Armadillo Species Research Articles

Not armoured enough: The black-and-white tegu Salvator merianae (Squamata: Teiidae) as a predator of armadillos (Cingulata)

Reporting predation events is crucial to understand how species behaviour and predator-prey interactions shape food webs. However, data is still lacking for most neotropical fauna, especially reptiles. Salvator merianae is a widespread lizard species, which is often found in human-altered habitats and has been introduced in multiple locations. This Neotropical lizard is omnivorous and acts as a necrophagous, seed disperser and predator of small-sized animals. However, in spite of extensive data on its generalist diet, detailed predation records over medium-sized vertebrates (between 1 and 40 kg) are scarce. Here we report the first records of S. merianae predation on three distinct armadillo species, all of which occurred in human-altered habitats in Brazil and Argentina. Our records contribute to a better understanding of trophic interactions in modified landscapes and how large reptiles, such as S. merianae, may play an important role in food webs in the absence of larger predators.

3D models related to the publication: Exon capture museomics deciphers the nine-banded armadillo species complex and identifies a new species endemic to the Guiana Shield.

3D models related to the publication: Exon capture museomics deciphers the nine-banded armadillo species complex and identifies a new species endemic to the Guiana Shield.

Exon capture museomics deciphers the nine-banded armadillo species complex and identifies a new species endemic to the Guiana Shield.

The nine-banded armadillo (Dasypus novemcinctus) is the most widespread xenarthran species across the Americas. Recent studies have suggested it is composed of four morphologically and genetically distinct lineages of uncertain taxonomic status. To address this issue, we used a museomic approach to sequence 80 complete mitogenomes and capture 997 nuclear loci for 71 Dasypus individuals sampled across the entire distribution. We carefully cleaned up potential genotyping errors and cross contaminations that could blur species boundaries by mimicking gene flow. Our results unambiguously support four distinct lineages within the D. novemcinctus complex. We found cases of mito-nuclear phylogenetic discordance but only limited contemporary gene flow confined to the margins of the lineage distributions. All available evidence including the restricted gene flow, phylogenetic reconstructions based on both mitogenomes and nuclear loci, and phylogenetic delimitation methods consistently supported the four lineages within D. novemcinctus as four distinct species. Comparable genetic differentiation values to other recognized Dasypus species further reinforced their status as valid species. Considering congruent morphological results from previous studies, we provide an integrative taxonomic view to recognise four species within the D. novemcinctus complex: D. novemcinctus, D. fenestratus, D. mexicanus, and D. guianensis sp. nov., a new species endemic of the Guiana Shield that we describe here. The two available individuals of D. mazzai and D. sabanicola were consistently nested within D. novemcinctus lineage and their status remains to be assessed. The present work offers a case study illustrating the power of museomics to reveal cryptic species diversity within a widely distributed and emblematic species of mammals.

Perceptions and knowledge of local people toward an endangered armadillo from the Buenos Aires coast, Argentina

ABSTRACT In a large area used for livestock production in the north east of the Pampas region of Buenos Aires, central Argentina, there is a subpopulation of endangered armadillo species (Chaetophractus vellerosus) which is threatened by mining activities. Knowledge and perception of local communities living in the range of the endangered species were evaluated using an anonymous online questionnaire. A total of 618 questionnaires were filled out, with the majority of respondent (82%) not being aware of the existence of this species. The study documented the lack of knowledge and the need to develop strategies to increase local communities’ awareness toward this species.

Long-term preservation of established fibroblast lines from six-banded armadillos (Euphractus sexcintus, Linnaeus, 1758) by extended passage and cryopreservation.

Establishing new somatic cell cultures has raised significant attention as an effective and convenient way to preserve genetic samples for different applications. Although many lines have been established in model animals, none derived from six-banded armadillo species is currently available. We report the successful isolation and characterization of fibroblasts from six-banded armadillos, evaluating the cell quality after extended culture and cryopreservation. Initially, we collected ear skin from five captive adult individuals and identified fibroblast lines by morphology, karyotyping, and immunophenotyping assays. The isolated fibroblasts were evaluated after several passages (fourth, seventh, and tenth passages) and cryopreservation by slow freezing. Cell morphology, viability, metabolism, proliferative activity, mitochondrial membrane potential, and apoptosis levels were analyzed. The skin explants had great adhesion, and cell outgrowth could be seen after 3-6 d. The cells were verified as fibroblasts at the fourth passage by vimentin expression and normal karyotype (2n = 58). The viability remained high (> 87%) and constant from the fourth to the tenth passage (p > 0.05). The passages did not change the cell morphology and metabolic and growth rates. Moreover, cryopreservation did not affect most evaluated parameters; post-thawed cells maintained their viability, growth, metabolism, and apoptosis levels. Nevertheless, cryopreservation increased mitochondrial membrane permeability and cell population doubling time compared to non-cryopreserved cells (p < 0.05). In summary, viable fibroblasts can be obtained from six-banded armadillo skin while conserving their quality as the number of passages increases and featuring few changes after cryopreservation.

Aportes al conocimiento del armadillo peludo de nariz larga (Dasypus pilosus)

The hairy long-nosed armadillo (Dasypus pilosus) is the least known of the five armadillo species reported for Peru. This species is endemic to the montane forests of northeastern Peru. During a wildlife inventory in Rio Abiseo National Park, eight specimens were collected in montane forest or low montane forest. Stomach content analyses show that they are opportunistic insectivores that feed mainly on larvae living underground or forming colonies. The most commonly consumed species (adults and larvae) were hymenopterans, lepidopterans, and coleopterans. In addition, previous species records were reviewed. Their analysis suggests that D. pilosus may use grasslands near the forest edge and those in the jalca, and that it is present in conservation areas of San Martin, Amazonas and Cajamarca. Effective conservation of D. pilosus requires a better understanding of the basic aspects of its biology and ecology.

Assessing the impact of environmental enrichment on behavior in understudied armadillo species: A case study.

The implementation of environmental enrichment (EE) can be effective in promoting zoo animal welfare by enhancing the performance of natural or species-typical behaviors. Research on the effects of EE is biased towards larger mammalian species, with less charismatic species being overlooked. Armadillos are one such overlooked example. A captive environment that results in inactivity, obesity, and associated poor health can negatively affect armadillo well-being. The aim of this study was to evaluate how the implementation of four physical object-based EEs could positively affect the behaviors of three armadillo species, housed in four similar exhibits. Behavioral data were collected both before (baseline) and during (treatment) EE periods, alongside of visitor number and environmental temperatures. The EE comprised of a plastic ball or a cardboard tube or a cardboard box, or a scatter-feed, and these were rotated each week of study until each exhibit had received them in turn. Despite the presence of different EE types, activity remained low throughout the study. However, results suggest that the plastic ball and cardboard box increased exploratory behaviors in the armadillos, but no overall increase in activity was noted during the scatter feed. Visitor presence had no effect on armadillo activity, and armadillos showed reduced activity with increasing environmental temperature. Overall, the use of physical object-based EE promoted beneficial natural behaviors in zoo-housed armadillos, but environmental conditions (i.e., temperature) also impacted armadillo activity, suggesting a complicated relationship between an enclosure's environmental variable and any behavioral husbandry measures.

Site occupancy of Dasypus novemcinctus (Mammalia, Cingulata) and daily activity of four armadillo species in the Uruguayan Savanna and southern Atlantic Forest

Site occupancy of Dasypus novemcinctus (Mammalia, Cingulata) and daily activity of four armadillo species in the Uruguayan Savanna and southern Atlantic Forest

High Trypanosoma cruzi prevalence in armadillo (Zaedyus pichiy; Xenarthra: Chlamyphoridae) populations from Mendoza, Argentina.

Armadillos are considered important reservoir hosts for Trypanosoma cruzi, the causative agent of Chagas disease. The first report of T. cruzi infection in pichis (Zaedyus pichiy), a small armadillo species endemic to central Argentina and Chile, dates back to 1935. However, more recent reports on T. cruzi in this species are scarce. The objective of this study was to assess T. cruzi infection and parasite load in Z. pichiy from Mendoza Province, an area endemic to human Chagas disease. Blood samples were obtained in 2014-2016 from pichis from Lavalle (low Monte), Malargüe (Patagonian steppe), and San Carlos (ecotone) departments, Mendoza Province, Argentina. The detection and quantification of T. cruzi was performed through qPCR amplification using satellite primers. Of the 265 analyzed samples, 201 (76%) were positive for T. cruzi. Parasite loads varied between < 0.1-55.8 parasite-equivalents/mL (par-eq/mL), with a median of 1.1 par-eq/mL in quantifiable samples. The prevalence was similar in Malargüe and Lavalle (85-94%), but significantly lower in pichis from San Carlos (50%). Animals from Lavalle captured after hibernation had significantly higher parasite loads (median 2.0 par-eq/mL). In Malargüe, T. cruzi infection and parasite loads were significantly lower before than after hibernation in 2016. The high prevalence and low median parasite load suggest a chronic and persistent infection of T. cruzi in pichis. Regional differences and a marked increase in precipitation during 2015-2016 could have influenced annual and seasonal infection rates of this vector-borne disease.

Trypanosoma cruzi Survey in Poached Pichis (Zaedyus pichiy; Mammalia, Cingulata) from Mendoza, Argentina.

The transmission cycles of Trypanosoma cruzi, the causative agent of Chagas disease, include a wide variety of mammals and hematophagous triatomine insects. Infection with this blood parasite has been confirmed in many armadillo species; however, information on infection in Zaedyus pichiy, a small armadillo that inhabits areas endemic to Chagas disease, is scarce. Our objective was to determine the infection frequency and parasite load of T. cruzi in 49 wild Z. pichiy confiscated dead from poachers in Mendoza, Argentina, 2010-2017. We detected T. cruzi DNA in 32 of 49 armadillos (65%) using real-time PCR, confirming infection with T. cruzi in a high proportion of confiscated pichis. No differences were found related to sex, age, or ecoregion origin of the assessed pichis. Parasite loads ranged between <0.1 and 8.88 parasite equivalents/microgram cardiac tissue. Additional studies on the infection status of Z. pichiy are needed to determine their role in the maintenance of the sylvatic transmission cycle and the potential zoonotic risk from hunted pichis.

The genus Armadillo Latreille, 1802 (Oniscidea, Armadillidae) from Cyprus, with descriptions of two new species.

The present work aims to morphologically characterize the species of Armadillo from Cyprus. Moreover, two new species of the genus are described, A. konstantinoui sp. nov. from several places along the island, and A. karametae sp. nov. from Pafos region. The circum-Mediterranean species A. officinalis is also redescribed.

Syncranial osteology of the Nine-Banded Armadillo, &lt;em&gt;Dasypus novemcinctus&lt;/em&gt;, from south Brazil

Several aspects of the bone morphology of armadillos have been investigated and used as taxonomic bases. The nined-banded armadillo, Dasypus novemcinctus, is the species of the genus that has the largest geographical distribution. Although is the most well-known armadillo species in its biology, skeletal studies are scarce and its original description is not detailed to permit accurate taxonomic revision including specimens from Southern end of Brazil. The objective of the present work was to provide a complete description of the synchranium of specimens from Pampa biome including areas located at south of Rio Grande do Sul State, Brazil. The bony elements were described in detail on the basis of thirty-two specimens prepared specifically for this study. In general, the shape of bones remained morphologically similar between adults of both sexes. The studied specimens differed morphologically from those of previous studies and from more northern regions. Differences were verified in the lateral border of the palatine bone, shape of the pterygoids bones,shape of the coanas, outline of foramen Magnum and of Tentorial process. The results obtained generated evidences that may contribute to future morphological and taxonomical studies including animals from Southern Brazil.

NEOICHNOLOGY OF ARMADILLOS: KEYS FOR THE PALEOECOLOGICAL AND BEHAVIORAL INTERPRETATION OF FOSSIL TETRAPOD BURROWS

ABSTRACTThis study is based on the analysis of burrow casts of three species of armadillos from central Argentina: Chaetophractus villosus, Chaetophractus vellerosus, and Zaedyus pichiy (Chlamyphoridae: Euphractinae). The aim of this work was to identify key ichnologic signatures of Euphractinae armadillo burrows for application to the paleoecological and behavioral interpretation of fossil examples. A total of 15 active burrows from different biogeographic provinces were casted with polyurethane foam and then excavated. About two hundred uncasted burrows and foraging pits were also measured at the same localities. Euphractinae burrows are clearly distinguished from Chlamyphorinae burrows by its filling, surface ornamentation, and size. It is suggested that fossil armadillo (Euphractinae) burrows would be characterized by a single ramp with one entrance and massive or laminated fill, horizontal diameter larger than 100 mm, strongly marked sets of three claw traces that are arranged oblique to the ramp axis, and absence of feces or plant remains. The distinctive surface ornamentation present in the casted burrows is tentatively linked to a particular excavation mechanism involving rotation of the body along the antero-posterior axis. Burrow systems with a chamber are interpreted as permanent burrows, whereas those lacking chamber are considered as temporary/shelter burrows. Armadillo burrow systems (either temporary or permanent) are longer, less inclined, and have lower relative diameter indices (RDI) than armadillo foraging pits. Euphractinae burrows are linked to producers with solitary, fossorial, opportunistic omnivorous habits that excavate several burrows during their lives. They are left open after abandonment, and preferably located in xeric shrub lands and grasslands. The described morphological features of the burrows systems can be useful for the interpretation of fossil (post-Eocene) burrows.

Biologging as an important tool to uncover behaviors of cryptic species: an analysis of giant armadillos (Priodontes maximus).

Advances in biologging have increased the understanding of how animals interact with their environment, especially for cryptic species. For example, giant armadillos (Priodontes maximus) are the largest extant species of armadillo but are rarely encountered due to their fossorial and nocturnal behavior. Through the analysis of speed, turning angles, and accelerometer activity counts, we estimated behavioral states, characterized activity budgets, and investigated the state-habitat associations exhibited by individuals monitored with GPS telemetry in the Brazilian Pantanal from 2019 to 2020. This methodology is proposed as a useful framework for the identification of priority habitat. Using the non-parametric Bayesian mixture model for movement (M3), we estimated four latent behavioral states that were named 'vigilance-excavation', 'local search', 'exploratory', and 'transit'. These states appeared to correspond with behavior near burrows or termite mounds, foraging, ranging, and rapid movements, respectively. The first and last hours of activity presented relatively high proportions of the vigilance-excavation state, while most of the activity period was dominated by local search and exploratory states. The vigilance-excavation state occurred more frequently in regions between forest and closed savannas, whereas local search was more likely in high proportions of closed savanna. Exploratory behavior probability increased in areas with high proportions of both forest and closed savanna. Our results establish a baseline for behavioral complexity, activity budgets, and habitat associations in a relatively pristine environment that can be used for future work to investigate anthropogenic impacts on giant armadillo behavior and fitness. The integration of accelerometer and GPS-derived movement data through our mixture model has the potential to become a powerful methodological approach for the conservation of other cryptic species.

Osteology and radiology of the thoracic limb of nine-banded armadillo, dasypus novemcinctus linnaeus, 1758

In Brazil, injured nine-banded armadillos are frequently taken to wildlife rehabilitation centers due to direct or indirect anthropic interactions, however, database about osseous structures useful to radiographic interpretation are limited. This work provides bones description from thoracic limb of Dasypus novemcinctus as well as references to radiographic interpretation and the best positioning to perform the radiographies. Twelve deceased specimens seized by IBAMA (Brazilian Institute of the Environment and Renewable Natural Resources) were used to check osteology and radiographic anatomy. Radiographic images were taken in practical routine plans of small animals and were followed by limbs dissection and bones preparations. The bone structure of the thoracic limb was similar to those of other species of armadillos. The scapula presented a prominent caudal angle, as well as a thick acromion with a wide hamate process; the humerus is short, spiraled with a prominent deltoid tuberosity and a wide lateral epicondylar crest; the radius and ulna did not present any fusion between then, allowing a wide rotation movement of the forearm. In general, the bone components of the hand maintained a short and robust shape, digits with developed distal phalange followed by long claws. Several sesamoid bones were found in the metacarpal and interphalangical joints. Clear visualization of bone characteristics was possible using proposed positioning to take the radiographies.

Aroma-dillo or Area-dillo? An examination of armadillos’ sensory modality bias

Many species of armadillo demonstrate impressive navigation abilities and may compensate for poor eyesight with a strong sense of smell. We examined which modality four three-banded armadillos and one hairy armadillo prioritized when two cues (olfactory or spatial) previously associated with reward were put in conflict. The armadillos learned to approach one of two locations - each paired with a distinctive scent - for reward. When the scent cues were reversed, the armadillos demonstrated a strong bias for attending to the location cue over the scent cue. Therefore, a follow-up test presented them with the same scents and assessed their spontaneous preferences. Although the armadillos did not show an immediate preference for the previously rewarded scent, they did learn to discriminate two novel scents when they were placed in a circular arena containing two tins - each scented with a unique scent. They learned to selectively open the tins containing reward based on scent. This result indicates that their bias towards location cues was not due to an inability to discriminate between scents. Armadillos may attend to either location or scent but may prioritize location when both cues are equally predictive.

Distress vocalizations in five species of armadillos (Xenarthra, Cingulata)

Abstract Distress vocalizations are emitted by animals experiencing extreme physical distress, such as when caught by a predator. These signals are emitted by numerous and phylogenetically distant vertebrate species and are composed of sequences of broadband and high-amplitude notes. In this study, we provide the first acoustic characterization of distress vocalizations in four armadillo species: pink fairy armadillo (Chlamyphorus truncatus), greater fairy armadillo (Calyptophractus retusus), Southern three-banded armadillo (Tolypeutes matacus), and Chacoan naked-tailed armadillo (Cabassous chacoensis). We also recharacterized the weeping call of the screaming hairy armadillo (Chaetophractus vellerosus) to compare vocalizations, discuss potential homologies, and examine possible causes of structural and acoustic similarities among these species. In three species the vocalizations were sequences of exhaled notes that differed in their fine spectral structure (exhaled harmonic notes in C. retusus, and exhaled harsh notes in C. truncatus and T. matacus). The vocalization of C. chacoensis was composed of exhaled harsh and inhaled harsh notes that occurred alternately and continuously in a quick sequence. Based on the mode of production and acoustic similarity, we propose that the notes of C. retusus and C. truncatus would be homologous to the conspicuous crying notes of C. vellerosus. The exhaled harsh notes of T. matacus and C. chacoensis may also be homologous to the crying notes of C. vellerosus, but the notes of T. matacus are quite different in various acoustic parameters. Furthermore, the inhaled and exhaled harsh notes of C. chacoensis are similar to the inhaled and exhaled sobbing notes of C. vellerosus, making assessments of homologies uncertain in these species. Because a common motivational state (physical distress) underlies these vocalizations, we propose that the notable differences in body size and habitat preferences of the armadillos could represent potential drivers of the acoustic divergence among their vocalizations.

Morphology of urinary system in six-banded armadillo (Euphractus sexcinctus, Linnaeus, 1758).

Euphractus sexcinctus is a wild mammal native to the Americas; they have great diversity and are not in danger of extinction like other armadillo species. Despite the diversity, the morphology of several biological systems of this species has not been fully described. This study details the gross and microscopic anatomy of the urinary system in Euphractus sexcinctus, a six-banded armadillo, compared with other mammalian study models. Six animals were dissected in the study. In the anatomical analysis, the kidneys, ureters, urinary bladder and urethra were dissected and photographed; then, fragments were submitted to histological routine for staining with haematoxylin-eosin, toluidine blue and Masson's trichrome for visualization under light microscopy. The six-banded armadillo ureter is histologically composed of four concentric layers. The urinary bladder is presented with three tissue layers. The pattern of constitution and distribution of urinary system structures was compatible with that of most domestic like Canis familiaris and wild animals like Bradypus torquatus, with adaptations for the arid and semi-arid habitat. The description of the morphology of Euphractus sexcinctus presents great relevance both for its conservation and for its use as a model for clinical research.

Anesthesia and Braquial Plexus Block in Nine-Banded Armadillo (Dasypus novemcinctus)-Case Report

The nine-banded armadillo (Dasypus novemcinctus) is the most common species of armadillos in North, Central and South Americas. This case report is about an anesthetic procedure of a male armadillo received for rehabilitation with a radioulnar fracture. For the anesthesia, we use methadone, midazolam, s-ketamine and isoflurane. We also use a human laryngeal mask for secure airway and brachial plexus block with a peripheral nerve stimulator. There is a little information about anesthesia of these species in the literature and the aim of this work is to contribute to this knowledge. Though it is unknown the minimum alveolar concentration of isoflurane in nine-banded armadillo, we concluded that, with the blockage of the brachial plexus, we saw cardiovascular stability and a decrease in isoflurane use. The reversal of midazolam added to a quick recovery. The human laryngeal mask is effective for inhalation anesthesia in nine-banded armadillo.

Noninvasive Low‐cost Method to Identify Armadillos' Burrows: A Machine Learning Approach

ABSTRACTHaving accurate information about population parameters of armadillos (Mammalia, Cingulata) is essential for the conservation and management of the taxon, most species of which remain poorly studied. We investigated whether we could accurately identify 4 armadillo species (Euphractus sexcinctus, Dasypus novemcinctus, Cabassous tatouay, and Cabassous unicinctus) based on burrow morphometry. We first selected published studies that reported measurements of width, height, and angle of the burrows used by the 4 species of armadillos. Then, using such data we simulated burrow measurements for each of the 4 species of armadillos and we created predictive models through supervised machine learning that were capable of correctly identifying the species of armadillos based on their burrows' morphometry. By using classification algorithms such as Random Forest, K‐Nearest Neighbor, Support Vector Machine, Naive Bayes, and Decision Tree C5.0, we achieved the overall accuracy for the classification task by about 71%, including an overall Kappa index by about 61%. Euphractus sexcinctus was the most difficult species to discriminate and classify (approximately 68% of accuracy), whereas C. unicinctus was the easiest to discriminate (approximately 93% of accuracy). We found that it was possible to identify similar‐sized armadillos based on the measurements of their burrows described in the literature. Finally, we developed an R function (armadilloID) that automatically identified the 4 species of armadillos using burrow morphology. As the data we used represented all studies that reported the morphometry of burrows for the 4 species of armadillos, we can generalize that our function can predict armadillo species beyond our data. © 2021 The Wildlife Society.