Small-sized Mammals Research Articles

Molecular-phylogenetic analyses of Babesia and Theileria species from small mammals and their ticks in northern China suggest new reservoirs of bovine and equine piroplasms

Babesia and Theileria species (Apicomplexa: Piroplasmida) are tick-borne protozoan parasites that can cause mild to severe infection in humans, wildlife, livestock and companion animals. To date, reports on the molecular study of piroplasms from wild living small mammals and their ticks are still limited, especially in Asia. This study encompassed an extensive survey involving 907 liver samples and 145 ixodid ticks from 16 different species of small mammals (Rodentia, Lagomorpha, Eulipotyphla). These were collected in 13 cities and counties in northern China. DNA extracts from these samples were screened for the presence of piroplasm 18S rRNA gene. Samples that tested positive were further evaluated for other genetic markers of piroplasms, including the cox1 gene and the ITS1-5.8S rDNA-ITS2 region. Several piroplasm species were identified, including Babesia sp. tavsan2, Babesia occultans, Theileria sp. Xinjiang, Theileria equi, and Theileria sp. Kalecik. Among these, Theileria sp. Xinjiang was shown to be the most prevalent. Importantly, Babesia sp. tavsan2 was identified in the tick Rhipicephalus sanguineus from the Yarkand hare and Theileria sp. Kalecik in Hyalomma asiaticum from the long-eared hedgehog, in line with the detection of these pathogens in tissue samples of the relevant hosts. This study further disclosed the presence of DNA from B. occultans and T. equi, typically found in cattle and horses respectively, with an additional discovery in small mammals. Moreover, Theileria sp. Kalecik, which was first detected in small-sized mammals, and Babesia sp. tavsan2, were both reported for the first time in China.

Climate change should drive mammal defaunation in tropical dry forests.

Human-induced climate change has intensified negative impacts on socioeconomic factors, the environment, and biodiversity, including changes in rainfall patterns and an increase in global average temperatures. Drylands are particularly at risk, with projections suggesting they will become hotter, drier, and less suitable for a significant portion of their species, potentially leading to mammal defaunation. We use ecological niche modelling and community ecology biodiversity metrics to examine potential geographical range shifts of non-volant mammal species in the largest Neotropical dryland, the Caatinga, and evaluate impacts of climate change on mammal assemblages. According to projections, 85% of the mammal species will lose suitable habitats, with one quarter of species projected to completely lose suitable habitats by 2060. This will result in a decrease in species richness for more than 90% of assemblages and an increase in compositional similarity to nearby assemblages (i.e., reduction in spatial beta diversity) for 70% of the assemblages. Small-sized mammals will be the most impacted and lose most of their suitable habitats, especially in highlands. The scenario is even worse in the eastern half of Caatinga where habitat destruction already prevails, compounding the threats faced by species there. While species-specific responses can vary with respect to dispersal, behavior, and energy requirements, our findings indicate that climate change can drive mammal assemblages to biotic homogenization and species loss, with drastic changes in assemblage trophic structure. For successful long-term socioenvironmental policy and conservation planning, it is critical that findings from biodiversity forecasts are considered.

Bone histology of the Late Pleistocene Prolagus sardus (Lagomorpha: Mammalia) provides further insights into life-history strategy of insular giant small mammals

Abstract Fossils provide an excellent opportunity to study and understand the evolution of insular environments free of human-made perturbations. Here, we evaluated the life-history traits and strategy of the extinct insular giant Prolagus sardus (Mammalia: Lagomorpha) by examining microscopically its fossilized bone tissues (osteohistology, skeletochronology, and quantitative geometry). For this task, a complete ontogenetic series of femora retrieved from the Late Pleistocene Grotta della Medusa (NW Sardinia, Italy) were analysed. Our results reveal that: (i) P. sardus’ pups were weaned at large size; (ii) the species’ maturation was delayed in its life cycle; and (iii) P. sardus lived longer than expected for its size. Hence, the giant P. sardus should have a slow pace of life triggered by the low levels of extrinsic mortality of the insular habitat. On the other hand, bone tissue differences between P. sardus and Ochotona were found in the vascularization, slow- growing bone presence, and cortical and medullary growth trajectories. The results obtained in this study concur with the eco-evolutionary responses described to date in extinct insular lagomorphs, as well as provide new empirical evidence about the phenomenon known as ‘insular gigantism’ as a pattern of evolution of small-sized mammals in genuine insular ecosystems.

The extinct osteoarthritic lagomorphs (Prolagus sardus) from Sardinia (Italy) reveal further evidence of life history evolution in insular domains

The study of past pathologies by means of quantitative reports is an underexplored approach to deal with the biology and ecology of extinct taxa. In the present study, we assessed the prevalence rate of primary osteoarthritis in a large sample of Prolagus sardus (Mammalia, Lagomorpha) from Medusa Cave (also known as Grotta Dragonara, Sardinia, Italy; Late Pleistocene) to shed light on the evolutionary history of small mammals under isolation regimes. The hip and knee joints of 246 femora were examined grossly, microscopically, and using advanced radiology, recording essential biological features such as age or weight. We noted that 27.7% of skeletally mature sample had degenerative disorder of the joints, with higher frequency in adults (p-value < 0.05), regardless of their body mass (p-value > 0.05). Histologically, affected joints displayed changes in subchondral plate potentially reflecting adaptive modeling. Our analysis revealed ageing (the extended lifespan) as the main driver of this prevalence rate, whereas mechanical factors (caused by a particular lifestyle) were considered of significantly lesser importance. Our results provide additional empirical support to the analytical framework of life history theory from a new perspective, according to which, under low extrinsic mortality regimes, selection should favor slow-strategies (extended lifespan) in small-sized mammals.

Paleobiological inferences on middle Eocenenative ungulates from South America: Functionalmorphological analysis of Notostylopsand Notopithecus.

Eocene early-diverging representatives of South American extinct notungulates are traditionally considered to have been "generalists"and "non-specialized"in terms of the appendicular skeleton and locomotor behavior, as is the case with the notostylopid Notostylops, a middle Eocene iconic taxon from Patagonia (Argentina). However, they are mainly known from dental remains, and associated cranial and postcranial elements are scarce. The discovery of a nearly complete specimen attributed to N. murinus allows us to: (1) increase the knowledge of the anatomy of its appendicular skeleton; (2) identify isolated bones from several collections and suggest different taxonomic interpretations for published specimens; (3) perform a biomechanical and functional study using functional morphological analysis to infer its paleoecological attributes (e.g. posture, locomotor habit, estimated speed, and body mass); and (4) establish morphofunctional comparisons, based on possible functional ranges, with other extinct early-diverging notoungulates from the middle Eocene, such as the Notopithecid Notopithecus. Our evidence suggests that Notostylops was a medium-sized mammal (8.5-20 kg), which could achieve a dynamic digitigrade posture that allowed a scansorial secondary locomotor habit and a speed of up to 50 km/h. However,Notopithecus was a small-sized mammal (0.6-1.4 kg) with a plantigrade posture both in a static and dynamic context, terrestrial habits, and a speed of up to 35 km/h. Therefore, we conclude that these Eocene notoungulates show different locomotor capabilities, which can be associated with early niche diversifications, clearly contrasting with the "all-generalists"paradigmatic view.

Ecological Drivers of Habitat Use by Meso Mammals in a Miombo Ecosystem in the Issa Valley, Tanzania

Vast stretches of East and Southern Africa are characterized by a mosaic of deciduous woodlands and evergreen riparian forests, commonly referred to as “miombo,” hosting a high diversity of plant and animal life. However, very little is known about the communities of small-sized mammals inhabiting this heterogeneous biome. We here document the diversity and abundance of 0.5–15 kg sized mammals (“meso-mammals”) in a relatively undisturbed miombo mosaic in western Tanzania, using 42 camera traps deployed over a 3 year-period. Despite a relatively low diversity of meso-mammal species (n = 19), these comprised a mixture of savanna and forest species, with the latter by far the most abundant. Our results show that densely forested sites are more intensely utilized than deciduous woodlands, suggesting riparian forest within the miombo matrix might be of key importance to meso-mammal populations. Some species were captured significantly more often in proximity to (and sometimes feeding on) termite mounds (genus Macrotermes), as they are a crucial food resource. There was some evidence of temporal partitioning in activity patterns, suggesting hetero-specific avoidance to reduce foraging competition. We compare our findings to those of other miombo sites in south-central Africa.

The Influence of Urbanization on Mammal Diversity and their Population Patterns: A Case Study of Tashkent, Uzbekistan

Abstract The article provides a survey of the mammalian fauna and ecology in different habitats across the city of Tashkent that vary in the degree of urbanization. The current mammalian fauna of Tashkent is represented by 32 species; during the city’s development, 9 species have disappeared from the place, either through an anthropogenic impact or having been forced out by alien species. The urban mammalian fauna has increased through arrival of five new invasive species. With the ongoing urbanization, the species diversity of small-sized mammals is decreasing, while their numbers are growing, resulting in simplification of the structure of small mammals’ urban communities and lowering of their biodiversity. The urbanization does not impact the age and sex structure of the house mouse population noticeably. The urban population shows a productivity 1.7 times higher than the wild populations, which is a compensatory response to the relatively high embryonic mortality that is almost totally absent in natural populations. Differences in the morphophysiological indicators of the house mouse synanthropic population and those of populations in the wild are an adaptive response to anthropogenic impact, which appears in the form of more rapid growth, a higher metabolism, exchange of energies, and overall stress load on the rodents in urban biocoenoses. The study showed that the skulls of urban animals grow more rapidly than those of wild mice, while their proportions change following the development pattern of juvenile mice, which suggests that individuals from the Tashkent population can be referred to as rapidly growing animals, with outdoor individuals showing greater relative cranial parameters.

New insights for understanding spatial patterning and formation processes of the Neanderthal occupation in the Amalda I cave (Gipuzkoa, Spain)

The Level VII of Amalda I cave (Gipuzkoa, Spain) represents one of the latest Middle Palaeolithic occupations in the Cantabrian Region. It is characterized by the presence of Middle Palaeolithic lithic industry and animal remains, with clear evidences of anthropic and carnivore manipulation. At this site, the Neanderthal presence has been questioned in relation to the role of carnivores in the accumulation of large, medium-sized and small mammals. It has also been proposed that the Neanderthal occupation could have consisted of short-term occupations, where different activities took place in a structured space within the cave. However, all hypotheses lacked any integrative analysis of the site formation processes. With the aim of understanding these processes, a combination of spatial techniques, based on GIS and inferential statistics (density analysis, hotspots tools and palaeotopographic reconstruction), along with the taphonomic study of identifiable and non-identifiable macromammals remains, were employed. This study has revealed distinct use of the cave space by Neanderthals and carnivores. The major concentrations of lithics and medium-size mammal remains were clearly accumulated by humans at the cave entrance, while the small-size mammals were gathered by carnivores in an inner zone. The activities of the Neanderthals seem to be distinctly structured, suggesting a parallel exploitation of resources.

Ancient Mitogenomes Reveal the Evolutionary History and Biogeography of Sloths

Living sloths represent two distinct lineages of small-sized mammals that independently evolved arboreality from terrestrial ancestors. The six extant species are the survivors of an evolutionary radiation marked by the extinction of large terrestrial forms at the end of the Quaternary. Until now, sloth evolutionary history has mainly been reconstructed from phylogenetic analyses of morphological characters. Here, we used ancient DNA methods to successfully sequence 10extinct sloth mitogenomes encompassing all majorlineages. This includes the iconic continental ground sloths Megatherium, Megalonyx, Mylodon, and Nothrotheriops and the smaller endemic Caribbean sloths Parocnus and Acratocnus. Phylogenetic analyses identify eight distinct lineages grouped in three well-supported clades, whose interrelationships are markedly incongruent with the currently accepted morphological topology. We show that recently extinct Caribbean sloths have a single origin but comprise two highly divergent lineages that are not directly related to living two-fingered sloths, which instead group with Mylodon. Moreover, living three-fingered sloths do not represent the sister group to all other sloths but are nested within a clade of extinct ground sloths including Megatherium, Megalonyx, and Nothrotheriops. Molecular dating also reveals that the eight newly recognized sloth families all originated between 36 and 28 million years ago (mya). The early divergence of recently extinct Caribbean sloths around 35 mya is consistent with the debated GAARlandia hypothesis postulating the existence at that time of a biogeographic connection between northern South America and the Greater Antilles. This new molecular phylogeny has major implications for reinterpreting sloth morphological evolution, biogeography, and diversification history.

AN UPDATED SPECIES LIST OF MEDIUM AND LARGE-SIZED MAMMALS OF THE AUGUSTO RUSCHI BIOLOGICAL RESERVE, USING A NOVEL SAMPLING DESIGN

Monitoring biological communities through time helps reveal the state of habitat conservation. We performed a new inventory of the medium and large-sized mammals in the Augusto Ruschi Biological Reserve, southeastern Brazil. Our assessment was based on a new camera-trapping sampling design that incorporates a one-year Enhanced Vegetation Index (EVI) to characterize environmental heterogeneity across the study area. We selected sampling locations in different microhabitats to conduct a 90-day camera trap monitoring. Our sampling effort was 28,704 hours, resulting in 755 photographic records, from which we identified 15 native medium and large-sized mammals, one small-sized mammal ( Guerlinguetus brasiliensis ), and one exotic species ( Canis familiaris ). The native mammals included four species not listed in the last inventory carried out in the study area: Dasypus novemcinctus (nine-banded armadillo), Tamandua tetradactyla (collared anteater), Herpailurus yagouaroundi (jaguarundi), and Cerdocyon thous (crab-eating fox). This outcome may indicate the efficiency of our sampling design, which represents an innovative approach to characterizing local mammal communities across an environmental gradient, ensuring broad representation of different resources and habitat characteristics. Consequently, our approach may ensure the recording of the local mammal assemblage and is an appropriate option for inventorying and monitoring medium to large-sized mammals.

ECOLOGIA TRÓFICA DE ONÇA-PARDA (Puma concolor) EM PAISAGEM AGRÍCOLA

Os carnívoros são importantes componentes ecológicos dos ecossistemas, pois controlam a abundância, a distribuição e a diversidade das populações de suas presas. Desta forma, são considerados como espécies-chaves na manutenção e restauração da diversidade e da resiliência dos ecossistemas. Nesse grupo, a onça-parda (Puma concolor) é a espécie de mamífero silvestre mais amplamente distribuída do hemisfério ocidental, porém, suas exigências em tamanho de área de vida e alimentação mostram-se um fator de restrição para sobrevivência da espécie por fatores como pressão de caça, diminuição de presas e desmatamento. Este estudo teve como objetivo avaliar a dieta do P. concolor em uma paisagem silvicultural no Estado de São Paulo. A paisagem é formada pela presença de remanescentes de cerrado, plantações de eucalipto e áreas de pastagens. Para análise da dieta foram coletadas, triadas e analisadas 103 amostras de fezes de P. concolor. Os resultados indicam grande consumo de aves e mamíferos de pequeno porte, diferindo da alimentação da espécie em ambientes naturais onde os mamíferos são o principais itens alimentares. Esta variação na dieta confirma a onça-parda como predador generalista, que consume as presas disponíveis sem apresentar preferência por determinadas espécies.

Body Temperature Patterns in Captive Barbary Striped Grass Mousse (Lemniscomysbarbarus): Influence of Photoperiod and Sex Steroids

This study use miniature temperature-sensitive data loggers to record core body temperature (Tb) in Lemniscomysbarbarus, a diurnal Muridae rodent living in Africa. The work shows the existence of a strong and bimodal daily Tb rhythm in this species whose external synchronizer is the light-dark cycle; it’s also confirmed the diurnal and photoperiodic character of this animal. The highest values of Tb were registered during the light-phase in anti-phase with the nocturnal species. In the experimental conditions of this work Lemniscomysbarbarus do not express the phenomenon of diurnal torpor. Nevertheless, this characteristic mechanism of energy saving in small-sized mammals could be appearing by the association of the combined effects of short photoperiod, low ambient temperature and limited food supply.

SURVEY OF SMALL MAMMALS (RODENTIA AND DIDELPHIMORPHIA) IN A CERRADO RESERVE: CENTRAL ESPINHAÇO MOUNTAIN RANGE, BRAZIL

Despite its high diversity, small mammals within the Cerrado (savanna) at the Central Espinhaco Range are poorly known, and precise information regarding the geographical distribution of all species is still scarce. Here we present data on terrestrial small-sized mammals (Didelphimorphia and Rodentia) from Parque Estadual do Rio Preto (PERP), a protected area in the Central Espinhaco and compare the species composition of this area with other protected areas in the Espinhaco Range. Over the course of 10,616 trap-nights, there were 700 captures of 245 individuals, being eight species from de order Didelphimorphia and eight from Rodentia, with an overall capture rate of 6.6%. We report both, Gracilinanus agilis and G. microtarsus , occurring in sympatry and the occurrence of Thalpomys lasiotis, known to be endemic to the Cerrado biome. We observed that the species composition of the Central Espinhaco contains a set of species different from those found in Southern Espinhaco (Serra de Ouro Branco). This may be most the result of vegetal physiognomies among the inventoried areas and less clearly the result of geographic distance between them. Considering that the conservation strategies focus basically on the richness and the occurrence of endemic species, we here emphasize the need for further research efforts in order to improve our knowledge about the Espinhaco fauna.

Structure and dynamics of the trophic spectrum of the American mink (Neovison vison) in the Southern Urals

The peculiarities of feeding of the American mink (Neovison vison) near lakes and mountain rivers of the Southern Urals are studied. Significant differences are shown between structure and dynamics of the mink diet near lakes and mountain rivers. The diet of minks near mountain rivers depends on the abundance of small-sized mammals inhabited at the banks, which is determined by properties of the hydrological regime in each season.

Rat-to-Chinese tree shrew heart transplantation is a novel small animal model to study non-Gal-mediated discordant xenograft humoral rejection.

Since α-1,3-galactosyltransferase knockout (GalT-KO) pigs became available, there has been an increasing interest in non-Gal natural antibody (nAb)-mediated xenograft rejection. To better understand mechanisms of non-Gal nAb-mediated rejection, a simple small animal model without gene manipulation would be extremely valuable. Here, we tested whether the Chinese tree shrew (CTS), which is a small-sized mammal that is phylogenetically close to primates, could serve as a model for discordant xenograft rejection. Study 1: Expression of α-Gal antigens in hearts and kidneys of CTSs and rats was assessed by IB4 lectin binding. Presence of anti-Gal and anti-non-Gal IgM and IgG nAb in CTS sera was tested by FACS using Gal+ and GalTKO PBMC as well as BSA-ELISA. Study 2: Rat hearts were transplanted into CTS recipients (group 1, n = 7), and CTS hearts were transplanted in rats [n = 10; seven received no immunosuppression (group 2) and three received FK506 + leflunomide (group 3)]. Study 1: Both CTSs and rats had α-Gal expression in hearts and kidneys. ELISA showed CTSs do not have anti-Gal nAb, and flow cytometry indicated CTSs have anti-non-Gal IgM and IgG nAb in serum. Study 2: Rat hearts in CTSs were uniformly rejected within 35 mins, while CTS hearts in rats continued beating until day 5 without immunosuppression, and up to day 8 with immunosuppression. Rat-to-CTS heart transplantation is a discordant xenotransplant model, CTS-to-Rat heart transplantation is a concordant xenotransplant model. CTSs are valuable small animals to study mechanisms and strategies to avoid non-Gal nAb-mediated xenograft rejection.

Neotropical small mammals’ diversity in the early cycle of commercial Eucalyptus plantations

Studies carried out in Brazil revealed that Eucalyptus plantations shelter numerous species of small-size non-flying mammals. However, their distribution pattern inside the Eucalyptus plantations remains unknown. This study aimed at the identification of possible influence of distances from the remaining native revegetation areas and riparian systems, on spatial distribution and abundance of small-size mammals in Eucalyptus plantations. This study was carried at Eucalyptus stands recently planted (0–3 years) at the municipality of Angatuba, Sao Paulo state, Brazil between August 2007 and July 2009. The survey was carried out using pitfall traps at 14 sampling units inside Eucalyptus plantations 60–1130 m away from the borders. With a sampling effort of 2,449 bucket night, the experiment captured 680 individuals belonging to 12 species of small-size mammals (rodents and marsupials). The colonization process of Eucalyptus plantations was apparently initiated by generalist species from open Cerrado. In the present study, we did not find any clear correlation between specific richness and abundance of individuals and the distance from native revegetation areas or closer riparian systems. The study suggests that Eucalyptus plantations are permeable matrices to, at least, more generalist species present in the silvicultural landscapes (i.e. composed by an Eucalyptus plantation as the matrix and native vegetation patches). However, further studies must prioritize analyzing the influence of agricultural/sivilcultural practices (e.g., plantation structure and harvest frequency) on habitat quality and carrying capacity of agricultural/silvicultural landscape matrices, as well as implementing long-term monitoring programs to assess the impact of complete production cycles (some years) and along cycles of Eucalyptus plantations (some decades), on rodents population’s diversity and dynamics patterns.

Multidisciplinary studies of Southern Brazil Holocene: Archaeological, palynological and paleontological data

In order to understand the relationship between human occupation and paleoenvironmental scenario in Southern Brazil during Holocene, multidisciplinary studies were carried out in two archaeological sites located at Northeast of Rio Grande do Sul State: Sangão rockshelter (RS-S-327) and Garivaldino rockshelter (RS-TQ-58). Both sites have radiocarbon ages from 9400 to 3730 14C BP, revealing a continuous occupation of this area by hunter-gatherer populations related to Umbu Tradition. Palynological studies conducted in areas near the archaeological sites demonstrated an increase in humidity and in arboreal taxa starting at 5400 14C BP, providing evidence of a mosaic of grasslands and forests. These findings are corroborated by the analysis of small-sized mammals related to non-human predation associated to these archaeological sites, which present contemporary taxa typical of forests and open areas. They also demonstrated that environmental changes were slow and gradual during the Holocene. Although paleoenvironmental data suggest that the landscape of this region evolve gradually from mosaic of forest and open landscapes to diverse and densest forests, zooarchaeological analysis indicates a pattern of adaptive stability that persists throughout the Holocene, characterized by generalist strategies of subsistence focused mainly in forest resources. Therefore, the favorable weather conditions and the presence of forest environments restricted to river valleys and mountain slopes until Mid-Holocene, played a central role for the initial human settlement of this area, related mainly with riverine routes.

Additional evidence for bone technology in the southern African Middle Stone Age

Few Middle Stone Age sites have yielded convincing evidence for a complex bone technology, a behavior often associated with the emergence of modern cultures. Here, we review the published evidence for Middle Stone Age bone tools from southern Africa, analyze an additional nine bone artifacts recently recovered from Middle Stone Age levels at Blombos Cave, describe an unpublished bone tool from probable Middle Stone Age levels at Peers Cave, examine a single bone awl found at Blombosch Sands (an open site near Blombos Cave), and reappraise marked bone artifacts and a bone point recovered from Klasies River. To determine the chronological and cultural attribution of these artifacts, document bone-manufacturing techniques associated with the southern African MSA, and discuss the symbolic significance of the markings present on some of these objects we use (1) available contextual information; (2) morphometric comparison of Later Stone Age, Modern San, and purported Middle Stone Age projectile points; (3) analysis of the carbon/nitrogen content of bone tools and faunal remains from Peers and Blombos caves; and (4) microscopic analysis of traces of manufacture and use. Previously undescribed bone artifacts from Blombos Cave include a massive point manufactured on weathered bone, two complete awls and two awl tips manufactured on small-sized mammal and bird bone, a probable projectile point with a tang manufactured by knapping and scraping, a shaft fragment modified by percussion, used as retoucher and bearing a set of incised lines on the middle of the periosteal surface, and two fragments with possible engravings. The point from Peers Cave can be assigned to the Middle Stone Age and bears tiny markings reminiscent of those recorded on projectile points from Blombos and used as marks of ownership on San arrow points. The awl from Blombosch Sands and the bone point from Klasies River can be attributed to the Later Stone Age. Two notched objects from Klasies are attributed to the Middle Stone Age and interpreted as tools used on soft material; a third object bears possible deliberate symbolic engravings. Although low in number, the instances of bone artifacts attributable to the Middle Stone Age is increasing and demonstrates that the bone tools from Blombos Cave are not isolated instances. New discoveries of bone tools dating to this time period can be expected.

Trophic ecology of Athene owls in mediterranean-type ecosystems: a comparative analysis

Populations of Athene owls are found in the mediterranean-type ecosystems of Chile (A. cunicularia cunicularia, formerly in the genus Speotyto), California (A. cunicularia hypugea), and Spain (A. noctua). We assess whether the tropic ecology of Athene owls in these chaparral habitats is more similar between these three populations than between any of these and populations in a different kind of habitat. The control is provided by a population of A. cunicularia hypugea inhabiting a grassland in Colorado. The trophic ecology of the four populations is characterized qualitatively by the taxonomic composition of the diets and quantitatively by means of trophic diversity measurements and computation of the mean weights of mammalian prey taken. At the intraspecific level of resolution, Chilean and Californian populations are more similar to each other than they are to the population in Colorado. At the interspecific level of resolution, A. noctua is not more similar to chaparral A. cunicularia than it is to grassland A. cunicularia. The differences between Colorado A. cunicularia and the conspecific populations in Chile and California are shown to be associated with a discrepancy in the size configuration of the owl assemblages between grassland and chaparral habitats, and perhaps to differences in the relative abundance of small-sized mammals. The dissimilarities in the trophic ecology between Spanish A. noctua and the New World A. cunicularia are hypothesized to stem from differential availability of amphibian and reptile prey.

On the Non-ciliated Cells in the Airway Epithelium in Certain Mammals

The observation was attempted to clarify the more detailed morphological and functional significances of the non-ciliated cells in the airway epithelium of animals. Small-sized mammals such as mice, rats and bats were used in this study, and the non-ciliated cells were usually observed in all over the airway epithelium in these animals.Non-ciliated cells were devided into two different types, i. e., the endocrine type and exocrine type.Endocrine type cells may be identical to the so-called brush cells and other related cells which were initially reported by Rhodin and Dalhamn (1954), on account of their morphological characteristics that are equipped with well-developed filament bundles, glycogen granules and many closely packed micrcvilli protruding from their apical surface into the lumen. All of these type cells generally contained many dense granules of smaller size which were released into the connective tissue layer under the epithelium. No synapse-like contacts between these cells and the intraepithelial nerve fibers were observed.Exocrine type cells were found to exist not only in the terminal bronchioles but in the trachea and other thicker part of the airway epithelium. These cells contained a lot of both types of ER and scarce secretory granules of seromucous in nature. In such animals, neither discernible well-defined glands in the connective tissue layer of the entire airway nor typical goblet cells in the epithelium were observed. Thus, such non-ciliated cells may concern with the production of lubricating material in the epithelium in these animals.