Pasture Matrix Research Articles

Dung beetle (Coleoptera: Scarabaeinae) persistence in Amazonian forest fragments and adjacent pastures: biogeographic implications for alpha and beta diversity

The aim of this study is to analyze the effects of habitat loss and forest replacement by cattle pasture on the alpha and beta diversity, abundance, biomass and species composition of dung beetles with different dispersal ability. Dung beetles were captured in 19 forest fragments and neighbouring pastures. Forest fragment area ranged from 3.7 to 4825 ha and in this study were grouped into four categories: small, medium, large and control forest. A total of 35,048 dung beetles representing 101 species were collected. Forest fragments had the highest richness with 81 species, followed by pasture with 58 species. Replacement of forest by pasture reduced species richness; however, due to the proximity and connectivity of these areas with Cerrado patches, pastures also had high species richness, but species composition was independent of adjacent fragments. Small fragments had lower abundance and species richness than our other habitat categories, even pastures. Our results highlight that proximity and connectivity with Cerrado areas influenced the patterns of alpha and beta diversity of dung beetles in fragments and pastures. We highlight that the ability to cross the pasture matrix is a strong adaptive trait for species living in human-modified landscapes. Consequently, species with these abilities are less susceptible to the effects of forest fragmentation and local extinction. Our results reinforce the importance of considering the biogeographic location and distribution pattern of species in forest fragmentation studies.

Returning Home: Movement Strategies of Sub-Andean Birds in a Modified Landscape

We documented movement of a long-distant migrant (Swainson's Thrush Catharus ustulatus) and two understory resident species (Chestnut-capped Brush-finch Buarremon brunneinuchus and Streak-capped Treehunter Thripadectes virgaticeps) in a fragmented landscape dominated by a pasture matrix in a Sub-Andean region of central Colombia. Swainson's Thrush had no detectable difficulties traversing a pasture matrix and returning to the capture site. Chestnut-capped Brush-finch and Streak-capped Treehunter (understory resident species) avoided making lengthy flights and used stepping-stones and nearby corridors to ease their movement. Providing stepping stones such as live fences and isolated trees and maintaining corridors can enhance functional connectivity in regions with fragmented forests, aiding the conservation of bird species.

The relationship between pond habitat depth and functional tadpole diversity in an agricultural landscape.

One of the most important goals of biodiversity studies is to identify which characteristics of local habitats act as filters that determine the diversity of functional traits along environmental gradients. In this study, we investigated the relationship between the environmental variables of ponds and the functional trait diversity distribution of anuran tadpoles in an agricultural area in southeastern Brazil. Our results show that the functional trait diversity of frog tadpoles has a bell-curve-shaped relationship with the depths of ponds inserted in a pasture matrix. Because we are witnessing increasing human pressure on land use, simple acts (e.g. maintaining reproductive habitats with medium depth) can be the first steps towards preserving the diversity of Neotropical frog tadpole traits in agricultural landscapes.

Ensamblaje de Hormigas del Bosque Seco Tropical, Jardín Botánico de Cali

The ant assemblages of a fragment of secondary tropical dry forest located in the Botanical Garden of Cali are presented. Two habitats were chosen: a fragment of forest and a pasture matrix. Samples were taken monthly for six months, using a linear transect of 100 m, with 10 stations spaced 10 m. At each station pitfall traps, epigeal bait and arboreal, sifting and removal of 1 m 2 of litter and manual capture survey techniques were applied. Richness, abundance and diversity of ant habitats were determined. Correlation coefficients and regression between temperature, relative humidity and richness of ants were calculated. A total of 13 170 ants representing 55 species, 35 genera and six subfamilies were collected. The forest had the highest species richness with 90.9%. This wealth of diversity indicates the conservation value of the Valle del Cauca myrmecofauna. Although the forest is in the process of regeneration, strongly disturbed by constant fire and human intervention, the ant species richness shows that it remains an invaluable source of biological resources for the conservation of species.

Adding fuel to the fire? Revegetation influences wildfire size and intensity

The regrowth of woody vegetation in cleared landscapes (i.e. revegetation) has the potential to dramatically alter the spatial characteristics of vegetation and fuels, which will potentially alter fire characteristics. Understanding how revegetation alters fire size and intensity will be critical in determining the social and environmental value of revegetation. We used simulation modelling to examine (i) whether increasing native woody vegetation extent across landscapes cleared for pasture (i.e. revegetation) affects fire size and median fireline intensity and (ii) whether fuel load in the pasture matrix, the initial extent of land clearing and weather conditions during a fire alter the direction and/or magnitude of the relationships between revegetation and fire size or intensity. Simulations revealed that fire size and intensity were altered by increasing woody vegetation extent, though the direction of change was dependent upon landscape context. Increased woody vegetation extent led to (i) increased fire size in landscapes with low pasture fuel load (2tha−1) regardless of the extent of land clearing, (ii) decreased fire size in highly cleared landscapes with moderate (4.5tha−1) and high (7tha−1) pasture fuel load, and (iii) little change to fire size in landscapes subjected to low levels of clearing when pasture fuel load was moderate or high. Similar patterns were observed for fireline intensity. The magnitude of change in fire size and intensity was greatest under extreme fire weather conditions. Revegetation rarely increased median fireline intensity beyond suppressible levels (i.e. 4000kWm−1), with fire weather and pasture fuel load being the main determinants of suppression potential. Our findings show that the response of fire size and intensity to revegetation will depend on landscape scale pasture management.

Diversity and Distribution of Lizards in Fragmented Atlantic Forest Landscape in Southeastern Brazil

Abstract In this study, we evaluated how different lizard species were distributed in a fragmented Atlantic Forest landscape and the influence of landscape metrics on lizard species richness in sampled fragments. We sampled (between July 2007 and March 2010) three continuous forest sites of the Reserva Ecologica de Guapiacu (REGUA), 12 forest fragments of different sizes and five pasture matrix areas. We recorded 8 lizard species, the most abundant being Ecpleopus gaudichaudii and Enyalius brasiliensis. Species richness in the continuous forest sites (N = 4) was lower than in the set of fragments (N = 8); fragments harbored both typical forest species and more generalist species. The forest areas differed in the composition of lizard species, with continuous forest sites having a composition similar to each other and to larger fragments, whereas the smaller fragments differed from the larger fragments but showed similarity to each other. These data indicated that fragment size (area) can be an important f...

Effects of landscape matrix type, patch quality and seasonality on the diet of frugivorous bats in tropical semi-deciduous forest

Context Dry forests usually have a marked seasonality in resource availability; as a consequence, wildlife is subjected to drastic changes in food availability during the year. The presence of high-quality sites that provide food during lean periods is crucial in these habitats, especially in human-modified landscapes where resources are limited and scattered. Aims We assessed whether seasonal fluctuations in the availability of fruit resources in two contrasting landscape matrices (continuous tropical semi-deciduous forest and pasture) affect the diet diversity for frugivorous bats, and whether the presence of cenotes (freshwater-filled sinkholes) in these matrices had any effect during the rainy and dry seasons. Methods For each matrix type, two sites with a cenote and two sites with no cenote were sampled. The highest richness of chiropterochorous plants and the longer availability of fruit in the forest surrounding cenotes than in forest with no cenote helped evaluate the importance of patch quality on diet diversity. Two dry and two wet seasons were sampled to assess the effect of the season on diet diversity. Key results After four seasons, 1398 frugivorous bats belonging to seven species had been captured, with Artibeus jamaicensis being the most abundant and important seed disperser. Thirteen plant species made up the diet of the frugivorous bats, with Ficus and Solanum being the most frequent genera. Diet diversity was greater in the pasture matrix than in the continuous forest. During the dry season, diet diversity was higher at sites with a cenote in both landscape matrices, but this interaction was not statistically significant. Conclusions Frugivorous bats are flexible and capable of tracking variations in food availability at different temporal and spatial scales. The latter allows these bats to use several vegetation types during the year to complement their diet in highly seasonal forests. Implications Owing to their foraging habits and the high number and variety of seeds that bats can disperse, they create strong connections between both fragmented and continuous landscapes. Management practices that conserve the areas with arboreal vegetation are essential to the movement of bats and the seeds they disperse across fragmented landscapes that later contribute to forest regeneration.

Variabilidad ambiental y respuestas fisiológicas de <i>Polylepis cuadrijuga</i> (Rosaceae) en un ambiente fragmentado en el Páramo de la Rusia (Colombia)

Polylepis cuadrijuga is an endemic woody species from the Colombian Eastern range, being the only tree species with capacity to live on mountainous environments beyond 4 000m of altitude. Grazing and agriculture have transformed at least 30% of the Guantiva-La Rusia region, turning continuous extensions of high Andean forest in a fragmented landscape, and P cuadrijuga remnants have become smaller and more isolated. The aim of this study was to establish the environmental differences between a matrix of grazing pastures and the interior of fragments, to evaluate the physiological responses of P cuadrijuga and determining the edge effect. Air temperature and humidity, soil water holding capacity and photosynthetic active radiation, were measured along two 50X2m transects from the matrix toward the center of fragment. Six trees inside the transects were chosen in each one of three sites (matrix, edge and interior) to measure the index chlorophyll content and to sample leaves to assess the leaf area, leaf biomass, specific leaf area, anatomy, health condition and pubescence. Results showed significantly differences between the matrix and the interior and intermediate conditions in the edge. Radiation, temperature and air desiccation were higher in the matrix than in the interior, submitting P cuadrijuga trees to a stressing environment, where they presented stratification of epidermis and palisade parenchyma, and a higher leaf area, leaf thickness, chlorophyll content and pubescence than in the interior of fragments. All these physiological traits allow avoiding the photoxidation and damages by freezing or desiccation to which trees are exposed in a grazing pasture matrix. Nevertheless, there was a higher frequency of healthy leaves in the interior of fragments, showing that high irradiations and extreme air temperature and humidity reach adversely affect to P cuadrijuga. Individuals in the edge had ecophysiological traits similar to the matrix ones, which confirm an edge effect that could penetrate 17m inside the fragments. We conclude that P cuadrijuga is a plastic species, able to overcome the stress conditions from anthropogenic transformations, species able to be used in high Andean forest restoration programs

Leaf anatomy and chlorophyll content in Psychotria vellosiana Benth influenced by the edge and two matrices

The distance effect of the edge and two matrices (pasture and sugar cane) on the microclimate and anatomical and physiological properties of Psychotria vellosiana leaves were studied in two semideciduous forest fragments in southern Minas Gerais. The plots were set at distances (0, 20, 40, 60 and 80 m) from the edge to the interior of each fragment: 0, 20 and 40 m distances were considered edge, whereas 60 and 80 m were considered interior. Microclimate data were collected in all plots and radiation data and canopy openness at 0, 40 and 80 m. Leaves were collected for analysis of their chlorophyll content and anatomical properties. No differences were found for the canopy openness and radiation between the edge and interior of the fragments. The temperature and humidity data and the soil humidity displayed no differences within or between each fragment. Only the soil temperature data differed between the fragments. The leaves displayed the same chlorophyll content for the edge and interior of the fragments and between the fragments. These results may be related to the microclimate properties found along the 80 m transect in each fragment. Some anatomical data suggested a better adaptation of P. vellosiana to the fragment surrounded by the pasture matrix. However, we require a more detailed analysis that includes nutrient information and water availability from the soil.

Matrix composition and corridor function for austral thrushes in a fragmented temperate forest

Although it is widely recognized that animal movement may be facilitated by corridors and hindered by the matrix, the influence of matrix composition on the use of corridors still remain poorly understood. We used translocation experiments and state-space models to assess if the movement response of the frugivorous bird, the austral thrush, to riparian forest strips varies depending on matrix composition (open pasture vs. eucalyptus plantation). In agricul- tural landscapes, the directions displayed by most birds when moving in the open pasture matrix were consistent with an edge-following behavior. Riparian strips also functioned as passive drift fences in agricultural landscapes, with strips being used as conduits for movements once birds entered into a riparian strip. Our results suggest that visual percep- tion of riparian strips by birds is hampered by the complex habitat structure in the eucalyptus matrix and that the use of riparian strips as habitat is conditioned by the surrounding matrix.

Deforestation and Primate Habitat Availability in Los Tuxtlas Biosphere Reserve, Mexico

Los Tuxtlas Biosphere Reserve (LTBR) in southeast Mexico is characterized by high rates of deforestation and habitat deterioration, containing two Mexican primate species, <i>Alouatta palliata </i>and <i>Ateles geoffroyi.</i> In this study, we integrate the analysis of landscape dynamics with primate population research covering a period of 21 years (1986-2007), assessing the impacts of habitat transformation on primate populations in a study area located in the southeast region of the LTBR. We found the higher deforestation rate (1.5%) from 1986 to 2000, compared to 2000-2007 (0.5%), but reduction in primate’s habitat was of 62% from 1986-2007. Land cover changes have modified the landscape in such a way that current available habitat for primates is constituted by small forest patches, immersed in a pasture matrix. A total of 37 <i>A. palliata</i> and 68 <i>A. geoffroyi</i> individuals were counted; these data were compared with information available for the same primate populations in 1987 and 2000, revealing that despite habitat loss, primate population sizes have remained relatively stable. The analysis of occupation and colonization of forests fragments by primates suggests that fragment size and connectivity are key landscape features for the persistence of primates in the region. Our results imply that strong anthropogenic pressure against primate habitat is still taking place in this portion of LTBR; and that habitat availability, as well as primate population viability in this region, are linked to political and socioeconomic factors affecting land use and production systems adopted by locals, as well as to the management efforts of the LTBR.

Influence of terrestrial habitat isolation on the diversity and temporal distribution of anurans in an agricultural landscape

Discontinuity between suitable aquatic and terrestrial habitats forces many amphibian species with aquatic larvae to undertake risky breeding migrations through disturbed environments, potentially contributing to population declines by reducing survival of adults and juveniles (Beckeret al. 2007). The north-western region of the state of São Paulo, Brazil, is characterized by fragments of mesophytic semideciduous forest and savanna, surrounded by a matrix of pasture, plantations and urban areas with only 4% of the remaining original vegetation of the state (Ribeiroet al. 2009). Currently, 36 anuran species have been recorded in this region, corresponding to almost 15% of the state's species (Araújoet al. 2009). The anuran species of this region are associated with open environments or are widely distributed in the different Brazilian biomes (Duellman 1999). Silva &amp;amp; Rossa-Feres (2007) showed the importance of forest fragments in this region for 12 anuran species that breed in pools located in a pasture matrix.

Litter Quality of Two Remnant Tree Species Affects Soil Microbial Activity in Tropical Seasonal Pastures in Western Mexico

In degraded soils of tropical seasonal pastures, native remnant tree species that differ in foliar morphology, litter quality, and quantity might be quite useful as an organic input for improving soil fertility. The objective of this study was to analyze litter quality effects on soil microbial activity from two native remnant trees: Caesalpinia eriostachys Benth. (Caesalnaceae) and Cordia elaeagnoides DC (Boraginaceae), located within a tropical seasonal pasture matrix dominated by Panicum maximum Jacq. (Poaceae). The substrate-induced respiration method was used to determine soil microbial activity in a laboratory incubation experiment. A 3 × 3 factorial laboratory experiment for litter type and soil origin was carried out by adding leaf litter to soil in a reciprocal fashion to evaluate the relative effect of litter quality on substrate-induced respiration. Potential C mineralization rate and net microbial C immobilization from soil under C. elaeagnoides and C. eriostachys were higher with endogenous litter (260 ± 24 µg C g−1 d−1 and 242 ± 11 µg C g−1 d−1 for C. elaeagnoides and C. eriostachys, respectively) than with exogenous litter. Potential carbon mineralization and net microbial C immobilization in soil under P. maximum increased with litter from C. eriostachys due to other leaf-litter quality parameters as lignin concentration and lignin:N ratio. Therefore, C. eriostachys litter addition on soil under grass species may help to stabilize soil organic matter, promoting soil microbial biomass and activity. The net immobilization of microbial N under two remnant tree species and grass species was negative, indicating an N mineralization from microbial biomass.

Live fences as tools for biodiversity conservation: a study case with birds and plants

Live fences may act as tools for biodiversity conservation by providing habitat for native species and increasing connectivity in the landscape. We studied the influence of live fence characteristics on species richness and fence use by birds by examining both local and landscape factors. We studied three types of live fences: planted fences of a native tree, planted fences of an exotic, and spontaneous. They were either connected to forest fragments or isolated, and were all within a pasture matrix. Spontaneous and planted live fences maintain a diverse plant (77 shrub and tree species) and bird communities (98 species). Fence types strongly differed in vegetation composition and structure. We found that by analyzing each fence characteristic independently, there was no difference in bird richness or abundance. However, there was a significant correlation when plant richness, structure, and connectivity were analyzed together. This could be the result of some variables counterbalancing each other. Birds used fences for a variety of purposes including foraging, breeding, and moving across the landscape. Native birds and plants used live fences as habitat and refuge in a landscape where large forest tracts have been lost for decades. Live fences in conjunction with small forest fragments maintain a diverse array of plant and birds species that are a subsample of the species originally found in the landscape before extensive deforestation. We recommend the establishment of live fences, allowing growth of spontaneous understory.

Aspectos ecológicos de stenocercus caducus (squamata:iguanidae) en fragmentos boscosos en el suroeste de mato grosso, brasil

Stenocercus caducus es un Tropidurinae descrito para Paraguay, Brasil (Mato Grosso e Pará) Bolivia (Beni, Chuquisaca, Cochabamba, La Paz, Santa Cruz, Tarija) y Argentina (Jujuy, Salta). Aparentemente es poco exigente en cuanto al hábitat, ya que es encontrado en áreas de cerrados, cerradones, matas ciliares y eventualmente en áreas antropizadas. En este estudio se presentan aspectos ecológicos de S. caducus, muestreados en 18 fragmentos insertados en una matriz de pradera, en la región sudeste de Mato Grosso en un área de la Floresta Estacional Semidecidua Submontana. Se realizaron las colectas en período seco y lluvioso entre diciembre de 2002 y agosto de 2004, a través de trampas tipo pitfall, con esfuerzo muestreal de 9.000 baldes/día. Fue determinada la estructura poblacional, observando la ocurrencia de solo adultos en el período lluvioso y predominancia de jóvenes en el período seco. La relación sexual encontrada estuvo próxima a 1:1 en ambos períodos, no siendo encontrada diferencias significativas en los patrones morfométricos entre los sexos. En cuanto al uso de hábitat, la especie se mostró generalista, utilizando tanto la matriz de pastos o pradera, orilla e interior de los fragmentos, aparentando preferencia por la orilla. En relación con la dieta, estaba exclusivamente compuesta por artrópodos, detectándose una ingestión que incluye un amplio espectro de presas, siendo más frecuentes y numerosas los insectos de los órdenes Coleóptera, Himenóptera (Formicidae) e Isóptera. La aparente plasticidad de la especie en cuanto al uso de hábitat y dieta contribuye para que sea exitosa, ya que una vez que se amplía el territorio de forrajeo aumenta la capacidad de sobrevivencia, siendo favorecida por la transformación de las áreas de Cerrado en un mosaico de fragmentos, debido a los constantes impactos antrópicos que suceden.

Edge effects and landscape matrix use by a small mammal community in fragments of semideciduous submontane forest in Mato Grosso, Brazil

A community of small mammals was studied in seasonal semideciduous submontane forest in the state of Mato Grosso, Brazil. This study evaluated the use of edge and matrix pasture, by different small mammal species. Overall, 31 areas were studied, with a total sampling effort of 33,800 trap x nights. Only seven of the 25 species captured in the study sites were able to use the pasture matrix; we classified these species as generalists. Fourteen species were found to be intermediate in habits, being able to use forest edges. We found only four species habitat specialists, occurring only on transect lines in the interior of the fragment, at least 150 m from the edge. Transects located in the pasture matrix and 50 m from the edge had significantly lower species richness and abundance than transects located in the fragment edge or in the interior of the fragment. All transects located within the fragment had similar species richness and abundance, but transects located 50 m from the edge had slightly lower, but non-significant, species richness than transects located 100 m apart from edges. Rarefaction curves demonstrated that only medium-sized fragments (100-300 ha) reached an asymptote of species accumulation. The other areas require further sampling, or more sampling transect, before species accumulation curves stabilize, due to a continued increase in species number.

Effects of isolation on the colonisation of restored habitat patches by forest‐dependent arthropods of soil and litter

Abstract. A novel experimental approach was taken to investigate the effects of distance from rainforest remnants on the recolonisation patterns of ants and other soil and litter arthropods in ‘restored’ habitat patches within a pasture matrix. Experimental habitat patches were created by adding a thick mulch of sterilised woodchips and leaves, and simulating shade using shadecloth, to create conditions similar to those that occur during rainforest restoration. These patches were deployed at five experimental sites in the Maleny plateau of subtropical eastern Australia. Artificial habitat patches were located at varying distances from a rainforest edge at each site, as well as within the rainforest. The experiment also included a test for efficacy of inoculation, which involved translocation of a small quantity of litter (containing live arthropods) from rainforest habitat to isolated habitat patches. The results showed that, after 9 months, there was little colonisation by rainforest‐dependent taxa in any of the experimental plots beyond those closely adjacent to forest patches. Inoculation was unsuccessful in increasing the extent of arthropod establishment. A number of explanations that potentially account for the observed results are suggested. An experimental approach provides an opportunity to test explicitly for factors considered important for the development of biota in restored habitat patches. There are, however, unavoidable limitations associated with the design of experiments that simulate small‐scale analogues of restoration treatments. Avoiding these limitations may require controlled and replicated efforts in experimental restoration over larger areas, based on collaborations between researchers and practitioners.

Composition of grazed and cleared temperate grassy woodlands in eastern Australia: patterns in space and inferences in time

Abstract. A regional vegetation survey of the temperate grassy woodlands (temperate savanna) in Australia was designed to assess the effects of clearing and grazing on the composition of vegetation remnants and the adjacent pasture matrix. Vegetation was sampled across a range of habitats using 77 0.1024‐ha quadrats; the relative abundance of species was recorded. Classification analysis clustered the sites into three main groups that corresponded to intensity of grazing/clearing followed by groups based on underlying lithology (basalt, metasediment, granites). Using Canonical Correspondence Analysis, exogenous disturbance and environmental variables were related to the relative abundance of species; grazing intensity had the highest eigenvalue (0.27) followed by tree canopy cover (0.25), lithology (0.18), altitude (0.17) and slope (0.10). Based on two‐dimensional ordination scores, six species response groups were defined relating to intensity of pastoralism and nutrient status of the landscape. Abundance and dominance of native shrubs, sub‐shrubs, twiners and geophytes were strongly associated with areas of less‐intense pastoralism on low‐nutrient soils. The strongest effects on species richness were grazing followed by canopy cover. Continuously grazed sites had lower native species richness across all growth forms except native grasses. There was no indication that intermediate grazing intensities enhanced forb richness as a result of competitive release. Species richness for all native plants was lowest where trees were absent especially under grazed conditions. Canopy cover in ungrazed sites appeared to promote the co‐existence of shrubs with the herbaceous layer. Predicted declines in forb richness in treeless, ungrazed, sites were not detected. The lack of a disturbance‐mediated enhancement of the herbaceous layer was attributed to habitat heterogeneity at 0.1 ha sampling scale.

Composition of grazed and cleared temperate grassy woodlands in eastern Australia: patterns in space and inferences in time

Abstract. A regional vegetation survey of the temperate grassy woodlands (temperate savanna) in Australia was designed to assess the effects of clearing and grazing on the composition of vegetation remnants and the adjacent pasture matrix. Vegetation was sampled across a range of habitats using 77 0.1024-ha quadrats; the relative abundance of species was recorded. Classification analysis clustered the sites into three main groups that corresponded to intensity of grazing/clearing followed by groups based on underlying lithology (basalt, metasediment, granites). Using Canonical Correspondence Analysis, exogenous disturbance and environmental variables were related to the relative abundance of species; grazing intensity had the highest eigenvalue (0.27) followed by tree canopy cover (0.25), lithology (0.18), altitude (0.17) and slope (0.10). Based on two-dimensional ordination scores, six species response groups were defined relating to intensity of pastoralism and nutrient status of the landscape. Abundance and dominance of native shrubs, sub-shrubs, twiners and geophytes were strongly associated with areas of less-intense pastoralism on low-nutrient soils. The strongest effects on species richness were grazing followed by canopy cover. Continuously grazed sites had lower native species richness across all growth forms except native grasses. There was no indication that intermediate grazing intensities enhanced forb richness as a result of competitive release. Species richness for all native plants was lowest where trees were absent especially under grazed conditions. Canopy cover in ungrazed sites appeared to promote the co-existence of shrubs with the herbaceous layer. Predicted declines in forb richness in treeless, ungrazed, sites were not detected. The lack of a disturbance-mediated enhancement of the herbaceous layer was attributed to habitat heterogeneity at 0.1 ha sampling scale.

Factors Influencing Movement Patterns of Keel‐Billed Toucans in a Fragmented Tropical Landscape in Southern Mexico

Abstract:Various factors influence animal movements in fragmented landscapes, and determining these factors is key to understanding ecological processes at a landscape scale. My goals were (1) to determine what factors influence movements of Keel‐billed Toucans ( Ramphastos sulfuratus ) in a fragmented landscape in southern Mexico and (2) to use this information to predict how movement patterns might change if the landscape was altered. I developed a cost‐distance geographic information system model that adjusts Euclidean distances by a cost of moving through a certain habitat type. Cost was based on habitat preferences exhibited by toucans. I then used this model to predict how movements might be affected by removal of isolated trees and living fences from the pasture matrix and by removal of forest remnants. Toucans moved more frequently between remnants separated by a low cost‐distance value. There was a cost‐distance threshold beyond which movements between remnants were rare. Below this threshold, fruit abundance influenced toucan movements but remnant area was not influential in that toucans did not preferentially move to large patches. Remnants close to various other remnants were more frequently visited by toucans, indicating that landscape connectivity influences toucan movements. Toucans incurred a 10–30% cost increase when moving in computer‐simulated landscapes, indicating that changes in forest cover or configuration of habitats may negatively affect toucan populations, assuming that increased cost has a fitness consequence. Cost‐distance modeling has been relatively unexplored and may be a valuable tool for determining how the configuration of a landscape impedes or facilitates animal movements.