DSpace Angular :: Browsing by Author "Bonacic, Cristian"

Browsing by Author "Bonacic, Cristian"

Now showing 1 - 20 of 22

A conflict between a threatened deer and indigenous agriculture: Tarukas (Hippocamelus antisensis D'Orbigny) and Aymara farmers in northern Chile
(EDICIONES UNIV, CONCEPCION, 2021) Munoz, Alejandra E.; Petitpas, Robert; Marin, Juan C.; Bonacic, Cristian
The taruka is one of the least known deer species of the world. Its range includes the northern Andean mountains in Chile, where their relationship with Aymara peasants is conflictive because of crop raiding. The aim of this study is to understand the nature of this conflict in Chile, and identify socio-ecological features that may explain it. Data of different sampling dates from 2003 to 2011 of night transects on roads, crop examination, interviews and direct sighting of tarukas were used to understand its ecology and relationship with local peasants. Peasants interviewed (n=47) cultivated mainly corn (85.1%) and alfalfa (74.5%) in small farms and 83% of them raise livestock. The conflict is widespread in Parinacota Province, where tarukas effectively consume crops, mainly abandoned alfalfa at night. The occurrence of crop raiding is not positively correlated with dry season as expected. However crop consumption is low (10.3% average of damaged plants in crop plots). In Del Tamarugal Province only 29.4% of peasants manifested conflict with tarukas but they did report conflict with other ungulates. Day sightings showed 78 tarukas in 34 encounters during 59 days. Night surveys yielded 11.6 +/- 7.4 tarukas/survey, sighted only in alfalfa plots. Aymara agriculture feeds tarukas and is declining because of rural-urban migration. The conflict must be considered in the conservation strategy of the species.
Activity patterns by two colour morphs of the vulnerable guina, Leopardus guigna (Molina 1782), in temperate forests of southern Chile
(2015) Hernandez, Felipe; Galvez, Nicolas; Gimona, Alessandro; Laker, Jerry; Bonacic, Cristian
Here we provide the first analysis of activity patterns exhibited by spotted and melanistic colour morphs of the vulnerable guina Leopardus guigna, in a forest landscape of southern Chile. Camera traps showed guinas were mainly active at night (64% of photos). Melanistic guinas were more nocturnal (82% of photos) than the more common spotted cats (57%). Spotted guinas were more active on cloudy and moonless nights. Our study provides novel findings about the behavioural plasticity of guina in different ambient conditions, and the relative advantage to each colour morph to persist in an increasingly human-dominated landscape.
Age and sex structure of Andean Condor (Vultur gryphus) in feeding areas of central Chile
(NEOTROPICAL ORNITHOLOGICAL SOC, USGS PATUXENT WILDLIFE RESEARCH CTR, 2015) Escobar Gimpel, Victor; Alvarado, Sergio; Vargas, Hernan; Bonacic, Cristian
The age and sex structures of the Andean Condor are known for some parts of its range while in other such areas data are lacking. The aim of this study was to obtain demographic data from the Andes of central Chile and to compare them with those available from other areas of distribution. From 2009-2010, we studied the age and sex structure of the Andean Condor in central Chile at feeding sites. Four carrion points were provided by us. The carrion comprised carcasses of sheep, donkey, and guanaco. Condor abundance at experimental carrion (mean = 36.25, SE = 48.45) was highly variable (CV = 134%), and we observed a higher proportion of adults (54%) than immatures (46%). Overall the sex ratio of adults was male-biased (52:48). The age and sex structures in our study are consistent with those found in other areas of the species' distribution. Our results show a higher proportion of adult birds and males at feeding sites in the Andes of central Chile, which has implications on the population viability of the Andean Condor.
Altered fire regimes modify lizard communities in globally endangered Araucaria forests of the southern Andes
(NATURE PORTFOLIO, 2021) Infante, Jose; Novoa, Fernando J.; Ibarra Eliessetch, José Tomás; Melnick, Don J.; Griffin, Kevin L.; Bonacic, Cristian
Wildfire regimes are being altered in ecosystems worldwide. The density of reptiles responds to fires and changes to habitat structure. Some of the most vulnerable ecosystems to human-increased fire frequency are old-growth Araucaria araucana forests of the southern Andes. We investigated the effects of wildfires on the density and richness of a lizard community in these ecosystems, considering fire frequency and elapsed time since last fire. During the 2018/2019 southern summer season, we conducted 71 distance sampling transects to detect lizards in Araucaria forests of Chile in four fire "treatments": (1) unburned control, (2) long-term recovery, (3) short-term recovery, and (4) burned twice. We detected 713 lizards from 7 species. We found that the density and richness of lizards are impacted by wildfire frequency and time of recovery, mediated by the modification of habitat structure. The lizard community varied from a dominant arboreal species (L. pictus) in unburned and long-recovered stands, to a combination of ground-dwelling species (L. lemniscatus and L. araucaniensis) in areas affected by two fires. Araucaria forests provided key habitat features to forest reptiles after fires, but the persistence of these old-growth forests and associated biodiversity may be threatened given the increase in fire frequency.
Analysis of the echolocation calls and morphometry of a population of Myotis chiloensis (Waterhouse, 1838) from the southern Chilean temperate forest
(2010) Ossa, Gonzalo; Tomas Ibarra, Jose; Barboza, Kathrin; Hernandez, Felipe; Galvez, Nicolas; Laker, Jerry; Bonacic, Cristian
G. Ossa, J.T. Ibarra, K. Barboza, F. Hernandez, N. Galvez, J. Laker, and C. Bonacic. 2010. Analysis of the echolocation calls and morphometry of a population of Myotis chiloensis (Waterhouse, 1838) from the southern Chilean temperate forest. Cien. Inv. Agr. 37(2): 131-139. Echolocation is characteristic of bats of the suborder Microchiroptera. Though recent studies of echolocation calls in Latin America have generated significant advances in knowledge about distribution, habitat use and ecology of bats, the recording and analysis of bat calls is barely known in Chile. As a first step in studies on the ecology of the endemic Chilean myotis bat (Myotis chiloensis), we carried out morphometric measures and analyzed echolocation calls in a rural site near Puck (39 degrees 15'S 17 degrees W) in the Araucania Region of southern Chile. During January 2009, we obtained 22 records from captured and 75 records from flying individuals. The analysis of calls in searching phase showed that the terminal frequency for this species is 43.4 +/- 1.2 kHz, with a mean duration of 2.1 +/- 1.0 ms and an interval between pulses of 77.5 +/- 16.9 ms. The calls are FM - QCF, as is characteristic for the family Vespertilionidae. The contribution of new morphometric data from captured and released individuals indicates differences from previous studies. The records and acoustic analysis establishes a baseline for more detailed future ecological investigation of this and other bat species in Chile.
Behavioural and physiological consequences of capture for shearing of vicunas in Argentina
(ELSEVIER SCIENCE BV, 2010) Arzamendia, Yanina; Bonacic, Cristian; Vila, Bibiana
Behavioural. physical and physiological responses of Argentinean vicunas to capture, handling and shearing were studied for the first time. The research was undertaken in a study area of 2414 ha with a mean density of 12-40 vicunas/km(2). Captures were conducted on groups of wild vicunas that had not received any prior management. Groups were herded into a funnel system that ended in a corral with several internal subdivisions. Three distinct capture methods were compared, according to the method by which the animals were herded into the corral (vehicles system: vehicles only; mixed system: people on foot and vehicles; and Chaku system: people on foot only). Attempts to escape, alarm calls, increased vigilance, vocalizations, and kicking were measured to quantify the stress response. A total of 478 vicunas were captured between May 2003 and November 2005. Vicunas captures by mixed system showed alert and active behaviours and vocalized more in the handling corral. The most active animals inside the corrals showed higher respiratory and heart frequency during handling (r = 0.44, P < 0.05 and r = 0.58, P < 0.001, respectively) and the heart rate increase was inversely proportional to blood glucose and creatin kinase (CK levels) (r = -0.31, P = 0.05 and r = -0.4, P = 0.05, respectively). Females captured by people on foot showed greater concentrations of cortisol (174 +/- 10.5 nmol/L), compared to vicunas captured by people and vehicles (127.38 +/- 12.5 nmol/L) (F((1,21)) = 7.22, P < 0.05). Cortisol levels peaked between 90 and 120 min post-capture (female = 177.13 +/- 7.67 nmol/L: male = 135.11 +/- 13.23 nmol/l.). CK (In) increased significantly according to time spent in captivity. The system that caused the fewest stress responses in vicunas was capture by people on foot. (c) 2010 Elsevier B.V. All rights reserved.
Could invasive lagomorphs increase the predation risk for guanaco (Lama guanicoe) by puma (Puma concolor) in the Chilean Central Andes?
(2024) Infante-Varela, Jose; Bonacic, Cristian
Invasive species can have complex direct and indirect impacts on ecosystems. The impacts of invasive prey species on native prey can be difficult to observe if the latter migrate seasonally, and when the interaction is indirect. We hypothesize that invasive lagomorphs and snow dynamics indirectly drive predation risk for guanaco by puma. We employed camera-trapping data collected over multiple years and seasons in an altitudinal gradient in the Andes of Central Chile. We predicted a high spatial and temporal association between puma and lagomorph detections, given these prey species comprise most of puma diet in the area. We also expected a higher spatiotemporal association between guanaco and puma detections towards higher snow cover in the study area, because of downward altitudinal migration of the ungulate. We obtained 4863 mammalian detections. Our data shows that the detection of puma was positively associated with hare capture rate year-round. In addition, puma detection was positively associated with the interaction of snow cover and guanaco capture rate. Puma temporal activity strongly overlapped with hare, whereas puma apparently increased diurnal activity with an increase in guanaco capture rate. Predation risk for guanaco increased when snow cover was higher and decreased when guanaco migrated to higher altitudes during dryer months. We conclude it is of conservation concern that lagomorphs may be subsidizing pumas and modifying patterns of consumptive and non-consumptive effects of the predator on native prey populations.
Diversity and singularity of the avifauna in the austral peat bogs of the Cape Horn Biosphere Reserve, Chile
(2010) Tomas Ibarra, Jose; Anderson, Christopher B.; Altamirano, Tomas A.; Rozzi, Ricardo; Bonacic, Cristian
Ibarra, J.T., C.B. Anderson, T.A. Altamirano, R. Rozzi, and C. Bonacic. 2010. Diversity and singularity of the avifauna in the austral peat bogs of the Cape Horn Biosphere Reserve, Chile. Cien. Inv. Agr. 37(1): 29-43. Sphagnum-dominated peat bogs that are strongly embedded within the southern temperate forest matrix are increasingly being used for agriculture. Nevertheless, little is known about their biodiversity. Moreover, the remote areas of southern Chile where peat bogs are found, such as the Cape Horn Biosphere Reserve (CHBR, 54-55 degrees S), where birds are the most diverse and best represented group of vertebrates, have not been well-investigated. With the aim to broaden this knowledge in the CHBR, we studied the diversity of the avian assemblage in peat bogs on Navarino Island. We compared the composition of avian species between wetlands with and without peat bogs to test if Sphagnum bogs represented a singular habitat for birds in this area. Furthermore, the 37 bird species recorded in these habitats were classified according to guild structure. The community similarity values showed that peat bogs hosted a bird composition that was different from that present in wetlands without Sphagnum, suggesting that peat bogs are a singular type of habitat for birds in the CHBR. The most frequently feeding groups recorded in these wetlands were insectivores (48.7%), followed by omnivores (23.1%). Our results showed that, in contrast to previous studies of birds in peat bogs, these environments constituted a distinct wetland habitat for feeding, reproduction and sheltering for some species in the CHBR. Thus, plans for the conservation and rational use of peat ecosystems should consider the high value of these habitats for biodiversity on a landscape scale, especially for birds of the southernmost extreme of the Americas.
Endocrine changes during pregnancy, parturition and post-partum in guanacos (Lama guanicoe)
(ELSEVIER SCIENCE BV, 2009) Luis Riveros, Jose; Urquieta, Bessie; Bonacic, Cristian; Hoffmann, Bernd; Bas, Fernando; Schuler, Gerhard
Plasma concentrations of progesterone (P4), estradiol-17 beta (E2), estrone (E1) and estrone sulfate (E1S) were measured during gestation in eight guanacos kept in captivity. Gestational length was 346.1 +/- 9.8 days. P4 plasma concentrations increased after ovulation and remained elevated until parturition. However, during the last 4 weeks of gestation, a gradual decrease from 4.17 x 1.17(+/- 1) nmol/L to 2.02 x 1.95(+/- 1) nmol/L on day 5 before parturition was observed, followed by a more abrupt final decline to baseline concentrations which were reached on the day after parturition. Mean E2 plasma concentrations started to increase during the eighth month of gestation, and were significantly elevated up to maximum concentrations of 484.7 x 1.21(+/- 1) pmol/L during the last 2 months of pregnancy. Concentrations returned to baseline during the last 2 days of gestation. An increase of E1S concentrations (p < 0.01) was observed in the eleventh month of gestation. Mean El S concentrations remained rather constant during the last 3 weeks of gestation between 4 to 8 nmol/L until parturition, when a steep precipitous decline was observed. E1 concentrations were slightly elevated during the last 4 weeks of gestation, however, maximum concentrations did not exceed 1.5 nmol/L The results show distinct species specific features of gestational steroid hormone profiles in the guanaco in comparison to domestic South American camelids, such as a more pronounced gradual prepartal decrease of P4 concentrations prior to the final decline to baseline, and clearly lesser EIS concentrations during the last 4 weeks of gestation, which lack a continuous prepartal increase. (C) 2009 Elsevier B.V. All rights reserved.
Invasive American mink Mustela vison in wetlands of the Cape Horn Biosphere Reserve, southern Chile: what are they eating?
(CAMBRIDGE UNIV PRESS, 2009) Ibarra Eliessetch, José Tomás; Fasola, Laura; Macdonald, David W.; Rozzi, Ricardo; Bonacic, Cristian
The impact of alien American mink on the native fauna of oceanic islands has been demonstrated in a number of locations. In the sub-Antarctic Cape Horn Biosphere Reserve of southern Chile the species is currently expanding in an area where the native fauna evolved in the absence of terrestrial predators. To evaluate any emerging problems we therefore investigated seasonal variation in prey use by mink on Navarino Island within the Reserve. We identified undigested remains in 414 scats collected from the shores of 27 ponds over January-November 2006. Diet consisted mainly of mammals and birds. Mammals, including both native and exotic rodents, were the predominant prey in all seasons but birds were of equal importance during the summer (when birds breed and their abundance and diversity increases on the island). Exotic rodents were the only identifiable mammalian prey item during winter. Native wetland birds constituted a substantial proportion of mink diet, and greater than that reported in other areas. Many birds breeding on Navarino Island are ground-nesting, a strategy that evolved in the absence of native mammalian predators. Considering the international importance of this region, our results emphasize the need for an assessment of the impact of mink predation on the populations of native prey.
Is tourism impacting pumas in the Torres del Paine UNESCO Biosphere Reserve in southern Chile?
(2023) Cifuentes-Ibarra, Mauricio; Elbroch, L. Mark; Ohrens, Omar; Infante, Jose; Bonacic, Cristian
Ecotourism generates $7.6 trillion annually and supports 292 million jobs around the world, and because of these benefits, it has been emphasized as a conservation strategy. Ecotourism, how-ever, is not the solution for every community, and there is growing evidence that tourism can have unintended consequences for local people and wildlife, unless well managed. Here, we assessed the relative impacts of anthropogenic activities related to tourism (e.g. road density, distance to ranches and camping areas) and prey distributions on puma occupancy and abun-dance in the open steppe habitat of the southeast portions of the Torres del Paine UNESCO Biosphere Reserve, where pumas are protected. In winter, puma abundance and occupancy were explained by both prey and anthropogenic metrics. In summer, puma abundance was explained by both prey and anthropogenic metrics, but occupancy only by anthropogenic metrics. Across both periods, puma abundance was only explained by anthropogenic metrics, and occupancy was explained by both prey and anthropogenic metrics. Guanacos, the most important prey species for local pumas, never appeared in any top model, except in summer, during which puma abundance was explained by lower not higher guanaco abundance. Not unexpectedly, puma abundance and occupancy were negatively correlated with trail and road density across all analyses. In the high tourism season of summer, roads had 2-3 times the impact on puma abundance than prey metrics in top models. During our study, the average number of monthly visitors per month in summer (November-January) was 892 % higher than winter (May-July). As a whole, we believe our analyses suggest that tourism may be negatively impacting pumas, but the severity of this impact remains questionable. Future work should include studying stress in puma populations experi-encing heavy tourism, simultaneous with the work needed to understand relative thresholds of impact on puma fitness metrics (e.g. survival, hunting success). We believe our work also high-lights the need for standards and guidelines to be created and adopted among those involved in puma tourism in Torres del Paine and beyond.
Mitochondrial DNA variation and systematics of the guanaco (Lama guanicoe, Artiodactyla: Camelidae)
(2008) Marin, Juan C.; Spotorno, Angel E.; Gonzalez, Benito A.; Bonacic, Cristian; Wheeler, Jane C.; Casey, Ciara S.; Bruford, Michael W.; Palma, R. Eduardo; Poulin, Elie
Guanacos (Lama guanicoe) are the most important native herbivorous species in the South American steppes and the dominant ungulate in a fauna rich in rodents but poor in large mammal species. Between 2 and 4 subspecies are usually recognized within Lama guanicoe, based on subtle morphological differences and geographic distribution. To evaluate whether molecular variation is consistent with the latter hypotheses, we analyzed the complete cytochrome-b and partial control region mitochondrial DNA sequences of L. guanicoe from 22 localities in Peru, Bolivia, Argentina, and Chile. Sequence analyses of both genes support the monophyly of the species but failed to distinguish the occurrence of subspecies along the geographic range. Despite that, the northernmost populations (Peru and northern Chile) showed some degree of genetic differentiation with respect to southern representatives from Argentina, Bolivia, and rest of Chile. Analysis of genetic diversity also showed a strong signal of past low population size and a recent population expansion.
Molecular detection and characterization of Bartonella spp. in rodents from central and southern Chile, with emphasis on introduced rats (Rattus spp.)
(2023) Sepulveda-Garcia, Paulina; Rubio, Andre, V; Salgado, Rodrigo; Riquelme, Maira; Bonacic, Cristian; Canales, Nivia; Mueller, Ananda
Bartonella spp. was screened in 155 rodents from Chile, mainly the invasive rats Rattus norvegicus and Rattus rattus. A total of 155 spleen and 50 blood samples were analyzed through real-time PCR for Bartonella spp. (nuoG gene). Positive samples were subjected to amplification of fragment of loci gltA, rpoB and ITS by conventional PCR (cPCR). Overall, 43 spleen samples (27.7%) and 6 rodent blood samples (12%) were positive for nuoG- Bartonella spp. Positive samples were found in R. norvegicus, R. rattus, Abrothrix olivacea and Oligoryzomys longicaudatus. Bartonella spp. DNA was amplified by cPCR in 16 samples, resulting in 21 sequences (6 gltA, 5 ITS and 10 rpoB). Sequencing and phylogenic analyses identified genotypes from Rattus spp., potentially belonging to Bartonella coopersplainsensis, Bartonella henselae, Bartonella tribocorum, and an undescribed Bartonella sp. From native rodents, one sequence was identified, being related B. machadoae. In conclusion, this work describes diverse and potentially zoonotic Bartonella spp. genotypes in Rattus spp. Additionally, this is the first report of Bartonella in O. longicaudatus, including a potentially novel Bartonella genotype or species.
Molecular genetic evidence for social group disruption of wild vicunas Vicugna vicugna captured for wool harvest in Chile
(ELSEVIER, 2009) Sarno, Ronald J.; Gonzalez, Benito A.; Bonacic, Cristian; Zapata, Beatriz; O'Brien, Stephen J.; Johnson, Warren E.
Since 1994 wild vicunas have been captured and shorn for their wool, yet, there remains a noticeable lack of data regarding the possible influence of capture and shearing upon vicuna biology. Therefore, we assessed post-capture group composition, genetic relatedness, and paternity among animals that were captured for live shearing and release. We captured twenty-six groups (134 animals) on the Chilean Altiplano. Seventy-three percent of Male Groups (designated prior to chase) contained exclusively adult males upon capture,whereas remaining "Male Groups" contained crias and/or adult females and crias. Forty-seven percent of Family Groups (designated prior to chase) contained I adult male, adult females, and the number of crias <= the number of adult females. Remaining Family Groups contained no or multiple adult males, and more crias than adult females. Average relatedness among all vicunas was -0.007. Paternity analysis revealed that 35% of crias were captured with their biological mother and that only 1 cria was captured with both biological parents. Based on previous observations of group composition in the wild, animals from different groups may separate and/or mix during the chasing stage. Improvement of the chasing technique and instituting a post-capture monitoring program may aid in the detection of medium- and long-term impacts regarding group stability, cria survival, and ultimately wool production. (C) 2009 Elsevier B.V. All rights reserved.
Ovarian follicular dynamics and hormonal secretory profiles in guanacos (Lama guanicoe)
(ELSEVIER SCIENCE BV, 2010) Luis Riveros, Jose; Schuler, Gerhard; Bonacic, Cristian; Hoffmann, Bernd; Graciela Chaves, M.; Urquieta, Bessie
The objective of the present study was to describe ovarian activity in 11 adult non-mated guanacos, evaluated every second day for 40 days by transrectal ultrasonography and by plasma estradiol-17 beta and progesterone concentrations. An inverse relationship (r = -0.29, P < 0.001) was observed between the diameter of the largest ovarian follicle and the total number of follicles indicating that follicular growth in guanacos occurs in waves. The mean duration of follicular wave was 15.1 +/- 4.2 days with a range from 9 to 26. The follicular growth phase was 7.0 +/- 2.4 days, the static phase 3.0 +/- 1.2 days, the regression phase 5.2 +/- 2.1 days and the inter-wave interval was 12.6 +/- 5.6 days. The maximum follicular diameter in each follicular wave was 10.2 +/- 2.1 mm with a range from 7.2 to 16.1 mm. Inter-wave intervals of longer duration were associated with a larger maximum follicle diameter (P<0.001). Follicular activity alternated between ovaries in 93% of the waves with 48% of dominant follicles occurring in the left and 52% in the right ovary without differences (P>0.05). Plasma estradiol-17 beta concentrations showed a wave-like pattern, varying from 20.0 to 92.1 pmol/L. Plasma progesterone concentrations remained below 1 nmol/L without any ultrasonic evidence of ovulation during the study. These results in guanacos suggest a follicular wave pattern more similar to the llama (Lama glama) than previously described in other South American and Old World camelid species. (C) 2009 Published by Elsevier B.V.
Ravines as conservation strongholds for small wildcats under pressure from free-ranging dogs and cats in Mediterranean landscapes of Chile
(TAYLOR & FRANCIS LTD, 2021) Beltrami, Esperanza; Galvez, Nicolas; Osorio, Christian; Kelly, Marcella J.; Morales Moraga, David; Bonacic, Cristian
The Chilean Mediterranean ecosystem is threatened by anthropogenic pressures, such as habitat loss by intensive agriculture and urban sprawl. Abandoned dogs (Canis lupus familiaris) and cats (Felis silvestris catus) pose conservation challenges for Chilean wildlife including the pampas cat (Leopardus colocolo) and the guina (Leopardus guigna). We used camera trap data to investigate influences of natural and anthropogenic landscape features on spatiotemporal trends of these species. We also used co-occurrence modeling and kernel density estimation to investigate spatial and temporal patterns overlap of wildcats, free-ranging (FR) dogs, and FR-cats. FR-dogs showed the highest detection and site use probabilities, while guinas had the lowest across 80 camera trap sites. Top models showed no spatial avoidance between species and co-occurrence of wildcats was positively influenced by forest habitat. However, FR-dogs negatively affected detection of wildcats. Ravines surrounded by forest positively influenced guina and pampas cat detection probabilities when dominant species were not present. FR-dogs and wildcats had significantly different temporal activity patterns and low overlap coefficients, while wildcats and FR-cats showed high overlap in activity patterns. We suggest changing current policies to control domestic animals and strategic planning in agricultural areas of central Chile to better conserve native wildcat species.
Response of mesocarnivores to anthropogenic landscape intensification: activity patterns and guild temporal interactions
(OXFORD UNIV PRESS INC, 2021) Galvez, Nicolas; Meniconi, Paola; Infante, Jose; Bonacic, Cristian
Carnivores face important anthropogenic threats in agricultural areas from habitat loss and fragmentation, disturbance by domestic free-roaming dogs and cats, and direct hunting by humans. Anthropogenic disturbances are shifting the activity patterns of wild animals, likely modifying species interactions. We estimated changes in the activity patterns of the mesocarnivore guild of agricultural landscapes of the La Araucania region in southern Chile in response to land-use intensification, comparing intra- and interspecific activity patterns at low and high levels of forest cover, fragmentation, and land ownership subdivision. Our focal species comprise the guina or kod-kod (Leopardus guigna), two fox species (Lycalopex culpaeus and L. griseus), a skunk (Conepatus chinga), and one native mustelid (Galictis cuja), in addition to free-roaming dogs (Canis lupus familiaris) and cats (Felis catus) and their main mammalian prey species (i.e., Rodentia and Lagomorpha). In 23,373 trap nights, we totaled 21,729 independent records of our focal species. Our results show tendencies toward nocturnality at high land-use intensification, with potential impacts on species fitness. Nocturnal mesocarnivores decreased their diurnal/crepuscular activity, while cathemeral activity shifted to nocturnal activity at high land-use intensification, but only when in sympatry with a competitor. High land-use intensification decreased the activity overlap between native and domestic mesocarnivores but increased the overlap between native mesocarnivores. High intensification also reduced overlap with prey species. Notably, foxes displayed peaks of activity opposing those of dogs, and plasticity in activity pattern when in sympatry with dogs, such as strategies to avoid encounters. We stress the need to suppress the free-roaming and unsupervised activity of dogs to mitigate impacts of high land-use intensification on mesocarnivores.
Rufous-legged Owl (Strix rufipes) and Austral Pygmy Owl (Glaucidium nanum) stand use in a gradient of disrupted and old growth Andean temperate forests, Chile
(TAYLOR & FRANCIS LTD, 2012) Ibarra Eliessetch, José Tomás; Galvez, Nicolas; Gimona, Alessandro; Altamirano, Tomas A.; Rojas, Isabel; Hester, Alison; Laker, Jerry; Bonacic, Cristian
We studied how human induced structural changes in forests affect stand use of the Rufous-legged Owl (forest-specialist) and the Austral Pygmy Owl (forest-facultative), in a gradient from lowland disrupted forests to protected Andean forests in Chile. We also tested if the calls of one species influenced the calling behaviour of the other. We detected a total of 34 Rufous-legged Owls and 21 Austral Pygmy Owls during the four seasons. Rufous-legged Owls were found principally in old growth Araucaria-Nothofagus stands (32.4%), and Pygmy Owls in old growth evergreen stands (52.4%). For both species there was a seasonal effect on call response, with a drop in responses in autumn and winter. Our models suggested that Rufous-legged Owls inhabit a more specific range of habitat characteristics than Pygmy Owls. The former selected stands with tall trees, relatively low tree density, and high bamboo density. Pygmy Owls selected stands with tall trees and relatively high tree density. There was no evidence that either species influenced the calling behaviour of the other, suggesting no negative association between use of a territory by the two species. Our results emphasize the importance of structural components of old growth forests for both species, but also the relevance of stands surrounding protected areas.
Species delimitation and intraspecific diversification in recently diverged South American foxes
(2024) Pizarro, Eduardo J.; Julio-Kalajzic, Bernardita; Sallaberry-Pincheira, Nicole; Munoz, Valentina; Gonzalez-Acuna, Daniel; Cabello, Javier; Acosta-Jamett, Gerardo; Bonacic, Cristian; Iriarte, Agustin; Rodriguez, Alejandro; Travaini, Alejandro; Cevidanes, Aitor; Brito, Jose Luis; Millan, Javier; Marin, Juan Carlos; Vianna, Juliana A.
The divergence between the Andean fox (Lycalopex culpaeus) and the South American gray fox (L. griseus) represents a recent speciation event in South America. These taxa are partially sympatric and share biological, morphological, and ecological traits. Previous studies failed to recover reciprocal monophyly, suggesting the occurrence of introgression or incomplete lineage sorting (ILS). Here, we obtained mitochondrial and nuclear markers for 140 L. culpaeus and 134 L. griseus from the Southern Cone of South America to assess their inter and intraspecific divergence. We recovered reciprocal monophyly of L. culpaeus and L. griseus, with mild signatures of introgression or ILS. Therefore, taxonomic misidentification and the use of a limited number of markers may be the main reason behind the past debate about the delimitation of both species. Two main divergent clades were found in L. culpaeus with a phylogeographical boundary in the High Plateau of northeastern Chile. The southern clade along with three northern sub-clades corresponded to four morphological subspecies. Less genetic differentiation was found in L. griseus with a spatial population structure that does not support the occurrence of distinct subspecies. The results found in this study suggest the extant evolutionary significant units that need to be considered for biological conservation management of these species.
Species richness, diversity and human activities in an elevation gradient of a high-ecosystem in Lagunas Huascoaltinas, Atacama Region, Chile
(2009) Sanhueza, Doris; Miranda, Marcelo; Gomez, Miguel; Bonacic, Cristian
D. Sanhueza, M. Miranda, M. Gomez, and C. Bonacic. 2009. Species richness, diversity and human activities in an elevation gradient, a high-ecosystem, Lagunas Huascoaltinas, Atacama Region, Chile. Cien. Inv. Agr. 36(3):411-424. The relationship between species richness, diversity and grazing frequency along an altitudinal gradient (1900-3400 m) of an Andean ecosystem indicates that there is an intense human pressure on vegetation use. To identify the vascular flora and its conservation, 20 sites were sampled in two visits during 2006. We identified 79 taxa, including 62.03% native species, 22.78% adventitious and 8.86% endemic (the remaining 6.33% was identified only at the genus level). Some genera were underrepresented. We also observed latitudinal limits (Alstremeria andina), monotypic genera (Geoffroea, Kurzamra, Phragmiles, Tessaria and Salix) and monogeneric families (Buddlejaceae, Ephedraceae, Equisetaceae, Malesherbiaceae, Salicaceae and Oxalidaceae). Moreover, we found differences in the species distribution patterns during periods of grazing use and identified statistically significant differences in the species richness (p < 0.001), diversity (p = 0.010) and grazing frequency (p = 0.047).

Browsing by Author "Bonacic, Cristian"

Results Per Page

Sort Options