Human access constrains optimal foraging and habitat availability in an avian generalist

Ecological Applications, Год журнала: 2024, Номер 34(3)

Опубликована: Фев. 28, 2024

Abstract Animals balance costs of antipredator behaviors with resource acquisition to minimize hunting and other mortality risks maximize their physiological condition. This inherent trade‐off between forage abundance, its quality, risk is intensified in human‐dominated landscapes because fragmentation, habitat loss, degradation natural vegetation communities often coupled artificially enhanced (i.e., food plots), creating high‐risk, high‐reward selection decisions. Our goal was evaluate autumn–winter trade‐offs for an intensively hunted avian generalist. We hypothesized human access a reliable cue predation risk. Therefore, we predicted patterns would be spatiotemporally dependent upon levels associated perceived Specifically, evaluated local‐scale flights diel periods 426 mallards ( Anas platyrhynchos ) relative wetland type, differing across nonhunting seasons. Mallards selected areas that prohibited generally avoided allowed diurnally, especially during the season. compensated by selecting high‐energy greater quality foraging patches on allowable nocturnally when they were devoid hunters. Postseason gradients did not return prehunting immediately, perhaps suggesting delayed response reacclimate nonhunted activities thus agreeing assessment mismatch hypothesis. Last, availability constrained optimal seed biomass productivity) diurnally preseason season, respectively; however, freed from these constraints season postseason periods. results suggest risk‐avoidance accessible hunted) primary driver could local landscape‐level process influencing distributions, instead abundance which has long‐been assumed waterfowl conservation planners North America. Broadly, even generalist, well adapted anthropogenic landscapes, avoids where are allowed. Future planning implementation must consider management recreational people) equally important as wintering waterfowl.

Язык: Английский

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Responses of black-headed gulls (Chroicocephalus ridibundus) to observers holding popguns: Adult and juvenile gulls differ

Journal for Nature Conservation, Год журнала: 2025, Номер 84, С. 126824 - 126824

Опубликована: Янв. 5, 2025

Язык: Английский

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Landscape risk predicts depletion of flooded unharvested corn by waterfowl

Journal of Wildlife Management, Год журнала: 2025, Номер unknown

Опубликована: Янв. 28, 2025

Abstract Animal foraging strategies are formulated in a complex decision‐making matrix that is predicated on balancing energy intake and expenditure within landscape of predation risk. Game species encounter dynamic risks during hunting season as ephemeral predators (i.e., hunters) alter the risk daily seasonally. Predators prey often concentrate around food sources season, further complicating balance minimization for species. For example, many wetland managers provide energy‐rich resources, such unharvested grain, attract waterfowl. Hunter access to these areas varies alters inherent wintering waterfowl face use resources. We hypothesized subsequent depletion flooded corn fields would be influenced by proximate anthropogenic disturbance risk, shifting bioenergetic first sampled 145 cornfields under different regimes estimate biomass October 2019 2020 western Tennessee, USA. then returned 30 those biweekly fall‐winter 2019–2021 rates 60 fields. modeled rate function forage accessibility including variables ear height above water surface, field size, ownership type, distance from sanctuary our statistical model. Biomass estimates derived initial surveys indicated private were hunted provided greatest (7,134 ± 448 kg/ha), followed public (5,272 320 kg/ha) finally sanctuaries closed (3,995 371 kg/ha). Corn was depleted 2–4 times faster than November December but 2 January. Depletion increased surface came closer ears unaffected size or unhunted sanctuary. Sanctuary devoid end January, whereas 55% 50% still had remaining 15 March, which time most ducks likely initiated migration. Private lands contributed nearly 7 more assumed 2015 Lower Mississippi Alluvial Valley Joint Venture energetic allocation models. Despite being hunters at night, not perceived nocturnally similar season. In turn, exploited later when resources scarce, providing available migrating birds. It may important retain through early spring given lack energy‐dense areas. Conservation planners should consider resource multiplicative abundance allocating habitat objectives non‐breeding

Язык: Английский

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Highs and Lows of Arboreal Life: Space use and Movement Strategies of Lion‐Tailed Macaques (Macaca silenus) in the Western Ghats of India

American Journal of Primatology, Год журнала: 2025, Номер 87(5)

Опубликована: Апрель 28, 2025

ABSTRACT Lion‐tailed macaques ( Macaca silenus ), endemic to the Western Ghats of India, are increasingly threatened by habitat loss and degradation, vulnerable environmental change. Insights into their spatial ecology can reveal strategies that enable these navigate use spatially complex heterogeneous spaces. This is crucial for conservation, given increasing human disturbance in around Ghats. study, conducted Silent Valley National Park between January June 2019, 2022, 2023, focused on two macaque troops occupying habitats with varying presence—in park's core (Sairandhri) buffer (Keeripara). The observed group sizes Sairandhri Keeripara were 51 21, respectively. We examined differences assessing vertical space use, two‐dimensional (2D) three‐dimensional (3D) home ranges, using an integrated step‐selection function understand movement‐based selection. similarities movement patterns across troops, notable mainly forest. troop, resident a more disturbed area, utilized smaller range (1.80 km²). They spent 94.2% time mid‐level canopy (6–20 m), descending rarely (1.1%) lower strata (≤ 5 likely due perceived high risk from predators humans, proximity roads. less had larger (3.05 km²) exhibited greater terrestriality (11.3%), 84.2% mid‐canopies. Both preferred areas cover fruiting trees, displaying similar slow movements (indicated through small step lengths large turning angles) near resources. Our findings suggest lion‐tailed may be strictly arboreal than previously believed, habitats. Strategic 3D based local ecological anthropogenic conditions highlights need conservation efforts maintain connectivity support flexibility this species.

Язык: Английский

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Proximity among protected area networks promotes functional connectivity for wintering waterfowl

Scientific Reports, Год журнала: 2024, Номер 14(1)

Опубликована: Июль 30, 2024

The equilibrium theorem provided a fundamental framework for understanding species' distributions and movement in fragmented ecosystems. Wetland-dependent avian species are model organisms to test insular predictions within protected area networks because their mobility allows surveillance of isolated patches without landscape barriers. We hypothesized size isolation would influence functional connectivity sanctuaries by GPS-marked wintering mallards (Anas platyrhynchos) mesocosm sanctuary network. evaluated use, measured movements between sanctuaries, using multistate modeling framework. Proximity drove connectivity, underscoring that patch isolation—not size—influenced even an with no ascertainable resistance or also found use increased overwintering survival reducing harvest mortality. Our theory demonstrated areas supersedes determining access these may have direct fitness consequences. findings could refine land acquisition, restoration, management practices equal greater emphasis on adjacency network design, especially wetland-dependent migratory gamebirds.

Язык: Английский

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Mallard winter use of conservation program and nonprogram lands in Mississippi

Wildlife Society Bulletin, Год журнала: 2024, Номер 48(3)

Опубликована: Сен. 1, 2024

Abstract Prior to the 19 th century, Mississippi Alluvial Valley (MAV) was a vast bottomland hardwood forest ecosystem with associated wetlands and intrinsic resources. Conversion for human uses in 20 century transformed MAV into an agriculturally dominated system. Since late 1980s, federal state incentivized conservation programs landowners have helped restore on private lands MAV. Given need evaluate relation waterfowl use, we used sample of 241 radiomarked female mallards ( Anas platyrhynchos ) evaluated their use public portion during winters 2010–2015. Our objective examine mallard public, private, non‐incentivized if changed by time day after hunting season. Among all diurnal nocturnal locations mallards, 43.3% n = 3,995) occurred lands, 19.5% 1,802) were 37.2% 3,432) lands. Of exhibited greatest Wetland Reserve Easements (WRE; 12.4%) Conservation Program tracts (CRP; 4.7%). Mallards more diurnally within seasons than post‐hunting season, which attributed presence designated sanctuaries that may provided refuge from other disturbances. Post‐hunting increased perhaps exploit seasonal emergent wetland remnant agricultural foods. Radiomarked variety landcover types across land, reinforcing importance habitat complexes wintering dabbling ducks. program such as CRP WREs, provide forested complement flooded natural When areal availability estimates are accessible government or partners, encourage future researchers investigate selectivity incentivized,

Язык: Английский

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Comparing winter distribution and harvest rates of transmitter‐marked and banded‐only mallards in western Tennessee

Wildlife Society Bulletin, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 5, 2024

Abstract The miniaturization of Global Positioning Systems (GPS) transmitters is providing insights into the ecology and management migratory bird species at biologically‐relevant spatial scales. However, their attachment methods could bias inferred behaviors, demographic rates, resulting decisions. We evaluated effects external harness‐style GPS by comparing direct harvest winter dispersal distances, subsequent distributions mallards ( Anas platyrhynchos ) equipped with n = 443) to a tarsal banded‐only control group 1,123) captured in western Tennessee during winters 2019–2022. found that transmitter‐marked had similar as mallards. Time between capture predicted distances but there was no effect marker type. Specifically, average time from 30 (SE 2) 31 3) days for mallards, respectively. Harvest rate () only 2.2% greater compared overall, affected susceptibility juveniles 14.5%). Based on rates cohorts, we suggest 7‐ 10‐day data censoring periods may be warranted, especially juveniles, acclimate transmitters. Overall, concluded modern provided reliable information wintering mallard space use, movements, mortality can used inform other dabbling ducks. Future studies should evaluate different portions ducks' life cycle, such migration or nesting, when they experience adverse effects.

Язык: Английский

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Mallard response to experimental human disturbance on sanctuary areas is mediated by hunting

Wildlife Biology, Год журнала: 2024, Номер unknown

Опубликована: Дек. 27, 2024

Wildlife managers often provide spatial sanctuaries for wildlife to escape both lethal (e.g. hunting) and non‐lethal non‐consumptive recreation) human disturbance. However, as societal interest in outdoor recreation continues climb, many areas face added pressure allow recreation, yet studies increasingly demonstrate negative effects of on wildlife. As such, an understanding how respond activities is essential develop sustainable guidelines preserve multiple benefits humans, while simultaneously protecting populations fitness. We examined GPS‐marked mallard responses three experimental disturbances meant mimic that could theoretically occur waterfowl during 1 November–28 February 2019–2022. evaluated movement, space use, site fidelity expected repeated disturbance would result habituation. further predictions the risk–disturbance hypothesis, whereby we predicted greater behavioral hunting period more intense stimuli. conducted 140 covered vehicle truck), 40 pedestrian, 43 uncovered ATV) across 10 sanctuaries, exposing 195 mallards ≥ (median = 2, range 1–12). Diurnal sanctuary use exceeded 83% proportional regardless period; however, only decreased when disturbed before with vehicle. Besides immediate increases hourly movements mornings received pedestrian disturbances, displayed minimal changes movements. At diel scale, pedestrians elicited greatest responses; doubled birds pre‐hunt early‐hunt periods. In contrast, movement but outside period. Repeated caused gradual declines use: used 12% less each additional hunting. Constrained unchanged after season suggests limited availability alternative safe constrained disturbances.

Язык: Английский

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Mallard Hybridization With Domesticated Lineages Alters Spring Migration Behavior and Timing

Ecology and Evolution, Год журнала: 2024, Номер 15(1)

Опубликована: Дек. 30, 2024

Introgressive hybridization, the interbreeding and gene flow between different species, has become increasingly common in Anthropocene, where human-induced ecological changes introduction of captively reared individuals are increasing secondary contact among closely related leading to wild domesticated lineages. As a result, domesticated-wild hybridization may potentially affect individual fitness, maladaptive effects such as shifts behavior or life-history decisions (e.g., migration patterns), which could influence population demographics. In North America, release captive-reared game-farm mallards (

Язык: Английский

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Sanctuary for migrating and wintering waterfowl: Synthesis and insights for waterfowl management and conservation planning

Journal of Wildlife Management, Год журнала: 2024, Номер 89(3)

Опубликована: Дек. 16, 2024

Abstract Waterfowl use a diversity of resources (e.g., food, structure, sanctuary) to meet energetic, social, and other life‐history demands during the non‐breeding period. often seek areas with limited human disturbance (i.e., autumn winter when hunting seasons are open perhaps reduce exposure mortality risks, minimize energy expenditure, increase foraging efficiency, all which should enhance survival subsequent fitness. Prior studies sanctuary by waterfowl have mostly focused on patterns abundance behavior, many documenting differential diel movements marked birds in around sanctuaries. Although reduced risk is likely associated use, much less known about potential effects body condition, reproductive consequences at individual level, seasonal distribution respect viewing harvest potential. We consider these aforementioned factors among most significant gaps our understanding function management. As hunter recruitment, retention, reactivation become major initiative natural resource agencies core principle North American Management Plan, we discuss role relative efforts. Herein, review historical aspects sanctuary, introduce hypotheses its habitat management conservation planning winter, knowledge waterfowl, share insights inform decisions given currently available evidence remaining uncertainties. Our describes existing for biological social outcomes draws some conclusions evidence, outlines research opportunities help us make informed regarding implementation waterfowl.

Язык: Английский

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