Microhabitat nest‐site selection by ducks in the boreal forest

The boreal forest is one of the North America’s most important breeding areas for ducks, but information about the nesting ecology of ducks in the region is limited. We collected microhabitat data related to vegetation structure and composition at 157 duck nests and paired random locations in Alberta’s boreal forest region from 2016 to 2018. We identified fine‐scale vegetation features selected by ducks for all nests, between nesting guilds, and among five species using conditional logistic regression. Ducks in the boreal forest selected nest sites with greater overhead and graminoid cover, but less forb cover than random sites. Characteristics of the nest sites of upland‐ and overwater‐nesting guilds differed, with species nesting in upland habitat selecting nests that provided greater shrub cover and less lateral concealment and species nesting over water selecting nests with less shrub cover. We examined the characteristics of nest sites of American Wigeon (Mareca americana), Blue‐winged Teal (Spatula discors), Green‐winged Teal (Anas crecca), Mallards (Anas platyrhynchos), and Ring‐necked Ducks (Aythya collaris), and found differences among species that may facilitate species coexistence at a regional scale. Our results suggest that females of species nesting in upland habitat selected nest sites that optimized concealment from aerial predators while also allowing detection of and escape from terrestrial predators. Consequently, alteration in the composition and heterogeneity of vegetation and predator communities caused by climate change and industrial development in the boreal forest of Canada may affect the nest‐site selection strategies of boreal ducks.     

Breeding habitat and nest‐site selection by an obligatory “nest‐cleptoparasite”, the Amur Falcon Falco amurensis

The selection of a nest site is crucial for successful reproduction of birds. Animals which re‐use or occupy nest sites constructed by other species often have limited choice. Little is known about the criteria of nest‐stealing species to choose suitable nesting sites and habitats. Here, we analyze breeding‐site selection of an obligatory “nest‐cleptoparasite”, the Amur Falcon Falco amurensis. We collected data on nest sites at Muraviovka Park in the Russian Far East, where the species breeds exclusively in nests of the Eurasian Magpie Pica pica. We sampled 117 Eurasian Magpie nests, 38 of which were occupied by Amur Falcons. Nest‐specific variables were assessed, and a recently developed habitat classification map was used to derive landscape metrics. We found that Amur Falcons chose a wide range of nesting sites, but significantly preferred nests with a domed roof. Breeding pairs of Eurasian Hobby Falco subbuteo and Eurasian Magpie were often found to breed near the nest in about the same distance as neighboring Amur Falcon pairs. Additionally, the occurrence of the species was positively associated with bare soil cover, forest cover, and shrub patches within their home range and negatively with the distance to wetlands. Areas of wetlands and fallow land might be used for foraging since Amur Falcons mostly depend on an insect diet. Additionally, we found that rarely burned habitats were preferred. Overall, the effect of landscape variables on the choice of actual nest sites appeared to be rather small. We used different classification methods to predict the probability of occurrence, of which the Random forest method showed the highest accuracy. The areas determined as suitable habitat showed a high concordance with the actual nest locations. We conclude that Amur Falcons prefer to occupy newly built (domed) nests to ensure high nest quality, as well as nests surrounded by available feeding habitats.     

Vegetation's importance in regulating surface elevation in a coastal salt marsh facing elevated rates of sea level rise

Rising sea levels threaten the sustainability of coastal wetlands around the globe, thus understanding how increased inundation alters the elevation change mechanisms in these systems is increasingly important. Typically, the ability of coastal marshes to maintain their position in the intertidal zone depends on the accumulation of both organic and inorganic materials, so one, if not both, of these processes must increase to keep pace with rising seas, assuming all else constant. To determine the importance of vegetation in these processes, we measured elevation change and surface accretion over a 4‐year period in recently subsided, unvegetated marshes, resulting from drought‐induced marsh dieback, in paired planted and unplanted plots. We compared soil and vegetation responses in these plots with paired reference plots that had neither experienced dieback nor subsidence. All treatments (unvegetated, planted, and reference) were replicated six times. The recently subsided areas were 6–10 cm lower in elevation than the reference marshes at the beginning of the study; thus, mean water levels were 6–10 cm higher in these areas vs. the reference sites. Surface accretion rates were lowest in the unplanted plots at 2.3 mm yr^?1, but increased in the presence of vegetation to 16.4 mm yr^?1 in the reference marsh and 26.1 mm yr^?1 in the planted plots. The rates of elevation change were also bolstered by the presence of vegetation. The unplanted areas decreased in elevation by 9.4 mm yr^?1; whereas the planted areas increased in elevation by 13.3 mm yr^?1, and the reference marshes increased by 3.5 mm yr^?1. These results highlight the importance of vegetation in the accretionary processes that maintain marsh surface elevation within the intertidal zone, and provide evidence that coastal wetlands may be able to keep pace with a rising sea in certain situations.     

Stratigraphy and geologic history of a southeastern salt marsh basin,North Inlet,South Carolina,USA

Forty seven vibracores and fifteen radiocarbon dates have beenobtained to outline the Holocene history of the North Inlet saltmarsh basin. Marsh deposits date from about 3500 years BP and havetransgressed over a Late Pleistocene beach-ridge terrain that waspartly eroded by Late Holocene tidal channel meandering. Marsh mudalso has prograded southward over shallow subtidal estuarine Macomamuds which date from about 4500 years BP and which are stillaccumulating in adjacent Winyah Bay. The southward migration of themarsh environment probably is due to the southward migration ofboth North Inlet and the mouth of Winyah Bay. The stratigraphy ofthe North Inlet basin offers no evidence for Late Holocene sea-level oscillations.Application of this model of marsh history to the study long-term ecosystem succession driven by slowly rising sea level isdiscussed.     

Avian fitness consequences match habitat selection at the nest‐site and landscape scale in agriculturally fragmented landscapes

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Experimental analysis of retreat‐site selection by thick‐tailed geckos Nephrurus milii

Abstract Although animals use habitats non‐randomly in the wild, complex correlations among environmental features mean that proximate influences on habitat selection can be identified only by experimental manipulation of potential cues. Thick‐tailed geckos Nephrurus milii are large lizards that are widely distributed through southern Australia. These nocturnally active animals typically spend daylight hours under surface rocks. We presented captive geckos with alternative retreat‐sites (rock crevices) differing in attributes potentially relevant to habitat selection. The lizards showed strong preference for shelter‐sites that enhanced thermoregulation (warm rather than cool) and that reduced the animal's vulnerability to predators (narrow crevices with small openings and not containing the scent of a predatory snake). Horizontal rather than sloping crevices were also preferred. Overall crevice size and thickness of the overlying rock did not influence retreat‐site selection in the laboratory, but could be important in the field because of their influence on thermal regimes under rocks. The present study supports the idea that nocturnal reptiles base their selection of diurnal shelters on multiple aspects related to the fitness consequences of occupancy of alternative available retreat‐sites.     

Nest‐site selection by Interior Least Terns and Piping Plovers at managed,off‐channel sites along the Central Platte River in Nebraska,USA

Given the high productivity of Interior Least Terns (Sternula antillarum athalassos) and Piping Plovers (Charadrius melodus) on constructed off‐channel nesting sites along the central Platte River in Nebraska, USA, and the possibility of creating similar habitats at other locations in their breeding range, understanding how these species use off‐channel nesting habitats is important. We used data collected along the central Platte River in Nebraska, USA, over a 15‐year period (2001–2015), and a discrete‐choice modeling framework to assess the effects of physical site attributes and inter‐ and intraspecific associations on off‐channel nest‐site selection by Interior Least Terns and Piping Plovers. We found that Piping Plovers avoided nesting near each other, whereas colonial Interior Least Terns selected nest sites near those of conspecifics. In addition, the relative probability of use for both species was maximized when distance to the nearest predator perch was ≥ 150 m and elevation above the waterline was ≥ 3 m. Probability of use for nesting by Interior Least Terns increased as distance to water increased, whereas the probability of use by Piping Plovers was maximized when distance to water was ~50 m. Our results suggest that important features of constructed, off‐channel nesting sites for both species should include no potential predator perches within 150 m of nesting habitat and nesting areas at least 3 m above the waterline. Efficient site designs for Interior Least Terns would be circular, maximizing the area of nesting habitat away from the shoreline, whereas an effective site design for Piping Plovers would be more linear, maximizing the area of nesting habitat near the waterline. An efficient site design for both species would be lobate, incorporating centralized nesting habitat for Interior Least Terns and increased access to foraging areas for nesting and brood‐rearing Piping Plovers.     

Nesting in a thermally challenging environment: nest‐site selection in a rock‐dwelling gecko,Oedura lesueurii (Reptilia: Gekkonidae)

In egg‐laying species, maternal oviposition choice can influence egg survival and offspring phenotypes. According to the maternal‐preference offspring‐performance hypothesis, females should choose oviposition sites that are optimal for offspring fitness. However, in thermally challenging environments, maternal oviposition behaviour may be constrained by the limited availability of suitable oviposition sites. We investigated nest‐site selection in a nocturnal lizard [velvet gecko Oedura lesueurii (Duméril and Bibron)] that inhabits a thermally challenging environment in south‐eastern Australia. The viability of these gecko populations is critical for the persistence of an endangered snake species (Hoplocephalus bungaroides Wagler) that feeds heavily on velvet geckos. Female geckos chose nest sites nonrandomly, with 87% of nests (N = 30) being laid in deep crevices. By contrast, only 13% of clutches were laid under rocks, which were the most readily available potential nest sites. Nest success in crevices was high (100%), but no eggs hatched from nests under rocks. Temperatures in nest crevices remained relatively low and constant throughout the incubation period (mean = 22.7 °C, range 21.0–24.5 °C), whereas thermal regimes under rocks showed large diurnal fluctuations. Geckos selected crevices that were deeper, had less canopy cover, and were warmer than most available crevices; in 85% of cases, such crevices were used simultaneously by more than one female. The thermally distinctive attributes of nest sites, and their frequent communal use, suggest that nest sites are a scarce resource for female velvet geckos, and that the shading of rock outcrops through vegetation encroachment may influence nest success in this species. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 250–259.     

Thresholds of sea‐level rise rate and sea‐level rise acceleration rate in a vulnerable coastal wetland

Feedbacks among inundation, sediment trapping, and vegetation productivity help maintain coastal wetlands facing sea‐level rise (SLR ). However, when the SLR rate exceeds a threshold, coastal wetlands can collapse. Understanding the threshold helps address key challenges in ecology—nonlinear response of ecosystems to environmental change, promotes communication between ecologists and resource managers, and facilitates decision‐making in climate change policies. We studied the threshold of SLR rate and developed a new threshold of SLR acceleration rate on sustainability of coastal wetlands as SLR is likely to accelerate due to enhanced anthropogenic forces. Deriving these two thresholds depends on the temporal scale, the interaction of SLR with other environmental factors, and landscape metrics, which have not been fully accounted for before this study. We chose a representative marine‐dominated estuary in the northern Gulf of Mexico, Grand Bay in Mississippi, to test the concept of SLR thresholds. We developed a mechanistic model to simulate wetland change and then derived the SLR thresholds for Grand Bay. The model results show that the threshold of SLR rate in Grand Bay is 11.9 mm/year for 2050, and it drops to 8.4 mm/year for 2100 using total wetland area as a landscape metric. The corresponding SLR acceleration rate thresholds are 3.02 × 10^?4 m/year² and 9.62 × 10^?5 m/year² for 2050 and 2100, respectively. The newly developed SLR acceleration rate threshold can help quantify the temporal lag before the rapid decline in wetland area becomes evident after the SLR rate threshold is exceeded, and cumulative SLR a wetland can adapt to under the SLR acceleration scenarios. Based on the thresholds, SLR that will adversely impact the coastal wetlands in Grand Bay by 2100 will fall within the likely range of SLR under a high warming scenario (RCP 8.5), highlighting the need to avoid RCP 8.5 to preserve these marshes.     

Effects of vertebrate herbivores on soil processes, plant biomass, litter accumulation and soil elevation changes in a coastal marsh

1 Submergence of coastal wetlands in Louisiana is currently rapid and widespread. A number of factors contribute to this loss of habitat, including the activities of herbivores. The objective of this study was to examine the effects of large mammals, predominantly nutria and wild boar, on processes controlling soil elevation in coastal marshes.
2 Effects of herbivores on soil and vegetation were assessed by the use of paired fenced and unfenced plots over two successive growing seasons. Above-ground biomass, litter production, changes in soil elevation, vertical soil accretion, shallow subsidence, below-ground production of roots and rhizomes, the thickness of the root zone, soil bulk density, and soil organic matter were measured.
3 Above-ground biomass, below-ground production, soil elevation and the expansion of the root zone decreased due to herbivore activity. Litter production, the rate of soil surface accretion and shallow soil subsidence were all higher in grazed compared to ungrazed plots, while soil organic matter and bulk density did not differ significantly between treatments.
4 The results indicate that herbivores can have a negative effect on soil building processes, primarily by reducing below-ground production and expansion of the root zone. Where natural rates of mineral sediment deposition are high, coastal marshes are expected to persist, despite herbivore activities. However, where sediment inputs are substantially less, herbivores may lead to destruction of habitat.     

Habitat selection in a large orb‐weaving spider: vegetational complexity determines site selection and distribution

1. The distribution of the large orb‐weaving spider Argiope trifasciata in old field habitats of North America and the habitat selection process this species used was studied for 2 years. 2. Because web spiders have limited dispersal abilities and an energetically costly prey capture device, they do not have the ability to sample potential foraging sites. Structural complexity of the vegetation to which the web must be attached is relatively easy to assess. The hypothesis that the structural complexity is a primary factor in determining initial web site selection was tested both by relating the natural distribution of the spiders across habitats to vegetational complexity and by manipulating the complexity of the habitats in a series of experiments. 3. Argiope trifasciata was not distributed evenly among three old field vegetation types. Habitat complexity was related to spider density in both years although no measure of insect activity, prey capture, or prey consumption was correlated with spider distribution. 4. Three experimental manipulations were conducted to test the impact of habitat structure on spider establishment: (1) the amount of natural vegetation was reduced, (2) structures were added to a simple habitat, and (3) the complexity of the structures added was varied. In each case, spiders were introduced and establishment of webs was monitored. In all manipulations, spider establishment was related to the complexity of the substrate available. 5. These results are important for understanding the cues that influence foraging site selection and therefore provide insight into the distribution of species with limited dispersal abilities and high site investment requirements.     

Roost site selection by Little Owls Athene noctua in relation to environmental conditions and life‐history stages

Roost site selection is a state‐dependent process, affected by the individual's costs and benefits of roosting at a specific site in the available environment. Costs and benefits of different roost sites vary in relation to intrinsic factors and environmental conditions. Thus, the cost–benefit functions of roost sites are expected to differ between seasons and life‐history stages, resulting in adjustments in roost site selection. Studying roost site selection throughout the year therefore provides information about year‐round habitat requirements at different life‐history stages. However, little is known about the roosting behaviour of birds. Here, the roost site selection of Little Owls Athene noctua was studied by repeated daytime location of 24 adult and 75 juvenile radiotagged individuals from July to November. Little Owls preferred sheltered roost sites such as tree cavities with multiple entrances. They increasingly used sheltered sites from summer to winter and preferentially used sheltered roost sites with low ambient temperatures. Juveniles used significantly less sheltered sites during dispersal than before and afterwards, and used less sheltered sites than adults within their home‐range. The survival probability of birds roosting frequently at exposed sites was reduced. Roost site selection is probably driven by the two mechanisms of predator avoidance and thermoregulation, and the costs of natal dispersal may include increased predation threat and higher energy expenditure for thermoregulation. We suggest that adequate roost sites, such as multi‐entrance tree cavities, are an important habitat requirement for Little Owls and that habitat quality can be affected by manipulating their availability.     

Sea‐level rise,habitat loss,and potential extirpation of a salt marsh specialist bird in urbanized landscapes

Sea‐level rise (SLR) impacts on intertidal habitat depend on coastal topology, accretion, and constraints from surrounding development. Such habitat changes might affect species like Belding's savannah sparrows (Passerculus sandwichensis beldingi; BSSP), which live in high‐elevation salt marsh in the Southern California Bight. To predict how BSSP habitat might change under various SLR scenarios, we first constructed a suitability model by matching bird observations with elevation. We then mapped current BSSP breeding and foraging habitat at six estuarine sites by applying the elevation‐suitability model to digital elevation models. To estimate changes in digital elevation models under different SLR scenarios, we used a site‐specific, one‐dimensional elevation model (wetland accretion rate model of ecosystem resilience). We then applied our elevation‐suitability model to the projected digital elevation models. The resulting maps suggest that suitable breeding and foraging habitat could decline as increased inundation converts middle‐ and high‐elevation suitable habitat to mudflat and subtidal zones. As a result, the highest SLR scenario predicted that no suitable breeding or foraging habitat would remain at any site by 2100 and 2110. Removing development constraints to facilitate landward migration of high salt marsh, or redistributing dredge spoils to replace submerged habitat, might create future high salt marsh habitat, thereby reducing extirpation risk for BSSP in southern California.     

Honey Buzzard Pernis apivorus nest‐site selection in relation to habitat and the distribution of Goshawks Accipiter gentilis

The selection of a suitable nest‐site is critical for successful reproduction. Species' preferences for nest‐sites have presumably evolved in relation to local habitat resources and/or interactions with other species. The importance of these two components in the nest‐site selection of the Eurasian Honey Buzzard Pernis apivorus was assessed in two study areas in eastern Austria. There was almost no difference in macro‐ and micro‐habitat features between nest‐sites and random plots, suggesting that Honey Buzzards did not base their choice of nest‐site on habitat characteristics. However, nests were placed significantly further from nests of Northern Goshawk Accipiter gentilis than would be expected if nest‐sites had been chosen at random. Furthermore, in one study area Honey Buzzards appeared to favour areas close to human settlements, perhaps indicating a mechanism to avoid Goshawks, which tend to avoid the proximity of humans. No habitat variable was significantly associated with the loss of Honey Buzzard young, but predation was higher in territories closer to breeding pairs of Goshawks at both study sites. Although Honey Buzzards are restricted to nesting in forests, their choice of nest‐site therefore appears to be largely dictated by the distribution of predators. Studies of habitat association may yield misleading results if the effects of predation risk on distribution are not considered.     

The conservation value of elevation data accuracy and model sophistication in reserve design under sea‐level rise

Many studies have explored the value of using more sophisticated coastal impact models and higher resolution elevation data in sea‐level rise (SLR) adaptation planning. However, we know little about to what extent the improved models and data could actually lead to better conservation outcomes under SLR. This is important to know because high‐resolution data are likely to not be available in some data‐poor coastal areas in the world and running more complicated coastal impact models is relatively time‐consuming, expensive, and requires assistance by qualified experts and technicians. We address this research question in the context of identifying conservation priorities in response to SLR. Specifically, we investigated the conservation value of using more accurate light detection and ranging (Lidar)‐based digital elevation data and process‐based coastal land‐cover change models (Sea Level Affecting Marshes Model, SLAMM) to identify conservation priorities versus simple “bathtub” models based on the relatively coarse National Elevation Dataset (NED) in a coastal region of northeast Florida. We compared conservation outcomes identified by reserve design software (Zonation) using three different model dataset combinations (Bathtub–NED, Bathtub–Lidar, and SLAMM–Lidar). The comparisons show that the conservation priorities are significantly different with different combinations of coastal impact models and elevation dataset inputs. The research suggests that it is valuable to invest in more accurate coastal impact models and elevation datasets in SLR adaptive conservation planning because this model–dataset combination could improve conservation outcomes under SLR. Less accurate coastal impact models, including ones created using coarser Digital Elevation Model (DEM) data can still be useful when better data and models are not available or feasible, but results need to be appropriately assessed and communicated. A future research priority is to investigate how conservation priorities may vary among different SLR scenarios when different combinations of model‐data inputs are used.     

The effects of elevated CO2 and eutrophication on surface elevation gain in a European salt marsh

Salt marshes can play a vital role in mitigating the effects of global environmental change by dissipating incident storm wave energy and, through accretion, tracking increasing water depths consequent upon sea level rise. Atmospheric CO₂ concentrations and nutrient availability are two key variables that can affect the biological processes that contribute to marsh surface elevation gain. We measured the effects of CO₂ concentrations and nutrient availability on surface elevation change in intact mixed‐species blocks of UK salt marsh using six open‐top chambers receiving CO₂‐enriched (800 ppm) or ambient (400 ppm) air. We found more rapid surface elevation gain in elevated CO₂ conditions: an average increase of 3.4 mm over the growing season relative to ambient CO₂. Boosted regression analysis to determine the relative influence of different parameters on elevation change identified that a 10% reduction in microbial activity in elevated CO₂‐grown blocks had a positive influence on elevation. The biomass of Puccinellia maritima also had a positive influence on elevation, while other salt marsh species (e.g. Suaeda maritima) had no influence or a negative impact on elevation. Reduced rates of water use by the vegetation in the high CO₂ treatment could be contributing to elevation gain, either directly through reduced soil shrinkage or indirectly by decreasing microbial respiration rates due to lower redox levels in the soil. Eutrophication did not influence elevation change in either CO₂ treatment despite doubling aboveground biomass. The role of belowground processes (transpiration, root growth and decomposition) in the vertical adjustment of European salt marshes, which are primarily minerogenic in composition, could increase as atmospheric CO₂ concentrations rise and should be considered in future wetland models for the region. Elevated CO₂ conditions could enhance resilience in vulnerable systems such as those with low mineral sediment supply or where migration upwards within the tidal frame is constrained.     

Nest‐site selection by Slender‐billed Parakeets in a Chilean agricultural‐forest mosaic

ABSTRACT Species in the family Psittacidae may be particularly vulnerable to anthropogenic habitat transformations that reduce availability of suitable breeding sites at different spatial scales. In southern Chile, loss of native forest cover due to agricultural conversion may impact populations of Slender‐billed Parakeets (Enicognathus leptorhynchus), endemic secondary cavity‐nesting psittacids. Our objective was to assess nest‐site selection by Slender‐billed Parakeets in an agricultural‐forest mosaic of southern Chile at two spatial scales: nest trees and the habitat surrounding those trees. During the 2008–2009 breeding seasons, we identified nest sites (N= 31) by observing parakeet behavior and using information provided by local residents. Most (29/31) nests were in mature Nothofagus obliqua trees. By comparing trees used for nesting with randomly selected, unused trees, we found that the probability of a tree being selected as a nest site was positively related to the number of cavity entrances, less dead crown, and more basal injuries (e.g., fire scars). At the nesting‐habitat scale, nest site selection was positively associated with the extent of basal injuries and number of cavity entrances in trees within 50 m of nest trees. These variables are likely important because they allow nesting parakeets to minimize cavity search times in potential nesting areas, thereby reducing energetic demands and potential exposure to predators. Slender‐billed Parakeets may thus use a hierarchical process to select nest sites; after a habitat patch is chosen, parakeets may then inspect individual trees in search of a suitable nest site. Effective strategies to ensure persistence of Slender‐billed Parakeets in agricultural‐forest mosaics should include preservation of both individual and groups of scattered mature trees.     

Pre‐moult patterns of habitat use and moult site selection by Brent Geese Branta bernicla nigricans: individuals prospect for moult sites

In environments where habitat quality varies, the mechanism by which individuals assess and select habitats has significant consequences on their spatial distribution and ability to respond to environmental change. Each year, thousands of Black Brent Geese Branta bernicla nigricans migrate to the Teshekpuk Lake Special Area (TLSA), Alaska, to undergo a flightless wing‐moult. Over the last three decades, moulting Brent Geese have changed their distribution within the TLSA, redistributing from inland, freshwater wetlands towards coastal, brackish wetlands. To understand better the mechanism by which Brent Geese select a moult site, as well as reasons behind the long‐term shift of moulting distributions, we examined movements and habitat use of birds marked with GPS‐transmitters during the pre‐moult period. Brent Geese did not generally migrate directly to their moulting site during the pre‐moult period, defined as the time from arrival at the moulting grounds to the onset of flightlessness. Rather, individuals used an average of 3.7 ± 0.6 (se) wetland complexes and travelled a minimum of 95.14 ± 15.84 km during the pre‐moult period. Moreover, 69% of Brent Geese visited their final moult site only to leave and visit other sites before returning for the flightless moult. Brent Geese spent significant time in both inland freshwater and coastal estuarine habitats during the pre‐moult, irrespective of the habitat in which they ultimately moulted. Whereas previous research suggested that Brent Geese choose moult sites based largely upon the experience of previous years, our observations suggest a mechanism of moult site selection whereby Brent Geese ‘prospect’ for moult sites, visiting multiple potential moult sites across varied habitat types, presumably gathering information from each site and correspondingly using this information to choose an appropriate moult site. By allowing individuals to adjust their distributions in response to habitat quality cues that may change annually, such as forage type and availability, prospecting may have influenced the long‐term shift in moulting distributions of Brent Geese in the TLSA.     

Habitat selection by feral cats and dingoes in a semi‐arid woodland environment in central Australia

Habitat use by feral cats and dingoes was examined within a heterogeneous semi‐arid woodland site in central Australia over 2 years. Density estimates of feral cats based on tracks were higher in mulga habitat than in open habitat. Isodar analysis implied that this pattern of habitat use by feral cats was consistent with the consumer‐resource model of density‐dependent habitat selection, which is an ideal free solution. The reason why mulga supported higher densities of feral cats was unclear. Foraging success of feral cats may be higher in the mulga because the stalk and ambush hunting tactics typically employed by felids are well suited to dense cover. Mulga may also have offered feral cats more protection from dingo predation. Dingo activity was distributed uniformly across habitats. The dingo isodar was statistically non‐significant, suggesting that habitat selection by dingoes was independent of density.