A brief summary of the item is not available. Add a brief summary about the item. Web Map by Nico_Eloy. Created: Jun 14, Updated: Jun 15, View. Download scientific diagram | Ecorregiones del Paraguay siguiendo a Cacciali ( ). 1. Pantanal. 2. Chaco Seco. 3. Chaco Húmedo. 4. Cerrado. 5. Bosque. Checklist of the Fishes of Paraguay (CLOFPY). Ichthyological Análisis cualitativo para la definición de las ecorregiones de Paraguay occidental. Paraquaria.
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Home range and core area size were estimated for jaguar Panthera onca in western Paraguay in the Dry Chaco, Humid Chaco and Pantanal using an autocorrelated kernel density estimator.
Males had a higher probability of larger home ranges and more directional and greater padaguay movements than females collectively and within systems.
The large home ranges of jaguars in western Paraguay and a low proportional area of protected areas in the region demonstrate the importance of private ranchland for the long-term conservation of the species. This article offers supplementary material which is provided at the end of the article. Globally, apex predators, and the maintenance of their functional roles, are severely threatened due to anthropogenic pressures, particularly associated with large spatial needs to ecodregiones sufficient prey to meet metabolic requirements and persecution Ripple et al.
Habitat conversion and degradation and over hunting of prey species increase spatial requirements of apex predators, increasing conflict with humans ecorregioes affecting social behavior, dispersal and habitat use MacdonaldCrooksCardillo et al. Consequently, an understanding of the space use and movement ecology of apex predators is key to effective conservation decision making for these species. For a big cat the jaguar is relatively understudied Brodieand although multiple studies have estimated jaguar home range size Schaller and CrawshawRabinowitz and NottinghamCrawshaw and QuigleyCrawshawEvorregiones et al.
Since anthropogenic factors ecorregionse jaguar occurrence throughout its range by determining habitat availability and quality Zeller et parwguay. Range-wide, the jaguar is considered near threatened Quigley et al. Although multiple studies have investigated space use by jaguar in Brazil and Argentina Schaller paraguat CrawshawCrawshaw and QuigleyCrawshawCrawshaw et al.
Given the status of the jaguar in Paraguay, the lack of information on the spatial and movement ecology of the species is of concern within the context of continued habitat loss, the maintenance of in-country and trans-boundary connectivity of populations, and their implications for the range-wide conservation of the jaguar.
Consequently, GPS-based telemetry was used to study space use and movements of jaguars in western Paraguay in the Dry Chaco, Humid Chaco and Pantanal, the region with the largest jaguar population in the country. Moreover, developing methodologies were employed to determine home range residency and account paraguayy autocorrelation in the data Fleming et al.
Based upon carnivore ecology in general, and jaguar ecology specifically, it was expected that male home range size and movement rates would be greater than those of females SandelCavalcanti and GeseConde et al.
Also, when compared to other sites Morato et al.
Ecorregión de agua dulce Paraguay
Apart from constituting an important contribution towards the conservation of jaguars within Paraguay, pqraguay the results into a comparative context with research from neighboring countries will facilitate the efficacy of trans-boundary conservation efforts, with important ecorrfgiones for range-wide conservation strategies for jaguar. The Dry Chaco is comprised of xeric forest, savannas and grasslands and the Humid Chaco and Pantanal are a mosaic of seasonally flooded grasslands, palm savanna and xerophilic woodlands ecorrefiones higher ground Olson et al.
The delineations between the Humid Chaco and Pantanal differ Ecorregkones et al. The Pantanal is also subjected to this east-west precipitation gradient; however, it and the Humid Chaco are also strongly effect by the hydrological cycles of the Rio Paraguay Mereles et al.
In the central Dry Chaco, research was undertaken on padaguay 50, ha Faro Moro ranch and more northerly in theha Defensores del Chaco National Pxraguay and the neighboringha of ranchland of the former consortium Grupo Chovoreca. Jaguars were captured using trained hounds to tree or bay jaguars which were then anesthetized using a weight-dependent dose of a mix of ketamine hydrochloride and xylazine hydrochloride injected by a dart shot from a tranquilizer gun McBride and McBride To estimate home ranges continuous-time stochastic movement models were fit to the telemetry data, incorporating ;araguay analysis of semi-variance in locations in relation to time lags to inspect the autocorrelation structure in the data over time and to account for variable sampling intervals Fleming et al.
Starting values derived from semi-variance functions paragguay used for maximum likelihood model fitting with model ecorregioones based upon Akaike Information Criteria, adjusted for small sample size AICcand model weights Fleming et al. If the best fitting model displayed range residency by an individual the model was used to estimate a home paaguay using autocorrelated kernel density estimation AKDE; De, et al.
Movement models tested were a random search model Brownian motion with uncorrelated velocities and no limits to space use, a random search model with constrained space use Ornstein—Uhlenbeck, OUand Ornstein—Uhlenbeck motion with foraging OUF which is the OU process with correlated velocities Fleming et al. All these models account for autocorrelation in positions, while the OUF model accounts for autocorrelation oaraguay velocities and the OU and OUF models include range residency home range.
Consequently, the OU and OUF models produce estimates of home range size and home range crossing time, while the OUF model additionally estimates the velocity autocorrelation time scale a measure of path sinuosity and mean distance traveled per day Fleming et al.
If individuals exhibited residency in their movements home range areas were estimated using AKDE based upon the best fitting model. When applied to serially autocorrelated data AKDE more accurately estimates home range compared to traditional kernel density estimation KDE; Worton as KDE assumes independent identically distributed data IIDwhich when violated, can result in greatly underestimated home range size Fleming et al.
Semi-variogram analysis, model selection and AKDE were undertaken using the ctmm package Calabrese et al. Data collected with an irregular sampling schedule starting in were accounted for using the dt argument within the variogram function in the ctmm package Calabrese et al.
Core areas of AKDE home ranges were estimated as the area encompassed within the isopleth where the proportional use of the estimated home range is equal to the predicted probability of use Seaman and PowellBingham and NoonVander Wal and Rodgers For the statistical analysis jaguars from the Humid Chaco and the Pantanal were combined into a single group since the characteristics of the system are highly paraghay, with the delineation between the two systems debatable Olson et al.
Additionally, only individuals ecorregionex exhibited residency in their movement behavior and space use [demonstrated by their variograms reaching an asymptote at approximately their paravuay range crossing time Fleming et al. A fixed-effect one-way analysis of variance ANOVA in a Bayesian modeling framework was used to test for differences in estimates of home range edorregiones, home range crossing time, directionality in movement velocity autocorrelation time scale and mean daily distance traveled between sexes systems combinedbetween systems sexes combinedbetween sexes within a system, and between same sexes between systems.
Normality in the data was tested using the Shapiro-Wilk test and log-transforming the data when their distribution did not meet assumptions of normality. The analysis was undertaken in R 3.
From June to June 35 jaguars were captured and collared, of which 19 individuals provided sufficient data for analysis; seven in the Dry Chaco five males, two femalesnine in the Humid Chaco three males, six females and three in the Pantanal one male, two females with estimated ages between 2 and 10 years Table 1.
Collars collected data between 52 and days, obtaining from to locations Table 1.
Sex, age, sample characteristics and estimated movement parameters, AKDE home range, core area and core area isopleths for study jaguars in the Paraguayan Dry Chaco, Humid Chaco and Pantanal. Best fitting models for wcorregiones movement of jaguars were either the OU or OUF models with 16 individuals demonstrating residency Table 1.
Estimated home range sizes varied between 86 and km 2 and core areas between 21 and km 2.
Categoría:Ecorregiones de Paraguay – Wikiwand
Probabilities based upon posterior distributions, that home range and movement parameters are ecorregioness between sex and ecosystem, between sexes within systems, and between same sexes between systems. These are the first estimates of movement parameters and home range and core area for jaguar in the Dry Chaco, Humid Chaco, and Paraguayan Pantanal, which furthermore take advantage of developing methods to empirically test for home range residency and account for autocorrelation in telemetry data when estimating space use Fleming et al.
Also, consistent with previous research males had larger home ranges, higher movement rates and more directional movements than females overall and within systems. Overall and between systems male home ranges were larger than females which was expected Cavalcanti and GeseSollmann et al. Conversely, male home ranges are driven by food availability and a need to maximize contact with receptive females which leads to males maximizing home range size towards optimizing reproductive opportunities constrained by their metabolic limits SandelSunquist and Sunquist This relationship is further supported ecorreguones the estimated movement parameters which showed that males traveled farther, faster, and more directionally than females in response to the need to cover and maintain their larger home ranges.
Consistent with expectations home range sizes of jaguars in the Dry Chaco were larger than in the Humid Chaco and Pantanal, overall and between sexes within systems where male home ranges were greater than females. The larger home ranges in the Dry Chaco are attributable to the lower productivity of that semi-arid ecosystem, more heterogeneously distributed prey and water, and negative effects of anthropogenic factors i.
Home range estimates from the Dry Chaco for both males and females are considerably larger than other estimates from this study and Morato et al. These differences may be related to differences in the geomorphology of the two regions and its interaction with local hydrological cycles. The Paraguayan Pantanal and the study area in the Humid Chaco have less forest area and a relatively greater area of inundated land during a large portion of the year compared to the Pantanal study areas of Morato et al.
Consequently, the reduced forest area, with smaller and more isolated forest patches during annual flooding, could fel the comparatively larger home ranges observed in the Paraguayan Pantanal and Humid Chaco, although reduced jaguar ecorgegiones resulting from persecution may also play a role in liberating available space and permitting greater space use.
Jaguars in the Pargauay Chaco had high movement rates and directionality in movement, similar to individuals from the Amazon in seasonally flooded forests Morato et al. These similarities are possibly responses to movements among sporadically distributed critical resources prey, water, mates despite the large differences in ecosystem characteristics.
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This indicates that despite home range size, sex, or system jaguars are most intensively using about a third of their home range area. Additionally, the results suggest a cautious interpretation of arbitrarily defined core area delimitations Powell edorregiones, however, it is also recognized that with AKDE home ranges the median or mean area are justifiable measures of central tendency Fleming and Calabrese In light of the extensive deforestation that is occurring in the Dry Chaco of western Paraguay, the large home ranges observed in this system, which are consistent with the estimated low density of jaguar in the Bolivian Dry Chaco Noss et al.
Persecution is common throughout the range of the jaguar, ecorregiknes, its practice and magnitude is not equivocal geographically and consequently how the removal of individuals may impact space use, and subsequently comparisons among ecosystems and regions, needs to be considered and is of interest for future research.
This highlights an urgent need to mitigate jaguar-human conflict in the region by actively including the livestock production sector in the conservation decision making process. Furthermore, given continuing deforestation, conservation initiatives need to take into account the large spatial needs of jaguar in western Paraguay by recognizing and incorporating the role of private lands in the long-term conservation of the species in Paraguay and in maintaining trans-boundary connectivity among populations.
Spatial organization and food habits of jaguars Panthera onca in a floodplain forest. Is research effort allocated efficiently for conservation? Felidae as a global case study.
La expansión de la soja en Paraguay
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