Unusual social feeding and soaring by the Common Raven ( Corvus corax )

Common ravens are usually rather shy birds around their nests and avoid nesting too near human activity. We here report the use of overpasses along heavily traveled Interstate Highway 84 in Idaho and Utah for nest placement. Nests are within 6 m of passing vehicles.     

Ground nesting and aggressive behavior by the Swainson's Hawk ( Buteo swainsoni )

A successful ground nesting by Swainson’s Hawks, Buteo swainsoni, is reported for central Utah. Unusual aggressive nest defense behavior is described for this ground nesting pair.     

Second nesting record and northward advance of the Great-tailed Grackle ( Quiscalus mexicanus ) in Nevada

The second nesting record for the Great - tailed Grackle ( Quiscalus mexicanus ) in Nevada is reported from the central part of the state approximately 240 km north of the previous record. Since 1912 this species has undergone a dramatic northward extension of its previous range in the United States, presumably as a result of increased agricultural irrigation in areas that were previously desert or short - grass prairie.         

Observations on the nesting behaviour of seven species of Crabro (Hymenoptera,Sphecidae)

Summary

Data are presented on the nests and prey of seven species of Crabro from diverse localities in North America. In two instances (virgatus and largior) this is the first published report. Further information is provided for the following previously studied species: argusinus, advena, cribrellifer, latipes, and monticola. Behavioural differences among these species are not conspicuous. Most are rather general fly predators, but cribrellifer appears to show a strong preference for Asilidae. There are also differences in type of soil used for nesting and in antipredator behaviour such as approach flights and daily cycles of activity. Two species, largior and monticola, provision their nests early in the morning, before miltogrammine flies are active in numbers. All species probably make cells of two sizes, larger cells containing more prey and producing females, smaller cells males.     

Comparisons in nesting biology of two sympatric carpenter bee species (Apidae: Xylocopini)

This work analyses the biology and nesting behaviour of Xylocopa ordinaria and Xylocopa frontalis, providing information for their conservation and management. The study was performed from August 2006 to December 2007 and considered 25 nests of X. ordinaria and 23 of X. frontalis. The X. frontalis nested between December and April, while X. ordinaria nested throughout the year. Nests of X. ordinaria dug in wider substrates had more tunnels, and the width of nest tunnels and the dimensions of brood cells were smaller than were observed for X. frontalis. Females spent most of their time in activities inside their nests, followed by nectar and pollen flights and nectar dehydration. Pollen resources used by these bees presented more than 40% similarity, and they were constant to flower resources while provisioning cells. Cissites maculata and a Diptera species were the natural enemies found.     

The evolution of nest building and communal nesting in Ageniellini (Insecta: Hymenoptera: Pompilidae)

Pompilid wasps prey upon spiders and use a single spider per nest cell. The majority of species dig simple burrows in the soil in which to cache their spider, on which an egg is laid. The nest is not revisited, but another nest is prepared elsewhere. However, members of the tribe Ageniellini show much diversity in nesting behaviour. Species of the genus Ageniella nest in pre-existing cavities in the soil, closing off their cells with bits of debris. Most other Ageniellini that have been studied carry water to make mud pellets, from which ovoid nest cells are made. Usually a series of such cells is made in close proximity, often under loose bark or stones or in hollow stems. A few species make free nests above ground, usually in protected places or with thick mud walls. In some cases nest sites are known to be re-occupied by members of successive generations. Several species are known to nest communally, co-operating in nest defense and in cell building. In many ways the evolution of nesting behaviour in this group parallels that in the mud-using Vespidae, but the use of a single prey per cell precludes development of progressive provisioning and of eusociality similar to that of many Vespidae.     

Habitat and spatial relationships of nesting Swainson's Hawks ( Buteo swainsoni ) and Red-tailed Hawks ( B. jamaicensis ) in northern Utah

A total of 28 Swainson's Hawk ( Buteo swainsoni ) and 30 Red-tailed Hawk ( B. jamaicensis ) nests were found in Cache Valley, Utah, during the summers of 1992 and 1993. All nests were in trees, but only Red-tailed Hawks nested in dead trees (30%). In the intensive study area, nesting densities were 0.10 nests/km 2 for Swainson's Hawk and 0.08 nests/km 2 for Red-tailed Hawk. Nearest-neighbor nest distances were significantly shorter among Swainson's Hawks (1.74 km) than among Red-tailed Hawks (2.83 km). Congeneric nearest-neighbor distances were significantly shorter than conspecific distances for Red-tailed Hawks (1.59 vs 2.83 km) but not for Swainson's Hawks (1.52 vs. 1.74). GIS analysis of habitat types was made for 2-km radii around nest sites. Cropland was the dominant land cover type at nest sites of both species and no significant difference was found between species. Swainson's Hawk nest sites contained significantly more pasture, whereas Red-tailed Hawk nest sites contained significantly more juniper, maple, and sagebrush. Only Red-tailed Hawk nests ( n = 8; 27%) were found on the periphery of the valley at the base of foothills of the Cache Mountains. This preference resulted in a significantly higher elevation for Red-tailed Hawk nest sites. Swainson's Hawk nests occurred only on the valley floor on level terrain. Distance to the nearest paved road and building was very similar for both species, implying that little difference exists in tolerance levels for human activities. Overall, multivariate niche overlap for habitat was high (0.89), indicating a lack of habitat partitioning between these 2 Buteos in Cache Valley.     

Roosting behavior of the Mexican free-tailed bat ( Tadarida brasiliensis ) in a highway overpass

A colony of Mexican free-tailed bats ( Tadarida brasiliensis ) roosting in an interstate highway overpass in Belton, Bell County, Texas, was studied weekly from 28 June to 21 November 1996 (except for the week of 4 July). We examined 2 aspects of roosting behavior: site-specific fidelity to locations within the roost and gender-related segregation within the roost. Colony estimates based on guano production showed a marked decrease in the number of bats from 19 to 26 July; many of these departing bats were adult females. No female bats sampled after this interval were pregnant. Male bats outnumbered females on nearly all sampling occasions. Throughout the study, one section of the roost was dominated by males, ranging from 83% to 100% of total bats. The majority of bats recaptured at least once were faithful to specific locations within the roost, and more than 70% of bats recaptured multiple times were faithful to specific roost locations.     

The nesting habits and flower relationships of the bee Melitoma ameghinoi (Holmberg) (Hymenoptera,Apidae), with notes on its taxonomy and distribution

ABSTRACT

The nesting behaviour of Melitoma ameghinoi was studied in the province of Chaco, Argentina. Contrary to other Melitoma species, which are known to nest on banks or other vertical or sloping surfaces, the nests were found on horizontal ground, in extremely hard clay soil. The nests were shallow, with three to four vertical cells. The short turrets pointed upwards for a short stretch and then were strongly curved, with the entrance directed towards the soil surface. The floral relationships of this species were studied by pollen analysis of faeces from cells, a pollen mass, scopal loads of specimens, and direct observation of floral visits. Pollen counts and field observations indicate that M. ameghinoi collects pollen exclusively from Ipomoea species. A compilation of pollen sources for species of Melitoma is presented. All known species, including M. ameghinoi, fall in the category of narrowly oligolectic. A discussion of the taxonomic relationships of the species is presented, and a lectotype is designated.     

Current status and distribution of the Ciconiiforms nesting in Wyoming

Five species of Ciconiiforms breed in Wyoming: the American Bittern ( Botaurus lentiginosus ), Great Blue Heron ( Ardea herodias ), Snowy Egret ( Egretta thula ), Black-crowned Night-Heron ( Nycticorax nycticorax ), and White-faced Ibis ( Plegadis chihi ). Field surveys conducted from 1984 through 1986 indicate that at least 151 Great Blue Heron colony sites exist in Wyoming, making it the most abundant and widespread Ciconiiform in the state. Only small breeding populations have been discovered for the remaining species. Except for the Snowy Egret, where numbers of active nests have remained relatively stable, population trends are unknown for the other species. We believe most colonies have been found in Wyoming, but additional inventories may result in the discovery of other nesting areas, especially for the Great Blue Heron.     

Two nesting behaviours and life history of a subsocial African dungrolling beetle,Scarabaeus catenatus (Coleoptera: Scarabaeidae)

Nesting behaviour of a large-sized dung beetle, Scarabaeus catenatus (Gerstaecker), was observed at the Tsavo West National Park, south-eastern Kenya. Although this species is taxonomically a member of a dung-roller group (that is, subfamily Scarabaeinae), it had not only a rolling behaviour but also a tunneller behaviour for nesting. In the former case, the scarab rolled a chunk or a ball of dung some distance (0·5–15·5m) away from the dung pat and buried it under the ground. In the latter case, it dug a tunnel near the dung pat (0–1 m) and transported several pieces of dung into the burrow. In both cases, brood nests were completed by a female alone or by male-female co-operation. Four days after dung burial, the female made one to four brood balls out of buried dung, in each of which she deposited an egg. On the other hand, the male left the nest soon after the female completed oviposition. Even after oviposition, the female stayed in the nest and cared for her progeny until they emerged. This indicates that S. catenatus is subsocial. A major source of offspring mortality was likely to be predation by driver ants (Dorylus sp.). Most females seemed to breed one time in each of two or more successive rainy seasons.     

Use of nonalpine anthropogenic habitats by American pikas ( Ochotona princeps ) in western Oregon

The American pika ( Ochotona princeps Richardson) has long been characterized in field guides and popular literature as an obligate inhabitant of alpine talus and as having relatively low dispersal capability. However, recent work reveals pikas to have broader habitat associations than previously reported. Over a large portion of the western slope of the Cascade Range in Oregon, pikas inhabit relatively low-elevation sites far from alpine areas and frequently occur in rocky man-made habitats such as roadcuts or rock quarries. We present observations of pikas in these previously overlooked habitats and discuss implications for (1) the proposed listing of the American pika as an endangered or threatened species; (2) furthering our understanding of pika population dynamics, habitat associations, and dispersal capabilites; and (3) management of federal, state, and private forest lands. Por mucho tiempo la pika americana ( Ochotona princeps Richardson) ha sido caracterizada en guías de campo y literatura popular como un habitante obligado de taludes alpinos y por tener una capacidad de dispersión relativamente baja. Sin embargo, trabajo reciente ha revelado que las pikas tienen asociaciones de hábitat más amplias de lo que hasta ahora se creía. En una gran parte de la vertiente occidental de la cordillera Cascade en Oregón, las pikas habitan sitios de elevación relativamente baja, lejos de las áreas alpinas y frecuentemente aparecen en hábitats rocosos artificiales tales como canteras y cortes de carretera. Presentamos observaciones de pikas en estos hábitats pasados por alto anteriormente y discutimos las implicaciones para (1) la propuesta de agregar la pika americana a la lista de especies amenazadas o en peligro; (2) ampliar nuestro conocimiento sobre la dinámica poblacional, las asociaciones de hábitat y la capacidad de dispersión; y (3) la gestión de tierras forestales federales, estatales y privadas.     

Emersion behaviour and foraging ecology of the common Chilean clingfish Sicyases sanguineus (Pisces: Gobiesocidae)

The present study is the first to correlate information on emersion behaviour and foraging ecology of Sicyases sanguineus, a common clingfish of the Chilean coast. Individuals smaller than 15 cm in total length were frequently found at the highest points in the inter-tidal zone and consumed inter-tidal animals and seaweeds. Fish larger than 23 cm were infrequently observed emersed in the lower inter-tidal zone, but were collected sub-tidally by divers. These large clingfish ate mainly benthic animals occurring in the low inter-tidal and sub-tidal zones. Size-dependent factors, dessication and wave impact restrict the area of action of S. sanguineus to certain areas of the rocky inter-tidal and shallow sub-tidal zone. However, the fish can be locally very abundant, consuming a great diversity of prey items including both direct primary space users and mobile animals able to affect community structure through grazing. We argue, therefore, that S. sanguineus may be important in structuring communities in some areas of the rocky inter-tidal and shallow subtidal zones of Central Chile.     

Use of space by the marsupials Gracilinanus microtarsus (Gardner and Creighton, 1989) and Marmosops incanus (Lund, 1840) in an Atlantic Forest of southeastern Brazil

The use of space by animals is determined by environmental conditions, biological and ecological adaptations and interactions and mostly by resource availability. We sampled two species of Neotropical mammals to investigate their use of different strata in Atlantic Forest habitat in Brazil, as well as the home range sizes and movements of both sexes of each species. We found no difference in home ranges and movements between the sexes and species, but we found differences in the use of strata, with Gracilinanus microtarsus mostly using the canopy and Marmosops incanus using the ground. Gracilinanus microtarsus males mostly use the understorey in the wet season and the canopy in the dry season. We believe that these patterns of strata use reflect intrinsic characteristics of the species; and the shifts in resources and interspecific competition, which are lower in the dry season, seem to be responsible for the shifts in space use observed for G. microtarsus males. We recommend studies with spool-and-line techniques or radio tracking to further test refined hypotheses regarding the use of space, including the role of territoriality in females.     

Use of boulder pocket habitat by rainbow trout ( Oncorhynchus mykiss ) in Fall River, Idaho

Abundance of rainbow trout ( Oncorhynchus mykiss ) in relation to characteristics of pockets created by boulders was studied in Fall River, southeastern Idaho. To determine depth and surface area of pockets most selected by rainbow trout, fish were counted by snorkeling, and pocket physical dimensions were measured. An electivity index defined habitat selection in the following terms: the most suitable habitat was ≥0.7 m maximum depth, ≥0.5 m minimum depth, and ≥3 in 2 surface area. Some study reaches of Fall River had more suitable pockets available for trout than were being utilized.     

Anatomy,reach and classification of the parasitoid complex of a common British moth,Anthophila fabriciana (L.) (Choreutidae)

The small plurivoltine moth Anthophila fabriciana is widespread and often abundant in Britain wherever its main larval foodplant, stinging nettle, occurs. It overwinters as a larva (first generation) then has one or more partly overlapping summer broods (notionally second generation). A total of 5017 larvae were collected and reared from widely distributed populations in Britain, and the resulting 2167 host mortalities due to parasitoids were assessed. Small collections of pupae were also made. Altogether 25 parasitoid species, including secondary parasitoids, were found. Larval parasitism was heaviest in the second generation. In each generation there was a dominant parasitoid that was absent from the other. Summary information on the developmental biology and host range (expressed quantitatively and resulting from very broad rearing programmes) for each parasitoid is given. They are classed as ‘absolute specialists’, ‘taxon oligospecialists’, ‘niche oligospecialists’, ‘niche generalists’, ‘casuals’ and ‘strays’. Both kinds of oligospecialists can be ‘paraspecialists’ if only one potential host occurs locally. Although constructing a quantitative food web is not appropriate, providing both source web and sink web data in quantitative form enables the parasitoid complex to be understood in the wider context of the ecosystem, necessary for both biodiversity and nature conservation interests. In Appendix 1, parasitoids reared from other European Choreutidae are listed quantitatively.     

Genetic differentiation of rare and common varieties of Eriogonum shockleyi (Polygonaceae) in Idaho using ISSR variability

Idaho populations of Eriogonum shockleyi are divided taxonomically into 2 varieties: E. shockleyi var. packardae , which is endemic to Idaho, and the typical variety, which is widespread in the western United States. Recent morphological investigations of E. shockleyi in Idaho have identified potentially reliable morphological characters for field identification of the subspecific taxa. This paper investigates the genetic basis for the separation of the 2 varieties of E. shockleyi using inter simple-sequence repeats (ISSR) markers. Although we found some morphological differences between the populations that correlated with the 2 varieties, we identified no molecular markers in this study to distinguish between them. Morphological measurements obtained in the field indicate that although a population may have an overall average morphology that defines the variety, some individuals in nearly all populations have putative diagnostic characters that define the other variety. The morphological characters used to distinguish the 2 varieties are most likely the result of environmental variability and could result from differences in precipitation and soil water retention. Alternatively, high levels of outcrossing through pollen flow could be obscuring selection for morphological characters at particular sites.