scholarly journals Habitat features act as unidirectional and dynamic filters to bat use of production landscapes

2017 ◽  
Vol 209 ◽  
pp. 280-288 ◽  
Author(s):  
Joanna M. Burgar ◽  
Vicki L. Stokes ◽  
Michael D. Craig
Mammalia ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nayara Yoshie Sano ◽  
Heitor Miraglia Herrera ◽  
Grasiela Edith de Oliveira Porfirio ◽  
Filipe Martins Santos

AbstractTo date, there have been no studies that have evaluated small mammal utilization of the understory of forests. In this study, we described the use of vertical strata by small mammals in patches of unflooded forests, known as “cordilheiras”, in the Nhecolândia sub-region of the Pantanal, Brazil. We collected all species using the ground and understory, including the terrestrial didelphid Monodelphis domestica. We suppose that local habitat features (e.g., Acuri palms), rather than intrinsic species characteristics, may be more conducive to the use of understory vegetation by small mammals in the Nhecolândia region.


2019 ◽  
Author(s):  
Clark Alexander ◽  
Michael Robinson ◽  
Claudia Venherm
Keyword(s):  

1999 ◽  
Vol 56 (9) ◽  
pp. 1576-1584 ◽  
Author(s):  
Roland A Knapp ◽  
Haiganoush K Preisler

It is widely believed that stream salmonids select spawning sites based on water depth, water velocity, and substrate size. Attempts to predict spawning locations using these habitat features have met with little success, however. In this study, we used nonparametric logistic regression to determine what habitat features were associated with the locations chosen by spawning California golden trout (Oncorhynchus mykiss aguabonita). From this nonparametric model, we developed a parametric model that incorporated the habitat features most strongly associated with spawning sites and used this model to calculate the probability of use by spawning golden trout for specific stream locations. The overall nonparametric model was highly significant and explained 62% of the variation in spawning location. Four of the eight habitat variables, substrate size, water depth, water velocity, and stream width, had highly significant effects and alone explained 59% of the variation in spawning location. The results of a cross-validation procedure indicated that the parametric model generally provided a good fit to the data. These results indicate that location-specific probabilities of use were predictable based on easily measured habitat characteristics and that nonparametric regression, an approach still rarely used in ecological studies, may have considerable utility in the development of fish-habitat models. Given the escalating pace at which fish habitats are being altered, such models are increasingly important in predicting the effects of these alterations on populations.


2010 ◽  
Vol 21 (1) ◽  
pp. 59-71 ◽  
Author(s):  
JESÚS CARO ◽  
DIEGO ONTIVEROS ◽  
MANUEL PIZARRO ◽  
JUAN M. PLEGUEZUELOS

SummaryBonelli’s Eagle Hieraaetus fasciatus and Golden Eagle Aquila chrysaetos are two declining species, in which floaters tend to be located outside of breeding territories during the dispersal period, in so-called settlement areas. We studied settlement areas for both these long-lived raptors in the southern Iberian Peninsula, to gain a better understanding of the ecological requirements of the eagles during their long pre-adult stage, a period accounting for around 80% of the species’ mortality. Eagle abundance was calculated by road censuses, and habitat characteristics of settlement and non-settlement areas compared by General Discriminant Analysis (GDA) and Logistic Regression (LR). The best model of GDA and LR incorporated the abundance of main prey for eagles (rabbits, partridges) and orchard surface area, and explained 100% of eagle presence; the best model selected by GDA also included habitat heterogeneity. Both eagles tended to share settlement areas in the southern Iberian Peninsula and, when they did not, the mean annual temperature and slope appeared to explain the segregation between the two species. Management measures for the conservation of both threatened species during the dispersal period should be focused on identifying settlement areas, maintaining high prey densities and maximum habitat heterogeneity.


2004 ◽  
Vol 34 (10) ◽  
pp. 2099-2109 ◽  
Author(s):  
Kathryn EH Aitken ◽  
Kathy Martin

Cavity-nesting vertebrates, a significant component of forest wildlife communities, are connected ecologically in nest webs arranged in guilds of cavity producers (strong and weak excavators) and cavity consumers. The availability of tree cavities for nesting and roosting is considered critical to maintaining communities of cavity nesters. Using univariate tests and resource selection indices, we examined nesting use of both natural and excavated cavities in small aspen–conifer groves of interior British Columbia in relation to availability of cavity, tree, and habitat features. In a 2-year study, we monitored 197 cavities for use, 8% of which were lost between years. Of those that survived, 26% were occupied in both years, 29% were used in only one year, and 45% were not used in either year. Occupied cavities were larger internally than those not occupied in either year and were more likely to be in trees with only one cavity. In species-level resource selection analyses, tree swallows (Tachycineta bicolor Vieillot), European starlings (Sturnus vulgaris L.), and chickadees (Poecile spp.) used live, heart rot infected trees more than expected from their proportional abundance and used dead trees less than expected, while northern flickers (Colaptes auratus L.), mountain bluebirds (Sialia currucoides Bechstein), and red squirrels (Tamiasciurus hudsonicus Erxleben) used live and dead trees in proportion to their availability. Managed, open landscapes with small mixed or deciduous forest groves can sustain healthy communities of cavity nesters, if there is a range of suitable trees for excavators and open areas for foraging.


1998 ◽  
Vol 76 (2) ◽  
pp. 278-287 ◽  
Author(s):  
J D Matheson ◽  
D W Larson

Cliffs along the Niagara Escarpment in Ontario, Canada, support a long, narrow presettlement forest that includes three distinct geomorphic and vegetation zones: cliff edge, cliff face, and talus slope. This unique landform provides an opportunity to evaluate differences in bird communities between the escarpment and adjacent forest relative to habitat features. We sampled forest birds 12 times during the summer of 1994 in plots located in plateau forests, on talus slope, at cliff edges, and on cliff faces. Eleven habitat variables considered important to birds were also sampled in the plots. We arranged plots along six randomly spaced transects at a south site and a north site. Both sites had the consistent habitat heterogeneity considered important to birds. Bird species richness and composition responded to this heterogeneity, but differently at each site: plateau deciduous forests always had the lowest richness and the simplest species composition, whereas both cliff edges and talus slopes had a higher diversity of birds. Cliff faces had large numbers of species in the south but smaller numbers in the north. Escarpment zones form a habitat mosaic that supports many species not found in the adjacent forest and is consistent with the effect of habitat edge. The results suggest that cliffs represent a significant additive influence on avian biodiversity, even when the cliff is a very narrow component of the landscape.


Author(s):  
D. A. Crook ◽  
A. I. Robertson

This paper reviews studies of relationships between riverine fish and woody debris at micro- and meso-habitat scales, and discusses the potential functions of instream structure for lowland river fish. Experimental research, mainly in North America, has identified three main functions of woody debris as microhabitat for fish in upland streams: overhead cover that decreases predation risk both vertically and horizontally; horizontal visual isolation that reduces contact between fish; and velocity refuge which minimizes energetic costs. As with habitat features in other aquatic environments, increasing spatial complexity of woody debris may modify predator–prey interactions and provide greater surface areas for the growth of prey items. Woody debris may also provide spatial reference points for riverine fish to assist them in orienting within their surroundings. Lowland rivers differ from upland streams in terms of a number of physical variables, including turbidity, depth and water turbulence. Relationships between fish and woody debris in lowland rivers are likely to rely on mechanisms different to those in upland streams. Recent initiatives involving the reintroduction of woody debris into previously cleared lowland rivers to replace lost fish habitat are a positive development for lowland river restoration. However, if woody debris reintroduction is to maximally benefit lowland river fisheries, there is a requirement for better understanding of the ecological functions of woody debris in lowland rivers.


Birds ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 261-274
Author(s):  
Heather L. Bateman ◽  
Sidney B. Riddle ◽  
Erin S. Cubley

Passive acoustic recorders have been used successfully as automated survey tools to detect terrestrial wildlife. However, few studies have monitored Neotropical migratory bird use of riparian forest habitat using this technology. Within dryland ecosystems, the forests along rivers support high bird diversity. Many bird species of conservation concern require these floodplain forest habitats for foraging, migration stop-overs, and breeding. Few studies have explored the use of acoustic records in riverine systems designated for conservation for their natural resource value via the Wild and Scenic Rivers Act in the USA. Using acoustic recorders, we document vocal activity of four riparian-obligate species (Bell’s Vireo, Vireo bellii; Summer Tanager, Piranga rubra; Yellow Warbler, Setophaga petechial; and Yellow-billed Cuckoo, Coccyzus americanus) to determine species occurrence along a Wild and Scenic River. We established three study reaches along the perennial Lower Verde River, in the Sonoran Desert of central Arizona, USA. Nine acoustic recorders were used over the period of 80–120 days during the summer of 2018. We measured vegetation composition and structure in 100 m2 plots paired with acoustic recorders. Visualizing vocal activity showed that three species were calling and singing at each reach; whereas, one species, the cuckoo, had fewer recordings and occurred later in the summer. We demonstrate the utility of acoustic monitoring even when applied to rare birds in complex riparian habitats. This information is important for land management and conservation efforts concerning these species of interest and identifying important habitat features in Southwestern US riparian woodlands.


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