Anthropogenic perturbation modifies interactions between mammals and fruits in a tropical forest of southern Mexico

2021 ◽  
Vol 71 (3) ◽  
pp. 311-327
Author(s):  
Mayra Zamora-Espinoza ◽  
Juan Carlos López-Acosta ◽  
Eduardo Mendoza

Abstract Studies of tropical mammal defaunation highlight the loss of species as well as their reduction in abundance and diversity; however, there is a complex series of effects associated with this anthropogenic disruption, including increases in the relative abundance of disturbance-tolerant mammals and the arrival of alien mammals whose effects on biotic interactions have been poorly studied. We compared the species richness, composition, interaction strength, and patterns of daily activity of mammals that consume the fruits of Pouteria sapota on the forest floor, both inside and outside of the Los Tuxtlas Field Station (LTFS) in Veracruz, southern Mexico. Using camera traps, we recorded eight mammal species interacting with the fruits inside the LTFS ( trees) and nine species interacting outside ( trees). Alien species such as Canis lupus familiaris were recorded both inside and outside of the LTFS, whereas Bos taurus was only recorded outside. Medium-sized generalist mammals were overrepresented both inside and outside of the LTFS, evidencing an impoverishment of the fauna, when compared to the mammal assemblage reported to interact with P. sapota fruits in a more intact forest. The daily activity patterns of the mammals that interacted strongly with P. sapota fruits were different inside and outside the LTFS, particularly in the case of Cuniculus paca. Our results show that the impact of human activity is highly pervasive, directly affecting the mammalian fauna at different levels and indirectly affecting the biotic interactions in which these animals are involved.

Author(s):  
C. M. Delgado-Martínez ◽  
E. Mendoza

Habitat loss and hunting are important drivers of mammal defaunation, affecting not only species presence but also their ecological roles. Frugivory is a key biotic interaction in the tropics due to its wide representation among mammals and its effects on forest dynamics. We assessed how human disturbance affects interactions between mammalian frugivores and Attalea butyracea fruit deposited on the forest floor by comparing visits to palms at two sites with contrasting levels of human disturbance (non–disturbed vs. disturbed sites) in the Lacandon rainforest in southern Mexico. Using camera traps, we recorded mammal species interacting with fruit and estimated their interaction strength. The frugivore ensemble was richer in the non–disturbed forest (nine species) than in the disturbed forest (four species), which lacked the largest body–sized mammals. Large–bodied mammals showed a stronger interaction with fruit in terms of the frequency and length of their visits. Our study highlights the need to undertake conservation actions not only to ensure that the species are maintained in disturbed forests but also to ensure that their biotic interactions remain unchanged.


2015 ◽  
Vol 15 (4) ◽  
Author(s):  
Leonardo de Paula Gomes ◽  
Clarisse Rezende Rocha ◽  
Reuber Albuquerque Brandão ◽  
Jader Marinho-Filho

At least 251 mammal species are recorded for the Brazilan cerrado, which, therefore, is the third richest Brazilian biome. Most mammal surveys in Brazilian cerrado result from studies performed opportunistically and in short time periods. The aims of the present study were (1) provide a checklist for the mammalian fauna based on a five-year sampling in Serra do Facão region, Southeastern Goiás state; (2) compare small non-flying mammals diversity in open and forest areas and (3) compare species diversity before and after the flood caused by a hydroelectric reservoir filling. The data was gathered in 19 sampling periods, from May 2008 to September 2013. We sampled open and forest habitats and captured non-flying small mammals with Sherman and Tomahawk live traps and pitfalls; bats were sampled with mist-nets; large mammals were recorded with camera traps, and by direct observations and track surveys in field. We found 20 species of small non-flying mammals, 10 species of bats and 33 species of larger mammals. Species diversity was greater for forest than open habitats, and was also greater before than after the complete reservoir filling. About 10% of the recorded species are included in the Brazilian official list of threatened species. The total richness represents 25% of all cerrado mammal fauna, highlighting the importance of this area for regional mammal fauna conservation.


Paleobiology ◽  
1991 ◽  
Vol 17 (3) ◽  
pp. 266-280 ◽  
Author(s):  
S. David Webb

When the isthmian land bridge triggered the Great American Interchange, a large majority of land-mammal families crossed reciprocally between North and South America at about 2.5 Ma (i.e., Late Pliocene). Initially land-mammal dynamics proceeded as predicted by equilibrium theory, with roughly equal reciprocal mingling on both continents. Also as predicted, the impact of the interchange faded in North America after about 1 m.y. In South America, contrary to such predictions, the interchange became decidedly unbalanced: during the Pleistocene, groups of North American origin continued to diversify at exponential rates. Whereas only about 10% of North American genera are derived from southern immigrants, more than half of the modern mammalian fauna of South America, measured at the generic level, stems from northern immigrants. In addition, extinctions more severely decimated interchange taxa in North America, where six families were lost, than in South America, where only two immigrant families became extinct.This paper presents a two-phase ecogeographic model to explain the asymmetrical results of the land-mammal interchange. During the humid interglacial phase, the tropics were dominated by rain forests, and the principal biotic movement was from Amazonia to Central America and southern Mexico. During the more arid glacial phase, savanna habitats extended broadly right through tropical latitudes. Because the source area in the temperate north was six times as large as that in the south, immigrants from the north outnumbered those from the south. One prediction of this hypothesis is that immigrants from the north generally should reach higher latitudes in South America than the opposing contingent of land-mammal taxa in North America. Another prediction is that successful interchange families from the north should experience much of their phylogenetic diversification in low latitudes of North America before the interchange. Insofar as these predictions can be tested, they appear to be upheld.


2020 ◽  
Vol 101 (3) ◽  
pp. 697-709 ◽  
Author(s):  
Paula Akkawi ◽  
Nacho Villar ◽  
Calebe P Mendes ◽  
Mauro Galetti

Abstract In tropical forests, the diets of many frugivorous mammals overlap, yet how hyper-diverse assemblages of consumers exploit resources and coexist remains poorly understood. We evaluated competitive interactions among three species of terrestrial frugivorous mammals, the ungulate Tayassu pecari (white-lipped peccary), its close relative Pecari tajacu (collared peccary), and a large rodent (Dasyprocta azarae, agouti), in their exploitation strategies of palm resources of different quality. We conducted the study in a large isolated fragment at the tropical Atlantic Forest of Brazil, where these mammal species show high spatial and temporal overlap. We evaluated if body mass and foraging group size define a hierarchy in exploitation of preferentially richer palm resources. We used camera traps and two-species occupancy models to examine patterns of co-occurrence and variable interaction strength between these consumers and three species of palms. Our analyses supported the hypothesis of partial resource overlap but no competition among frugivores, and a body mass dominance hierarchical exploitation of resources. The larger frugivore (white-lipped peccary) dominated patches of the lipid-rich palm Euterpe edulis, where the smallest frugivore (agouti) was absent. Instead, the smallest frugivore concentrated its foraging in areas with the poorest palm resource, Syagrus oleracea. Collared peccaries preferred areas of high abundance of Syagrus romanzoffiana when the other two mammal species were rarely detected or absent, strongly avoided patches of E. edulis, and showed higher average detection probabilities when agoutis were present. Our study highlights the important role of behavioral plasticity in promoting coexistence and indicates that through context-dependent interactions and hierarchical partitioning of resources, consumers can avoid strong competition, even under conditions of high spatial and temporal overlap and high levels of habitat fragmentation and isolation.


2008 ◽  
Vol 68 (4) ◽  
pp. 771-779 ◽  
Author(s):  
AC. Srbek-Araujo ◽  
AG. Chiarello

Presence of exotic species in forest remnants is a major concern for the conservation of wild species, not only on islands, where potential impact is higher. Although the problem is widespread and increasing, there are few studies on Neotropical forests. Here we quantify the occurrence of domestic dogs (Canis lupus familiaris) in an Atlantic forest reserve in south-eastern Brazil (Santa Lúcia Biological Station - SLBS). Throughout two years of monitoring with camera traps (2,142 camera-days), 25 records of 16 individual dogs were obtained in the interior of SLBS, making dogs the fourth most frequently recorded species of mammals in general and the first-ranking among Carnivora, ahead of the ocelot and puma, the top two terrestrial predators present in SLBS. Dogs entered the forest year round, in almost half of the sampled months (48%), and predominantly during daytime (89%). They were detected in various trails inside the reserve, but mostly in areas nearest to the reserve's border (<200 m from the edge). Record rates of domestic dogs did not correlate significantly with climate variables, with frequency of mammal records and richness in general, or with any particular mammal species (Spearman rank correlation, p > 0.05 in all cases), suggesting an erratic, non-seasonal pattern of entrance in the reserve. Data indicate that domestic dogs can be abundant and frequent visitors to little disturbed Atlantic forest reserves even when these are located in regions of low density of human population. The potential impact to native fauna is discussed.


2020 ◽  
Vol 8 ◽  
Author(s):  
Lucas Lamelas-Lopez ◽  
Xose Pardavila ◽  
Isabel Amorim ◽  
Paulo Borges

The present publication provides a dataset from five camera-trapping sampling campaigns on two islands of the Azorean archipelago (Pico and Terceira islands), between 2013-2018. This dataset was obtained as a by-product of campaigns designed for different purposes. The sampling campaigns were designed to: (i) study the ecology of introduced mammals; (ii) assess the impact of introduced mammals on native birds (Azores woodpigeon - Columba palumbus azorica and Cory's shearwater - Calonectris diomeda borealis), through nest predation; and (iii) obtain information about the impact of vertebrates on agricultural systems, particularly on Azorean traditional vineyards. A total of 258 sites and 47 nests were sampled using camera traps. These sampling campaigns provided a large data series that allowed the creation of a vertebrate wildlife inventory. We obtained a total of 102,095 camera-trap records, which allowed us to to identify 30 species of vertebrates: one amphibian, one reptile, 17 birds and ten mammal species. This represented 100% of the amphibians and terrestrial mammals, 58% of the breeding birds and 50% of the reptile species known for Pico and/or Terceira islands. Concerning the colonisation status of the species, we recorded 15 indigenous (native non-endemic or endemic) and three introduced bird species; all known terrestrial amphibians, reptiles and mammals in the Azores are introduced species. The data collected contribute to increasing knowledge on the distribution of vertebrate species on Pico and Terceira islands, where most existing records of some species were only available to Island level (e.g. mustelids and hedgehogs). None of the identified species was previously unknown to the study area.


2016 ◽  
Vol 16 (2) ◽  
Author(s):  
Roberta Montanheiro Paolino ◽  
Natalia Fraguas Versiani ◽  
Nielson Pasqualotto ◽  
Thiago Ferreira Rodrigues ◽  
Victor Gasperotto Krepschi ◽  
...  

Habitat loss and degradation is threatening mammals worldwide. Therefore, Protected Areas (PA) are of utmost importance to preserve biodiversity. Their effectiveness, however, depends on some management strategies such as buffer zones, which prevent/mitigate the impact of external threats and might increase the amount of available habitat for wildlife existing within reserves. Nevertheless, how intensively terrestrial mammals use buffer zones remains little studied, particularly in the Neotropical region. Aiming to analyse the use of a buffer zone (5 km wide) by medium and large-sized mammals, we modelled the occupancy probabilities of five species of conservation concern including local (interior and buffer zone) as a site covariate, simultaneously controlling for imperfect detection. Data collection was made with camera traps from April to September 2013 in a 9000 ha Cerrado PA (“interior”) and in its surrounding area (39721.41 ha; “buffer zone”). This PA (Jataí Ecological Station) is immersed in a landscape where sugarcane plantations predominate in the northeastern of the state of São Paulo. We also conducted an inventory to compare the number and composition of species between interior and buffer zone. A total of 31 mammal species (26 natives) was recorded via camera traps and active search for sightings, vocalizations, tracks and signs. Occupancy estimates for Myrmecophaga tridactyla, Leopardus pardalis and Pecari tajacu were numerically higher in interior. On the other hand, Chrysocyon brachyurus had the highest occupancy in buffer zone, while the largest predator, Puma concolor, used both areas similarly. However, as the confidence intervals (95%) overlapped, the differences in occupancy probabilities between interior and buffer were weak for all these species. Additionally, regarding only the species recorded by cameras, the observed and estimated richness were similar between interior and buffer zone of the PA. Our data demonstrated that the buffer zone is indeed used by medium and large-sized mammals, including conservation-dependent ones. The lack of enforcement of current legislation regarding buffer zones is therefore a real threat for mammals, even when protection is guaranteed in the interior of protected areas.


2020 ◽  
Vol 12 (17) ◽  
pp. 17330-17339
Author(s):  
J.H. Zothanpuii ◽  
Sushanto Gouda ◽  
Abinash Parida ◽  
G.S. Solanki

Fragmented forests often have conservation value, serving as a refuge or corridors for small mammalian species.  In the study, the diversity of mammals was studied within Mizoram University (MZU) campus.  Forty-eight plant species from 25 families were recorded on different sites.  Thirty quadrates were nested at the locations of occurrence of mammalian species for vegetation type analysis.  Schima wallichi was the most dominant plant species with the highest IVI values of (31.7%), followed by Aporosa octandra (22.93%) and Castanopsis tribuloide (21.17%).  Camera trap method was used to collect information about the mammalian diversity in the campus.  The mammalian species recorded in this study makes 15% of mammalian fauna of the state of Mizoram.  Twelve mammal species and six bird species were recorded by the camera traps.  With proper awareness among residents of the campus and a planned approach for developmental activities, the findings of our study can make an important extension for the coexistence of mammalian species and long term survivability within MZU campus.


Mammalia ◽  
2017 ◽  
Vol 81 (2) ◽  
Author(s):  
Wellington Hannibal ◽  
Mauricio Neves Godoi ◽  
Walfrido Moraes Tomas ◽  
Grasiela Porfirio ◽  
Vanda Lúcia Ferreira ◽  
...  

AbstractThe distributional data of mammalian fauna are important to reach a comprehensive overview of biogeographic patterns and to highlight regional conservation status, especially in a poorly known region such as the Chiquitano dry forest in western Brazil. Our aims were to survey the mammal species occurring in the Urucum Mountains, located in the southeast end of the Chiquitano forest, compare its species composition to areas elsewhere in different ecoregions, and discuss their conservation statuses. Small mammals were sampled using pitfall and live traps, and medium and large mammals were sampled by direct observation, indirect evidence (e.g. faeces and tracks), and camera traps. Patterns of species composition were compared to other surrounding areas of different ecoregions in South America using multivariate analyses. The results indicated that both faunas have similar biogeographical influences. The Urucum Mountains have an influence on the faunas from the Cerrado, Chaco and Pantanal ecoregions, and only secondarily from forested ecoregions (e.g. Amazon forest). The Urucum harbours a rich non-volant mammalian fauna with species that are widely and restrictedly distributed. The conservation of Urucum Mountains is important because these mountains harbour threatened plant, invertebrate, and vertebrate (mammals) species, which could be suffering due to the mining activity carried out in the region. We stress that the Chiquitano dry forest is unique to western Brazil, situated in a complex biogeographical region, and harbouring a rich and diversified mammal fauna.


2004 ◽  
Vol 359 (1442) ◽  
pp. 221-241 ◽  
Author(s):  
Adrian M. Lister

The Quaternary was a time of extensive evolution among mammals. Most living species arose at this time, and many of them show adaptations to peculiarly Quaternary environments. The latter include continental northern steppe and tundra, and the formation of lakes and offshore islands. Although some species evolved fixed adaptations to specialist habitats, others developed flexible adaptations enabling them to inhabit broad niches and to survive major environmental changes. Adaptation to short–term (migratory and seasonal) habitat change probably played a part in pre–adapting mammal species to the longer–term cyclical changes of the Quaternary. Fossil evidence indicates that environmental changes of the order of thousands of years have been sufficient to produce subspeciation, but speciation has typically required one hundred thousand to a few hundred thousand years, although there are both shorter and longer exceptions. The persistence of taxa in environments imposing strong selective regimes may have been important in forcing major adaptive change. Individual Milankovitch cycles are not necessarily implicated in this process, but nor did they generally inhibit evolutionary change among mammals: many evolutionary divergences built over multiple climatic cycles. Deduction of speciation timing requires input from fossils and modern phenotypic and breeding data, to complement and constrain mitochondrial DNA coalescence dates which appear commonly to overestimate taxic divergence dates and durations of speciation. Migrational and evolutionary responses to climate change are not mutually exclusive but, on the contrary, may be synergistic. Finally, preliminary analysis suggests that faunal turnover, including an important element of speciation, was elevated in the Quaternary compared with the Neogene, at least in some biomes. Macroevolutionary species selection or sorting has apparently resulted in a modern mammalian fauna enriched with fast–reproducing and/or adaptively generalist species.


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