Ronald J. Sarno

Ecology of the Patagonia puma Felis concolor patagonica in southern Chile

The ecology of the Patagonia puma was studied in Torres del Paine National Park, Chile. Thirteen pumas were captured from 1986 to 1989 and equipped with radio transmitters. During the winter of 1988 there was one puma per 17 km 2 in the 200 km 2 study area. Home ranges varied from 24 to 107 km 2 . Female home ranges overlapped with those of other males and females extensively, but male ranges overlapped each other for only short time periods. Seven adult pumas had home ranges extending outside the park boundaries and at least three preyed on sheep. Guanacos Lama guanicoe, especially young animals, were the puma’s most important prey item by biomass, but European hares Lepus capensis were preyed upon more than expected relative to available biomass. Of 731 guanaco skulls collected from 1979 to 1988, 33% showed clear evidence of having been killed by pumas. Over the past decade puma numbers are believed to have increased in the park, perhaps in response to an increase in guanaco numbers and continued protection. With decreased hunting pressure and harassment by horses and dogs, pumas have habituated to people and are being observed more often by park visitors. # 1999 Elsevier Science Ltd. All rights reserved.

Spatial distribution of guanaco mating sites in southern Chile: conservation implications

We investigated the distribution, habitat characteristics and conservation value of mating areas in a wild population of guanacos in Torres del Paine National Park, Chile. Copulating guanacos were observed directly during December–January 1994–1995, 1995–1996 and 1997–1998. The timing of the breeding season was homogeneous across years. Copulation sites occurred in vega (ephemeral wetland) habitats (48.6%) greater than expected based on their relative availability (12.6%). A multivariate habitat analysis revealed that habitat composition of breeding habitats differed significantly from non-breeding areas (P < 0.001). Availability of trees and shrubs (breeding=5.5%; non-breeding=35.6%; P < 0.001) and grassland (breeding=34.6%; non-breeding =9.5%; P < 0.001) contributed most to the variation in habitat types among areas. Relative occurrence of pumas was significantly lower in breeding areas (P=0.04). The spatial arrangement of mating sites was similar among years suggesting that adult female and male guanacos exhibited site fidelity to breeding sites. Since vegas were important habitats for mating it is critical that natural resource managers consider the importance of these ephemeral wetland resources to ensure for proper reproduction and viability of local guanaco populations. # 2002 Elsevier Science Ltd. All rights reserved.

Forced dispersal of juvenile guanacos (Lama guanicoe): causes, variation, and fates of individuals dispersing at different times

We examined adult-juvenile conflict in the guanaco (Lama guanicoe). During spring, territorial males become increasingly aggressive toward all juveniles born the previous year and begin expelling them from family groups. In an apparent effort to reduce aggression, juveniles display submissive crouches when being observed, approached, or attacked by the territorial male. Therefore, we assessed the influence of juvenile submissive behavior on the timing of dispersal and also examined if dispersal time was related to survival and reproductive performance as adults. We also evaluated hypotheses regarding the evolution of juvenile mammalian dispersal in the context of if and how each may favor the forced dispersal of juvenile guanacos by territorial males. Juveniles generally dispersed in late spring and early summer, and a nearly equal proportion of females (n=46; 48%) and males (n=49; 52%) dispersed. More-submissive animals generally dispersed later than less-submissive animals. Juvenile sex and dispersal time were not related to survival. In contrast, juvenile sex and dispersal time were related to reproductive performance. The probability of reproducing was highest when juveniles dispersed early and decreased with increasing time in family groups prior to dispersal. The largest proportion of juveniles was forced to disperse during a 2-week interval following the peak of the breeding season. Competition for food resources is likely very intense at this juncture and territorial males may force older juveniles to disperse in order to divert food resources to younger neonates. Additionally, juveniles may be forced to disperse after territorial males mate their mothers to prevent lost mating opportunities, because females leave territories when their offspring disperse and possibly prior to mating with males. We conclude that the forced dispersal of juvenile guanacos by territorial males is ultimately driven by competition for food resources on territories. The timing of dispersal, however, may be tempered by the chronology of matings between territorial males and particular adult females, and/or genetic relatedness between territorial males and juveniles.

Molecular Genetic Insights on Cheetah (Acinonyx jubatus) Ecology and Conservation in Namibia

Abstract The extent and geographic patterns of molecular genetic diversity of the largest remaining free-ranging cheetah population were described in a survey of 313 individuals from throughout Namibia. Levels of relatedness, including paternity/maternity (parentage), were assessed across all individuals using 19 polymorphic microsatellite loci, and unrelated cheetahs (n = 89) from 7 regions were genotyped at 38 loci to document broad geographical patterns. There was limited differentiation among regions, evidence that this is a generally panmictic population. Measures of genetic variation were similar among all regions and were comparable with Eastern African cheetah populations. Parentage analyses confirmed several observations based on field studies, including 21 of 23 previously hypothesized family groups, 40 probable parent/offspring pairs, and 8 sibling groups. These results also verified the successful integration and reproduction of several cheetahs following natural dispersal or translocation. Animals within social groups (family groups, male coalitions, or sibling groups) were generally related. Within the main study area, radio-collared female cheetahs were more closely interrelated than similarly compared males, a pattern consistent with greater male dispersal. The long-term maintenance of current patterns of genetic variation in Namibia depends on retaining habitat characteristics that promote natural dispersal and gene flow of cheetahs.

Predation of guanacos (Lama guanicoe) by southernmost mountain lions (Puma concolor) during a historically severe winter in Torres del Paine National Park, Chile

The effects of mountain lion Puma concolor predation on guanaco Lama guanicoe mortality was investigated during the historically severe winter of 1995 in Torres del Paine National Park, Chile. The 45 guanaco carcasses located represented 3% of the entire guanaco population of which 74% were mountain lion kills, 13% died from malnutrition, 2% died from fence entanglement and 11% died from unknown causes. Depleted bone marrow fat was observed in 20% of all carcasses. The number of guanaco deaths differed among sex and age classes, particularly in juveniles (< 1 year of age), which died more often than expected (P < 0.001). Fresh guanaco carcasses (n= 19) killed by mountain lions were located in tree and shrub habitats 79% of the time and were significantly greater than expected values based on the relative availability of these habitats (P < 0.001). Observations of the spatial distribution of mountain lion kills and guanaco mixed-sex groups were similar (P= 0.10), suggesting that mountain lions responded to winter migratory movements made by guanacos. Overall, adult guanacos experienced surprisingly lower levels of mortality (adult male = 1%, adult female = 2%) than expected, despite the severe winter conditions, while juveniles experienced higher levels of mortality (13%) than expected. In comparison to other years (1991–96), the severe winter of 1995 (i.e. this investigation) had the greatest total mortality for juveniles, although the proportion of deaths caused by mountain lion predation for juveniles was greatest during other winters.

rPatterns of mtDNA and microsatellite variation in an island and mainland population of guanacos in southern Chile

The archaeological record indicates that guanacos inhabited the Patagonia of Chile and Argentina about 13,600 years ago, but were unable to migrate further south owing to the presence of glacial and water barriers that covered much of southern South America including the island of Tierra del Fuego. As environmental and ecological conditions improved, guanacos, along with other large mammals including horses, colonized the area. As a result of continued world-wide glacial melting, ocean levels rose and Tierra del Fuego became isolated from the mainland approximately 8000 years ago. Although island populations generally exhibit lower levels of genetic variation than their counterpart mainland populations, it is difficult to predict how much less variation island populations will exhibit. An analysis of mitochondrial cytochrome b and ATPase-8 sequences and 15 nuclear microsatellite loci revealed that both populations retained appreciable genetic diversity. The island population, however, exhibited much less variation than the mainland population. Measures of genetic variation revealed modest, but significant genetic differentiation, consistent with separation of the two populations approximately 8000 years ago. The assessment of levels of genetic diversity and population differentiation among populations of the wild South American camelids is becoming increasingly important as interest mounts in their utilization as a renewable resource.

Phylogeography and Subspecies Assessment of Vicuñas in Chile and Bolivia Utilizing mtDNA and Microsatellite Markers: Implications for Vicuña Conservation and Management

The rearing and maintenance of wildvicuñas in semi-captivity for economicutilization is practiced mainly in Peru, butArgentina, Bolivia, and Chile are quicklydeveloping their own programs of economic use. Large scale rearing practices will likelyisolate populations and may foster selectivebreeding. In addition to these concerns, thereare also uncertainties about the distributionand validity of the currently recognizedsubspecies. To better understand the potentialimpact that economic utilization will have onthe vicuña, we describe the moleculargenetic variation among four populations andboth described subspecies. An analysis of 794~bp of mitochondrial DNA sequences (16s,cytochrome b genes, and mtDNA control region)revealed appreciable genetic diversity, low tomoderate levels of genetic differentiation, andrestricted gene flow with isolation by distanceamong populations. Analysis of microsatellitedata also indicated genetic differentiationamong populations. Past climatic and geologicevents, coupled with human history, have likelysubjected the vicuña to various episodes ofpopulation isolation and admixture. Therefore,we suggest that managers aim to ensure geneflow among adjoining populations, as observedat mtDNA and microsatellite loci, as well asmaintaining apparent restricted gene flow withisolation by distance among populationsseparated by great distances. Intensiverearing procedures like those being practicedin Peru will ultimately disrupt movements andmigration among wild populations. Furthermore,animals that are not exposed to predation byremaining inside fences, may overtime, loseportions of their behavioral repertoire thatenable them to recognize potentially dangeroussounds associated with the presence ofpredators. Therefore, we do not recommend thatanimals be placed behind fences as this couldlead to a loss of genetic and behavioraldiversity as well as halting natural ecologicalprocesses. If, however, vicuñas are placedbehind fences for commercial purposes (withlittle or no regard for the retention ofgenetic, and/or behavioral diversity as well asnatural population processes) then we suggestclose genetic monitoring of animals that are(will be) maintained in captivity.

Activity and population characteristics of Andean Condors in southern Chile

Se recolectaron datos sobre los patrones generales de actividad y caractersticas de la poblacion del Condor Andino Vultur gryphus. El estudio se realizo en el Parque Nacional Torres del Paine, Chile, entre julio 1992 y junio de 1994, totalizando 3680 horas de observacion. Durante el estudio fueron evidentes diferencias estacionales en los patrones de actividad y abundancia relativa de estas aves. El numero promedio de condores por observacion durante el otono y el invierno fue significativamente diferente al promedio observado durante la primavera y el verano. Hubo una disminucion significativa desde la primavera - verano hacia el otono - invierno en el porcentaje de observaciones de condores solitarios y tambien hubo un aumento significativo en el numero de grupos de condores. El promedio mensual maximo del tamano de grupo fue significativamente mas alto en el otono - invierno que en la primavera - verano. La proporcion entre los sexos (machos:hembras ) en la poblacion juvenil favorecio significativamente a las hembras, mientras que en la poblacion adulta favorecio a los machos. Esta diferencia en la proporcion entre condores adultos y juveniles posiblemente esta relacionada con diferencias en la distribucion y el uso de habitat y/o bajas tasas de reproduccion. Diferencias en las tasas de mortalidad juvenil al igual que diferencias en las tasas de dispersion tambien pudieron contribuir a las diferencias en proporciones entre los sexos y las edades, pero se necesitan mas investigaciones al respecto. La actividad de los condores en el parque parecio ser dependiente de la fuerza del viento. Observamos mayores cantidades de condores durante dias con vientos de intensidades bajas y menos durante dias con vientos de intensidades altas. La temperatura ambiental tambien parecio influir en la actividad aerea de los condores ; fue mas comun observar a estas aves volar durante los dias con temperaturas mas calidas. Hubo una correlacion debil entre la intensidad del viento y la temperatura ambiental.

Population density and annual variation in birth mass of guanacos in Southern Chile

We investigated the influence of population density and meteorological conditions on annual birth mass of guanacos in Torres del Paine National Park, Chile, from 1987 to 1996. Between 1987 and 1990, density of guanacos on the study area nearly tripled from 16 to 43 animals/km 2 . Mean birth mass was significantly different across years, and there was a strong negative correlation between mean yearly birth mass and population density. There was no correlation between mean yearly birth mass and mean temperature or total precipitation in either winter or spring during this period. Since 1990, density of guanacos has decreased, which we suspect is the result of degraded range conditions, partly due to overgrazing. Population censuses from other sectors of the park and the adjacent sheep ranch revealed increasing numbers of guanacos, and the movement of tagged animals out of the study area into surroundings with lower guanaco density.

Predicting early mortality of newborn guanacos by birth mass and hematological parameters : A provisional model

We measured hematological determinants, endocrine parameters, and birth mass of 145 newborn (chulengo) guanacos (Lama guanicoe) in Torres del Paine National Park, Chile, to determine if these factors were predictors of early mortality. Within 10 days of life, 16% of chulengos died in 1991 and 14% died in 1992. The principal cause (68%) of chulengo mortality was predation by the Patagonian puma (Felis concolor patagonia), but the role of compromised health was unknown. We assessed the health status of hand-captured chulengos by measuring white blood cell (WBC) count, differential leukocyte count, neutrophil:lymphocyte ratio (N:L), metarubricyte count, cortisol levels, total T3 and T4, and birth mass. We evaluated the prognostic relation of these parameters on neonatal mortality through Chi-square and Bayesian analyses. Band neutrophil count >1000/μL, lymphocyte count >4000/μL, N:L ratio 300/μL, and birth mass 1000/μL (suggestive of sepsis) showed signs of puma predation, while 100% (4/4) with an N:L ratio <2.0 (possible prematurity) showed signs of puma predation. The hematological parameters showing the strongest relation with mortality were also some of the least expensive and easiest parameters to measure. Readers should consider this Bayesian model groundwork for future studies assessing health-related neonatal mortality in guanacos. The approach also has research and management implications for other wildlife species.