Browsing by Subject "Conservation biology"

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American black bears: Strategies for living in a fragmented, agricultural landscape
(2014-08) Ditmer, Mark Allan
The American black bear (Ursus americanus) is a forest-dwelling species, but also an ecological opportunist. Few studies have investigated ecological and landscape requirements for this species in highly-fragmented habitats. Northwestern Minnesota is particularly well suited for such a study because it marks the historical western edge of black bears in eastern U.S.. This area is a patchwork of forest (<20% coverage) and agricultural lands, with contiguous forests eastward and agriculture westward. My dissertation, spurred by this intriguing increase and expansion of bears at the edge of their range, focuses broadly on two interrelated fundamental ecological questions: (1) how do bears respond to fragmentation of forested habitat, and (2) how is the edge of a bear's geographic range delimited? Results from stable isotope analysis illustrated how a small portion of the landscape used for corn and sunflower production (1-4% annually) was a major portion of some bears' diets. We found the degree of crop consumption varied with natural forage availability, demographics, size and health, space use patterns and landscape fragmentation surrounding the individual. Captive bear food preference trials revealed that male bears were much more apt to try novel, high-calorie foods, but females learned to do so after more exposure. My analysis utilizing advanced biologger technology of bears' heart rates revealed that bears were not stressed when foraging in cropfields or in small patches of forest but when crossing open fields without foods, their heart rates were typically faster than expected for their rate of travel, indicating a stress response. I found bears in this area have the largest home ranges ever recorded for the species, so I used short-term (weekly) home ranges to estimate how landscape, habitat type, caloric availability and demographics affected the amount of area a bear used at different times of year. I used results from this analysis to produce regional maps of bear habitat quality under varying natural and anthropogenic food conditions, showing the probable geographic limit of this range. It appears that for bears to expand much farther west they would need to cross a large expanse of unsuitable habitat or slacken habitat requirements.
Assessing bat and bird fatality risk at wind farm sites using acoustic detectors
(2014-08) Heist, Kevin W.
Wind power is a promising and rapidly growing clean energy technology. Despite its environmentally friendly reputation, industrial wind energy generation can have serious impacts on wildlife. Bat and bird collision fatality rates have been alarmingly high at some wind farms. Proper siting of wind facilities may help minimize collision impacts; however, there is no reliable method for assessing risks prior to development. My goal was to develop a method for predicting fatality rates at prospective wind energy sites by monitoring acoustic activity of bats and birds. I monitored bat and bird activity using ultrasonic-acoustic detectors at 160 locations, in a variety of landscape settings to: 1) examine the utility of the detectors for monitoring bat and bird activity for pre-construction site assessment, 2) evaluate the ability of an automated bat call identification program to identify the species of recorded calls, 3) determine how pass rates relate to fatality rates, 4) examine how pass rates vary with respect to specific landscape features, 5) examine how activity differs before versus after a wind facility is built, and 6) investigate whether bat activity levels are elevated near turbines. Ground-based recording was found to be useful for studying near-ground bat activity patterns at multiple scales, but patterns of bird activity were apparent only at the coarsest geographic scale. The bat call identification program produced mixed results among species and regions. No relations between bat pass rates and fatality rates among wind farms were found. Large differences in bat and bird activity among geographic regions were found, with highest levels near Great Lakes coastlines. Also, bat and bird activity was elevated near edges of forested river corridors, relative to distances farther from the edge. Distance to water, distance to trees, and ecoregion were found to be good predictors of bat activity levels. Models of bird activity were of limited usefulness in explaining spatial variation in pass rates. Ground-based acoustic recorders were not found to be a good predictor of bat fatalities; however, they did reveal local and regional patterns that may be useful for siting wind energy facilities in low-impact areas.
The causes and consequences of individual variation in survival and fecundity of Great Lakes piping plovers (Charadrius melodus)
(2015-03) Saunders, Sarah Prairie
The piping plover (Charadrius melodus) is a small shorebird endemic to North America and restricted to three breeding populations: Atlantic Coast, Great Plains, and Great Lakes. Listed as federally endangered in 1986, the Great Lakes population has numbered from 17 to 71 known breeding pairs. Despite recovery efforts, the population is far from the federal recovery goal of 150 breeding pairs. The purpose of my dissertation research is to understand the causes and consequences of individual variation in survival and fecundity during key breeding stages through four distinct methods of investigation: life-history theory, quantitative genetic analysis, population demography, and behavioral assessment. Effective conservation of small wildlife populations requires the intersection of many scientific disciplines and I seek to achieve this unification through the four chapters of my dissertation. First, I investigate how age and parental experience with breeding, a mate, and a nesting location influence reproductive success (Chapter 1). In chapter 2, I investigate the heritabilities of three fitness-related traits (chick body mass, natal dispersal distance, and female timing of breeding) to determine which are strongly environmentally-determined and thus susceptible to impacts of global climate change. In chapter 3, I tease apart the relative influences of various developmental and environmental factors at pre-fledging, post-fledging, and adult stages to more precisely inform population recovery actions. In my final chapter, I test the hypothesis that captive-reared chicks have lower survival rates than those reared in the wild because of a lack of threat recognition. The insights gained from my research not only pertain to this small shorebird breeding in the Great Lakes, but also provide a more comprehensive framework for analyzing data on marked individuals with the goal of shaping conservation actions for an entire population. Further, the new analytical methods applied to ecologically complex data will be important to any study that uses long-term marking. Avian populations are predicted to become more threatened in the future, so it is increasingly critical to understand factors driving vital rates and to develop approaches to alleviate threats to population persistence.
Comparing methods for assessing habitat connectivity: a case study of guinas (Leopardus guigna) in a fragmented Chilean landscape
(2014-09) Castro Bustamante, Rodrigo Alfredo
Fragmentation creates a matrix which can facilitate or impede connections among patches of habitat. Least-cost path (LCP) and circuit theory (CT) are two methods commonly used to evaluate landscape-level connectivity among patches. Both methods use resistance surfaces that can be generated from Resource Selection Functions (RSF) or the Analytical Hierarchy Process (AHP). Despite the potential conservation implications of connectivity analyses, the methods are rarely compared. I quantified how RSF and AHP resistance surfaces affect estimates of connectivity among protected areas using a South American wild cat, güiña (Leopardus guigna), as a case study. I found that 1) path rankings and predicted locations of pinch points depended on the metric and resistance surface used, and 2) LCP is more sensitive to resistance surfaces than CT. These results confirm that connectivity analysis methods should be carefully considered and compared before they are used for conservation decisions.
Diet and activity patterns of Leopardus guigna in relation to prey availability in forest fragments of the Chilean temperate rainforest
(2014-09) Galuppo Gaete, Stephania Eugenia
The güiña (Leopardus guigna) or kod kod is one of the least known wild cats in the world. It is classified as vulnerable by IUCN with the most restricted distribution of any felid species in the world. I recorded the activity patterns of güiñas, determined diet composition, and measured prey availability in four cover types in Pucón, La Araucanía Region. I captured and followed five güiñas with VHF radio-telemetry and collected 67 scats for diet analysis. Güiña presented nocturnal and crepuscular peaks of activity. The güiña diet was mainly based on the most abundant rodents in the study area in accordance with a rodent survey and the teeth and hair analysis of scats. The small mammals captured were Oligoryzomys longicaudatus, Abrothrix longipilis, Abrothrix olivaceus, and Rattus rattus. This study contributes to the understanding of the influence of a highly fragmented habitat in activity, diet and prey offer of güiña.
Distribution, abundance and overwinter survival of young-of-the-year common carp in a Midwestern watershed.
(2012-03) Osborne, Jacob B.
The common carp (Cyprinus carpio) is one of the most widespread and damaging invasive fishes in North America, yet little is known about its early life history. This paper reports the results of two studies which tested the hypothesis that shallow lakes prone to winter hypoxia (i.e. unstable lakes) serve as nurseries for common carp in interconnected lake systems while lakes that do not experience winterkill (i.e. stable lakes) do not function as nurseries. Six lakes in an interconnected lake system in southcentral Minnesota (four stable and two unstable) were sampled using trap-nets in June- August of 2009, 2010 and 2011 and in all three years age-0 carp were captured only in the two unstable lakes. These surveys also revealed that the fish communities in stable lakes were dominated by bluegill sunfish and largemouth bass, species which did not occur naturally in the unstable lakes. Mark-recapture and ageing studies conducted in 2010 in the two carp nurseries indicated that there were ~13,000 age-0 carp in Casey Lake and ~35,000 age-0 carp in Markham Lake. Additional mark-recapture efforts the following summer indicated that ~33% of those fish survived their first winter in Casey Lake while ~4% survived in Markham Lake. Independent trap-net and electro-fishing surveys in the nursery lakes in 2010 revealed that their fish communities were dominated by shorter length classes of hypoxia-tolerant species. Implications of these results for management of nuisance carp populations in interconnected lake systems in North America are discussed.
The diversity of conservation: Exploring narratives, relationships and ecosystem services in Melanesian market-based biodiversity conservation
(2014-10) Henning, Bridget M.
Papua New Guinea (PNG) is a biodiversity hotspot with large carbon pools making it a target of international conservation efforts. Protection of biodiversity in this Pacific island nation requires conservationists to work with customary landowners, whose land rights are ensured in the constitution. New projects using market-based conservation have recently been attempted in PNG. Landowners welcome direct payments from conservationists but conservationists and landowners have contrasting cultural perspectives. This dissertation examines the perspectives of landowners and conservationists in a market-based project. The first chapter describes Wanang village and the development of Wanang Conservation, the first project in PNG to use direct payments for conservation. The second chapter explores the multiple meanings of conservation to villagers. Conservation is discussed in terms of ancestral resource protection, material benefits, exchange relationships, political leadership, and as a connection to ancestors. These narratives demonstrate that the diverse roles conservation plays at Wanang are far more complex than simple biodiversity protection. In the third chapter, villagers' and conservationists' interests in ecosystem services and how these interests align are discussed through an examination of the bundling of carbon storage, hunted game, useful plants, and forest spirits in mature and recently disturbed forests. Villagers' interests in hunting, forest spirits, and plants used for tools, medicine, food, and rituals, align with conservationists' interests in carbon storage in mature forests. The fourth chapter examines the complexity of using economic incentives in Melanesia. Conservationists use economic discourse to explain how the project functions and how they appeal to villagers as rational, self-interested, economic actors. However, villagers see incentives as part of an exchange relationship with moral obligations that extend beyond the transaction. The parties are able to build a relationship around the idea of material exchange, although they understand it differently. This dissertation demonstrates the complexity, unintended consequenses, and difficulty of sustaining payments for ecosystem services in PNG. Villagers have multiple interests and expectations of conservation and a different understanding of how projects function than do conservationists. Despite these differences, villagers and conservationists can find common ground to work together, yet the work is never finished, as continuous renegotiations are necessary. Future research should examine the role of social relationships, incentives, and ancestors in the sustainability of the direct payments model.
Field and laboratory studies suggest that recruitment of the invasive common carp is controlled by native fish in Stable Lakes of the Upper Mississippi Basin.
(2011-10) Silbernagel, Justin J.
Recent studies have shown that recruitment of the common carp in many lakes of the Upper Mississippi Basin is limited to areas that experience an ecological disturbance that alters the fish community. It has been hypothesized that recruitment of carp is limited by native predatory fish and that carp are only able to recruit in habitats where these native species have been excluded due to winter hypoxia. We tested this hypothesis by comparing the survival of carp eggs and larvae in the presence and absence of native predatory fishes in three experiments. First, we sampled fish diets and carp egg abundance on a daily basis in lakes where wild carp had spawned to identify fish predators and track carp egg abundance in the environment. We simultaneously estimated the date of carp egg hatching using eggs raised in the lab at water temperatures that represented lake temperatures. We found that the bluegill sunfish was the main predator of carp eggs (94% of egg predators were bluegill sunfish), and that egg abundance declined before the estimated date of hatching in areas where bluegill sunfish were present. In our second experiment, carp egg survival was tested in the presence and absence of bluegill sunfish in the laboratory. Carp eggs were fertilized in the laboratory, placed on artificial vegetation in 70 liter aquaria that contained a bluegill sunfish or no fish, and counted twice daily until hatching. We found that the survival to hatching of carp eggs in aquaria decreased from 74% to 15% in the presence of bluegill sunfish (p-value < 0.001). In our third experiment, carp larval survival was tested in the presence of bluegill and green sunfish in the laboratory. Larval carp were raised from eggs fertilized in the laboratory until they reached their free swimming stage and introduced into 1,600 liter tanks with five individuals of a single species of predatory fish or no fish. Larvae were then sampled twice daily for two days. Both bluegill and green sunfish reduced larval carp survival to zero percent after 34 hours (p-value < 0.001). These results suggest that the bluegill sunfish is a voracious predator of the early life stages of common carp and is likely responsible for reducing the recruitment of common carp through predation on its eggs and larvae.
Landscape-scale conservation planning and wildlife monitoring In Southeast Asia
(2014-09) Cutter, Peter Guild
Advances in data availability and methodology have greatly expanded the potential for landscape scale monitoring of biodiversity and the use of resulting insights for conservation planning. This collection of papers explores the use of modeling, monitoring, and conservation planning techniques to better facilitate landscape scale conservation in Southeast Asia.Chapter 1 focuses on the use of linear and logistic regression techniques for modeling occurrence patterns of tigers and tiger prey over a large landscape in western Thailand. I discuss the strengths and limitations of using these techniques to inform landscape scale monitoring and planning activities. Chapter 2 explores the potential for sign surveys of a landscape scale predator (tiger) to inform management decisions. I compare presence/absence and count survey frameworks and assess their value in informing landscape level management. A controlled study of tiger sign interpretation provides the much of the basis for the raw data used in this chapter and this study is presented in a detailed appendix. Chapters 3 through 5 focus on a biodiversity gap analysis conducted for Cambodia's protected area system. Chapter 3 provides a detailed account of methods used to map biodiversity surrogates for the country. Chapter 4 reviews the history and current status of Cambodia's protected area system and includes recommendations for revising IUCN category assignments for the system. Chapter 5 is a detailed account of a national level conservation planning exercise in Cambodia and how this process was translated into specific recommendations for improving Cambodia's protected area system.
Lessons from two sculpin species in southeastern Minnesota: Species interactions in native populations and reproduction dynamics in reintroduced populations.
(2010-05) Fujishin, Lorissa M.
Cottus cognatus and Cottus bairdi are small, benthic, freshwater fish species native to southeastern Minnesota. Current conservation efforts conducted by the Minnesota Department of Natural Resources (MNDNR) have included reintroducing sculpin to rehabilitate the native fish fauna in streams historically impacted by agricultural land-use. These restoration activities have provided diverse opportunities to study aspects of sculpin ecology in southeastern Minnesota. The MNDNR reintroduction plan did not attempt to differentiate between C. cognatus and C. bairdi, in part because the two are morphologically similar and difficult to identify in the field. The two species are known to occur syntopically in some areas, and hybridization between the two has been documented. Fish survey data from the Minnesota Pollution Control Agency along with personal observation were used to identify sites in southeast Minnesota with syntopic populations. Fin clips were taken from fish in syntopic populations and genotyped using three species-specific microsatellite DNA markers. Habitat data were collected from syntopic sites to further understand conditions that allow for species co-occurrence. There was no evidence for hybridization in syntopic C. cognatus and C. bairdi populations in southeastern Minnesota, even though there was no spatial or temporal separation during breeding season. Syntopy occurred only in areas where a 1st- 2nd order spring-fed tributary flowed into a larger stream. Temperatures in syntopic locations were intermediate to temperatures recorded in allopatric locations for both species. The results of this study suggest that differences between the species limit or prevent hybridization in southeastern Minnesota. Sculpin reintroduction efforts should take into account the different preferences of each species to increase success in introduced populations. Currently, the only species used for reintroductions is C. cognatus. Research started in 2005 at the University of Minnesota examined overall ancestry, changes in genetic diversity, and fitness in reintroduced C. cognatus populations up to two generations after stocking. New introductions were conducted to examine the initial dynamics in survival and reproduction and how they affect genetic diversity. Two streams were stocked in the fall of 2007 with an equal mix of individuals from two source strains. Fin clip samples were taken from all individuals stocked into each stream, and samples from their offspring were collected the following fall. Parentage analysis requires highly polymorphic genetic markers, and microsatellite loci developed for other Cottus species were insufficient for the needs of this study. To fulfill this need, thirteen polymorphic microsatellite loci were developed from C. cognatus libraries enriched for tri- and tetranucleotide repeats. These loci had 2 to 22 alleles and observed heterozygosities ranged from 0.36 to 0.86 in a sample of 47 individuals from one population. All parents and offspring from the two reintroduction sites were genotyped at 12 microsatellite loci, 6 from those described above and 6 from an existing set. Parentage analysis revealed small founder numbers, differential strain success, and skewed contributions by individuals. One family in each reintroduction stream was responsible for 21-28% of the offspring genotyped, and there was evidence for polygamy in both streams. Allelic diversity in the offspring was reduced by 35-49%. These findings indicate that the effective population size in reintroduced sculpin populations is likely low, and a large number of fish would have to be stocked to maintain genetic diversity in new populations.
Methods for refining waterbird colony persistence research and their application to Great Lakes colonial waterbirds.
(2012-05) Wyman, Katherine E.
After decades of research on waterbird colony persistence, or the re-occupation of a colony site in successive breeding seasons, many environmental correlates of colony persistence have been identified. However, little is understood about what truly drives waterbird colony persistence at a given site; without identifying causative factors, a full understanding of the form and function of colony site use patterns is impossible. To improve understanding of the biology of colonial waterbirds as well as conservation and management efficiency, greater research attention should be directed towards multivariate analyses of predictors of colony persistence and towards experimentation to test theoretical predictions about mechanisms determining colony site use. The former type of research allows scientists to identify the most important variables among a suite of potential predictors, while the latter is the only legitimate way to determine true causative relationships. A series of decadal surveys of Great Lakes waterbird colonies provides an opportunity to illustrate the method of multivariate analysis to inform biological and conservation understanding. I used a hierarchical occupancy model analyzed within a Bayesian statistical framework to determine the most important predictors of site colonization and colony persistence probabilities for the ten most common species in the U.S. Great Lakes colonial waterbird community. Species varied considerably in their responses to site location, human disturbance, and species richness at colony sites. Sites with large colonies and those not susceptible to flooding were most likely to be reoccupied in the following census period, suggesting that sites with these characteristics should be conservation priorities. However, the most effective conservation strategy will take advantage of knowledge about species-level variation to tailor conservation and management activities to the particular species of interest.
Seed size in lacustrine and riverine populations of wild rice (Zizania palustris)
(2010-10) Eule-Nashoba, Amber Rae
To study the effects of the hydrological regimes of lakes and rivers on seed size of wild rice (Zizania palustris), four lakes and four rivers were sampled to measure and model the factors affecting seed size. Based on casual observation by harvesters and biologists it has been hypothesized that seeds produced in riverine habitats are smaller than those produced in lacustrine habitats. We found mean seed mass in lake populations was 15.4 mg (41%) larger than in river populations. When seed mass was partitioned between water body type, regional population pair, and individual population, water body type accounted for 71.3% of the variance. Data collected on seed mass, panicle density, seed scars, root mass, sediment characteristics, and water depths were used to create a statistical model to quantify the effects of each factor on seed size. The two most important environmental factors contributing to seed size were sediment bulk density and water depth at seed collection. Important biological components were seed scar density, proportion of filled seed, and root dry mass.
Source-sink population structure of invasive common carp in a model Midwestern watershed: empirical evidence and notes on management
(2014-08) Koch, Justine Danielle
Effective management of invasive fishes requires a detailed understanding of the factors that influence population structure and persistence across relevant spatial and temporal scales. It has been hypothesized that the common carp (Cyprinus carpio) is often invasive in the North American Midwest due to its propensity to utilize shallow, predator-free basins as productive nursery habitat. Although it has been demonstrated that such basins often support extremely high abundances of young carp, the fate of these carp is unknown. To determine whether these putative nurseries serve as important sources of recruits at a watershed scale, we used mark-recapture and genetic assignment methods to investigate carp recruitment in a system of interconnected lakes, ponds, and associated wetlands in central Minnesota. Annual trap net surveys in 4 lakes and 8 ponds in the Phalen Chain watershed from 2009-2013 revealed that young-of-year carp were found exclusively in shallow pond habitats. Mark-recapture studies in 2011 and 2012 indicated that, of the 613 carp marked in one of the putative nursery ponds, ~31% of recaptured carp (25 of 80) had emigrated from the nursery pond to a connected water body. Microsatellite analysis of carp tissue samples (n=1041) from all basins throughout the watershed and from individuals moving between lakes and putative nurseries during the spawning season revealed two genetically distinct strains of carp within the watershed. The distribution and movements of genetically distinct carp revealed patterns in dispersal and colonization consistent with the carp nursery hypothesis (i.e. source-sink population structure). Additionally, there was evidence of reproductive homing by adult common carp. Our results and continued research on carp recruitment dynamics will aid in the development of population models and integrated pest management strategies to combat this highly invasive species.
Wild turkeys in the urban matrix: how an introduced species survives-and thrives-in a multifunctional landscape
(2014-12) Tinsley, Karl Andrew
An understanding of how species responds to urbanization is important for conservation and management of possible human-wildlife conflicts. Wild turkeys (Meleagris gallopavo) have recently successfully entered many urban landscapes, however their apparent success remain poorly understood. Most studies of wild turkeys have occurred in forested or agricultural landscapes. I estimated several important demographic, home range, and habitat use behaviors for wild turkey in areas of varying degrees of urbanization in the Minneapolis-St. Paul, Minnesota, USA, metropolitan area. My research objectives centered on providing the first information on urban wild turkey ecology, including: 1) assessing urban wild turkey nesting behavior and possible changes to reproductive measures, 2) investigation of urban wild turkey survival and the influence of local mortality agents, and 3) assessing urban wild turkey home range characteristics and habitat use.I captured and equipped 60 female wild turkeys with back-pack style VHF radio transmitters during 2010-2013. Monitored female wild turkey reproductive measures and nest survival were remarkably similar both among my study areas and previous rural wild turkey research. For all monitored females across all study areas and years, first nesting rate was 73.7% (n = 57), average date of onset of incubation was 2 May (n = 42), and hatch rate was 84% (n = 26). For all monitored females across all study areas and years mean clutch size was 10.2 (n = 42), and differed by study area (÷2 = 8.30, DF = 2, P = 0.02). For all monitored females across all study areas and years nest survival rate was 0.56 (n = 42). Monitored nests tended to have high visual concealment at the nest bowl, with a strong trend for habitat variables related to vegetative density and height at the nest bowl scale, and distance to open water on the greater landscape.Across all study areas and all female wild turkeys in 2010-2013 the annual survival rate was 0.43 (CI = 0.32 - 0.58; n = 55). Across all study areas and all female wild turkeys in 2010-2013, seasonal survival rates were as follows: 1) spring survival rate was 0.61 (CI = 0.50 - 0.75; n = 55); 2) summer survival rate was 0.83 (CI = 0.71 - 0.96; n = 34); 3) autumn survival rate was 0.89 (CI = 0.75 - 0.99; n = 28); and 4) winter survival rate of 0.96 (CI = 0.89 - 1.0; n = 25). During the brooding seasons of 2010 through 2012, an estimated 216 poults successfully hatched. Combined poult survival rate to 2 weeks post-hatch was 0.35, declining to 0.26 4-weeks post-hatch. Overall, mammalian and avian predation accounted for 63.3% of all observed female mortalities, followed by vehicle strikes (23.3%), harvest (3.3%), and unknown causes (10.0%). Predation remained the leading cause of mortality regardless of age-class, although predation tended to be higher in female adults (61.5%) than juveniles (47.1%).Across all study areas and all female wild turkeys, average annual home range size was 41.3 ha (n = 28). Annual home range size for suburban females (64.5 ha, n = 9) was larger than rural (38.0 ha, n = 11) or urban females (19.6 ha, n = 8), with home range size differing between study areas (÷2 = 12.26, DF = 2, P = 0.002). Spring/summer home ranges included both females that attempted to nest, brooding hens, and non-reproductively active females. Across all study areas and all female wild turkeys, average spring/summer home range size was 26.4 ha (n =37). Spring/summer home range size for suburban (44.8 ha, n = 11), rural (23.0 ha, n = 17), and urban females (10.3 ha, n = 9) did not differ. Across all study areas and all female wild turkeys average autumn/winter home range size was 25.1 ha (n = 28). Autumn/winter home range size for suburban (30.9 ha, n = 9), rural (28.6 ha, n = 11), and urban females (13.8 ha, n = 8) did not differ.Habitat use by wild turkey populations in urban settings relied heavily on `natural-like' habitat, as well as on developed, human-dominated areas. For this study `natural-like' habitat (i.e., parkland, conifer tree) was predictive of spring/summer habitat use and developed habitat (i.e., residential areas, agricultural) was predictive of autumn/winter habitat use. These range shifts are likely linked to resource availability and specific habitat availability (i.e., nesting and brood habitats).

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