animal matter, largely invertebrates, is highly utilized at most sites and may in fact be a limiting factor on small mammal populations. The energy consumed by the small mammal population was greatest at the tallgrass prairie site, where the average annual consumption was 172 x 103 kcal/ha (= 720 MJ/ha). However, efficiency of biomass support was greatest at the northern shortgrass prairie site, where consumption of 32 x 103 kcal/ha (= 134 MJ/ha) supported proportionately more biomass (277 g live wt./ha) of animals than at the tallgrass site (935 g/ha). The estimates of population energy requirements presented here compare well with other available estimates. These results emphasize the great between year and site variability, however. Daily population respiration in summer may be as little as 14 and as large as 1,038 kcal°ha—1°day—1. Highest small mammal biomass occurred at the tallgrass (3,075 g live wt./ha) and the desert (2,304 g/ha) sites, and lowest at the midgrass (14 g/ha) site. Within the period of study, small mammal biomass was most stable at the southern shortgrass site and most variable at the tallgrass site. The role of small mammal populations in grassland ecosystem remains incompletely defined. A broader view of the total consumer community in relation to resources is required.

Convergent evolution of desert rodents: multivariate analysis and zoogeographic implications

Ecological investigations were conducted on rodent faunas in the Sonoran Desert of the southwestern United States and the Monte Desert of northwestern Argentina. Both study areas are physiognomically quite similar and the rodents are only distantly related. Such conditions are ideal for an assessment of possible evolutionary convergence. Multivariate analyses of morphoecological characters support the subjective interpretation that ecological equivalents between the deserts differ in their degree of similarity. The data indicate that the Monte rodent fauna is composed of two distinct groups: a) the caviomorph rodents, which are highly desert adapted; and b) the murids, which range widely beyond the desert's boundaries and are probably not as highly desert adapted, as a group, as are the caviomorphs. When the Monte and Sonoran faunas are compared with a North American coniferous forest rodent fauna, data show that both desert groups have converged toward one another. The different degrees of desert adaptation and different distributional patterns indicate that the Monte Desert was colonized in two different periods (one in the early Tertiary and one in the late Pliocene or early Pleistocene) and can be interpreted as supporting theories regarding South America's colonization by mammals which were first proposed by Simpson (1951).

South American mammal zoogeography: evidence from convergent evolution in desert rodents.

Current theories regarding colonization of South America by mammals are divided between those supported by fossil evidence, which suggest the original mammal fauna of the isolated continent was augmented by early immigrants (primates, caviomorph rodents, and later, procyonids) with a final large influx of northern mammals occurring with the formation of the Panama land bridge, and an opposing view which states that the purported "recent invaders" are too taxonomically and ecologically differentiated to have colonized since the land bridge arose. The second theory suggests that most extant mammals entered before the Plio-Pleistocene land connection. An analysis of degree of physiological adaptation, natural history, distribution patterns, and a multivariate assessment of convergent evolution of Monte Desert rodents indicate that South American cricetine rodents are not highly specialized for desert life. Their degree of adaptation could be accounted for, in large part, by adaptations for arid or semiarid Andean habitats. No Monte Desert rodent has developed the specialized desert traits that have evolved in most desert rodent faunas of the world, although extinct marsupials similar to living bipedal desert rodents were present in the Monte as recently as late Pliocene. Evidence suggests that Monte caviomorphs have been associated with the desert for a longer period than cricetines, and that the latter represent a fairly recent invasion of the Monte Desert. The data thus support the first hypothesis of South American mammal colonization.

Species Diversity of Seed‐Eating Desert Rodents in Sand Dune Habitats

The seed—eating rodent faunas were sampled on 18 dunes of semistabilized, wind—drifted sand in eastern California, Nevada, and western Utah. These dunes were similar in general appearance and in the form and spacing of vegetation, yet the number of common species of granivorous rodents ranged from 1 to 5. The faunas of all dunes were characterized by a regular spacing of body sizes, and the difference in size between coexisting species was inversely related to the number of species present. Differences in species diversity between dunes can be attributed to ecological, biogeographic, and evolutionary processes. A common pool of species had equal opportunity to colonize 13 of the dunes. The numbers of species inhabiting these dunes are determined primarily by ecological factors. Species diversity is most closely correlated with the predictable amount of annual rainfall, the best available estimate of the abundance of seeds. At least three dunes apparently are biogeographically depauperate; biogeographic barriers have prevented colonization of particular species that probably could exist on those dunes. Two of the dunes occur at high altitudes and these appear to be depauperate in an evolutionary sense; although these dunes seem to be capable of supporting additional rodent species, it is likely that no existing species possess the adaptations necessary to colonize them.

Notes on the Rodent Faunas of Two Panamanian Forests

Twenty-one species of rodents were trapped or observed in two forests in the Panama Canal Zone. Data on the ecology, molt, and food habits of seven species are presented. Among the terrestrial rats and mice, three species ( Liomys adspersus, Oryzomys capito, and Proechimys semispinosus ) were common in the Pacific slope forest, whereas two ( Oryzomys capito and Proechimys semispinosus ) were common in the Atlantic slope forest. Year-round breeding occurs in eight of nine species; Liomys adspersus breeds seasonally. Adults of L. adspersus and P. semispinosus molt during restricted portions of the year, but there was no apparent synchrony of molt in adults of Heteromys desmarestianus, Oryzomys capito, Zygodontomys microtinus, and Sigmodon hispidus. Ecological segregation serves to minimize competition among the rodents in both forests.

O foco pestoso dos municípios de Teresópolis e Nova Friburgo, estado do Rio de Janeiro-Brasil: estudo paisagística da região

O autor do presente trabalho realizou um estudo paisagístico do foco pestoso do município de Teresópolis, Estado do Rio de Janeiro. O estudo compreendeu a revisão dos casos humanos desde 1938, os aspectos geológicos, climáticos, geográficos, fitofisionômicos e a fauna de roedores. Discussões foram feitas em tôrno do Homem e suas interações com o ambiente, relacionando-as com o problema da peste.

New data on the Holocene history of the rodent fauna in the Pre-Uralian Subarctic (the Chernyshev Ridge, northeastern part of European Russia)

New data on the Holocene history of the rodent fauna in the Pre-Uralian Subarctic (the Chernyshev Ridge, northeastern part of European Russia)

Succession of Rodent Faunas during the Upper Pleistocene of Israel

Succession of Rodent Faunas during the Upper Pleistocene of Israel

Rodents of the Mio-Pliocene Norden Bridge Local Fauna, Nebraska

The Norden Bridge Quarry in the Mio-Pliocene Valentine Formation of Brown County, Nebraska, has produced a rodent fauna of 14 species in eight families. Most species belong to genera previously known from the North American late Miocene and early Pliocene; however, Plesiosminthus and Allomys were previously known only from the early Miocene, and Leptodontomys from the middle Pliocene. One species (Allomys stirtoni) is described as new. The Norden Bridge rodent fauna is much richer than other known local faunas in the Valentine Formation, but seems to be similar to the next best known one.

Fossil Rodents from Fort Ternan, Kenya

THE rodent fauna from Fort Ternan which Dr. L. S. B. Leakey has sent to me for examination consists for the moment of only a few specimens comprising the following: Seventeen mandibles, a fragment of a skull in which the teeth are unfortunately very worn, and 26 incisors. The mandibles represent creatures of small size, but on the other hand six of the incisors suggest the presence of species of the size of the large Phiomyidae of Rusinga and Songhor. Nine mandibles belong to the Cricetodontini, one represents a small Phiomydae similar to one of the forms from Songhor, one represents a Sciuridae, while three of the mandibles belong to a new genus, Leakeymys ternani nov. gen., nov. sp., to which genus and species I also provisionally attribute the skull fragment. (The collection also includes a mandible of a murine, but in this specimen the bone is not completely fossilized as it is in all the other material, and it is, therefore, I believe, an intrusive specimen which can be ignored at the present time.)

Notes on three additions to the rodent fauna of Alberta

Notes on three additions to the rodent fauna of Alberta

大阪市内の鼠族について〔IV〕(第 4 回大会講演要旨)

大阪市内の鼠族について〔IV〕(第 4 回大会講演要旨)