Southwestern Peru Research Articles

Ants of the genus Protalaridris (Hymenoptera: Formicidae), more than just deadly mandibles

The ants of the genus Protalaridris are revised based upon their morphology. Seven species are recognized; the type species (P. armata Brown, 1980) and six species described as new: P. aculeata Lattke & Alpert, sp. n., P. arhuaca Guerrero, Lattke & Alpert, sp. n., P. bordoni Lattke, sp. n., P. leponcei Delsinne & Lattke, sp. n., P. loxanensis Lattke, sp. n., and P. punctata Lattke, sp. n. The genus is patchily distributed in mesic forested areas from western Panama to northern Venezuela and along the Andes to the Amazon watershed of southwestern Peru. The generic description is modified to accommodate a short-mandibulate species. Sporadic biological observations of one long-mandibulate species suggest they are sit-and-wait ambush predators that open their jaws to approximately 180° when stalking. All species are described and imaged, an identification key and a distribution map is provided. Comparing the mandibular morphology of long-mandibulate Protalaridris with other extant and extinct ants bearing elongate, dorsoanterior arching mandibles suggests the supposed mandibular apex in these taxa is actually a hypertrophied, preapical tooth and their supposed basal mandibular tooth is the main mandibular shaft.

First record of the Andean-mountain cavy Microcavia niata (Caviidae, Rodentia) from Peru

We report for the first time the presence of the Andean-Mountain Cavy, Microcavia niata, in Peru, being a new genus and species for Peruvian wildlife. We base our report on two specimens found in the highlands of Tacna, southwestern Peru.

Reproductive Biology of the Tawny-Crowned Tunchiornis (Tunchiornis ochraceiceps) In Manu National Park, Perú

ABSTRACT.— The genus Hylophilus sensu lato was recently recognized as polyphyletic and split in to several genera, including the monotypic genus Tunchiornis. We describe in detail the nesting features of T. ochraceiceps that could provide additional evidence to support the split of the genus. Nests were found at two stations in southwestern Peru, Manu National Park. We found three cup-nests covered externally with green moss and internally with thin and light straw fibers, with inner and outer major and minor axes of 48.6 × 49.2 mm and 66.6 × 61 mm, respectively, a wall thickness of 9.8 mm, and an inner depth of 38.7 mm. The eggs were creamy-white with dark-brown spots concentrated at the base and measured 18.3 ± 0.4 × 13.1 ± 0.3 mm with a mass of 1.73 ± 0.12 g. Overall nest attentiveness was 64% and the egg were incubated at 32.35 ± 3.11 °C. The incubation and nestling period lasted 15 and 11 days, respectively. The nest materials used by Tunchiornis are similar to Hylophilus but differ from Pachysylvia,...

Unravelling the calls of discrete hunters: acoustic structure of echolocation calls of furipterid bats (Chiroptera, Furipteridae)

Detailed descriptions of echolocation calls for most of the Neotropical bat species have been published only recently. Yet, the available descriptions are from bats that emit high-intensity calls. The families of insectivorous bats that emit low-intensity calls, such as Furipteridae, are less frequently recorded by more traditional equipment; thus, there are no detailed descriptions of echolocation calls for these species. The family Furipteridae includes only two species of small insectivorous bats from Neotropics, the thumbless bat Furipterus horrens and the smoky bat Amorphochilus schnablii. The ecology, behaviour and even the natural history of both species are barely known. In order to contribute to the description of echolocation calls of Neotropical bat species and to the knowledge of these two poorly known species, here we describe in more detail the echolocation calls of furipterids. Thumbless bats were recorded from two colonies, one located in south-western Bahia, Brazil, and another located in the Amazon forest of Matoury, French Guyana, whereas the smoky bats were recorded in the Pacific coast of Arequipa, south-western Peru. Echolocation calls of both species were characterized by pulses of downward broadband frequency-modulated sweeps of short duration. Our results show that the ultrasound calls emitted by thumbless bats is one of the highest in frequency among Neotropical bats. This detailed characterization of furipterid calls and their distinct features, like very high frequencies and wide bandwidth, making it relatively easy to identify, aids in the inclusion of these species in acoustic surveys and monitoring.

Distribution of Promops davisoni Thomas, 1921 (Chiroptera: Molossidae) in Peru with a new record and southward range extension

Promops davisoni is a poorly known insectivorous bat represented by fewer than two dozen specimens in collections. These species are endemic from the Andean western slopes of Ecuador and Peru where it is known from the Mongoya River, province of Manabí, central Ecuador to the Santuario Nacional Lagunas de Mejia, Arequipa department, southwestern Peru. We report a new record of P. davisoni from Pampa Alta, Tacna department, Peru. This new specimen documents a 125 km range extension and the southernmost record of P. davisoni from Peru.

A new species of Eumops (Chiroptera: Molossidae) from southwestern Peru.

The genus Eumops is the most diverse genera of molossid bats in the Neotropics. In Peru this genus is widely distributed and represented by nine species: E. auripendulus, E. delticus, E. hansae, E. maurus, E. nanus, E. patagonicus, E. perotis, E. trumbulli, and E. wilsoni. After several years of mammalian diversity surveys in the coastal desert and western slopes of southwestern Peru, a specimen of Eumops was collected whose unique set of traits allows us to assert that deserves to be described as a new species. Based on molecular and morphological evidence, the new species is related to medium-large sized species (i.e. E. glaucinus, E. auripendulus, and E. perotis). Cytochrome b genetic divergence between the new species and the other species of the genus was high (> 12%) and it is consistent with morphological divergence presented for this new species. This new species, endemic to Peru, increases the diversity of Eumops to 16 species.

Glacier fluctuations in the southern Peruvian Andes during the late‐glacial period, constrained with cosmogenic 3He

AbstractThe occurrence of pronounced climate reversals during the last glacial termination has long been recognised in palaeoclimate records from both hemispheres and from high to low latitudes. Accurate constraint of both the timing and magnitude of events, such as the Younger Dryas and Antarctic Cold Reversal, is vital in order to test different hypotheses for the causes and propagation of abrupt climate change. However, in contrast to higher‐latitude regions, well‐dated records from the Tropics are rare and the structure of late‐glacial tropical climate remains uncertain. As a step toward addressing this problem, we present an in situ cosmogenic 3He surface exposure chronology from Nevado Coropuna, southern Peru, documenting a significant fluctuation of the ice margin during the late‐glacial period. Ten tightly clustered ages from a pair of moraines located halfway between the modern glacier and the Last Glacial Maximum terminus range from 11.9 to 13.9 ka and give an arithmetic mean age of 12.8 ± 0.7 ka (1σ). These data constitute direct evidence for a readvance, or prolonged stillstand, of glaciers in the arid Andes of southwestern Peru. Copyright © 2011 John Wiley & Sons, Ltd.

Entomological Factors Affecting the Low Endemicity of Chagas Disease in Nazca, Southwestern Peru

Chagas disease is prevalent in Peru. The province of Nazca, in the southwestern region of the country, shows a high intradomiciliary infestation rate of Triatoma infestans bugs. Although the vector is present, the number of Chagas disease cases appears to be much lower than those reported in the neighboring region of Arequipa. We examined 624 T. infestans from Nazca to determine the current Trypanosoma cruzi infection rates, and found that no bugs were infected with this parasite. These results contrast with those found in Arequipa, where 19-30% triatomines have been reported infected. To compare their vectorial capacity, we infected 30 T. infestans specimens, selected both from Nazca and Arequipa, by feeding bugs on T. cruzi-infected mice. The parasites developed all stages expected in the vector; furthermore, the infective stage, metacyclic trypomastigote, was found in both insect populations from the second week after infection. In addition, those insects that accepted to be fed with mice blood defecated immediately after finishing blood meal, indicating that they might be efficient vectors. We maintain that differences observed in infection rates between vectors from Nazca and Arequipa may be explained by differences in host availability. In Arequipa hosts are mainly small animals, whereas in Nazca the main blood source comes from birds, which are refractory to the infection.

Thylamys pallidior (Didelphimorphia: Didelphidae)

Abstract Thylamys pallidior (O. Thomas, 1902) is a didelphid marsupial commonly called the white-bellied fat-tailed mouse opossum. A small mouse opossum, with tricolored pelage and a white venter, it has a seasonally incrassated tail, where fat deposits, primarily at the tail base, function in food storage. It is the most widely distributed species in the genus occurring from southwestern Peru and northern Chile southward along the eastern slopes of the Andes to southern Argentina. This species is found primarily in arid and semiarid habitats at elevations from sea level to about 4,500 m. It is not of special conservation status but may be uncommon in some areas.

The Arequipa Massif of Peru: New SHRIMP and isotope constraints on a Paleoproterozoic inlier in the Grenvillian orogen

The enigmatic Arequipa Massif of southwestern Peru is an outcrop of Andean basement that underwent Grenville-age metamorphism, and as such it is important for the better constraint of Laurentia–Amazonia ties in Rodinia reconstruction models. U–Pb SHRIMP zircon dating has yielded new evidence on the evolution of the Massif between Middle Paleoproterozoic and Early Paleozoic. The oldest rock-forming events occurred in major orogenic events between ca. 1.79 and 2.1 Ga (Orosirian to Rhyacian), involving early magmatism (1.89–2.1 Ga, presumably emplaced through partly Archaean continental crust), sedimentation of a thick sequence of terrigenous sediments, UHT metamorphism at ca. 1.87 Ga, and late felsic magmatism at ca. 1.79 Ga. The Atico sedimentary basin developed in the Late-Mesoproterozoic and detrital zircons were fed from a source area similar to the high-grade Paleoproterozoic basement, but also from an unknown source that provided Mesoproterozoic zircons of 1200–1600 Ma. The Grenville-age metamorphism was of low-P type; it both reworked the Paleoproterozoic rocks and also affected the Atico sedimentary rocks. Metamorphism was diachronous: ca. 1040 Ma in the Quilca and Camana areas and in the San Juan Marcona domain, 940 ± 6 Ma in the Mollendo area, and between 1000 and 850 Ma in the Atico domain. These metamorphic domains are probably tectonically juxtaposed. Comparison with coeval Grenvillian processes in Laurentia and in southern Amazonia raises the possibility that Grenvillian metamorphism in the Arequipa Massif resulted from extension and not from collision. The Arequipa Massif experienced Ordovician–Silurian magmatism at ca. 465 Ma, including anorthosites formerly considered to be Grenvillian, and high-T metamorphism deep within the magmatic arc. Focused retrogression along shear zones or unconformities took place between 430 and 440 Ma.

Exceptional preservation of the white shark Carcharodon (Lamniformes, Lamnidae) from the early Pliocene of Peru

ABSTRACT An exceptionally well-preserved white shark fossil (Carcharodon sp.) is described here from the early Pliocene (ca. 4 Ma) Pisco Formation of southwestern Peru. This specimen preserves 222 teeth and 45 vertebrae as well as fragmentary jaws. The teeth show characters of Carcharodon, including weak serrations and a symmetrical first anterior tooth that is the largest in the tooth row. This dentition also shows a character of Isurus with a distally inclined but mesially slanted intermediate tooth. Although the Pisco specimen demonstrates characters of both Isurus, also known form the Pisco Formation, and modern Carcharodon carcharias, it is assigned to the genus Carcharodon and referred to herein as Carcharodon sp. While Carcharodon sp. From the Pisco Formation shows numerous diagnostic characteristics shared with C. carcharias, it differs from the extant species in having a distal inclination of the intermediate tooth. The precaudal vertebral centra of the Pisco Carcharodon preserve distinctive dark and light incremental bands that, based on calibration with oxygen isotopes, indicate annular growth couplets. The fossil shark was at least 20 (±1) years old at the time of its death. Based on measurements of teeth and vertebral centra, this specimen is estimated to have had a minimum total body length of 4.80-5.07 m, similar to estimates for modern older individuals of C. carcharias. Relative to the extant Carcharodon carcharias, the Pisco Carcharodon sp. grew at a slower rate. The fossil record of lamnoid sharks preserved in the Pisco Formation demonstrates that the modern white shark is more closely related to Isurus (I. hastalis) than it is to the species Carcharodon megalodon, and the latter is therefore best allocated to the genus Carcharocles.

Biodiversity conservation implications of landscape change in an urbanizing desert of Southwestern Peru

Internal migration from the Peruvian highlands and rural areas has burdened urban areas with rapid growth. Urban expansion is threatening the desert habitat and unique vegetation communities surrounding Arequipa, one of Peru's largest cities. A 511 ha tract contiguous to the city of Arequipa has been informally designated an ecological park. Analysis of Landsat satellite imagery over a 16-year interval indicates that urban expansion is occurring in the direction of the park. The land use/land cover change analysis revealed other landscape patterns and processes, such as agricultural expansion, which are relevant to the study area. These dynamics, plus principles of landscape ecology, suggest that the park's size and shape may not be the most suitable. Conservation alternatives include the expansion of the park, the spatial connection to another nature reserve, or the design of co-management strategies. Given local historical events and the paucity of regional conservation efforts, social actors in Arequipa and in national governmental institutions will need to find practical ways to collaborate.

Constraints on the ore fluids in the Sando Alcalde AuAg epithermal deposit, southwestern Peru: fluid inclusions and stable isotope data

The Sando Alcalde ore deposit (southwestern Peru) has been studied in order to characterize the physicochemical parameters of the ore fluids and to determine the fluid process (mixing or boiling) which involves the precious metal mineralization. Mineralogy, δ18Oquartz isotopic values and fluid inclusion data give arguments in favour of a boiling phenomenon. This conclusion corroborates fluid inclusion studies previously performed in this area on the low-sulphidation epithermal deposits of Arcata, Orcopampa and Apacheta, where boiling has been described as the main factor for ore deposition. To cite this article: A.-S. Andre-Mayer et al., C. R. Geoscience 337 (2005).

Enfermedad de Chagas en el grupo familiar de un caso crónico de curso fatal en un área sin triatominos del Departamento de Ica, Perú

The purpose of this communication is to present two cases of Chagas’ disease in a familial group of a index case, coming from the Arequipa region in southwestern Peru, an endemic area. The case suffered sudden death because of chagasic cardiomyopathy in an area free triatomines in Department Ica. His sister and his nephew showed IgG specific antibodies anti - Trypanosoma cruzi detected by enzime-linked immunosorbent assay (ELISA) and indirect immunofluorescence assay (IFA), both households had lived in an endemic valley (Vitor-Arequipa). Our results underscore the importance of the epidemiological survey in the familial group of the chronic case in low risk-areas.

Co-, Post- and Pre(?)-seismic Displacements Associated with the Mw 8.4 Southern Peru Earthquake of 23 June 2001 from Continuous GPS Measurements

On 23 June 2001, at 20:33 UTC, a major earthquake occurred near the coast of southern Peru, about 190 km west of Arequipa (16.15°S, 73.40°W). A revised magnitude of 8.4 was computed for this earthquake by the United States Geological Survey, NEIC (see http://neic.usgs.gov/neis/bulletin/01_EVENTS/0l0623203313/010623203313.html for further information). The earthquake occurred along the west coast of Peru (Figure 1) at the boundary between the Nazca and South American Plates and resulted from thrust faulting along this boundary as the Nazca Plate subducts beneath the South American Plate. The two plates are converging toward each other at a rate of 78 mm/yr (DeMets et al. , 1990). Southwestern Peru has a history of very large earthquakes. The 23 June shock originated just southeast of the source of a magnitude 7.7 earthquake that occurred in November 1996. This area of the plate boundary has not recorded a major rupture since the 1868 earthquake of magnitude approximately 8.5–9 (Dorbath et al. , 1990; Comte and Pardo, 1991). The 23 June shock occurred in a previously identified seismic gap (Nishenko, 1985). The 1868 earthquake was more destructive than the 23 June earthquake and produced a tsunami that killed hundreds of people along the South American coast. The 23 June earthquake is very similar to the 1995 Mw 8.1 Antofagasta earthquake (Ruegg et al. , 1996), which ruptured a zone of about 180 × 70 km2 of the Chilean coast, along which no major historical earthquake has been recognized before. The city of Arequipa, located 190 km east of the main shock epicenter, experienced damage during the 23 June earthquake. At Arequipa several precise positioning systems are permanently operating, including continuous GPS station of the IGS, DORIS beacon, Satellite Laser Ranging. In this study we give a quick report about surface deformation …

A new species of Chiliotrichiopsis (Asteraceae: Astereae) from Peru

Chiliotrichiopsis peruviana Nesom, H. Rob. & Granda, a new species from Dept. Ayacucho in southwestern Peru, is described and illustrated. It is the only rayless species of the genus, now expanded to four species, and the only one that occurs outside of Argentina.Chiliotrichiopsis is one of six shrubby South American genera of Astereae (subtribe Hinterhuberinae) with paleate receptacles. Observations on morphology and a key to these genera provide perspective for the generic placement of the new species.

Two New Species of Sisymbrium (Brassicaceae) from Coastal Peru

Two new species ofSisymbrium are described from the Department of Arequipa in south-western Peru. Both are annuals from the loma vegetation.Sisymbrium lactucoides has glabrous leaves with clasping bases and is very distinct.Sisymbrium ferreyrae is probably closest toS. llatasii, but it is a much smaller plant with petals and sepals of subequal length (vs. petals longer than sepals inS. llatasii).

Human infection with Trypanosoma cruzi in Nasca, Peru: A seroepidemiological survey (1)

We estimated the proportion of seropositivity for infection with Trypanosoma cruzi (Chagas' disease) in a sample of the rural population of the Province of Nasca, Department of Ica, southwestern Peru. Although Triatoma infestans, the only vector species identified in the Department of Ica, is often found in domestic environments, data of the extent of human infection with T. cruzi are scant. This study comprised 446 houses, known to be infested with triatomines, distributed in 19 rural localities. While visiting those houses we collected filter paper bloodspots from 864 occupants (of both sexes, aged one year or over). By means of the indirect fluorescent antibody test (IFAT), we detected anti-T. cruzi IgG antibodies in samples from 178 individuals (20.6%). Seropositivity was significantly more frequent in females (23.8%) than in males (17.5%). Among the 410 individuals in the 1- to 10-year-old age group (47.5% of the population sample), 85 (20.7%) were found seropositive, which is indicative of an early acquisition of the infection. Within this group no significant differences in seropositivity were associated with sex.

Bat and hummingbird pollination of an AUTOTETRAPLOID COLUMNAR CACTUS, Weberbauerocereus weberbaueri (Cactaceae)

I present data on flower morphology, pollination, breeding system, and genetic diversity of the columnar cactus Weber‐bauerocereus weberbaueri at 2500 m elevation in southwestern Peru. Weberbauerocereus weberbaueri is a self‐compatible columnar cactus that is visited and pollinated by one species of rare endemic bat, Platalina genovensium, and two species of hummingbirds, Patagona gigas and Rhodopis vesper. W. weberbaueri exhibits pronounced interplant variation in floral color and size, and flowers exhibit traits corresponding to both bat and hummingbird pollination syndromes. Starch‐gel electrophoresis of flower bud tissue indicated that W. weberbaueri is an autotetraploid and that genetic diversity (Hep = 0.257) of the study population was high relative to diploid plants but similar to other tetraploid species. Initial fruit set from pollinator exclusion experiments conducted in 1991 and 1993, at the onset of and after a drought associated with the El Niño event of 1991–1992, revealed that bats were the most important pollinators in 1991, but that hummingbirds and diurnal insects were most important in 1993. In both years, however, autogamy and lepidopteran larval infestation of fruits reduced differences in mature fruit production among pollinator exclusion treatments so that differences in mature fruit set were not statistically significant. Reduced bat pollination in 1993 is attributed to the reduced abundance of bats at the study site during a drought caused by El Niño. I hypothesize that interaction among several factors, including tetraploidy, autogamy, larval infestation of developing fruits, and variation in pollinator abundance, may not result in strong selection for a bat vs. hummingbird floral morph, thus allowing the persistence of floral variation in this cactus.

Historical 1942 Ecuador and 1942 Peru subduction earthquakes and earthquake cycles along Colombia-Ecuador and Peru subduction segments

Two large shallow earthquakes occurred in 1942 along the South American subduction zone inclose proximity to subducting oceanic ridges: The 14 May event occurred near the subducting Carnegie ridge off the coast of Ecuador, and the 24 August event occurred off the coast of southwestern Peru near the southern flank of the subducting Nazca ridge. Source parameters for these for these two historic events have been determined using long-periodP waveforms,P-wave first motions, intensities and local tsunami data. We have analyzed theP waves for these two earthquakes to constrain the focal mechanism, depth, source complexity and seismic moment. Modeling of theP waveform for both events yields a range of acceptable focal mechanisms and depths, all of which are consistent with underthrusting of the Nazca plate beneath the South American plate. The source time function for the 1942 Ecuador event has one simple pulse of moment release with a duration of 22 suconds, suggesting that most of the moment release occurred near the epicenter. The seismic moment determined from theP waves is 6–8×1020N·m, corresponding ot a moment magnitude of 7.8–7.9. The reported location of the maximum intensities (IX) for this event is south of the main shock epicenter. The relocated aftershcks are in an area that is approximately 200 km by 90 km (elongated parallel to the trench) with the majority of aftershocks north of the epicenter. In contrast, the 1942 Peru event has a much longer duration and higher degree of complexity than the Ecuador earthquake, suggesting a heterogeneous rupture. Seismic moment is released in three distinct pulses over approximately 74 seconds; the largest moment release occurs 32 seconds after rupture initiation. the seismic moment as determined from theP waves for the 1942 Peru event is 10–25×1020N·m, corresponding to a moment magnitude of 7.9–8.2. Aftershock locations reported by the ISS occur over a broad area surrounding the main shock. The reported locations of the maximum intensities (IX) are concentrated south of the epicenter, suggesting that at least part of the rupture was to the south. We have also examined great historic earthquakes along the Colombia-Ecuador and Peru segments of the South American subduction zone. We find that the size and rupture length of the underthrusting earthquakes vary between successive earthquake cycles. This suggests that the segmentation of the plate boundary as defined by earthquakes this century is not constant.