Temporal patterns of visitation of birds and mammals at mineral licks in the Peruvian Amazon

Mineral licks are key ecological resources for many species of birds and mammals in Amazonia, providing essential dietary nutrients and clays, yet little is known about which species visit and their behaviors at the mineral licks. Studying visitation and behavior at mineral licks can provide insight into the lives of otherwise secretive and elusive species. We assessed which species visited mineral licks, when they visited, and whether visits and the probability of recording groups at mineral licks were seasonal or related to the lunar cycle. We camera trapped at 52 mineral licks in the northeastern Peruvian Amazon and detected 20 mammal and 13 bird species over 6,255 camera nights. Generalized linear models assessed visitation patterns and records of groups in association with seasonality and the lunar cycle. We report nocturnal curassows (Nothocrax urumutum) visiting mineral licks for the first time. We found seasonal trends in visitation for the black agouti (Dasyprocta fuliginosa), red howler monkey (Alouatta seniculus), blue‐throated piping guan (Pipile cumanensis), red brocket deer (Mazama americana), collared peccary (Pecari tajacu), and tapir (Tapirus terrestris). Lunar trends in visitation occurred for the paca (Cuniculus paca), Brazilian porcupine (Coendou prehensilis), and red brocket deer. The probability of recording groups (>1 individual) at mineral licks was seasonal and related to lunar brightness for tapir. Overall, our results provide important context for how elusive species of birds and mammals interact with these key ecological resources on a landscape scale. The ecological importance of mineral licks for these species can provide context to seasonal changes in species occupancy and movement.

Many species of animals in the Amazon visit mineral licks, consuming soil to supplement their diet. Using camera trap data, we show that visits to mineral licks are seasonal for many species. These trends in visitation are likely due to species‐specific factors such as reproduction, predator avoidance, seasonal diet shifts, and resource use.     

Patterns of mineral lick visitation by spider monkeys and howler monkeys in Amazonia: are licks perceived as risky areas?

Mineral licks--also known as "salados," "saladeros," or "collpas"--are specific sites in tropical and temperate ecosystems where a large diversity of mammals and birds come regularly to feed on soil. Although the reasons for vertebrate geophagy are not completely understood, animals are argued to obtain a variety of nutritional and health benefits from the ingestion of soil at mineral licks. We studied the temporal patterns of mineral lick use by white-bellied spider monkey (Ateles belzebuth) and red howler monkey (Alouatta seniculus) in a lowland rain forest in Amazonian Ecuador. Using camera and video traps at four different mineral licks, combined with behavioral follows of one group of spider monkeys, we documented rates of mineral lick visitation by both primate species and the relative frequency and intensity of mineral lick use by spider monkeys. On the basis of 1,612 days and 888 nights of mineral lick monitoring, we found that A. belzebuth and A. seniculus both visit mineral licks frequently throughout the year (on average ～14% of days for both species), and mineral lick visitation was influenced by short-term environmental conditions (e.g. sunny and dry weather). For spider monkeys, the area surrounding the lick was also the most frequently and most intensively used region within the group's home range. The fact that spider monkeys spent long periods at the lick area before coming to the ground to obtain soil, and the fact that both species visited the lick preferentially during dry sunny conditions (when predator detectability is presumed to be relatively high) and visited simultaneously more often than expected by chance, together suggest that licks are indeed perceived as risky areas by these primates. We suggest that howler and spider monkeys employ behavioral strategies aimed at minimizing the probability of predation while visiting the forest floor at risky mineral lick sites.     

Elemental analysis of mineral lick soils from the Serengeti National Park, the Konza Prairie and Yellowstone National Park

We analyzed mineral lick soils and non-mineral lick soils from the Serengeti National Park, the Konza Praine, and Yellowstone National Park The concentrations of 14 different elements considered important for ungulate nutrition were analyzed to determine the relative importance of Na vs other elements in attracting animals to lick areas Only Na was consistently higher in the mineral lick soils of the three ecosystems Mean Na concentrations were c 20x greater in Serengeti licks, 10x greater in Konza licks and 3x greater in Yellowstone licks compared to the respective non-lick soils Despite the numerous elements analyzed for this survey, our results suggest that Na is the primary element initiates mineral lick use in these widely separated ecosystems The widespread distribution of Na-deficient forage likely explains the importance of Na in most mineral licks     

Mineral licks as a sodium source for Isle Royale moose

Summary Natural mineral licks and their use by moose (Alces alces) on Isle Royale National Park, Michigan, were studied during 1982–85. The distribution of known licks suggested that they occurred in association with glacial debris, primarily in the western portions of the island. Moose utilized mineral springs extensively during the spring-summer period, and at least 5 licks were used year-round. During summer, a pronounced diel pattern of moose visitation was apparent, with peak use occurring between 0400–0800 h. Although daytime lick use declined by late June, morning and evening use continued to be relatively high throughout the study period. Peak lick use coincided with leaf-emergence in spring. Moose continued to utilize mineral licks despite the availability of ponds containing aquatic plants. Sodium appeared to be the element attracting moose to licks where they ingest copious amounts of water. Observed sodium ingestion rates (0.35 g/min) at licks indicate that licks provide a more concentrated source of sodium compared to aquatic plants (0.023 g/min). Based on the data presented, we reject the conclusions of earlier workers that aquatic plants constitute the only significant source of sodium for Isle Royale moose.     

Salt licks do not increase local densities of the deer ked,Lipoptena cervi,an abundant ectoparasite of cervids

The deer ked, Lipoptena cervi (Diptera: Hippoboscidae), is a common ectoparasite of the moose, Alces alces (Artiodactyla: Cervidae). Salt licks are widely used to manipulate moose movements to prevent damage to saplings and traffic accidents. They may cause moose to gather in small areas, which could create aggregates of deer ked pupae as the parasite is a short‐distance flyer and its dispersion depends on its hosts. We investigated whether the population density of flying deer keds could be influenced by manipulating salt licks and how environmental variables affect parasite density. Densities were estimated in 40 experimental sites with four treatments (no salt licks, introduced salt licks, removed salt licks, permanent salt licks) in September during 2007–2010. Forest edges, mixed forests on mineral soil and coniferous forests on peat soil were the habitats with high numbers of parasites. The manipulation of salt licks seemed to be ineffective in reducing the density of deer keds as the only factor to show statistical significance with parasite numbers in the mixed‐model analysis was year of determination. Annual deer ked densities correlated with the abundance of moose in the region. Moreover, high spring and summer temperatures seemed to increase the numbers of flying imagos.     

SOME ASPECTS OF BIG-GAME UTILIZATION OF MINERAL LICKS IN YANKARI GAME RESERVE, NIGERIA

At least ten major mineral licks occur along the Gaji River which bisects the Yankari Game Reserve. The licks show varying degrees of utilization and have craters of up to 1200m³ in volume. Three hundred and eighty five hours of observation were kept at one of the licks. Its use by different species was highly variable. Some species occurring in the reserve made no visits to the lick, whereas Western hartebeest (51 groups), waterbuck (53 groups) and warthog (276 groups) made frequent visits. Lick use was much greater in the daytime than at night, with the peak occurring around 1400 h. A limited number of soil samples (29) were analysed but no single element can be considered as the factor attracting wildlife. However, the lick areas were richer in most minerals than were samples of soil from drier habitat in the open woodland. It is possible that significantly increased lick use might in the future indicate degrading environmental conditions in the drier parts of the reserve. If hides are constructed, the commonly utilized licks will provide excellent opportunities for behaviour observatioii and photography by tourists.     

Use of Mineral Licks by White-Bellied Spider Monkeys (<Emphasis Type="BoldItalic">Ateles belzebuth</Emphasis>) and Red Howler Monkeys (<Emphasis Type="BoldItalic">Alouatta seniculus</Emphasis>) in Eastern Ecuador

Geophagy occurs in all primate groups and is particularly common in species that consume greater quantities of plant material, i.e., leaves, fruit. The function of geophagy is not fully understood and likely varies over space and time, perhaps in connection with changes in diet. Central to a better understanding of geophagy in primate ecology is knowledge of the occurrence of such behavior among different species and seasons. We used camera traps triggered by heat and motion to document the use of mineral licks by primates over a 3-yr period at a lowland forest site in eastern Ecuador (Tiputini Biodiversity Station). Such mineral licks can be important sources of minerals, nutrients, and other compounds for a wide range of species in Amazonian forests. Although 10 species of primates are known from the study site, we obtained photographs of only 2 species, Ateles belzebuth (white-bellied spider monkey) and Alouatta seniculus (red howler) at 2 of 4 saladeros surveyed. From late December 2004 through early January 2008, we recorded 192 photographs with a total of 318 Ateles belzebuth representing ≥66 separate visits. Comparable numbers for Alouatta seniculus were 80, 121, and 37. We recorded both species visiting a mineral lick at the same time on ≥7 occasions. Use of mineral licks varied across months; we recorded more visits from November through February, the drier period at Tiputini. Visits also varied by hour, with no visits before 0830 or after 1630; Ateles belzebuth showed a stronger mid-day peak in visits. Average visit length (calculated as the time between the first and last photographs of a given visit) was similar between the 2 species but median visit length was more than twice as long for Ateles belzebuth (15 min) as for Alouatta seniculus (6 min). Results indicate that mineral licks are important in the ecology of these species, but further studies are needed to determine the precise benefit(s) obtained and how benefits may vary with diet and other factors.     

Geophagy in brown spider monkeys (Ateles hybridus) in a lowland tropical rainforest in Colombia

Spider monkeys and howler monkeys are the only Neotropical primates that eat soil from mineral licks. Not all species within these genera visit mineral licks, and geophagy has been restricted to populations of Ateles belzebuth belzebuth,Ateles belzebuth chamek and Alouatta seniculus in western Amazonian rainforests. With the aid of a camera trap we studied the visitation patterns of a group of brown spider monkeys (Ateles hybridus) to a mineral lick at Serrania de Las Quinchas, in Colombia. Spider monkeys visited the lick frequently throughout the year, with a monthly average of 21.7 ± 7.2 visits per 100 days of camera trapping (n = 14 months). Spider monkeys visited the mineral lick almost always on days with no rain, or very little (<3 mm) rain, suggesting that proximate environmental variables might determine spider monkeys' decisions to come to the ground at the licks. This study expands the geographical occurrence of mineral lick use by spider monkeys providing additional data for future assessments on the biogeographical correlates of mineral lick use by platyrrhines.     

Historical dynamics of Batrachochytrium dendrobatidis in Amazonia

The Amazon forest is known for its astonishing amphibian diversity, yet the potential distribution and underlying impacts of the most important amphibian pathogen is unknown for most of Amazonia. In this retrospective survey of preserved Leptodactylus frogs, collected over a 119 yr period, we used quantitative PCR to detect the fungal pathogen Batrachochytrium dendrobatidis (Bd) and performed spatial scan analyses to identify spatiotemporal clusters of Bd. We also quantified the potential effect of environmental factors on the likelihood of Bd occurrence and generated an updated suitability map for Bd in the Amazon that included our retrospective sampling. We detected Bd in lowland Amazon as early as 1935, in the state of Pará, Brazil, and we found low prevalence (～ 3.8%) over time. We identified two statistically significant spatiotemporal clusters of Bd: a recent and narrow cluster in the Amazon River delta and a spatiotemporally broad cluster in the southern edge of Amazon and Brazilian savanna. Furthermore, we found an increase in Bd‐positive samples in the southwestern Amazon after the 1990s, coinciding with reported amphibian declines in neighboring high elevation sites on Andean slopes of Peru. Spatial regressions indicated that higher human interference, higher precipitation, and lower temperatures were significant predictors of Bd occurrence. Environmental niche modeling predicted some narrow areas of suitable climates along the Amazon's periphery and generally low climatic suitability for Bd in the central Amazon; although, we found clusters of Bd‐positive samples with unexpectedly high infection loads in areas of predicted low suitability. Our study indicates that accelerated human development may put Amazonian amphibians at risk from Bd introductions, and it highlights the potential need to monitor Bd dynamics near Amazonian port cities.     

Endemism and conservation of Amazon palms

Endemicity is important for the delimitation of conservation areas. Endemic areas are those that contain two or more taxa with their distribution restricted to the area. The aim of this study was to detect endemic areas for palms in the Amazon region and to determine whether the species that define these endemic areas are protected within conservation units. Records of occurrence were extracted from the global biodiversity information facility (GBIF). The final dataset consisted of 17,310 records, for 177 species of Amazonian palms. For analysis we used parsimony analysis of endemicity (PAE) and NDM-VNDM program, and grid square size of 1° and 3° as operational geographic units (OGUs). The distribution of endemic species was superimposed on occurrence of the conservation units (CUs). PAE did not show endemic areas in grid squares of 1°, but found 10 palm endemic areas in grid squares of 3° in the western Amazon and Andean sub-region. However, the NDM-VNDM program identified an endemic area in grid squares of 1° located at the eastern Guiana with endemicity score = 2.9, and in grid squares of 3° it identified seven consensus areas with endemicity score > 6.0, all in the western Amazon. The combination of PAE and NDM-VNDM analyses resulted in eight endemic palm areas in the combined western Amazon and Andean sub-region. Of the species that define the endemic areas, five are threatened with extinction in one of three IUCN categories (EN, VU, NT), and they are not protected in any conservation units. The western Amazon, besides having high palm richness, also has palm endemic areas, especially, near the Andean sub-region and the Peruvian Amazon.     

Parrots consume sodium‐rich palms in the sodium‐deprived landscape of the Western Amazon Basin

Herbivorous animals face shortages of different minerals in different geographic areas. In the Amazon Basin, sodium is often limiting, driving herbivores to seek supplemental sources. In the lowlands of the western Amazon Basin, parrots commonly consume sodium‐rich soils at clay licks but lick use varies widely among species, and to date, parrots in the region have not been reported consuming other supplemental sodium sources. We document 11 species of psittacines consuming sodium‐rich leaves and trunks of Attalea butyracea palms growing on sodium‐rich soils in lowland Peru. Consumed palms had more sodium and less potassium than uneaten A. butyracea palms and other palm species in the area. Among A. butyracea palm parts, sodium and Na:K ratios were highest in trunks (consumed by parrots in 94% of the 387 foraging bouts recorded) and lowest in leaves (consumed in only 14% of foraging bouts). The low potassium and high Na:K ratio suggest that birds may be seeking not just any sodium sources, but those low in potassium, as potassium is known to exacerbate dietary sodium shortages. Use of the palms and species’ abundance in the study area were not correlated. Instead, parrot species that consumed palms the most were those that use relatively few traditional soil clay licks. This finding suggests that parrot species in the region have fundamental differences in preferred strategies for obtaining supplemental sodium and may help explain documented interspecific differences in geophagy.     

The application of non-invasive genetic tagging reveals new insights into the clay lick use by macaws in the Peruvian Amazon

Genetic tagging, the unique identification of individuals by their DNA profile, has proven to be an effective method for research on several animal species. In this study we apply non-invasive genetic tagging from feather samples to reveal the genetic structure and estimate local population size of red-and-green macaws (Ara chloropterus) without the need to capture these animals. The study was centered in the Tambopata region of the Peruvian Amazon. Here macaws frequently visit clay licks and their naturally molted feathers provide a unique source of non-invasively sampled DNA. We analyzed 249 feathers using nine microsatellite loci and identified 221 unique genotypes. The remainder revealed 21 individuals which were ‘recaptured’ one or more times. Using a capture-mark-recapture model the average number of different individuals visiting clay licks within one breeding season was estimated to fall between 84 and 316 individuals per clay lick. Analysis of population genetic structure revealed only small genetic differences among regions and clay licks, suggesting a single red-and-green macaw genetic population. Our study confirms the utility of non-invasive genetic tagging in harsh tropical environment to obtain crucial population parameters about an abundant parrot species that is very difficult to capture in the wild.     

Nutrition or detoxification: why bats visit mineral licks of the Amazonian rainforest

Many animals in the tropics of Africa, Asia and South America regularly visit so-called salt or mineral licks to consume clay or drink clay-saturated water. Whether this behavior is used to supplement diets with locally limited nutrients or to buffer the effects of toxic secondary plant compounds remains unclear. In the Amazonian rainforest, pregnant and lactating bats are frequently observed and captured at mineral licks. We measured the nitrogen isotope ratio in wing tissue of omnivorous short-tailed fruit bats, Carollia perspicillata, and in an obligate fruit-eating bat, Artibeus obscurus, captured at mineral licks and at control sites in the rainforest. Carollia perspicillata with a plant-dominated diet were more often captured at mineral licks than individuals with an insect-dominated diet, although insects were more mineral depleted than fruits. In contrast, nitrogen isotope ratios of A. obscurus did not differ between individuals captured at mineral lick versus control sites. We conclude that pregnant and lactating fruit-eating bats do not visit mineral licks principally for minerals, but instead to buffer the effects of secondary plant compounds that they ingest in large quantities during periods of high energy demand. These findings have potential implications for the role of mineral licks for mammals in general, including humans.     

Some aspects of geophagia in Wyoming bighorn sheep (<Emphasis Type="Italic">Ovis canadensis</Emphasis>)

Geophagia has been commonly reported for bighorn sheep (Ovis canadensis) and other ungulates worldwide. The phenomenon is often attributed to the need to supplement animal diets with minerals available in the soil at mineral lick locations. Sodium is the mineral most frequently cited as being the specific component sought, although this has not been found universally. In this study area, bighorn sheep left normal summer-range to make bimonthly 26-km, 2,000-m-elevation round-trip migrations, the apparent purpose of which was to visit mineral licks on normal winter-range. Lick soil and normal summer-range soil were sampled for their available mineral content and summer-range forage was sampled for total mineral content, and comparisons were made to determine the specific components sought at the lick by bighorn sheep consuming soil. It was concluded that bighorn sheep were attracted to the lick by a desire for sodium but that geophagia also supplemented a diet deficient in the trace element selenium. Where sheep are denied access to licks, populations may be limited by mineral deficiency.     

Influence of clay licks on the diversity and structure of an Amazonian forest

The spatial heterogeneity of resource availability is a major driver of biodiversity patterns. Some environmental conditions and resources are characterized by large‐scale patterns of variation within the landscape. Clumped local discontinuities or discrete elements also increase spatial heterogeneity, promoting local ‘biodiversity hot spots’ by modifying habitat characteristics and promoting plant–animal interactions. Clay licks are faunal attractors owing to their role in the nutritional ecology of the user species; nevertheless, the effect of their presence on the surrounding vegetation has been poorly quantified. Here, we use data from 100 × 10 m transects and evaluate the effects of the presence of clay licks on forest diversity and structure at local and landscape scales. In clay lick areas, there was a higher abundance of certain species, which helps to homogenize species composition between localities counteracting the natural distance‐decay of compositional similarity between transects without clay lick influence (controls). Compared to control sites, clay lick′s forests had higher palm densities, shorter but more variable individuals in the canopy and understory, a thinner canopy layer, and denser herbaceous and ground level covers. These differences were found along the whole length of transects in both sampled areas types. These results reveal that the presence of discrete elements (i.e., clay licks) may help to explain the compositional and structural heterogeneity of Amazonian forests influencing ecological processes such as seed dispersal and trampling. These considerations may be relevant for other biomes where clay licks are present and give weight to their inclusion in conservation initiatives in tropical forests.     

Multiple facets of biodiversity are threatened by mining-induced land-use change in the Brazilian Amazon

Aim

Mining is increasingly pressuring areas of critical importance for biodiversity conservation, such as the Brazilian Amazon. Biodiversity data are limited in the tropics, restricting the scope for risks to be appropriately estimated before mineral licensing decisions are made. As the distributions and range sizes of other taxa differ markedly from those of vertebrates—the common proxy for analysis of risk to biodiversity from mining—whether mining threatens lesser-studied taxonomic groups differentially at a regional scale is unclear.

Location

Brazilian Amazon.

Methods

We assess risks to several facets of biodiversity from industrial mining by comparing mining areas (within 70 km of an active mining lease) and areas unaffected by mining, employing species richness, species endemism, phylogenetic diversity and phylogenetic endemism metrics calculated for angiosperms, arthropods and vertebrates.

Results

Mining areas contained higher densities of species occurrence records than the unaffected landscape, and we accounted for this sampling bias in our analyses. None of the four biodiversity metrics differed between mining and nonmining areas for vertebrates. For arthropods, species endemism was greater in mined areas. Mined areas also had greater angiosperm species richness, phylogenetic diversity and phylogenetic endemism, although less species endemism than unmined areas.

Main Conclusions

Unlike for vertebrates, facets of angiosperm and arthropod diversity are relatively higher in areas of mining activity, underscoring the need to consider multiple taxonomic groups and biodiversity facets when assessing risk and evaluating management options for mining threats. Particularly concerning is the proximity of mining to areas supporting deep evolutionary history, which may be impossible to recover or replace. As pressures to expand mining in the Amazon grow, impact assessments with broader taxonomic reach and metric focus will be vital to conserving biodiversity in mining regions.     

Lust for Salt in the Western Amazon

Although the use of mineral licks by diverse Amazonian birds and mammals is well‐known, the ultimate motivation for such behavior remains unclear. As aerosol deposition of salts declines with distance from oceanic sources, lick visitation in the western Amazon can be explained by demand for sodium, given the low concentration of this micronutrient in the plant tissues consumed by these taxa. Sodium limitation also influences ant foraging behavior, and impinges on ecosystem rates of carbon cycling. The biogeographical context of sodium availability has been largely overlooked, but has substantial pantropical implications for herbivore and decomposer performance in inland rain forests. Abstract in Spanish is available in the online version of this article.     

Feeding ecology of a large social antelope in the rainforest

We studied the feeding ecology of the bongo (Tragelaphus eurycerus) in the Dzanga National Park in the rainforest of the Central African Republic to understand better the trade-off between food selectivity, ranging behaviour and social organization of a large, forest-dwelling, social antelope. Food plants and vegetation types were registered along a 311-km route travelled by bongos. Food availability was determined by identifying and counting the plants in 19 randomly chosen forest plots. Bongos showed pronounced selectivity for 26 out of 100 woody forest species. They predominantly consumed younger leaves, which suggests that high protein and low fibre content influence plant choice. In addition to leaves, bongos also ate fruits of two and flowers of one species. Furthermore, the diet was supplemented by grasses and herbs consumed on large natural licks. Such licks were regularly visited by the bongos. According to Jarman's ecological classification of antelopes, selective browsers are relatively small and live alone or in pairs to avoid competition over food. The bongo's large size and gregariousness should not allow it to survive in the rainforest as a pure selective browser. Our data suggest that the bongo relies on the opportunity to graze in bulk which it finds on the natural licks. We hypothesize that such licks either limit the distribution of bongos in other rainforest areas or allow larger group sizes than in areas without licks. Received: 8 June 1998 / Accepted: 30 November 1998     

Species distribution and conservation assessment of the black-headed night monkey (Aotus nigriceps): a species of Least Concern that faces widespread anthropogenic threats

Deforestation rates in the Brazilian Amazon have been steadily increasing since 2007. Recent government policy, the projected growth of agriculture, and the expansion of the cattle industry are expected to further pressure primates within the Amazon basin. In this study, we examined the anthropogenic impact on the widely distributed black-headed night monkey, Aotus nigriceps, whose distribution and population status have yet to be assessed. We (1) modeled potential species distribution in A. nigriceps, (2) estimated the impact of habitat loss on population trends, and (3) highlight landscape-based conservation actions that maximize the potential for their long-term sustainability. We found the black-headed night monkey to be restricted by several biotic and environmental factors including forest cover, isothermality, precipitation, temperature, and elevation. Over the last two decades, over 132,908 km² of tree cover (18%) has been lost within their currently recognized range based on satellite imagery. Based on a balance training omission, predicted area, and threshold values (BPTP), suitable habitat was only 67% (1,069,948 km²) of their hypothesized range, a loss of 16.5% from 2000, with just nearly a third of suitable habitat currently within protected areas. Over the last two decades, an estimated minimum 1.6 million individuals have been lost due to loss of suitable habitat. Projected deforestation rates equate to an additional loss of 94,458 km² of suitable habitat over the next decade. Although classified as a species of Least Concern, we suggest that A. nigriceps may likely be more at risk than previously described. The future impact of the continued expansion of monoculture crops, cattle ranching, and wildfires is still unknown. However, we outline several steps to ensure the long-term viability of this nocturnal primate and other sympatric species throughout the Amazon Basin.

     

Climatic and anthropogenic factors affect Ailanthus altissima invasion in a Mediterranean region

Ailanthus altissima is an aggressive invasive tree worldwide, but the ecological factors that lead to the spread of this species in Mediterranean ecosystems are still unclear. Here we aim to identify such factors, focusing on the interaction of human activity with climatic conditions. We determined the occurrence and abundance of Ailanthus in 240 sites and studied their relationship with 20 variables representing climatic, geographic, and topographic factors, as well as land use, in the region of Campania (southern Italy). Overall, we found that temperature and rainfall in Campania are suitable for Ailanthus, with the only major constraint being the temperature at an altitude exceeding 900 m a.s.l.. We found that Ailanthus is unable to spread where the mean annual temperature is lower than 11.1 °C. By contrast, precipitation variables showed poor correlation with Ailanthus distribution, suggesting that rainfall in the selected study sites is suitable to sustain the growth of this tree. About land use variables, roads were the primary landscape feature along which this species spread and invaded new areas. Roads probably combine high propagule pressure and favorable growing conditions in terms of available resources i.e., light, water, and mineral nutrients, that allow Ailanthus to establish and spread along roadside edges in different ecosystems. In conclusion, we found that climate and human-associated variables are correlated with the current occurrence of Ailanthus, with the temperature being more influential at high elevation sites and road distance playing a prominent role in low elevation areas.