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At least 469 records · Page 26Linked to original sources
USGS2017

Occurrence of amphibians in northern California coastal dune drainages

Many coastal dune ecosystems have been degraded by non-native dune vegetation, but these systems might still provide valuable habitat for some taxa, including amphibians. Because restoration of degraded dune systems is occurring and likely to continue, we examined the occurrence of amphibians in drainages associated with a coastal dune ecosystem degraded by invasive plants (European Beachgrass, Ammophila arenaria , and Iceplant, Carpobrotus edulis ). We found that occupancy of 3 amphibian species (California Red-legged Frog, Rana draytonii ; Sierran Treefrog, Hyliola sierra ; and Rough-skinned Newt, Taricha granulosa ) among 21 coastal-dune drainages was high, with most coastal-dune drainages occupied by all 3 species. Furthermore, reproduction of Sierran Treefrogs and California Red-legged Frogs was estimated to occur in approximately ½ and ⅓ of the drainages, respectively. The probability of occurrence of Rough-skinned Newts and pre-metamorphic life stages of both anurans decreased during the study, perhaps because of ongoing drought in California or precipitation-induced changes in phenology during the final year of the study. Maintaining structural cover and moist features during dune restoration will likely benefit native amphibian populations inhabiting coastal-dune ecosystems.

Northwestern Naturalist↗
USGS2017

Ecology of the Sand Roller (Percopsis transmontana) in a lower Snake River Reservoir, Washington

The Sand Roller ( Percopsis transmontana ), has not been abundant in the Snake River since it was first found in the system in the 1950s, but its population has apparently increased in recent years. As a result, we initiated a study to better understand its ecology in habitats of Lower Granite Reservoir. From November 2014 to October 2015, Sand Rollers were present along shorelines, with peak abundance being observed during spring months. Logistic regression analyses showed that Sand Rollers were more likely to be present in shoreline habitats at temperatures ≤18.4°C. Fish were found over a range of substrates, with the lowest odds of fish presence being associated with riprap, which is common in hydropower reservoirs. From length-frequency analysis, we suggest that Sand Roller spawning occurs primarily in May and early June. Assessment of Sand Roller diets found dipteran (chironomid) larvae and pupae were the most important prey consumed by all sizes of Sand Rollers, but Opossum Shrimp ( Neomysis mercedis ) were also prominent in diets of larger fish in shoreline and offshore habitats. At a time when the populations of so many native species are in decline, the increase of the Sand Roller population in the lower Snake River represents a positive, yet curious occurrence.

Washington↗
USGS2019

Trends in landbird density at two national parks in fragmented, mixed-use landscapes of the Pacific Northwest

National parks play a key role in conserving species by providing landscapes where threats from anthropogenic disturbance are reduced. In a recent study of 3 large wilderness parks in the Pacific Northwest, nearly all landbird species were found to be stable or increasing. Nonetheless, contemporary results from the Breeding Bird Survey and mark-recapture studies fuel concerns that some landbirds in the Pacific Northwest are trending in sync with many North America species in widespread decline. Although landbird populations might be thriving in large parks with extensive old-growth forest, those in smaller parks with less intact wilderness and higher ratios of edge-to-interior habitat might reflect the stressors inherent in more human-dominated landscapes. We conducted landbird point-count surveys from 2005 to 2016 in 2 national historical parks situated in the more human-dominated landscapes of this region, San Juan Island National Historical Park and Lewis and Clark National Historical Park. Established primarily to protect cultural resources, these parks lack old-growth forest and consist of relatively small parcels embedded in fragmented, multi-use landscapes. Here, we apply recent developments in point-count analysis to estimate trends in population density for 50 landbird species commonly detected in these small parks, including lagged effects of precipitation and temperature on the annual density of each species, and effects of survey conditions on species detection. All but 3 species exhibited stable densities in both parks, and more than half of the populations analyzed clearly increased in density over the study period. Notable exceptions were single-park declines in Olive-sided Flycatcher ( Contopus cooperi ), Northern Flicker ( Colaptes anratus ), and Hutton's Vireo ( Vireo huttoni ). Annual variation in population density was often related to climate, with generally positive responses to a recent deficit in annual precipitation-as-snow, and more variable responses to higher mean spring temperature. These results reinforce trends estimated for 3 large national parks in the Pacific Northwest, suggesting recent stability of landbird populations in parks of this region, independent of park size or setting.

Northwestern Naturalist↗
USGS2019

Fall Chinook salmon (Oncorhynchus tshawytscha), sand roller (Percopsis transmontana), and smallmouth bass (Micropterus dolomieu) interactions in a Snake River reservoir: A tale of three species

We studied some of the relationships between federally listed fall Chinook Salmon, Oncorhynchus tshawytscha , endemic Sand Roller, Percopsis transmontana , and non-native Smallmouth Bass, Micropterus dolomieu , in Lower Granite Reservoir on the Snake River. Because of its recent reappearance and population increase, the Sand Rollers could be filling the role of a “native invader” in the reservoir food web. We speculated that Sand Rollers could either negatively affect fall Chinook Salmon by potentially competing with them for resources in shoreline habitats or, alternatively, benefit the salmon by providing a buffer against Smallmouth Bass predation. Nighttime beach seining showed that habitat use by fall Chinook Salmon and Sand Rollers overlapped completely in spring when both species were present along shorelines. Diet data from stomach samples also showed high overlap, but data on stable isotopes of 13 C and 15 N suggested that each species could be obtaining much of their dietary energy from different reservoir locations. Although habitat and diet overlap are evidence of competition, diel and spatial partitioning of resource use between fall Chinook Salmon and Sand Rollers may act to reduce potential competition. Analyses of Smallmouth Bass diets showed that fall Chinook Salmon and Sand Rollers comprised the majority of prey fish consumed by bass. Across years, as Smallmouth Bass increased their consumption of Sand Rollers (range 0.219 to 0.392 fish smallmouth -1 day -1 ), they decreased their consumption of fall Chinook Salmon (range 0.114 to 0.050 fish smallmouth -1 day -1 ). The greatest effect Sand Rollers may have on fall Chinook Salmon in Lower Granite Reservoir is to serve as a buffer against Smallmouth Bass predation.

Idaho, Washington↗
USGS2021

Diet composition of Fishers (Pekania pennanti) reintroduced on the Olympic Peninsula, Washington

Knowledge of diet composition can inform management strategies and efforts to recover endangered carnivore populations in vacant portions of their historic ranges. One such species, the Fisher ( Pekania pennanti ), was extirpated in Washington State prior to any formal documentation of its food habits in the coastal coniferous forests of western Washington. Fisher recovery efforts in Washington, based on translocating Fishers from extant populations, have been ongoing since 2008, beginning with the release of 90 Fishers on Washington's Olympic Peninsula from 2008 to 2010. We collected fecal samples or digestive tracts from 13 Fishers opportunistically on the Olympic Peninsula from 2009 through 2013. Subsequently, we identified the species composition of each sample's contents to determine the primary foods consumed by the reintroduced Fishers. Fisher diets were diverse and dominated by mammalian prey. Contents of feces and digestive tracts of Fishers were composed primarily of Snowshoe Hare ( Lepus americanus ) remains, followed by lesser proportions of Mountain Beavers ( Aplodontia rufa ), Northern Flying Squirrels ( Glaucomys sabrinus ), Douglas Squirrels ( Tamiasciurus douglasii ), Southern Red-backed Voles ( Myodes gapperi ), shrews ( Sorex spp.), and unidentified ungulate species. The diet of Fishers comprised species that occur across a wide range of land uses and management prescriptions, including previously logged forests and mature forests that have been set aside for retention of old-growth forest characteristics. Additional study of prey abundance and Fisher foraging behaviors related to structural habitat characteristics across a gradient of land uses would provide useful insights for enhancing the effectiveness of conservation efforts to benefit Fishers in Pacific Northwest coastal forests.

Washington↗
USGS2022

Rural turtles: Estimating the occupancy of Northwestern Pond Turtles and non-native red-eared sliders in agricultural habitats in California's Sacramento Valley and Sacramento-San Joaquin River Delta

The Northwestern Pond Turtle ( Actinemys marmorata ; WPT) was once widespread throughout the Sacramento Valley and the Sacramento-San Joaquin River Delta. Much of its historical range has been converted into agricultural land, reducing and altering aquatic habitat and surrounding uplands. Red-eared Sliders ( Trachemys scripta elegans ; RES) have been introduced throughout much of the existing WPT range, particularly near urban centers, potentially competing with WPT for resources. Previous surveys for turtles in central California have primarily focused on rivers, lakes, and protected wetlands. Little is known about where WPT and RES occur in the vast expanses of agricultural land across the Sacramento Valley and Sacramento-San Joaquin River Delta. Using aquatic hoop nets, we surveyed 142 locations (102 irrigation canal sites, 39 wetlands, 1 tidally influenced slough) across 8 counties during the summers of 2018 and 2019. Both species were detected in agricultural habitats. Using occupancy modeling, we estimated that WPT occur at 44 (95% CRI = 38–53) of our trapping sites and RES occur at 51 (41–66) sampled sites. Co-occurrence of these 2 species was rare; the species were found together at only 6 sites. RES were primarily found in restored wetlands near major roads and the Sacramento metropolitan area, whereas WPT were more commonly found farther from urban areas in wider canals. Our work provides a picture of how WPT and RES occupy this modified agroecosystem that can inform future conservation efforts.

California↗
USGS2023

Fishes of Harney Basin revisited: An assessment of the distribution of native and nonnative fishes over a half century

The Harney Basin is Oregon's largest internally draining basin and contains a unique native fish assemblage. The first and only comprehensive study of the origin and distribution of Harney Basin fishes occurred in 1971. Here, we update this study and identify potential threats to the basin's native fishes a half century later. Our assessment documents that all species of native fishes are still present, and with some exceptions distributed as originally reported. The distinctive fish assemblages in each of the 3 major subbasins within the Harney Basin (Silvies River, Silver Creek, and Donner und Blitzen River) support the hypothesis that terminal lakes in the Harney Basin (Malheur, Mud, and Harney Lakes) act as dispersal barriers, at least for native species. More than half of the fish species in the basin at present are introduced, primarily inhabiting low-elevation sites. We suggest that native non-salmonid species cohabiting these sites face the most immediate threats from climate change, water demands, and impacts from introduced fishes. Overall, our results show that native fish are still relatively widespread across the Harney Basin, but also face increasing threats despite the basin having experienced less development than many other areas in the Pacific Northwest. Improved understanding of the unique fishes of the Harney Basin, along with more detailed assessments of likely future trajectories of environmental risks are proactive measures that could improve conservation outcomes.

Oregon↗
USGS2026

Status and trend of white-cheeked geese wintering in coastal Nestucca Valley, Oregon

The status and trend of wintering goose populations along the coast of the Pacific Northwest is relatively unstudied. We estimated the status and trends of 6 subspecies of white-cheeked geese wintering in Nestucca Valley, Oregon, USA. Surveys conducted from 2007 to 2019 revealed significant variability in weekly counts among subspecies and years. Dusky ( Branta canadensis occidentalis ) and Cackling ( B . hutchinsii minima ) Geese typically arrived by mid-October and stayed until mid-April, while Aleutian Geese showed lower autumn numbers but doubled in spring. Trends indicated a significant delay in Dusky Geese arrival in recent years, with departure dates remaining constant. Total goose use-days averaged 903,899, with notable declines over the period for Aleutian ( B. h. leucopareia ), Taverner's ( B. h. taverneri )/Lesser ( B. c. parvipes ), and Western ( B. c. moffitti ) Geese. Supporting approximately 6000 geese daily, these results underscore the importance of Nestucca Bay National Wildlife Refuge and adjacent lands for wintering geese. These findings also highlight Nestucca Valley's role as a critical late-winter staging ground, particularly for Aleutian Geese, and emphasize that continued monitoring and adaptive management are essential to sustain these populations.

Oregon↗
USGS2003

Den site activity patterns of adult male and female swift foxes, Vulpes velox, in northwestern Texas

Activity of Swift Foxes ( Vulpes velox ) at den sites was studied in northwestern Texas during pup rearing seasons in 2000 and 2001 to determine role of males in parental care. Twenty-four percent of radio-collared females with a potential to breed successfully raised pups to eight weeks of age. We intensively monitored presence and absence of male and female Swift Foxes at two den sites each year. Females were present >2.6 times more at den sites than males during the pup rearing season. Female and male Swift Foxes largely stayed at dens during diurnal hours and were active away from dens during nocturnal and crepuscular hours. Females and males spent 12.4% and 3.0% more time at dens before pups emerged, than after pups emerged, respectively. Following depredation of one male parent, the female spent 29% less time at the den site. Decrease in time spent at the den by the female following loss of her mate suggested that loss of one parent might severely impact recruitment of Swift Foxes. Our observations indicated that intense Coyote ( Canis latrans ) depredation may severely impact pup-rearing success as well as the parental care within Swift Fox family groups.

Texas↗
USGS2004

Unusual behavior by Bison, Bison bison, toward Elk, Cervus elaphus, and wolves, Canis lupus

Incidents are described of Bison ( Bison bison ) in Yellowstone National Park mauling and possibly killing a young Elk ( Cervus elaphus ) calf, chasing wolves ( Canis lupus ) off Elk they had just killed or were killing, and keeping the wolves away for extended periods. During one of the latter cases, the Bison knocked a wolf-wounded Elk down. Bison were also seen approaching wolves that were resting and sleeping, rousting them, following them to new resting places and repeating this behavior. These behaviors might represent some type of generalized hyper-defensiveness that functions as an anti-predator strategy.

Idaho, Montana, Wyoming↗
USGS2004

Record high Wolf, Canis lupus, pack density

This report documents a year-around Wolf ( Canis lupus ) density of 18.2/100 km 2 and a summer density of 30.8/100 km 2 , in a northeastern Minnesota Wolf pack. The previous record was a summer density of 14.1/100 km 2 , for a Wolf pack on Vancouver Island, British Columbia, Canada.

Minnesota↗
USGS2004

Extraordinary size and survival of American black duck, Anas rubripes, broods

Two female American black duck, Anas rubripes, were initially observed during June 1982 with 20 Class Ib or 18-22 Class Ia-b ducklings in two wetlands in Hancock County, Cherryfield, Maine. Fifteen of 20 ducklings (75%) in one brood and 16 of 18-22 ducklings (72-89%) in the other brood survived to fledge. These large broods probably resulted from post-hatch brood amalgamation.

Maine↗
USGS2004

Interactions of brown bears, Ursus arctos , and gray wolves, Canis lupus , at Katmai National Park and Preserve, Alaska

We describe several encounters between Brown Bears ( Ursus arctos ) and Gray Wolves ( Canis lupus ) that were observed at Katmai National Park and Preserve in southwest Alaska. Katmai Brown Bears and Gray Wolves were observed interacting in a variety of behavioral modes that ranged from agonistic to tolerant. These observations provide additional insight regarding the behavioral plasticity associated with bear-wolf interactions.

Alaska↗
USGS2005

Microhabitat characteristics of Lapland Longspur, Calcarius lapponicus, nests at Cape Churchill, Manitoba

We examined microsite characteristics at 21 Lapland Longspur ( Calcarius lapponicus ) nests and land cover types in which they occurred in Wapusk National Park, Cape Churchill, Manitoba. Nests were located in four of six physiographic-vegetation land-cover types. Regardless of land-cover type, all but one nest was built on a pressure ridge or mound. Nests were built midway between the bottom and top of ridges or mounds with steeper slopes than was randomly available. Longspur nests had a distinctive southwest orientation (P < 0.001). Longspurs selected nest sites that consisted of comparatively greater amounts of shrub species and lesser amounts of moss than were randomly available. Nests were generally well concealed by vegetation (mean = 67.0%) and concealment was negatively associated with amount of graminoid species at the nest (P = 0.0005). Our nesting habitat data may facilitate a better understanding of breeding Lapland Longspur habitat requirements, and potential impacts of habitat degradation by increasing Snow Goose ( Chen caerulescens ) populations in the study area.

Manitoba↗
USGS2007

Pattern and potential causes of White-faced Ibis, Plegadis chihi, establishment in the northern prairie and parkland region of North America

The Northern Prairie and Parkland Waterbird Conservation Plan calls for renewed attention to determining the current status of waterbird populations, their distributions, and conservation needs. It highlights the need for baseline information on the White-faced Ibis (Plegadis chihi). In response, we examined the historical and current distribution of the ibis in North Dakota and summarized first sightings and nest records for the provinces and other states composing the northern prairie and parkland region. The establishment of breeding colonies of White-faced Ibis here may be due to climate and precipitation patterns, invasion and spread of Narrowleaf Cattail (Typha angustifolia), changes in agricultural practices, habitat loss and range expansion in the southern and western portions of the species' range, and increases in ibis populations in the Intermountain West. We placed special emphasis on North Dakota, a state for which there is scant published information concerning the current status of this species. In recent decades, the ibis has become a regular breeding-season resident in North Dakota and in other areas of the northern prairie and parkland region. From 1882 to 2002, there were 145 reports of one or more White-faced Ibis in North Dakota, including 93 reports during the breeding season (15 May to 31 August), 49 during the non-breeding season (1 September to 14 May), and three for which the season of occurrence was not reported. Prior to the 1960s, there were only three records of the species in North Dakota. Observations of White-faced Ibises in North Dakota increased dramatically between the 1960s and the early 21st century, and the species has been observed nearly annually since 1971. The first White-faced Ibis nesting activity in the state was recorded in 1978, and to date, there have been 21 known records of nesting activity in the state. The species nested in large (>300 ha) semipermanent or permanent wetlands within mixed-species colonies ranging in areal extent from small (0.1 ha) to fairly large (27 ha), and colonies were located in patches of emergent vegetation dominated by cattails (Typha) and bulrushes (Scirpus). We classify the White-faced Ibis as a fairly common migrant and a locally uncommon breeder east of the Missouri River and a casual migrant west of the Missouri River.

Canadian Field-Naturalist↗
USGS2007

Brown-headed cowbird, Molothrus ater, parasitism and abundance in the northern Great Plains

The Brown-headed Cowbird ( Molothrus ater ) reaches its highest abundance in the northern Great Plains, but much of our understanding of cowbird ecology and host-parasite interactions comes from areas outside of this region. We examine cowbird brood parasitism and densities during two studies of breeding birds in the northern Great Plains during 1990–2006. We found 2649 active nests of 75 species, including 746 nonpasserine nests and 1902 passerine nests. Overall, <1% of nonpasserine nests and 25% of passerine nests were parasitized by Brown-headed Cowbirds. Although the overall frequency of cowbird parasitism in passerine nests in these two studies is considered moderate, the frequency of multiple parasitism among parasitized nests was heavy (nearly 50%). The mean number of cowbird eggs per parasitized passerine nest was 1.9 ± 1.2 (SD; range = 1–8 cowbird eggs). The parasitism rates were 9.5% for passerines that typically nest in habitats characterized by woody vegetation, 16.4% for grassland-nesting passerines, 4.7% for passerines known to consistently eject cowbird eggs, and 28.2% for passerines that usually accept cowbird eggs. The Red-winged Blackbird ( Agelaius phoeniceus ) was the most commonly parasitized species (43.1% parasitism, 49.6% multiple parasitism, 71.2% of all cases of parasitism). Passerine nests found within areas of higher female cowbird abundance experienced higher frequencies of cowbird parasitism than those found in areas of lower female cowbird abundance. Densities of female cowbirds were positively related to densities and richness of other birds in the breeding bird community.

Minnesota, Montana, North Dakota, South Dakota↗
USGS2008

Nesting biology of Lesser Canada Geese, Branta canadensis parvipes, along the Tanana River, Alaska

Lesser Canada Geese ( Branta canadensis parvipes ) are widespread throughout interior regions of Alaska and Canada, yet there have been no published studies documenting basic aspects of their nesting biology. We conducted a study to determine reproductive parameters of Lesser Canada Geese nesting along the Tanana River near the city of Fairbanks, in interior Alaska. Fieldwork was conducted in May of 2003, and consisted of locating nests along the riparian corridor between Fairbanks and Northpole, Alaska. Nests were found on gravel islands and shore habitats along the Tanana River, and were most commonly observed among driftwood logs associated with patches of alder ( Alnus spp.) and willow ( Salix spp.). Peak of nest initiation was 3-8 May, with a range from 27 April to 20 May; renesting was likely. Clutches ranged in size from 2 to 7 eggs and averaged 4.6 eggs. There was a negative correlation between clutch size and date of nest initiation. Egg size (mean mass = 128 g) was similar to other medium-sized Canada Geese. A positive correlation between egg size and clutch size was likely related to female age. Nineteen of 28 nests (68%) were active when visited; nests located on islands with nesting Mew Gulls ( Larus canus ) were more likely to be active than nests located elsewhere. Evidence at nest sites implicated Bald Eagles ( Haliaeetus leucocephalus ) and Red Foxes ( Vulpes vulpes ) as nest predators.

Alaska↗
USGS2009

Long daily movements of wolves ( Canis lupus ) during pup raising

Wolves, Canis lupus , on Ellesmere Island traveled a daily round-trip distance of 40.2 km from their den to a landfill during July 2008, plus an undetermined distance hunting after leaving the landfill. Although long travels by Wolves are well known, this appears to be the first documentation of long daily movements by Wolves rearing pups.

Canada↗