Chaetomys Research Articles

How to Eat Spiny Food? Predation by Bird of Prey on Thin-Spined Porcupine, Chaetomys subspinosus (Olfers, 1818)

Chaetomys subspinosus is an arboreal, cryptic, medium-sized porcupine. This species has the body densely covered by spines thinner and softer than those of other genera of Neotropical porcupines. Its known natural predators are big cats and harpy eagle, while other mammalian carnivores and large birds of prey in general are cited as potential predators. Here I report a new event of predation by bird of prey on Chaetomys subspinosus in the northern Espírito Santo state, southeastern Atlantic Forest. The predator removed the stomach and intestine of the prey, as well as the spines of its head and the ventral portion of the body. Although it was not possible to identify the predator precisely, it was a medium to large-sized bird of prey, probably a hawk or a hawk-eagle (Family Accipitridae). The presented data contributes information to the natural history of Chaetomys subspinosus, representing one of the first records of predation on this porcupine species by a bird of prey.

Translocation and long-term monitoring of threatened thin-spined porcupines (Chaetomys subspinosus) on the Brazilian coast

With increasing infrastructural development along Brazil’s coast, environmental regulation measures are becoming increasingly necessary in the face of the damage caused by large projects that impact tropical forests. Brazilian legislation supports implementation of translocation programs for impacted fauna, especially threatened species such as the thin-spined porcupine Chaetomys subspinosus (Rodentia, Erethizontidae). Thus, we present a case study of a pioneer translocation program for the thin-spined porcupine in southeastern Brazil. We aimed to analyze the home-range and habitat selection of three translocated porcupines and one resident individual. In addition, we analyzed the success of the translocations. The porcupines were monitored by radiotelemetry for 3–16 months from October 2015 to March 2017 in a mosaic landscape of restinga forests (sandbank forest vegetation) within a eucalyptus matrix. The translocated porcupines had considerably larger home-ranges (14.29–18.36 ha, minimum convex polygon method – MCP) than did the resident animal (1.22 ha – MCP). We observed stabilization in the home-range size curves of the translocated females in the 7th − 9th month of monitoring. All translocated individuals achieved permanence within a preselected area, indicating adaptation to the new area. In addition, individuals showed a clear preference for restinga forests over drained eucalyptus plantations. Thus, our results demonstrate the feasibility of thin-spined porcupine translocations and the importance of maintaining restinga forest remnants outside of protected areas for the conservation and permanence of viable populations of this rodent.

Functional histology of the integument of the thin-spined porcupine, Chaetomys subspinosus

This study examines the functional histology of the thin-spined porcupine's ( Chaetomys subspinosus (Olfers, 1818)) quills and integument, and compares them with the North American porcupine ( Erethizon dorsatum (Linnaeus, 1758)) equivalents. Erethizon quills disseminate warnings to potential predators. An olfactory warning is generated by sebaceous glands of the lower back, disseminated by osmetrichial specializations of lower-back quills. Chaetomys skin lacks functional sebaceous glands, and generates no warning odor. Erethizon quills also carry a visual warning, effective even in dim light. Chaetomys quills carry no warning color. The straight, stiff quills of Erethizon are tipped with one-way barbs and can be elevated to 90°. A protective collagenous spool at the base of the quill prevents back-stabbing on impact. Chaetomys quills lack barbs and the basal collagenous spool is poorly developed. The quill shafts are wavy and angled at the base, allowing them to act as shock absorbers during a fall from a tree. Nevertheless, Chaetomys quills of the head and shoulders can be elevated to 90° to function as stabbing devices. Major defensive quills of Erethizon protect the back; in Chaetomys, the front. Though both species have 1–3 arrector muscles, they differ in the details of quill stabilization. The Chaetomys quill surface has regional cuticular patterns, of which the distal, longest region is highly pitted. The function of the pitted region remains a mystery.

Snapshot of the Atlantic Forest canopy: surveying arboreal mammals in a biodiversity hotspot

AbstractThe Atlantic Forest of South America supports a rich terrestrial biodiversity but has been reduced to only a small extent of its original forest cover. It hosts a large number of endemic mammalian species but our knowledge of arboreal mammal ecology and conservation has been limited because of the challenges of observing arboreal species from ground level. Camera trapping has proven to be an effective tool in terrestrial mammal monitoring but the technique has rarely been used for arboreal species. For the first time in the Atlantic Forest, we obtained data on the arboreal mammal community using arboreal camera trapping, focusing on Caparaó National Park, Brazil. We placed 24 infrared camera traps in the forest canopy in seven areas within the Park, operating them continuously during January 2017–June 2019. During this period the camera traps accumulated 4,736 camera-days of footage and generated a total of 2,256 photographs and 30-s videos of vertebrates. The arboreal camera traps were able to detect arboreal mammals of a range of body sizes. The mammal assemblage comprised 15 identifiable species, including the Critically Endangered northern muriqui Brachyteles hypoxanthus and buffy-headed marmoset Callithrix flaviceps as well as other rare, nocturnal and inconspicuous species. We confirmed for the first time the occurrence of the thin-spined porcupine Chaetomys subspinosus in the Park. Species richness varied across survey areas and forest types. Our findings demonstrate the potential of arboreal camera trapping to inform conservation strategies.

First records and range extension of Bristle-spined Porcupine, Chaetomys subspinosus (Olfers, 1818) (Rodentia, Erethizontidae), in Minas Gerais state, Brazil

We report from three localities four new records of the threatened Brazilian Atlantic Forest endemic Chaetomys subspinosus (Olfers, 1818). These are the first records of this porcupine species from the state of Minas Gerais, and these new data extend the distribution of this species by approximately 220 km to the southwest. As C. subspinosus was observed in areas of transitional vegetation, this species may be found in a much broader spectrum of habitat types than previously thought. We recommend further surveys focusing on documenting this species.

Decreasing dietary diversity following habitat loss: the case of the thin-spined porcupine in the Atlantic forest

The thin-spined porcupine (Chaetomys subspinosus Olfers, 1818) is an endemic and threatened rodent from the Atlantic Forest biological hotspot. Previous studies have demonstrated it follows a strictly leaf-based diet, limited to a few tree species, although such information is derived from few individuals (n = 7) resident in small forest fragments. We aimed to evaluate whether such dietary specialization persists when animals inhabit larger forest fragments. For this, we assessed the diet composition of 19 radiotracked individuals inhabiting small ( 500 ha; n = 9) forest fragments in southern Bahia state. We compared the composition and diversity of the diet in terms of tree parts and species consumed in these contrasting fragment size environments. Secondly, we aimed to evaluate the influence of leaf chemical composition on the consumption of plant species. Our findings show that the thin-spined porcupine is a strict folivore, with individuals responding to the reduction in forest size by reducing the diversity of plant species consumed, but not by feeding on new plant parts. Although the diet was richer in larger forest fragments, certain tree species were the most consumed in both fragment-size categories and the unique item consumed were leaves. Fiber influenced positively the leaf consumption of the plant species, while there was no effect of other chemical characteristics. The influence of the habitat size reduction on food diversity may be a risk factor for the species.

Microscopy and development of a remarkable pitted quill from the thin-spined porcupine,Chaetomyssubspinosus

Scanning electron microscopy shows that the quill surface from the thin-spined porcupine (Chaetomys subspinosus (Olfers, 1818)) has several regional cuticular patterns of which the most expansive is highly pitted with 4 μm wide pores leading to pits, which in turn communicate circumferentially via tunnels to neighboring pits. The cell unit of the pitted layer is a hexagonal or pentagonal prism, the “pitted fibrillous cuticular cell” (PFCC), which has a superficial pitted cuticular scale derived part with an underlying part packed with fine fibrils and the nucleus. The scaled part has about six scales, which swell and fuse except where raised cuticular scales from the inner root sheath intervene. This unique and complicated cell soon dies even while below the skin’s surface during its development. The raised scale-bearing cells of the inner root sheath leave their imprints on the PFCC’s surface, thus indicating that the quill’s pitted layer is at one time soft. Histochemistry, energy dispersive X-ray spectrometry, and Fourier transform infrared spectrometry show that the PFCC is keratinous.

Combining species distribution modeling and field surveys to reappraise the geographic distribution and conservation status of the threatened thin-spined porcupine (Chaetomys subspinosus).

The threatened thin-spined porcupine (Chaetomys subspinosus), a forest-specialist endemic to the Brazilian Atlantic forest, was rarely detected in the wild during the 20th century. Previous geographic distribution assessments were carried out nearly three decades ago and were based on interview data. We performed extensive field surveys (based on active search and interviews), a literature review, and species distribution modeling to predict and validate a more reliable picture of its geographic distribution and environmental suitability gradient. We identified the main predictors of species’ incidence, its conservation status, and pinpointed key areas for species conservation. Our results indicated that C. subspinosus is distributed continuously in the Atlantic forest from southeastern Espirito Santo to central-eastern Sergipe state, totaling 104,326 km2 of occurrence area, although only 3,299 km2 (13.3%) is currently represented by native forests (species habitat). C. subspinosus was absent or at least so rare that it was not detected in more than half of the locations sampled by interviews (53.5%). Our results suggest that populations are sensitive to climatic conditions and habitat loss, becoming abruptly rarer when the remaining forest cover reaches less than 10% area within a region (~ 5,000 km2 scale). This result indicates that the high deforestation level of the Atlantic forest is already close to the limit of regional species resistance. Bahia state still harbors the bulk of the remaining forest with high climatic suitability, and generally under low levels of legal protection. Herein we highlight priority areas and research gaps that could guide decision makers to promote conservation strategies for this threatened species.

Some biological and behavioral aspects of Amblyomma longirostre (Acari: Ixodidae) under laboratory and natural conditions

Amblyomma longirostre (Koch, 1844) has been reported as one of the most common ticks parasitizing wild animals in Brazil; however, information about its life cycle is inexistent, as well as information on its behavior in nature. In order to determine some aspects of the life cycle of A. longirostre in the laboratory, we performed infestations of larvae and nymphs on Serinus canaria (Common Canary - Passeriformes), Calomys callosus (Vesper mouse), Sphiggurus villosus (Brazilian porcupine), and Gallus gallus (chicks - no Passeriformes); this later host species only for larvae. While the overall recovery rates of engorged larvae and nymphs were low (at most 11.1%), the highest rates were for ticks that had fed on S. canaria (Passerifomes). This result is supported by field data, which indicate Passeriformes as preferable hosts for larvae and nymphs of A. longirostre. Interestingly, the suitability of the porcupine S. villosus as host for larvae and nymphs was statistically similar to S. canaria, although the recovery rates on the later host species were slightly higher. The Cricetidae mouse C. callosus displayed the lowest recovery rates (0–0.5%) of engorged ticks, indicating that mice might not be suitable hosts for A. longirostre under natural conditions. We also report three adult females of A. longirostre that were collected from two Bristle-spined porcupine Chaetomys subspinosus. Curiously, each of the three ticks was attached to the median third of a spine of the porcupines. The hypostome was surrounded by a cement-like structure at the spine external surface, but did not break through the external surface of the spine. Biological explanations for this behavior are discussed.

Do we underestimate the impact of roads on arboreal animals? Roadkill as an important threat to Chaetomys subspinosus (Mammalia: Rodentia)

Abstract: The Thin-spined Porcupine (Chaetomys subspinosus) is a medium-sized and mainly arboreal rodent, endemic to the Brazilian Atlantic Forest, and threatened with extinction. Habitat loss, hunting, forest fires, agriculture and livestock are threats identified for the species. Here we raise the alert to the impact of roads on remaining populations of C. subspinosus based on roadkill records from the state of Espírito Santo, southeastern Brazil. Mortality due to roadkill is likely to impact C. subspinosus in different regions of the state, and is a widespread problem, not unique to a single location or population. The pattern of roadkills in the studied regions suggest that the species is more susceptible to collisions with vehicles in the breeding period. Additionally, concrete barriers that divide lanes on highways seens to increase the likelihood of roadkill for Thin-spined Porcupines. We recommend that roadkill should be included in the list of threats to C. subspinosus in the Espírito Santo. Mortality due to roadkill is probably relevant also for populations in the states of Bahia and Sergipe, and it should be evaluated locally. The installation of road-crossing structures for wildlife, such as arboreal overpasses, is recommended on roads crossing or close to protected areas with C. subspinosus presence in Espírito Santo and elsewhere.

Detection of Rickettsia bellii and Rickettsia amblyommii in Amblyomma longirostre (Acari: Ixodidae) from Bahia state, Northeast Brazil.

Studies investigating rickettsial infections in ticks parasitizing wild animals in the Northeast region of Brazil have been confined to the detection of Rickettsia amblyommii in immature stages of Amblyomma longirostre collected from birds in the state of Bahia, and in immatures and females of Amblyomma auriculariumcollected from the striped hog-nosed skunk (Conepatus semistriatus) and armadillos (Euphractus sexcinctus) in the state of Pernambuco. The current study extends the distribution of R. amblyommii (strain Aranha), which was detected in A. longirostre collected from the thin-spined porcupine Chaetomys subspinosus and the hairy dwarf porcupine Coendou insidiosus. In addition, we report the first detection of Rickettsia bellii in adults of A. longirostre collected from C. insidiosus in the state of Bahia.

Using DNA Barcodes to Identify Road-Killed Animals in Two Atlantic Forest Nature Reserves, Brazil.

Road mortality is the leading source of biodiversity loss in the world, especially due to fragmentation of natural habitats and loss of wildlife. The survey of the main species victims of roadkill is of fundamental importance for the better understanding of the problem, being necessary, for this, the correct species identification. The aim of this study was to verify if DNA barcodes can be applied to identify road-killed samples that often cannot be determined morphologically. For this purpose, 222 vertebrate samples were collected in a stretch of the BR-101 highway that crosses two Discovery Coast Atlantic Forest Natural Reserves, the Sooretama Biological Reserve and the Vale Natural Reserve, in Espírito Santo, Brazil. The mitochondrial COI gene was amplified, sequenced and confronted with the BOLD database. It was possible to identify 62.16% of samples, totaling 62 different species, including Pyrrhura cruentata, Chaetomys subspinosus, Puma yagouaroundi and Leopardus wiedii considered Vulnerable in the National Official List of Species of Endangered Wildlife. The most commonly identified animals were a bat (Molossus molossus), an opossum (Didelphis aurita) and a frog (Trachycephalus mesophaeus) species. Only one reptile was identified using the technique, probably due to lack of reference sequences in BOLD. These data may contribute to a better understanding of the impact of roads on species biodiversity loss and to introduce the DNA barcode technique to road ecology scenarios.

Home range and multiscale habitat selection of threatened thin-spined porcupine in the Brazilian Atlantic Forest

The threatened and poorly known thin-spined porcupine (Chaetomys subspinosus) is endemic to the highly deforested central portion of the Atlantic Forest of eastern Brazil. In southern Bahia, anecdotal observations suggested that native forest and shade cacao (Theobroma cacao) plantations are important habitats for this species. However, no studies have examined habitat preferences. We estimated the home-range size and determined the factors influencing habitat selection at landscape, home range, and tree scales in the cacao-growing region of southern Bahia. Radiotelemetry data from 21 individuals followed for 3–25 months from April 2005 to November 2013 showed a relatively small home range (0.5–9.5 ha using minimum convex polygon methods), with males showing larger home ranges than females. Habitat selection was congruent across spatial scales, with preference for structurally complex environments at all scales. The tagged porcupines preferred trees that were large, harboring many lianas, and closer to fo...

Identification and genetic characterization of Toxoplasma gondii in free-ranging bristle-spined porcupine (Chaetomys subspinosus), a threatened arboreal mammal from the Brazilian Atlantic Forest.

BackgroundStrains of Toxoplasma gondii in Brazil have high genetic diversity compared to North America and Europe. The bristle-spined porcupine, Chaetomys subspinosus, is often subject to hunting for human food, but it is not known whether it can be a reservoir of this parasite. The aim of this study was to verify the occurrence of T. gondii in C. subspinosus from southern Bahia, Brazil, and genetically characterize and compare the strains found with those isolated in previous studies of the same region to quantify their genetic diversity by multilocus PCR-RFLP and PCR sequencing.FindingsTwelve free-ranging C. subspinosus captured in forest fragments of the Una Biological Reserve and adjacent areas were evaluated. Three isolates of T. gondii (TgCsBr01-03) were detected. Two different genotypes were identified by applying multilocus PCR-RFLP with six molecular markers (SAG1, SAG2, SAG3, c22-8, PK1, and Apico). The isolates TgCsBr02 and TgCsBr03 were indistinguishable by this technique. However, the three isolates differed from all the reference strains and from the samples from the same region. Nevertheless, when the six genetic markers were used in multilocus PCR sequencing, all three isolates of T. gondii were different. The phylogenetic analysis revealed a greater genetic distance for TgCsBr01, which was closer to isolates from pigs from the same region, while TgCsBr02-03 was classified in the same lineage and was closer to isolates from sheep from this region.ConclusionsAll the isolates differed from the clonal genotypes of types I, II, and III using both genotyping techniques.

Short Communication: Elucidation of bacterial community structure on thin-spined porcupine (Chaetomys subspinosus) spines by denaturing.

Thin-spined porcupines (Chaetomys subspinosus) are threatened with extinction and are categorized as vulnerable. This is because of alteration to and loss of their habitat and possible hunting activities in their distribution area. Their spines constitute one of their defense mechanisms, which can be fomites for pathogens to humans. However, little is known about such pathogens. The present study aimed to detect bacteria on spines of C. subspinosus, from the Una Biological Reserve, South of Bahia, northeastern Brazil, by analyzing metagenomic DNA, isolating bacterial culture, using the denaturing gradient gel electrophoresis (DGGE) technique, and sequencing. Six anatomical points were selected for withdrawing spine samples from an individual C. subspinosus. At all sample points, bacteria were detected by bacteriological culture and/or DGGE and sequencing of excised bands. When all samples were combined, standard PCR-DGGE analysis of bacteria present in the spines identified 15 distinct bands, thereby revealing a distinct bacterial community. The main pathogens identified through sequencing were Bacillus cereus, B. thuringiensis, B. anthracis, and B. pumilus. The present study demonstrated the isolation and identification of non-pathogenic and pathogenic bacteria on the spines of C. subspinosus.

The Thin-Spined Porcupine, Chaetomys Subspinosus (Rodentia: Erethizontidae), within Protected Areas in the Atlantic Forest, Brazil: Local Knowledge and Threats

The thin-spined porcupine, Chaetomys subspinosus, is an endemic mammal of the Atlantic forest of northeastern Brazil. With its population declining, it has been listed as “vulnerable” in the Brazilian Red List. Its National Action Plan, published in 2011, intended to develop awareness projects about the species in local communities, to implement alternative income projects and protein consumption, and to evaluate hunting pressure. This study investigates rural residents' knowledge of the thin-spined porcupine and its uses within two protected areas. We also examine residents' behaviour and perceptions about wildlife conservation. One hundred twenty-five semi-structured interviews were conducted with rural residents of the Una Wildlife Refuge and the Serra do Conduru State Park. Local knowledge was higher among males with lower levels of formal education who were current or past hunters. Negative behaviour occurs among residents in both protected areas. There is a need for greater control of potential threats such as hunting, use of fire and deforestation, which are inconsistent with the existence of protected areas and conservation of the thin-spined porcupine. Information provided by this study can improve and promote actions within the National Action Plan for the conservation of C. subspinosus.

Home range, movements and diurnal roosts of the endangered thin-spined porcupine, Chaetomys subspinosus (Rodentia: Erethizontidae), in the Brazilian Atlantic Forest

Chaetomys subspinosus is the sole species within the Chaetomyinae subfamily of Caviomorph rodents. This poorly studied porcupine is restricted to the Atlantic Forest in eastern Brazil, where deforestation and habitat fragmentation threaten its survival. Data on the ranging and roosting behavior of C. subspinosus is fairly scarce as it is difficult to observe these behaviors in nature and, consequently, it is very rarely detected during field surveys. We monitored the home ranges of three radio-tagged females over the course of 1 year (2005–2006) and collected data on several aspects of their natural history including movement patterns and the use of diurnal roosts and latrines. The animals were monitored at Parque Estadual Paulo Cesar Vinha, a nature reserve dominated by restinga forests, a subtype of Atlantic Forest occurring on sandy soil. The estimated home range varied little between individuals and was relatively small (mean=2.14ha/individual and 1.09ha/individual using minimum convex polygon and kernel methods, respectively). The animals travelled an average of 147m/night (range: 21–324m/night) between two consecutive day roosts. The day roosts were mostly located on vine and liana tangles in the canopy which also aid in connecting the canopy to adjacent trees or the forest floor. Latrines were mostly located near the ground in places heavily protected by spiny bromeliads or by other tangled vegetation. Our data suggests that C. subspinosus has the smallest range among all Neotropical Erethizontids which is likely due to its small size and strictly folivorous diet. Our data also helps explain why C. subspinosus is so difficult to observe in nature: researchers should focus on arboreal masses of tangled vegetation where individuals will normally rest during the day.

Activity, movement and secretive behavior of a threatened arboreal folivore, the thin‐spined porcupine, in the Atlantic forest of southern Bahia, Brazil

AbstractActivity and behavior patterns are important components of a given species’ ecological strategy, as they have profound implications for its survival and reproduction. Here, we studied the activities, movements and secretive behavior of the thin‐spined porcupine Chaetomys subspinosus (Rodentia: Erethizontidae), a threatened arboreal folivore in the Brazilian Atlantic rainforest. We aimed to ascertain the behavioral strategies used by this species as well as its responses to seasonal and daily climatic changes. Four radio‐collared individuals were followed continuously for 72‐h in the summer and winter, as well as during 146 half‐night sessions conducted from April 2005 to September 2006 in forest remnants in southern Bahia. The thin‐spined porcupines were nocturnally active (17:30–05:40 h), with peaks in activity and movement from 19:00 to 20:00 h and 03:00 to 04:00 h. Animals followed a circadian rhythm of activity during both the summer and winter. During the diel cycle, porcupines spent 74% of their time resting, 14% feeding, 11% traveling and 2% performing other activities. Distance traveled during the diel cycle averaged 277.5 ± 117.9 m sd. The mean movement rate during the night was 21.6 ± 30.1 m/h sd. No significant changes in activity budget or daily distance traveled were observed between seasons, most likely in response to the low fluctuations in climatic conditions and food availability throughout the year in the study region. However, rainfall reduced the time that the animals spent on feeding activities and explained day‐to‐day differences in activity budgets. We also provide details about intraspecific interactions and defecation behavior. Our observations confirmed that thin‐spined porcupines, similar to other folivorous species, present low activity levels and short daily movements, and have adopted various cryptic habits, such as nocturnality, a solitary lifestyle, the tendency to leave offspring alone most of the time and defecation in concealed latrines.

Haematology and several health aspects of endangered free-ranging thin-spined porcupines, Chaetomys subspinosus (Olfers, 1818) (Erethizontidae: Chaetomyinae)

The thin-spined porcupine Chaetomys subspinosus is an endangered mammal from the Brazilian Atlantic Forest. Folivory, long periods spent resting and reduced home ranges are characteristics related to their slow behaviour. We captured and restrained four C. subspinosus individuals from Parque Estadual Paulo Cesar Vinha, Guarapari, Espirito Santo State, Brazil, and performed clinical, haematological and coproparasitological tests to partially assess the health status of these animals. We also describe the restraint and monitoring procedures used here. The observed haematological values were similar to previously published results from other Erethizontidae, except for higher platelet counts found in Chaetomys compared to other studies on Coendou and lower packed cell volumes and erythrocyte and leukocyte counts relative to Sphiggurus. No gastrointestinal parasites, ectoparasites or haemoparasites were found. Because all the individuals were in good physical condition, we suggest the use of our data as a reference for future studies on medicine, conservation, ecology and health of this endangered species.

Genetic assessment of the Atlantic Forest bristle porcupine, Chaetomys subspinosus (Rodentia: Erethizontidae), an endemic species threatened with extinction

The bristle-spined porcupine, Chaetomys subspinosus, an endemic rodent from Atlantic Forest, was considered to be abundant in the recent past, but population reductions due to habitat loss and expansion of human activities caused this species to be included in the "vulnerable" category of the World Conservation Union Red List. We performed the first genetic assessment in natural populations of this focal species along its geographical distribution. Thirty-five non-invasive samples (hair) were collected from three natural populations in the Brazilian States of Sergipe, Bahia and Espírito Santo. Genetic similarity obtained by Jaccard's index, based on dominant RAPD and ISSR markers, varied between 25 and 100%. Four clusters, mainly coincident with the geographical distribution of the populations, were observed. Analysis of molecular variance based on 47 polymorphic loci showed that there was 15.99% genetic variability among populations and 84.01% within populations. The estimated genetic structure among populations (Φ(ST)) was 0.16. The populations may have formed a continuum along the past distribution of the Atlantic rainforest but historical events of human occupation resulted in recent divergence among sampled populations.