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1.
Ecol Lett ; 27(5): e14443, 2024 May.
Article in English | MEDLINE | ID: mdl-38803140

ABSTRACT

Recent proliferation of GPS technology has transformed animal movement research. Yet, time-series data from this recent technology rarely span beyond a decade, constraining longitudinal research. Long-term field sites hold valuable historic animal location records, including hand-drawn maps and semantic descriptions. Here, we introduce a generalised workflow for converting such records into reliable location data to estimate home ranges, using 30 years of sleep-site data from 11 white-faced capuchin (Cebus imitator) groups in Costa Rica. Our findings illustrate that historic sleep locations can reliably recover home range size and geometry. We showcase the opportunity our approach presents to resolve open questions that can only be addressed with very long-term data, examining how home ranges are affected by climate cycles and demographic change. We urge researchers to translate historical records into usable movement data before this knowledge is lost; it is essential to understanding how animals are responding to our changing world.


Subject(s)
Cebus , Climate Change , Animals , Costa Rica , Cebus/physiology , Homing Behavior , Geographic Information Systems , Population Dynamics , Demography
2.
Animals (Basel) ; 13(21)2023 Oct 25.
Article in English | MEDLINE | ID: mdl-37958070

ABSTRACT

This study presents the first successful capture using GPS tagging of a jaguar (Panthera onca) using a minimally invasive capture system (MICS). We used snare-foot traps and a MICS during two capture campaigns in a fragment of Atlantic Forest in southeastern Brazil. The specimen disarmed snares on different occasions, and capture was only possible with the MICS. The captured jaguar, an estimated 16-year-old adult male, was monitored using a GPS Vertex Plus Iridium collar with an optimal performance of 86% in expected locations. The jaguar's home range (659 km2 by MPC and 174 km2 by 95%K) was within the observed range for the species and the animal was primarily maintained in protected areas. The habitat types most frequently used were native grassland (27.2% of 4798 fixes), marsh (24.8%), and dense lowland forest (24.7%). The use of a MICS for trapping jaguars is a promising technique that shows advantages in terms of efficiency, selectivity, portability, reduced potential risk of injury to animals or trappers, and animal stress compared to other capture methods used for the species.

3.
J Wildl Dis ; 59(4): 722-733, 2023 10 01.
Article in English | MEDLINE | ID: mdl-37846906

ABSTRACT

Rocky Mountain spotted fever (RMSF), caused by the bacterium Rickettsia rickettsii, is a re-emerging tick-borne zoonosis in North America, with hundreds of human fatalities in multiple outbreaks in northern Mexico and the southwestern US in the past few decades. Free-roaming dogs are key because they are reservoirs for the pathogen and the main hosts of the brown dog tick (Rhipicephalus sanguineus), which vectors RMSF in this region. Because coyotes (Canis latrans) can be infected with R. rickettsii and infested with Rh. sanguineus, we hypothesized that space sharing among dogs and coyotes could enhance disease risks. In summer 2021, we captured and sampled 11 coyotes at two sites in Baja California, Mexico, near population centers with human cases of RMSF, and fitted seven individuals with GPS logging collars. We also tested tissue samples, sera, and ectoparasites for DNA of R. rickettsii with PCR and used serology to detect antibodies to R. rickettsii. Finally, we deployed an array of cameras to document dog-coyote interactions. Mean home range size was 40.37 km2. Both GPS and camera data showed considerable home range overlap both between individual coyotes and between coyotes and dogs. Coyotes were active in areas where dogs occur including the domestic interface surrounding human settlements. Although none of our samples were positive for R. rickettsii on PCR, 72.7% (8/11) of the samples were seropositive with titers ≥64. Our data confirm shared space use and risk of shared parasites and disease between coyotes and dogs.


Subject(s)
Coyotes , Dog Diseases , Rhipicephalus sanguineus , Rickettsia Infections , Rocky Mountain Spotted Fever , Dogs , Humans , Animals , Rocky Mountain Spotted Fever/epidemiology , Rocky Mountain Spotted Fever/veterinary , Mexico/epidemiology , Rhipicephalus sanguineus/microbiology , Dog Diseases/epidemiology , Dog Diseases/microbiology , Rickettsia Infections/veterinary , Antibodies, Bacterial
4.
Am J Biol Anthropol ; 182(1): 59-68, 2023 09.
Article in English | MEDLINE | ID: mdl-37417878

ABSTRACT

OBJECTIVES: Long-distance vocalizations are used by primates in a variety of contexts and may have different functions. The long-distance vocalizations of howler monkeys (Alouatta spp.) underlie the spatial regulation of neighboring groups and could be associated with the defense of food resources. Here, we test the hypothesis that the behavioral responses of mantled howler monkeys (A. palliata) to neighbor long-distance vocalizations are influenced by the potential for range defensibility while accounting for location within the home range and food availability. METHODS: We studied two groups for 13 months and a total of 888 h at La Flor de Catemaco (Mexico). Group 1 had a 92-ha home range and Group 2 had a 24-ha home range. We recorded vocalizations (N = 178 calls) and movements (N = 74 movements) of focal groups following long-distance vocalizations produced by their neighbors. RESULTS: Movement responses, but not vocal responses, were predicted by range defensibility, location, and food availability. As predicted, the group living in the smaller and more defendable range showed stronger movement responses than the group in the larger home range. These movement responses had a shorter latency and longer duration in more valuable spatial and temporal contexts (i.e., the core area and during periods of low food availability). CONCLUSIONS: These results suggest that the tradeoff between the costs and benefits of range defense varies according to the interactions between home range size and both the spatial (core areas) and temporal (food availability) abundance of resources. Thus, the responses of mantled howler monkeys to neighbor long-distance vocalizations could be related to home range defensibility.


Subject(s)
Alouatta , Social Behavior , Animals , Alouatta/physiology , Food , Movement
5.
Animals (Basel) ; 13(7)2023 Apr 02.
Article in English | MEDLINE | ID: mdl-37048490

ABSTRACT

Immature individuals move from their natal area to the area where they settle and reproduce, and this may take several years. This process is essential for long-lived species such as vultures and condors, which spend long periods as immature and move extensively. We studied the movement behavior of 26 GPS-tagged immature Andean condors (Vultur gryphus) from northwestern Patagonia throughout the immature stage, analyzing whether these patterns differed according to age, sex and season. We found that season and age influenced home range size and flight distances, the warm season being when immature condors move most; movement patterns were greater in sub-adults than in juveniles. The age effect was associated with the sex of individuals, with males increasing their home range more than females. Our results provide the first description of how immature Andean condor movement patterns are affected by internal and external factors. This information could be key to understanding condor responses to environmental change and threats at different stages during their immature phase. Until now, condor conservation efforts have not considered the areas used by dispersing individuals. Our results increase our understanding of ranging behavior during the immature stage of this threatened bird, enabling us to improve the conservation policies and management strategies designed to protect them.

6.
Trop Med Infect Dis ; 8(2)2023 Feb 02.
Article in English | MEDLINE | ID: mdl-36828514

ABSTRACT

Tungiasis is a neglected disease caused by the sand flea Tunga penetrans, and dogs are considered the main reservoirs in Brazil. This study aimed to identify the role of dogs as tungiasis dispersers and to investigate the presence of T. penetrans in the soil of an endemic tourist area. Nine dogs infected by T. penetrans were included in this study and received GPS collars to analyze their movement through the village. Duplicate sand samples were collected in different areas of the community. Those areas were classified as peridomicile (n = 110), open area (n = 110), beach (n = 50), and river (n = 58). The analysis of the points recorded by the collars showed that the dogs roamed throughout the community, potentially facilitating the spread of the disease. Samples contaminated with developmental forms of the parasite were found in the circulation area of three dogs. Adult fleas were found in 3/328 samples. These data emphasize that infected dogs' roaming can influence the fleas' dispersion in the soil. Statistically, none of the study variables had a significant correlation (p > 0.5) with the presence of T. penetrans in the area analyzed. This study was the first to assess infected dogs' role as tungiasis propagators.

7.
Conserv Physiol ; 10(1): coac064, 2022.
Article in English | MEDLINE | ID: mdl-36159741

ABSTRACT

The northern Gulf of Mexico supports a diverse community of nearshore seabirds during both breeding and nonbreeding periods of the annual cycle and is also a highly industrialized marine ecosystem with substantial levels of oil and gas development particularly in the west and central regions. Stakeholders in the region often assess risk to species of interest based on these differing levels of development. We collected blood samples from 81 adult and 35 chick eastern brown pelicans (Pelecanus occidentalis carolinensis) from 10 colonies across the northern Gulf of Mexico and used these to establish baseline values for hematology and blood biochemistry. We assessed the potential influence of body condition, sex and home range size on hematology and blood biochemistry. We also assessed potential influences of oil and gas activity by considering differing levels of oil and gas development that occur regionally throughout the study area. Although blood analyte concentrations of adults and chicks were often associated with these regional differences, the pattern we observed was not entirely consistent with the differing levels of oil and gas activity across the Gulf, suggesting that regional levels of oil and gas activity around breeding sites may not be the primary drivers of hematology and blood biochemistry. We note that baseline values or reference intervals are not available for other nearshore seabirds that breed in the northern Gulf. Given that exposure and risk may differ among this suite of species based on diet, foraging strategies and life history strategies, similar assessments and monitoring may be warranted.

8.
Proc Biol Sci ; 289(1978): 20212808, 2022 07 13.
Article in English | MEDLINE | ID: mdl-35858053

ABSTRACT

Male-male relationships are mostly characterized by competition. However, males also cooperate with one another if socio-ecological conditions are suitable. Due to their male philopatry, the need for cooperation in home range defence and high degree of fission-fusion dynamics, spider monkeys provide an opportunity to investigate how male-male interactions are associated with socio-ecological factors, such as the presence of potentially receptive females, the degree of food availability and the likelihood of home range defence. We tested predictions about changes in social interactions between wild spider monkey males in relation to these factors. First, males did not change their interaction patterns when potentially receptive females were in the subgroup compared to when they were absent. Second, males tended to be less tolerant of one another when feeding, but spent more time grooming, in contact and proximity with one another when food availability was lower than when it was higher. Third, males exchanged fewer embraces, spent less time grooming, in proximity and in contact with one another, and spent more time vigilant at the home range boundary area than at other locations. Our findings contribute to the understanding of social flexibility and the importance of considering males in socio-ecological models of any group-living species.


Subject(s)
Atelinae , Animals , Female , Grooming , Homing Behavior , Male , Social Behavior , Social Interaction
9.
Mov Ecol ; 10(1): 14, 2022 Mar 14.
Article in English | MEDLINE | ID: mdl-35287742

ABSTRACT

BACKGROUND: Animal movement is a key ecological process that is tightly coupled to local environmental conditions. While agriculture, urbanisation, and transportation infrastructure are critical to human socio-economic improvement, these have spurred substantial changes in animal movement across the globe with potential impacts on fitness and survival. Notably, however, human disturbance can have differential effects across species, and responses to human activities are thus largely taxa and context specific. As human disturbance is only expected to worsen over the next decade it is critical to better understand how species respond to human disturbance in order to develop effective, case-specific conservation strategies. METHODS: Here, we use an extensive telemetry dataset collected over 22 years to fill a critical knowledge gap in the movement ecology of lowland tapirs (Tapirus terrestris) across areas of varying human disturbance within three biomes in southern Brazil: the Pantanal, Cerrado, and Atlantic Forest. RESULTS: From these data we found that the mean home range size across all monitored tapirs was 8.31 km2 (95% CI 6.53-10.42), with no evidence that home range sizes differed between sexes nor age groups. Interestingly, although the Atlantic Forest, Cerrado, and Pantanal vary substantially in habitat composition, levels of human disturbance, and tapir population densities, we found that lowland tapir movement behaviour and space use were consistent across all three biomes. Human disturbance also had no detectable effect on lowland tapir movement. Lowland tapirs living in the most altered habitats we monitored exhibited movement behaviour that was comparable to that of tapirs living in a near pristine environment. CONCLUSIONS: Contrary to our expectations, although we observed individual variability in lowland tapir space use and movement, human impacts on the landscape also had no measurable effect on their movement. Lowland tapir movement behaviour thus appears to exhibit very little phenotypic plasticity in response to human disturbance. Crucially, the lack of any detectable response to anthropogenic disturbance suggests that human modified habitats risk being ecological traps for tapirs and this information should be factored into conservation actions and species management aimed towards protecting lowland tapir populations.

10.
Brain Struct Funct ; 227(2): 469-477, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34455496

ABSTRACT

Brain lateralization is a widespread phenomenon although its expression across primates is still controversial due to the reduced number of species analyzed and the disparity of methods used. To gain insight into the diversification of neuroanatomical asymmetries in non-human primates we analyze the endocasts, as a proxy of external brain morphology, of a large sample of New World monkeys and test the effect of brain size, home range and group sizes in the pattern and magnitude of shape asymmetry. Digital endocasts from 26 species were obtained from MicroCT scans and a set of 3D coordinates was digitized on endocast surfaces. Results indicate that Ateles, Brachyteles, Callicebus and Cacajao tend to have a rightward frontal and a leftward occipital lobe asymmetry, whereas Aotus, Callitrichinae and Cebinae have either the opposite pattern or no directional asymmetry. Such differences in the pattern of asymmetry were associated with group and home range sizes. Conversely, its magnitude was significantly associated with brain size, with larger-brained species showing higher inter-hemispheric differences. These findings support the hypothesis that reduction in inter-hemispheric connectivity in larger brains favors the lateralization and increases the structural asymmetries, whereas the patterns of shape asymmetry might be driven by socio-ecological differences among species.


Subject(s)
Brain , Platyrrhini , Animals , Brain/diagnostic imaging , Neuroanatomy , Occipital Lobe , Phylogeny , Platyrrhini/genetics
11.
Proc Biol Sci ; 288(1952): 20210993, 2021 06 09.
Article in English | MEDLINE | ID: mdl-34102893

ABSTRACT

Harmonious coexistence between humans, other animals and ecosystem services they support is a complex issue, typically impacted by landscape change, which affects animal distribution and abundance. In the last 30 years, afforestation on grasslands across Great Britain has been increasing, motivated by socio-economic reasons and climate change mitigation. Beyond expected benefits, an obvious question is what are the consequences for wider biodiversity of this scale of landscape change. Here, we explore the impact of such change on the expanding population of common buzzards Buteo buteo, a raptor with a history of human-induced setbacks. Using Resource-Area-Dependence Analysis (RADA), with which we estimated individuals' resource needs using 10-day radio-tracking sessions and the 1990s Land Cover Map of GB, and agent-based modelling, we predict that buzzards in our study area in lowland UK had fully recovered (to 2.2 ind km-2) by 1995. We also anticipate that the conversion of 30%, 60% and 90% of economically viable meadow into woodland would reduce buzzard abundance nonlinearly by 15%, 38% and 74%, respectively. The same approach used here could allow for cost-effective anticipation of other animals' population patterns in changing landscapes, thus helping to harmonize economy, landscape change and biodiversity.


Subject(s)
Biodiversity , Ecosystem , Animals , Climate Change , Conservation of Natural Resources , Forests , Humans , United Kingdom
12.
Front Vet Sci ; 8: 617900, 2021.
Article in English | MEDLINE | ID: mdl-33748208

ABSTRACT

Dogs play a major role in public health because of potential transmission of zoonotic diseases, such as rabies. Dog roaming behavior has been studied worldwide, including countries in Asia, Latin America, and Oceania, while studies on dog roaming behavior are lacking in Africa. Many of those studies investigated potential drivers for roaming, which could be used to refine disease control measures. However, it appears that results are often contradictory between countries, which could be caused by differences in study design or the influence of context-specific factors. Comparative studies on dog roaming behavior are needed to better understand domestic dog roaming behavior and address these discrepancies. The aim of this study was to investigate dog demography, management, and roaming behavior across four countries: Chad, Guatemala, Indonesia, and Uganda. We equipped 773 dogs with georeferenced contact sensors (106 in Chad, 303 in Guatemala, 217 in Indonesia, and 149 in Uganda) and interviewed the owners to collect information about the dog [e.g., sex, age, body condition score (BCS)] and its management (e.g., role of the dog, origin of the dog, owner-mediated transportation, confinement, vaccination, and feeding practices). Dog home range was computed using the biased random bridge method, and the core and extended home range sizes were considered. Using an AIC-based approach to select variables, country-specific linear models were developed to identify potential predictors for roaming. We highlighted similarities and differences in term of demography, dog management, and roaming behavior between countries. The median of the core home range size was 0.30 ha (95% range: 0.17-0.92 ha) in Chad, 0.33 ha (0.17-1.1 ha) in Guatemala, 0.30 ha (0.20-0.61 ha) in Indonesia, and 0.25 ha (0.15-0.72 ha) in Uganda. The median of the extended home range size was 7.7 ha (95% range: 1.1-103 ha) in Chad, 5.7 ha (1.5-27.5 ha) in Guatemala, 5.6 ha (1.6-26.5 ha) in Indonesia, and 5.7 ha (1.3-19.1 ha) in Uganda. Factors having a significant impact on the home range size in some of the countries included being male dog (positively), being younger than one year (negatively), being older than 6 years (negatively), having a low or a high BCS (negatively), being a hunting dog (positively), being a shepherd dog (positively), and time when the dog was not supervised or restricted (positively). However, the same outcome could have an impact in a country and no impact in another. We suggest that dog roaming behavior is complex and is closely related to the owner's socioeconomic context and transportation habits and the local environment. Free-roaming domestic dogs are not completely under human control but, contrary to wildlife, they strongly depend upon humans. This particular dog-human bound has to be better understood to explain their behavior and deal with free-roaming domestic dogs related issues.

13.
BMC Infect Dis ; 21(1): 275, 2021 Mar 18.
Article in English | MEDLINE | ID: mdl-33736597

ABSTRACT

BACKGROUND: Transmission of multidrug-resistant tuberculosis (MDRTB) requires spatial proximity between infectious cases and susceptible persons. We assess activity space overlap among MDRTB cases and community controls to identify potential areas of transmission. METHODS: We enrolled 35 MDRTB cases and 64 TB-free community controls in Lima, Peru. Cases were whole genome sequenced and strain clustering was used as a proxy for transmission. GPS data were gathered from participants over seven days. Kernel density estimation methods were used to construct activity spaces from GPS locations and the utilization distribution overlap index (UDOI) was used to quantify activity space overlap. RESULTS: Activity spaces of controls (median = 35.6 km2, IQR = 25.1-54) were larger than cases (median = 21.3 km2, IQR = 17.9-48.6) (P = 0.02). Activity space overlap was greatest among genetically clustered cases (mean UDOI = 0.63, sd = 0.67) and lowest between cases and controls (mean UDOI = 0.13, sd = 0.28). UDOI was positively associated with genetic similarity of MDRTB strains between case pairs (P < 0.001). The odds of two cases being genetically clustered increased by 22% per 0.10 increase in UDOI (OR = 1.22, CI = 1.09-1.36, P < 0.001). CONCLUSIONS: Activity space overlap is associated with MDRTB clustering. MDRTB transmission may be occurring in small, overlapping activity spaces in community settings. GPS studies may be useful in identifying new areas of MDRTB transmission.


Subject(s)
Community-Acquired Infections/epidemiology , Community-Acquired Infections/transmission , Tuberculosis, Multidrug-Resistant/epidemiology , Tuberculosis, Multidrug-Resistant/transmission , Adult , Female , Geographic Information Systems , Humans , Male , Middle Aged , Peru/epidemiology , Social Networking , Young Adult
14.
Am J Primatol ; 83(3): e23237, 2021 03.
Article in English | MEDLINE | ID: mdl-33528872

ABSTRACT

There is wide variability in primate behavior and ecology. Understanding how frugivorous primates behave under different habitat fragmentation levels is key for effective conservation and management of species and their habitats. We evaluated the seasonality in activity budget, diet, and ranging behavior of two groups of Endangered Coimbra-Filho's titi monkeys (Callicebus coimbrai). One group inhabited a 14-ha forest fragment, whereas the other lived in a 522-ha fragment. We measured the monthly density of trees and lianas available as food sources over 8 months. We also collected behavioral and group location data every 5 min, from dawn to dusk, using the scan sampling method. The two forest fragments differed seasonally in the number of fruiting food-resource available. In the 14-ha fragment, we found that the time spent by titi monkeys feeding, foraging, resting, and traveling differed seasonally. In the 522-ha fragment, titi monkeys exhibited seasonal differences in time spent sleeping, socializing, foraging, and revisiting food sources. In both titi monkey groups, diets varied seasonally. Our findings indicate that Coimbra-Filho's titi monkeys can exhibit behavioral flexibility in their activity budgets, diets, and movement patterns. Such flexibility is important for this species to survive in fragmented habitats and may be linked to three key factors: species-specific resource availability, plant species diversity, and the vegetation structure of each forest fragment.


Subject(s)
Callicebus , Pitheciidae , Animals , Diet/veterinary , Ecosystem , Feeding Behavior , Haplorhini
16.
Am J Primatol ; 83(5): e23225, 2021 05.
Article in English | MEDLINE | ID: mdl-33368565

ABSTRACT

Patterns of ranging behavior and space use are key for evaluating current ideas about the evolution and maintenance of pair-living and sexual monogamy as they provide insights into the dispersion of females, the potential for territoriality, and whether males are limited to defending an area that can support only one female and her offspring. We examined ranging behavior and space use to evaluate the potential for territoriality in five groups of red titi monkeys (Plecturocebus discolor) during a 10-year study in Ecuadorian Amazonia. Mean home range size, calculated using a time-sensitive local convex hull estimation procedure, was 4.0 ± 1.4 ha. Annual home ranges of neighboring groups overlapped, on average, 0%-7%. Mean daily path length was 670 ± 194 m, resulting in defendability indices of 2.2-3.6 across groups. Groups visited, on average, 4 of 12 sections of their home range border area per day, but that was not more often than would be expected by chance, and intergroup encounters were infrequent. We did not find evidence of active monitoring for intruders in border areas, in that groups did not travel either faster or slower when at the border than when in central areas of their range. The absence of overt monitoring might be compensated for by engaging in loud calls, which the study groups did throughout their home ranges; these calls may serve as an advertisement of occupancy and a deterrent to intruding conspecifics. Our finding that red titis have a high potential for territoriality is consistent with several of the main hypotheses proposed to explain pair-living in mammals.


Subject(s)
Pitheciidae , Territoriality , Animals , Brazil , Callicebus , Female , Homing Behavior , Male
17.
Therya ; 12(1): 5-13, 2021.
Article in English | MEDLINE | ID: mdl-36118944

ABSTRACT

Small mammal populations can be affected by habitat degradation, causing changes in their abundance, density and movement. Akodon montensis, a persistent host for Orthohantavirus, is a common rodent species in primary and secondary forest habitats and is considered a generalist species. This paper analyzes how habitat degradation and resource availability affect the population characteristics of the species. Six plots were classified into three levels of degradation, with sampling conducted in June and November 2015. After the June sampling, three plots were selected for the increase of food resources for three months, to assess how this factor affects the population. Abundance was estimated with the capture-mark-recapture method and density was estimated by dividing abundance by the effective sampling area. Home range was calculated using the Minimum Convex Polygon method, and the Maximum Distance Traveled as the longest average movement between two sampling stations where an individual was encountered. More degraded habitats supported lower average density and abundance of A. montensis compared to less degraded habitats. Increasing food availability led to increases in abundance in the more degraded habitats and decreases in the least degraded. Changes in home range were most evident, decreasing in the least degraded plots after the increase in resources. The sex ratio did not differ from equity in any plot, nor with respect to any of the factors studied. Population characteristics of the species are determined by several factors, including habitat quality and food distribution and abundance. If changes occur in these factors (either artificially or naturally) then movement, abundance and population density are affected in response to such changes. Although some results were not statistically significant, an apparent interaction was observed between habitat quality and resource availability, thereby influencing the abundance and density of A. montensis.


Las poblaciones de pequeños mamíferos pueden verse afectadas por las degradaciones en el hábitat, ocasionando cambios en la abundancia, densidad y movimiento de los mismos. Akodon montensis, un persistente hospedero para el Orthohantavirus, es una especie de roedor bastante común en hábitats de bosque primario y secundario, y es considerado como una especie generalista. Este trabajo analiza cómo la degradación del hábitat y la disponibilidad de recursos alimenticios, afectan las características poblacionales de la especie. Seis parcelas se clasificaron en tres niveles de degradación, realizándose muestreos en junio y noviembre del 2015. Luego del muestreo de junio, tres parcelas fueron seleccionadas como experimentales con el aumento de recursos durante tres meses, para evaluar cómo afecta este factor a la población, y las otras tres parcelas se mantuvieron como control sin el aumento de recursos. La abundancia se estimó con el método de captura-marca-recaptura y la densidad se estimó dividiendo la abundancia por el área efectiva de muestreo. Se calculó el área de acción mediante el método de Polígono Mínimo Convexo. Hábitats más degradados registraron un menor promedio de densidad y abundancia comparando con las degradaciones más bajas. Con el aumento de recursos, la disponibilidad de alimento generó aumentos en la abundancia de los hábitats más degradados mientras que disminuyeron en el menos degradado. Se observaron principalmente cambios en el área de acción, que disminuyeron en las parcelas menos degradadas luego del aumento de recursos. La proporción de sexos no presentó diferencias a la equidad en ninguna parcela, ni con respecto a alguno de los factores estudiados. Las características poblacionales de las especies están determinadas por factores como la calidad del hábitat, la distribución y abundancia de alimento. Cambios (artificiales o naturales) en estos factores, afectan el movimiento, la abundancia y densidad de las poblaciones. Aunque algunos resultados no fueron estadísticamente significativos, se observa cierta interacción entre la calidad del hábitat y disponibilidad de recursos, que influyen principalmente en la abundancia y densidad de A. montensis.

18.
J Fish Biol ; 98(3): 694-706, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33188525

ABSTRACT

This study focused on the distribution of fish with high reproductive activity along a basin, using a 430 km stretch of the Cuiabá River in Brazil as a model. The main objective of this study was to identify those fish that migrate long distances for reproduction, among all the basin species. Thus, a set of working criteria are proposed to classify species according to their reproductive behaviour (i.e., reproductive activity and distribution). Samplings were performed in the Cuiabá River basin, encompassing several environments (river, channels and lakes) during the reproductive periods (between October and February), from 2000 to 2004. Species occurrence (presence and absence - proxy of distribution) across the basin and index of reproductive activity values were used as criteria to identify the species that perform long-distance longitudinal migrations for reproduction. The study confirmed the classification of long-distance longitudinal migration species; nonetheless, some species were not classified as described in the literature. The proposed sequential criteria have proven to be effective in the classification of long-distance longitudinal migrations species and certainly contribute to filling some existing knowledge gaps of reproductive traits. This classification is of fundamental importance in planning new dam projects, in decision making and in the development of management and conservation actions for the ichthyofauna.


Subject(s)
Animal Migration , Fishes/physiology , Reproduction/physiology , Animal Distribution , Animals , Brazil , Lakes , Rivers , Tropical Climate
19.
PeerJ ; 8: e10417, 2020.
Article in English | MEDLINE | ID: mdl-33240684

ABSTRACT

Worldwide urban expansion and deforestation have caused a rapid decline of non-human primates in recent decades. Yet, little is known to what extent these animals can tolerate anthropogenic noise arising from roadway traffic and human presence in their habitat. We studied six family groups of titis residing at increasing distances from a busy highway, in a park promoting ecotourism near Santa Cruz de la Sierra, Bolivia. We mapped group movements, sampled the titis' behavior, collected fecal samples from each study group and conducted experiments in which we used a mannequin simulating a human intrusion in their home range. We hypothesized that groups of titi monkeys exposed to higher levels of anthropogenic noise and human presence would react weakly to the mannequin and show higher concentrations of fecal cortisol compared with groups in least perturbed areas. Sound pressure measurements and systematic monitoring of soundscape inside the titis' home ranges confirmed the presence of a noise gradient, best characterized by the root-mean-square (RMS) and median amplitude (M) acoustic indices; importantly, both anthropogenic noise and human presence co-varied. Study groups resided in small, overlapping home ranges and they spent most of their time resting and preferentially used the lower forest stratum for traveling and the higher levels for foraging. Focal sampling analysis revealed that the time spent moving by adult pairs was inversely correlated with noise, the behavioral change occurring within a gradient of minimum sound pressures ranging from 44 dB(A) to 52 dB(A). Validated enzyme-immunoassays of fecal samples however detected surprisingly low cortisol concentrations, unrelated to the changes observed in the RMS and M indices. Finally, titis' response to the mannequin varied according to our expectation, with alarm calling being greater in distant groups relative to highway. Our study thus indicates reduced alarm calling through habituation to human presence and suggests a titis' resilience to anthropogenic noise with little evidence of physiological stress.

20.
Pap. avulsos Zool. ; 60: e20206048, Sept. 29, 2020. ilus, mapas, tab, graf
Article in English | VETINDEX | ID: vti-33426

ABSTRACT

The largest feline in the Americas and the third largest in the world, the jaguar is an apex predator in the food chain and a key species in the ecosystems where it occurs, developing important ecological functions in maintaining ecosystem balance. In Brazil, the Pantanal is considered an important refuge for the species, and protected areas such as the Taiamã Ecological Station (TES) are relevant for conservation of pristine ecosystem where the species persist. Thus, considering that this area is located in one of the regions with the highest concentration of this large cat in the Pantanal, the objective of this study was to evaluate the effectiveness of the protection given by the TES for the jaguar population. The station is a flooded island in the middle of the Paraguay river and surrounded by extensive wetlands. We monitored ten jaguars using GPS collar at the TES and its surroundings. The samples were separated into high-water season (January to June) and low-water season (July to December), and the estimated home ranges were grouped as: 1) residents only and 2) all monitored individuals. The stabilization of the home ranges of eight jaguars, considered residents, was determined through variograms. When all jaguars were analysed together there was 55% overlap between the clustered areas of the two analysed seasons. In the analysis excluding non-resident individuals there was 72% overlap between the clustered areas. The type of land cover inside these areas was very similar between these periods. The range of this protected area is not sufficient to effectively protect these jaguar populations, since the grouped home ranges of the resident animals studied are 3.5(wet)/2.5(dry) times larger than the area of the TES. However...(AU)


Subject(s)
Animals , Panthera , Protected Areas/analysis , Protected Areas/methods , Wetlands , Brazil , Rainy Season , Dry Season
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