Coexistence between wildlife and humans at fine spatial scales

Proceedings of the National Academy of Sciences, Journal Year: 2012, Volume and Issue: 109(38), P. 15360 - 15365

Published: Sept. 4, 2012

Many wildlife species face imminent extinction because of human impacts, and therefore, a prevailing belief is that some species, particularly large carnivores ungulates, cannot coexist with people at fine spatial scales (i.e., regularly use the exact same point locations). This provides rationale for various conservation programs, such as resettling communities outside protected areas. However, quantitative information on capacity mechanisms to humans scarce. Such vital, world becoming increasingly crowded. Here, we provide empirical about tigers (a globally endangered species) inside Nepal’s Chitwan National Park, flagship area imperiled wildlife. Information obtained from field cameras in 2010 2011 indicated presence foot vehicles) was ubiquitous abundant throughout study site; however, tiger density also high. Surprisingly, even scale camera locations), spatially overlapped vehicles both years. years, offset their temporal activity patterns be much less active during day when peaked. In addition displacement, tiger–human coexistence likely enhanced by prey low levels poaching. Incorporating fine-scale into plans can help address major global challenge—meeting needs while sustaining

Language: Английский

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Advances and applications of occupancy models

Methods in Ecology and Evolution, Journal Year: 2013, Volume and Issue: 5(12), P. 1269 - 1279

Published: July 24, 2013

Summary The past decade has seen an explosion in the development and application of models aimed at estimating species occurrence occupancy dynamics while accounting for possible non‐detection or misidentification. We discuss some recent estimation methods biological systems that motivated their development. Collectively, these offer tremendous flexibility, but simultaneously place added demands on investigator. Unlike many mark–recapture scenarios, investigators utilizing have ability, responsibility, to define sample units (i.e. sites), replicate sampling occasions, time period over which is assumed be static even criteria constitute ‘detection’ a target species. Subsequent inference interpretation model parameters depend definitions ability meet assumptions. demonstrate relevance by highlighting applications from single system (an amphibian–pathogen system) situations where use been criticized. Finally, we suggest future research

Language: Английский

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Occupancy in continuous habitat

Ecosphere, Journal Year: 2012, Volume and Issue: 3(4), P. 1 - 15

Published: April 1, 2012

The probability that a site has at least one individual of species (‘occupancy') come to be widely used as state variable for animal population monitoring. available statistical theory estimation when detection is imperfect applies particularly habitat patches or islands, although it also arbitrary plots in continuous habitat. such plot occupied depends on size and home‐range characteristics (size, shape dispersion) well density. Plot critical the definition occupancy variable, but clear advice missing from literature design studies. We describe models effects varying expected occupancy. Temporal, spatial, variation average expected, information home ranges difficult retrieve presence/absence data collected effect negligible are very large (>100 × area range), pose practical problems. At other extreme, sampling ‘point' with cameras passive detectors allows true ‘proportion occupied' estimated. However, this measure equally reflects density, doubtful value monitoring cross‐species comparisons. ill‐defined studies detect animals unknown distances, commonest example being unlimited‐radius point counts song birds. find recent treatments “multi‐scale” occupancy; respective scales better interpreted temporal (instantaneous asymptotic) rather than spatial. Occupancy an inadequate metric confounded distance.

Language: Английский

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Spatio-temporal interactions facilitate large carnivore sympatry across a resource gradient

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2017, Volume and Issue: 284(1848), P. 20161860 - 20161860

Published: Feb. 8, 2017

Species within a guild vary their use of time, space and resources, thereby enabling sympatry. As intra-guild competition intensifies, such behavioural adaptations may become prominent. We assessed mechanisms facilitating sympatry among dhole ( Cuon alpinus ), leopard Panthera pardus ) tiger tigris in tropical forests India using camera-trap surveys. examined population-level temporal, spatial spatio-temporal segregation them across four reserves representing gradient carnivore prey densities. Temporal overlaps were higher at lower Combined overlap was minimal, possibly due to chance. found fine-scale avoidance behaviours one high-density reserve. Our results suggest that: (i) patterns spatial, temporal sympatric carnivores do not necessarily mirror each other; (ii) are likely adopt as alternative facilitate sympatry; (iii) show adaptability resource availability, driver inter-species competition. discuss that permit co-occupy rather than dominate functional niches, varying intensities shape structure dynamics guilds.

Language: Английский

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Spatial and temporal structure of a mesocarnivore guild in midwestern north America

Wildlife Monographs, Journal Year: 2015, Volume and Issue: 191(1), P. 1 - 61

Published: April 27, 2015

Carnivore guilds play a vital role in ecological communities by cascading trophic effects, energy and nutrient transfer, stabilizing or destabilizing food webs. Consequently, the structure of carnivore can be critical to ecosystem patterns. Body size is crucial influence on intraguild interactions, because it affects access prey resources, effectiveness scramble competition, vulnerability predation. Coyotes (Canis latrans), bobcats (Lynx rufus), gray foxes (Urocyon cinereoargenteus), raccoons (Procyon lotor), red (Vulpes vulpes), striped skunks (Mephitis mephitis) occur sympatrically throughout much North America overlap resource use, indicating potential for interspecific interactions. Although known about autecology individual species separately, little factors that facilitate coexistence how interactions within this guild distribution, habitat temporal activity smaller carnivores. To assess affect widespread guild, we conducted large-scale, non-invasive survey using an occupancy modeling framework. We deployed remote cameras during 3-week surveys detect carnivores at 1,118 camera locations 357 2.6-km2 sections (3–4 cameras/section composing cluster) 16 southernmost counties Illinois (16,058 km2) January–April, 2008–2010. characterized microhabitat each location landscape-level features cluster. In multistage approach, used information-theoretic methods evaluate competing models detection, species-specific occupancy, multispecies co-occupancy, multiseason (colonization extinction) dynamics. developed represent hypothesized effects anthropogenic features, availability, landscape complexity, vegetative land cover. quantified patterns based their frequency appearance photographs. Further, assessed whether shifted diel response presence competitors. Of 102,711 photographs endothermic animals, recorded (n = 412 photographs), coyotes 1,397), 546), 40,029), 149), 2,467). Bobcats were active primarily crepuscular periods, was reduced with precipitation higher temperatures. The probability detecting decreased after bobcat photograph recorded, suggesting avoidance first encounter. Across southern Illinois, camera-location camera-cluster scale ( 0.24 ± 0.04, cluster 0.75 0.06) negatively influenced infrastructure. had high rates colonization 0.86) low extinction 0.07), expanding population, but agricultural less likely colonized. Nearly all clusters occupied 0.95 0.03). At local scale, coyote 0.58 0.03) hardwood forest stands open understories than other areas. Compared coyotes, portion study area 0.13 0.01, 0.29 scales. cluster, fox highest fragmented areas proportions forest, positively related 100% home-range buffers. Red similar proportion as 0.12 0.02, 0.26 0.04) more closely associated features. Only feature made up 90% confidence set scales analysis foxes. Extinction probabilities both 0.57) 0.35) (gray 0.16, 0.06), may declining Illinois. Striped large 0.47 0.79 Raccoons essentially ubiquitous area, being photographed 99% clusters. observed evidence spatial partitioning exception fox-coyote pairs, found preferences important structuring community. Habitat stronger did bobcats. However, level correlated activity. Gray number detections sites not occupancy. Overall, fewer conifer trees. occupy if also present enhance coexistence. 2 appeared co-occur frequently expected selection habitat. Similarly, when present. These positive associations among canids locally abundance unmeasured variables. Activity levels raccoons, bobcats, correlated. our co- occurrence indicate competitor-driven adjustments space use members community might rather norm. Nevertheless, although results currently coexist distribution appears contracting area. Coexistence larger enhanced reduce For instance, contain trees enhances tree-climbing foxes, behavior probably facilitates coyotes. Efforts populations would benefit from increasing amount mature oak-hickory forest. Additionally, varying different analyses underscore importance considering multiple studies. © 2015 Wildlife Society. Los gremios de carnívoros desempeñan un papel en las comunidades ecológicas causando efectos tróficos cascada, afectando la transferencia energía y nutrientes, estabilizando o desestabilizando redes alimentarias. En consecuencia, estructura los puede ser crítica para patrones ecosistemas. El tamaño corporal tiene una influencia interacciones intragremio, ya que afecta el acceso recursos presa, eficacia competencia por explotación, vulnerabilidad depredación intragremio. linces zorros grises mapaches zorro zorrillos rayados ocurren simpatría gran parte América del Norte se solapan utilizan, lo indica potencial interespecíficas. Aunque sabe mucho sobre autoecología especies individuales separado, poco acerca factores facilitan coexistencia cómo dentro este gremio influencian distribución, uso hábitat, actividad más pequeños. Para evaluar autecología hábitat interespecíficas afectan carnívoro amplia realizamos muestreo no invasivo escala, utilizando marco modelos ocupación. Instalamos cámaras remotas muestreos 3 semanas detectar 1118 locaciones-cámara secciones 2.6 km2 / sección conformaron agrupación) condados al sur (16058 entre enero abril Caracterizamos microhábitat cada locación-cámara características nivel paisaje agrupación cámaras. Con enfoque etapas múltiples, utilizamos métodos teoría información competitivos detección, ocupación específicas, co-ocupación multi-especies, dinámicas multi-especies multi-estación (colonización extinción). Desarrollamos especie representar hipotéticos antropogénicas, disponibilidad presas, complejidad paisaje, cobertura vegetal. Cuantificamos carnívora función su frecuencia aparición fotografías. Además, evaluamos si pequeños cambian sus diaria respuesta presencia competidores potenciales. De 102711 fotografías animales endotérmicos, registramos fotografías), 1397), 40029), rojos 2467). estuvieron activos principalmente durante períodos crepusculares, redujo con precipitación altas temperaturas. La probabilidad disminuyó después registrar fotografía lince, sugiere evasión primer encuentro. todo escala (local fue influenciado negativamente antropogénicas e infraestructura. tuvieron tasas colonización (γ bajas extinción población expansión, pero terrenos agrícolas menor colonizados. Casi todas agrupaciones fueron ocupadas (cluster A local, mayor bosques madera dura sotobosque abierto otras áreas. comparación ocuparon porción pequeña zona estudio escalas. cámaras, gris alta áreas fragmentadas proporciones bosque, positivamente relacionada amortiguación rango hogar. proporción 0.04), estrechamente asociados antropogénicas. Solo representaron confianza escalas análisis rojos. Las probabilidades rojo γ ambas pueden estar disminuyendo asociaron esencialmente ubicuos área estudio, siendo fotografiados cámara. Observamos poca evidencia particionamiento espacial base interespecíficas, excepción pares gris-coyote, encontramos preferencias importantes estructuración comunidad carnívoros. tuvo linces. Sin embargo, correlacionó número detecciones sitios ocupados redujeron así general menos árboles coníferas. ocupar coníferas cuando también presentes, indicando mejorar convivencia gris-coyote. parecen co-ocurrir esperado selección hábitat. Del mismo modo, presentes. Estas asociaciones espaciales positivas cánidos abundancia presas variables medidas. niveles mapaches, correlacionaron positivamente. general, nuestros co-ocurrencia indican ajustes espacio miembros podrían norma. pesar resultados colorados actualmente coexisten distribución parece contrayéndose nuestra estudio. grandes incrementarse mediante reduzcan Por ejemplo, contener mejore escalada grises, comportamiento probablemente facilita Esfuerzos incrementar poblaciones beneficiarían aumento cantidad bosque roble-nogal maduro. variados diferentes subrayan importancia considerar múltiples estudios Les guildes jouent rôle dans l'écologie des communautés, particulier les cascade trophiques et transferts l'énergie éléments nutritifs peuvent à fois stabiliser déstabiliser réseaux trophiques. Par conséquent, peut être critique pour le fonctionnement écosystèmes. taille espèces une forte intraguildes car elle affecte l'accès aux ressources proies, l'efficacité compétition course vulnérabilité prédation intraguilde. lynx roux renards ratons laveurs mouffettes rayées sont sympatriques toute l'Amérique du Nord utilisent mêmes indiquant potentiel d'interactions interspécifiques. Malgré fait l'on connaisse bien chaque espèce séparément, sait peu choses facteurs qui facilitent leur l'influence au sein cette guilde l'utilisation l'habitat rythme d'activité petits Pour évaluer comment interspécifiques affectent répandue, nous avons mené enquête grande échelle cadre d'une modélisation d'occupation. Nous déployé pièges photographiques pendant semaines afin détecter emplacements 2,6 caméras/section composent comtés plus sud l'Illinois (16 058 janvier avril caractérisé emplacement niveau paysage Dans approche multi-étapes, utilisé méthodes d'information théorique modèles concurrents détection, l'occupation spécifique espèce, co-occupation multi-espèces dynamique temporelle d'occupation multi-saisons (colonisation extinction). développé représenter effets supposés caractéristiques anthropiques, disponibilité complexité couverture végétative terrestre. quantifié fonction fréquence d'apparition photographies. outre, évalué modifiaient leurs habitudes nycthémérales réponse présence compétiteurs potentiels. Sur 102 711 photographies d'animaux endothermes, identifié photographies), 40 029), 149) étaient principalement actifs périodes crépusculaires activité était réduite lors précipitations températures élevées. probabilité détection diminuée après qu'une photographie ait été prise, ce suggère évitement première rencontre. l'Illinois, l'échelle l'emplacement 0,24 0,04, 0,75 0,06) négativement influencée par infrastructures anthropiques. avaient taux colonisation élevés 0,86) d'extinction faibles 0,07), population expansion, mais terres agricoles moins susceptibles d'être colonisées. Presque tous occupés 0,95 0,03). À locale, 0,58 0,03) élevée forêts feuillus avec sous-étages ouverts d'autres habitats. Comparés occupaient petite partie zone d'étude 0,13 0,01, 0,29 toutes échelles. zones fragmentées élevées forêt positivement liée anthropiques d'un buffer territoire. similaire 0,12 0,02, 0,26 0,04), étroitement associés composés uniquement paramètres composaient groupe confiance échelles d'analyse roux. probabilités 0,57) 0,35) (renard 0,16, renard 0,06), ces deux déclin l'Illinois. 0,47 0,79 associées essentiellement omniprésents d'étude, étant photographiés obtenu preuves partitionnement basé interspécifiques, l'exception paires gris-coyote constaté préférences d'habitat structuration communauté L'influence celle lynx. Cependant, corrélé l'activité L'occupation nombre détections réduits pas général, conifères. d'occuper peuplements conifères également présents, améliorer semblent coexister locale fréquemment qu'attendu sélection individuelle l'habitat. même, d'emplacements lorsque présents. Ces spatiales positives canidés l'abondance proies localement ou non mesurées. niveaux laveurs, corrélés. l'ensemble, nos co-occurrence indiquent ajustements d'utilisation résultant plutôt norme. Néanmoins, résultats qu'actuellement coexistent semble contracter notre d'étude. grands améliorée temporel activités réduisent exemple, contenir arbres améliore capacité grimper, comportement facilite probablement efforts promouvoir pourraient bénéficier l'augmentation quantité chênes caryers matures. variabilité différentes d'analyses soulignent l'importance considérer plusieurs études communautés

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A gentle introduction to camera‐trap data analysis

African Journal of Ecology, Journal Year: 2018, Volume and Issue: 56(4), P. 740 - 749

Published: Nov. 29, 2018

Abstract Camera traps are increasingly used to study wildlife ecology and inform conservation, but valid inference depends on appropriate data analysis. This article introduces the most common analytical approaches for camera‐trap data. generally as point‐based sampling devices, many methods require spatial independence of stations temporal subsequent records. Photographic rates species should be interpreted with care, because they confound abundance/use detectability. Occupancy models estimate occurrence while accounting imperfect detection can reveal species–habitat associations. Capture–recapture abundance probability from individual detection/nondetection applicable individually recognizable species. Spatial capture–recapture extends this framework by animal movement location relative trap array. is particularly useful often wide‐ranging typically studied camera presents possibilities modelling population processes. Several have been developed that cannot identified; all heavily rely model assumptions. Finally, time stamps records describe activity pattern interactions between Considering usefulness trapping, we expect ongoing development

Language: Английский

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Spatial occupancy models for large data sets

Ecology, Journal Year: 2012, Volume and Issue: 94(4), P. 801 - 808

Published: Nov. 21, 2012

Since its development, occupancy modeling has become a popular and useful tool for ecologists wishing to learn about the dynamics of species occurrence over time space. Such models require presence–absence data be collected at spatially indexed survey units. However, only recently have researchers recognized need correct induced overdisperison by explicitly accounting spatial autocorrelation in probability. Previous efforts incorporate such largely focused on logit‐normal formulations occupancy, with random effect within hierarchical framework. Although useful, computational generally limits an approach relatively small sets, there are often problems algorithm instability, yielding unsatisfactory results. Further, recent research revealed hidden form multicollinearity applications, which may lead parameter bias if not addressed. Combining several techniques, we present unifying model specification that is particularly effective large extents. This employs probit mixture framework can easily accommodate reduced‐dimensional process resolve issues confounding while improving convergence. Using open‐source software, demonstrate this new using case study involving caribou ( Rangifer tarandus ) set 1080 units spanning contiguous region (108 000 km 2 northern Ontario, Canada. Overall, combination more efficient software allows facile stable implementation sets.

Language: Английский

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Improving distribution data of threatened species by combining acoustic monitoring and occupancy modelling

Methods in Ecology and Evolution, Journal Year: 2016, Volume and Issue: 7(11), P. 1340 - 1348

Published: June 3, 2016

Summary Conservation of threatened species relies on predictions about their spatial distribution; however, it is often difficult to detect in the wild. The combination acoustic monitoring improve detectability and statistical methods account for false‐negative detections can distribution estimates. Here, we combine a novel automated species‐specific identification approach with occupancy models that imperfect provide more accurate map Elfin Woods Warbler Setophaga angelae , rare, elusive bird species. We also compared three identification/validation approaches determine which provided estimates similar manual validation all recordings. Acoustic data were collected along elevational gradients (95–1074 m a.s.l) El Yunque National Forest, Puerto Rico. detection matrices acquired through validations recordings used create models. Although this has wider than previously reported, depends Palo Colorado forest cover mainly occurs between 600 900 a.s.l. Unbiased precise developed by using only manually validating 4% Our draws strength two active areas ecological research: modelling. an effective efficient way translate enormous amount information passive devices into meaningful be applied understand

Language: Английский

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Tigers, leopards, and dholes in a half-empty forest: Assessing species interactions in a guild of threatened carnivores

Biological Conservation, Journal Year: 2013, Volume and Issue: 163, P. 68 - 78

Published: Jan. 29, 2013

Language: Английский

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Modeling false positive detections in species occurrence data under different study designs

Ecology, Journal Year: 2014, Volume and Issue: 96(2), P. 332 - 339

Published: Nov. 17, 2014

The occurrence of false positive detections in presence-absence data, even when they occur infrequently, can lead to severe bias estimating species occupancy patterns. Building upon previous efforts account for this source observational error, we established a general framework model positives studies and extend existing modeling approaches encompass broader range sampling designs. Specifically, identified three common designs that are likely cover most scenarios encountered by researchers. different all included ambiguous detections, as well some known-truth but their differed the level hierarchy at which information was incorporated (site or observation level). For each model, provide likelihood, R BUGS code needed implementation. We also establish clear terminology guidance help choosing appropriate design approach.

Language: Английский

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