Home range and activity patterns of black-tailed jackrabbits

Home range use and activity patterns of black-tailed jackrabbits ( Lepus californicus ) in northern Utah were studied using telemetry. Home range sizes ranged from 2 to 3 km 2 and did not differ between sexes or among seasons. Jackrabbits were inactive during daylight, became active at dusk, and remained active throughout the night. Animals often traversed their home ranges in a few hours. During the breeding season, males were more active than females. Jackrabbits were most active during well-lit nights, and high winds decreased jackrabbit activity.     

Home range size of Black-backed Woodpeckers in burned forests of southwestern Idaho

We examined home range size of Black-backed Woodpeckers ( Picoides arcticus ) in burned ponderosa pine ( Pinus ponderosa ) / Douglas-fir ( Pseudotsuga menziesii ) forests of southwestern Idaho during 2000 and 2002 (6 and 8 years following fire). Home range size for 4 adult males during the post-fledging period was 115.6–420.9 ha using the 95% fixed-kernel method, and 150.4–766.1 ha using the 100% minimum convex polygon method. Smoothed bootstrap estimates (95%) were 130.0–521.9 ha. Home range sizes were significantly smaller 6 years after fire than 8 years after fire. Each male had from 2 to 8 areas of concentrated use within his home range. We provide recommendations for estimating area requirements of Black-backed Woodpeckers in post-fire ponderosa pine / Douglas-fir forests.     

Home range and seasonal movements of Columbian Sharp-tailed Grouse associated with Conservation Reserve Program and mine reclamation

During 1999 and 2000 we trapped and radio-marked 156 Columbian Sharp-tailed Grouse ( Tympanuchus phasianellus columbianus ) on leks in Conservation Reserve Program (CRP, n = 73) and mine reclamation (MR, n = 83) lands in northwestern Colorado. Median spring--fall home range sizes using the 95% fixed kernal and minimum convex polygon estimators for 54 grouse were 86 ha and 61 ha, respectively. Median fixed kernal home range size did not differ between males (79 ha) and females (87 ha). Home ranges of grouse associated with CRP (112 ha) were larger than those of grouse in MR (75 ha). Directional orientation of movements from leks of capture to wintering areas was nonrandom, and there was a positive elevation gain (median = 102 m) associated with these movements. Movements did not differ between grouse captured in CRP and MR for any season but did differ between genders for the spring--fall period. Males exhibited stronger fidelity and less variation in their movements than females; 96% of males compared with only 77% of females remained within 2.0 km of their lek of capture from spring through fall. Ninety percent of females nested within 2.5 km of their lek of capture. During winter all grouse were found farther (median = 21.5 km) from lek sites than in any other season. Males remained on the breeding range longer in the fall and returned earlier in the spring than females even though they wintered similar distances away (median males = 21.5 km, median females = 21.4 km). Our findings support the 2.0-km radius used in the Habitat Suitability Index model for Columbian Sharptailed Grouse to assess nest and brood-rearing cover around leks, but not the 6.5-km radius used to evaluate winter cover.     

Size and seasonal activity patterns of abundant sympatric spider species in Cache County, Utah

Of the eight most frequently collected spiders at a northern Utah study site, each of two species employed one of the following hunting strategies: pursuing, web building, jumping, and ambushing. Within each pair, size differences between species were substantial for all but the ambushers. The ambushers had different seasonal activity patterns, as did the web builders.     

Home range and foraging habitat selection by breeding lesser kestrels (Falco naumanni) in Greece

Home range size and foraging habitat use in breeding lesser kestrels (Falco naumanni), a bird species of conservation concern, were investigated during the breeding season of the species in 2008 in an intensively cultivated area of central Greece, using radio-tracking. Grasshopper (the main prey) densities were measured at the most important habitats (cotton, cereals, grasslands and margins). Home ranges were not significantly different between sexes either as overall means or during incubation and nestling periods. Movements of both sexes were non-random during incubation but random during the nestling period. Habitats used by males during incubation ranked as: margins > other > cotton > corn > cereals and during nestling period as: cereals > margins > grasslands > corn > cotton. Female habitat use greatly differed ranking as cereals > cotton > grasslands during incubation and as grassland > cotton > corn > cereals > margins during nestling period. Female habitat use seemed to be in disagreement with the conditions generally favouring prey availability, probably for reasons associated with low and uniform distribution of grasshopper densities over the habitats.     

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.     

Home range behaviour in male and female poison frogs in Amazonian Peru (Dendrobatidae: Ranitomeya reticulata)

The poison frog Ranitomeya reticulata was studied for 3 months while mark–recapture surveys were performed. Ranitomeya species deposit terrestrial clutches and carry tadpoles to phytotelmata with few taxa performing biparental brood care including larval feeding. Home range size and spatial affinity to phytotelmata in the genus are linked to mating systems. In R. reticulata, individual home range size and overlap were similar in both sexes, indicating equal levels of site fidelity. Although territory defence was never observed, strong intrasexual intolerance within individuals' core areas was found. The large intersexual home range overlap for breeding pairs indicated that mate fidelity occurs. Individuals' home ranges were not overlapping, suggesting that R. reticulata lacks pair-bonding or strongly cooperative behaviour in parental duties. The number of ground bromeliads containing phytotelmata and home range size of males were positively correlated. Our findings suggest that females do not perform egg-feeding and male-only parental care is likely.     

Size selection of food by cutthroat trout, Salmo clarki, in an Idaho stream

The mean size of food and amount of food consumed by cutthroat trout from Palisades Creek in southeastern Idaho increased with trout length. Number of organisms of terrestrial origin, number of aquatic larvae, number of ants, and number of berries from redstem dogwood were related to trout length. The size range and number of taxa consumed increased with trout size, indicating that as trout get larger, they broaden their feeding menu. The minimum size of food consumed was relatively constant for all trout, but larger trout appeared to feed more from the stream bottom. Trout may have a minimum length of food, below which items cannot be detected as food. Other possible factors affecting the feeding of cutthroat trout are mentioned.         

Home range of the western jumping mouse, Zapus princeps, in the Colorado Rocky Mountains

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

Size, age, and density relationships to curlleaf mahogany ( Cercocarpus ledifolus ) populations in western and central Nevada: competitive implications

Size-density-age relationships in curlleaf mountain mahogany communities were studied in 25 study plots, each 30 x 30 m, in western and central Nevada. The influence of total vegetation cover (site potential) and relative mahogany cover (mahogany dominance) on the observed size-density-age relationships was investigated. A positive linear relationship was found between mean mahogany height and mean mahogany age. A positive nonlinear relationship was found between mean mahogany crown volume and mean mahogany age. Negative nonlinear relationships were found between mean mahogany density and mean mahogany age, and mean mahogany density and mean mahogany crown volume. Strong negative relationships were found between the mean combined density of established seedlings, juvenile, and immature mahogany and mean mahogany age and mean mahogany crown volume. Including total cover in the regression relationships between size, age, and density never increased the r 2 value by more than .05. The addition of relative mahogany cover improved the r 2 value for the relationship between mean mahogany density and mean mahogany crown volume by .28. The strong size-density and age-density relationships found indicate that intraspecific competition is probably occurring in the communities sampled, and that established seedlings, juvenile, and immature plants are the first individuals affected. Direct tests are needed to confirm these relationships.     

Size, structure, and habitat characteristics of populations of Braya humilis var. humilis (Brassicaceae): an alpine disjunct from Colorado

Size, structure, and habitat characteristics were studied in three populations of Braya humilis var. humilis (C. A. Meyer) Robins, in Gray & Wats. (Brassicaceae), a small, herbaceous perennial of the alpine tundra in central Colorado. There was a significant association between numbers of reproductive, juvenile, and seedling individuals and population location. Plant size within reproductive, juvenile, and seedling size classes varied significantly among three populations. Plots containing Braya had significantly lower total plant cover, a different set of dominant plant species, more rock, bare ground, and less litter than plots without Braya . Braya appears to be restricted to calcareous substrates that experience a moderate level of disturbance, such as solifluction lobes and abandoned roads. Populations are small despite the existence of much potential habitat. Population studies are necessary for active conservation management of Braya .     

Size criteria for the distinction between Cylindroiulus londinensis (Leach) and Cylindroiulus caeruleocinctus (Wood) (Diplopoda: Julidae)

Ring number, body height and live weight are given for each stadium and sex of two Cylindroiulus species often confused in the literature. In each stadium there is no overlap between the height and weight of the two species, which makes it possible to identify specimens using size criteria alone. According to data from different places in Europe, intraspecific variation is not substantial enough to fill the size gap between the two species.     

Home ranges and aspects of the natural history of the Black-masked Finch Coryphaspiza melanotis (Gray, 1840) (Aves,Thraupidae) in central Cerrado,Brazil

ABSTRACT

In the Cerrado, native grasslands have been dramatically lost, leading to an alarming decline in populations of bird species that require these vegetation physiognomies. Species such as the Black-masked Finch Coryphaspiza melanotis (Gray, 1840) are vulnerable to extinction and remain poorly studied. The objective of this study was to examine home ranges of the Black-masked Finch at the Parque Nacional da Chapada dos Veadeiros, central Brazil. Ten males were studied in a patch of shrubby grassland (campo sujo) between February and December 2008. The mean sizes of home ranges were 4.47 ± 1.49 ha (Minimum Convex Polygon) and 3.48 ± 1.44 ha (Kernel 95%), and this varied significantly between seasons. Home ranges were significantly larger in the non-breeding dry season than during other periods, and significantly smaller in the breeding season than during other periods. Core areas (Kernel 50%) had a mean of 0.46 ± 0.26 ha. A large overlap of home ranges was observed. The home ranges of all banded males overlapped those of at least three co-specifics, and most had an area overlap of more than 50%. A nest containing an egg and a nestling was found in November. Small and largely overlapped home ranges can be considered as positive for the conservation of the Black-masked Finch. This is because both small grassland fragments and conservation units can substantially contribute to the conservation of its populations through the Cerrado extension.     

Variance and replenishment of nectar in wild and greenhouse populations of Mimulus

We compared nectar production in wild populations and greenhouse-grown populations of the monkey flower species of section Erythranthe of the genus Mimulus . Nectar was sampled from over 1000 flowers. For each flower the volume of nectar was measured with a calibrated micropipette and the percentage of sugar with a hand refractometer. Percentage of sugar varied little from flower to flower in both field and greenhouse studies, but volume varied markedly from flower to flower in field studies and even more in greenhouse studies. This high variance in nectar volumes appears to be intrinsic. The amount of nectar in greenhouse populations tended to increase with time in the absence of pollinators. The amount of nectar in field populations tended to remain the same to pollinator withdrawals. The latter conclusion was corroborated by sampling nectar at 2-h intervals all day and comparing the total volume produced by a flower to the volume of nectar produced in control flowers sampled only at the end of the day.     

Introduced and cryptogenic marine and estuarine species of South Africa

The introduction history, systematics, transport vectors and distribution patterns of 85 introduced and 39 cryptogenic marine or estuarine animals and plants of South Africa are presented. This represents an addition of 93 species compared with previous lists. Taxa covered include protists, dinoflagellates, sponges, cnidarians, annelids, crustaceans, pycnogonids, insects, molluscs, brachiopods, bryozoans, echinoderms, ascidians, fish, algae and higher plants. For each species a justification motivating its inclusion as an introduction into South African shores or its cryptogenic status, is provided. Challenges associated with this type of inventory work are explored and major patterns of bioinvasion within the region are summarized briefly.     

Development of epipods and gills in some pagurids and brachyurans

Sepedon trichrooscelis is a semiaquatic, multivoltine species whose larvae feed on snails of the genus Succinea. The duration of the various developmental periods and larval biology are presented. The egg, three larval instars, and puparium of Sepedon trichrooscelis are described and illustrated. The distribution of the cuticular sensorial receptors, the shape of the hydrofuge setae on the posterior disc, and the details of the egg are illustrated by scanning electron micrographs.     

Invertebrate faunas and zoogeographic significance of lava tube caves of Arizona and New Mexico

A field survey in caves near Grants, New Mexico, and Flagstaff, Arizona, found only an exceptionally poor fauna of 14 species with no strong patterns of cave restriction. The faunal poverty is judged to be correlated with and influenced by the similarly impoverished boreal forests in nearby mountains. Species of flightless arthropods, suitable for cave colonization and restricted to cool-moist litter of boreal (Hudsonian-Canadian Life Zone) forests, are apparently not now present in suitable, nearby mountain habitats. They may not have dispersed to all available montane sites from the Southern Rocky Mountains during glacial conditions. Either the forests did not exist as continuous dispersal corridors for the litter arthropods, or the fauna could not track the rate of spread of the forests.