Publications

the lung-eardrum pathway in three treefrog and four dendrobatid frog species: some properties of sound transmission.	frequency-response curves of the tympanum and lateral body wall (lung area) were measured by laser doppler vibrometry in three treefrog (smilisca baudini, hyla cinerea, osteopilus septentrionalis) and four dendrobatid frog (dendrobates tinctorius, d. histrionicus, epipedobates tricolor, e. azureiventris) species. the high-frequency cut-off of the body wall response was always lower than that of the tympanum. the best response frequencies of the lateral body wall were lower than those of the tymp ...	1994	7964416
experimental transmission of cutaneous chytridiomycosis in dendrobatid frogs.	in a series of three experiments during march-october, 1998, two species of captive-bred poison dart frogs (dendrobates tinctorius and d. auratus) were exposed to batrachochytrium dendrobatidis, a recently-described chytridiomycete fungus (chytrid) that was originally isolated from a blue poison dart frog (d. azureus). all frogs exposed to the chytrids developed a fatal skin disease, whereas none of the control frogs developed skin lesions. the most consistent clinical sign in chytrid-exposed fr ...	2001	11272482
use of immunohistochemistry to diagnose chytridiomycosis in dyeing poison dart frogs (dendrobates tinctorius).	chytridiomycosis, caused by batrachochytrium dendrobatidis, is an emerging disease of both wild and captive amphibians, posing a threat to their survival in many parts of the world. as the disease can be difficult to diagnose on routine pathologic sections, the purpose of this study was to develop an additional method for visualization. to accomplish this, immunohistochemical staining was applied to histologic skin sections from four experimentally infected dyeing poison dart frogs (dendrobates ...	2003	14567242
refugial isolation and secondary contact in the dyeing poison frog dendrobates tinctorius.	recent palaeoclimactic research suggests that fluctuating environmental conditions throughout the pleistocene of amazonia occurred with previously unrecognized frequency. this has resulted in a theoretical shift from glacially influenced fluctuations to those driven by precessional rhythms. this theoretical revolution has a profound impact on expectations of biotic diversity within biogeographical regions that have long been based on the idea of large-scale landscape fragmentation associated wit ...	2006	17107474
the role of predator selection on polymorphic aposematic poison frogs.	demonstrations of interactions between diverse selective forces on bright coloration in defended species are rare. recent work has suggested that not only do the bright colours of neotropical poison frogs serve to deter predators, but they also play a role in sexual selection, with females preferring males similar to themselves. these studies report an interaction between the selective forces of mate choice and predation. however, evidence demonstrating phenotypic discrimination by potential pre ...	2009	19019778
spatial variation in the fitness of divergent aposematic phenotypes of the poison frog, dendrobates tinctorius.	aposematic species use brightly coloured signals to warn potential predators of their unpalatability. the function of these signals is largely believed to be frequency-dependent. all else being equal, stabilizing selection is expected to constrain the evolution of novel signals. however, despite the expected frequency-dependent function of aposematic signals, interpopulation variation in aposematic signals is ubiquitous in nature. here, we used clay models of the poison frog dendrobates tinctori ...	2011	21418119
chromosome analysis of five brazilian species of poison frogs (anura: dendrobatidae).	dendrobatid frogs have undergone an extensive systematic reorganization based on recent molecular findings. the present work describes karyotypes of the brazilian species adelphobates castaneoticus, a. quinquevittatus, ameerega picta, a. galactonotus and dendrobates tinctorius which were compared to each other and with previously described related species. all karyotypes consisted of 2n = 18 chromosomes, except for a. picta which had 2n = 24. the karyotypes of the adelphobates and d. tinctorius ...	2011	21677386
batrachochytrium dendrobatidis in amphibians confiscated from illegal wildlife trade and used in an ex situ breeding program in brazil.	this paper describes an outbreak of chytridiomycosis affecting a group of dendrobates tinctorius, a neotropical anuran species, confiscated from the illegal wildlife trade and housed in a private zoo in brazil as part of an ex situ breeding program. we examined histological sections of the skin of 30 d. tinctorius and 20 adelphobates galactonotus individuals. twenty d. tinctorius (66.7%) and none of the a. galactonotus were positive for batrachochytrium dendrobatidis (bd). multiple development s ...	2012	22436465
characterization of seven new polymorphic microsatellite loci in the brilliant-thighed poison frog allobates femoralis (dendrobatidae), and their cross-species utility in three other dendrobatid species.	here we document the development of seven novel polymorphic microsatellite markers for the brilliant-thighed poison frog allobates femoralis (dendrobatidae). we found between six and 27 alleles per locus in 100 individuals (50 males, 50 females) from the field site 'saut pararé', french guiana, with an average observed heterozygosity of 0.79. one locus (afem23) deviated significantly from hardy-weinberg equilibrium. we did not find any evidence for linkage disequilibrium among the new loci, or t ...	2013	25110383
monitoring strategy for eight amphibian species in french guiana, south america.	although dramatic amphibian declines have been documented worldwide, only few of such events have been quantitatively documented for the tropical forests of south america. this is due partly to the fact that tropical amphibians are patchily distributed and difficult to detect. we tested three methods often used to monitor population trends in amphibian species in a remote lowland tropical forest of french guiana. these methods are capture-mark-recapture (cmr), estimation of the number of calling ...	2013	23840717
differential detectability of polymorphic warning signals under varying light environments.	the striking colour-pattern variation of some aposematic species is paradoxical because selection by predators is expected to favour signal uniformity. although the mechanisms allowing for the maintenance of such variation are not well understood, possible explanations include both non-adaptive processes like drift and gene flow; and adaptive processes, such as an interaction between natural and sexual selection, spatial and temporal variation in selection, a link between behaviour or other fitn ...	2014	25158931
mind the gap: treefalls as drivers of parental trade-offs.	tree-fall gaps are small-scale disturbances whose formation, colonization, and role in forest dynamics are well documented, but whose effects on animal ecology are still greatly overlooked, except for studies comparing species richness of gaps 6+ months old to that in the closed canopy. other factors associated with the invasion of fresh tree-fall gaps such as animal breeding adaptations have been largely neglected. i studied the immediate (within hours and days) arrival of the poison frog dendr ...	2015	26445657
visual illusions in predator-prey interactions: birds find moving patterned prey harder to catch.	several antipredator strategies are related to prey colouration. some colour patterns can create visual illusions during movement (such as motion dazzle), making it difficult for a predator to capture moving prey successfully. experimental evidence about motion dazzle, however, is still very scarce and comes only from studies using human predators capturing moving prey items in computer games. we tested a motion dazzle effect using for the first time natural predators (wild great tits, parus maj ...	2015	25947086
widespread occurrence of bd in french guiana, south america.	the amphibian chytrid fungus batrachochytrium dendrobatidis (bd) is a purported agent of decline and extinction of many amphibian populations worldwide. its occurrence remains poorly documented in many tropical regions, including the guiana shield, despite the area's high amphibian diversity. we conducted a comprehensive assessment of bd in french guiana in order to (1) determine its geographical distribution, (2) test variation of bd prevalence among species in french guiana and compare it to e ...	2015	25902035
distance-dependent defensive coloration in the poison frog dendrobates tinctorius, dendrobatidae.	poison dart frogs provide classic examples of warning signals: potent toxins signaled by distinctive, conspicuous coloration. we show that, counterintuitively, the bright yellow and blue-black color of dendrobates tinctorius (dendrobatidae) also provides camouflage. through computational modeling of predator vision, and a screen-based detection experiment presenting frogs at different spatial resolutions, we demonstrate that at close range the frog is highly detectable, but from a distance the c ...	2018	29866847
from habitat use to social behavior: natural history of a voiceless poison frog, dendrobates tinctorius.	descriptive studies of natural history have always been a source of knowledge on which experimental work and scientific progress rely. poison frogs are a well-studied group of small neotropical frogs with diverse parental behaviors, distinct calls, and bright colors that warn predators about their toxicity; and a showcase of advances in fundamental biology through natural history observations. the dyeing poison frog, dendrobates tinctorius, is emblematic of the guianas region, widespread in the ...	2019	31576237
transcriptomic signatures of experimental alkaloid consumption in a poison frog.	in the anuran family dendrobatidae, aposematic species obtain their toxic or unpalatable alkaloids from dietary sources, a process known as sequestering. to understand how toxicity evolved in this family, it is paramount to elucidate the pathways of alkaloid processing (absorption, metabolism, and sequestering). here, we used an exploratory skin gene expression experiment in which captive-bred dendrobatids were fed alkaloids. most of these experiments were performed with dendrobates tinctorius, ...	2019	31546679
weak warning signals can persist in the absence of gene flow.	aposematic organisms couple conspicuous warning signals with a secondary defense to deter predators from attacking. novel signals of aposematic prey are expected to be selected against due to positive frequency-dependent selection. how, then, can novel phenotypes persist after they arise, and why do so many aposematic species exhibit intrapopulation signal variability? using a polytypic poison frog (dendrobates tinctorius), we explored the forces of selection on variable aposematic signals using ...	2019	31481623
conservation of glomerular organization in the main olfactory bulb of anuran larvae.	the glomerular array in the olfactory bulb of many vertebrates is segregated into molecularly and anatomically distinct clusters linked to different olfactory functions. in anurans, glomerular clustering is so far only described in xenopus laevis. we traced olfactory projections to the bulb in tadpoles belonging to six distantly related anuran species in four families (pipidae, hylidae, bufonidae, dendrobatidae) and found that glomerular clustering is remarkably conserved. the general bauplan co ...	2020	32792916
investigating the potential use of an ionic liquid (1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide) as an anti-fungal treatment against the amphibian chytrid fungus, batrachochytrium dendrobatidis.	the disease chytridiomycosis, caused by the pathogenic chytrid fungus, batrachochytrium dendrobatidis (bd), has contributed to global amphibian declines. bd infects the keratinized epidermal tissue in amphibians and causes hyperkeratosis and excessive skin shedding. in individuals of susceptible species, the regulatory function of the amphibian's skin is disrupted resulting in an electrolyte depletion, osmotic imbalance, and eventually death. safe and effective treatments for chytridiomycosis ar ...	2020	32302369
visible implant elastomer (vie) success in early larval stages of a tropical amphibian species.	animals are often difficult to distinguish at an individual level, and being able to identify individuals can be crucial in ecological or behavioral studies. in response to this challenge, biologists have developed a range of marking (tattoos, brands, toe-clips) and tagging (banding, collars, pit, via, vie) methods to identify individuals and cohorts. animals with complex life cycles are notoriously hard to mark because of the distortion or loss of the tag across metamorphosis. in amphibians, fe ...	2020	32864207
use of whole-body cryosectioning and desorption electrospray ionization mass spectrometry imaging to visualize alkaloid distribution in poison frogs.	ambient mass spectrometry is useful for analyzing compounds that would be affected by other chemical procedures. poison frogs are known to sequester alkaloids from their diet, but the sequestration pathway is unknown. here, we describe methods for whole-body cryosectioning of frogs and use desorption electrospray ionization mass spectrometry imaging (desi-msi) to map the orally administered alkaloid histrionicotoxin 235a in a whole-body section of the poison frog dendrobates tinctorius. our resu ...	2020	32452606
neural correlates of winning and losing fights in poison frog tadpoles.	aggressive competition for resources among juveniles is documented in many species, but the neural mechanisms regulating this behavior in young animals are poorly understood. in poison frogs, increased parental care is associated with decreased water volume of tadpole pools, resource limitation, and aggression. indeed, the tadpoles of many poison frog species will attack, kill, and cannibalize other tadpoles. we examined the neural basis of conspecific aggression in dyeing poison frog (dendrobat ...	2020	32446779
hormonal and neural correlates of care in active versus observing poison frog parents.	the occasional reversal of sex-typical behavior suggests that many of the neural circuits underlying behavior are conserved between males and females and can be activated in response to the appropriate social condition or stimulus. most poison frog species (family dendrobatidae) exhibit male uniparental care, but flexible compensation has been observed in some species, where females will take over parental care duties when males disappear. we investigated hormonal and neural correlates of sex-ty ...	2020	31987899
comparison of subcutaneous administration of alfaxalone-midazolam-dexmedetomidine with ketamine-midazolam-dexmedetomidine for chemical restraint in juvenile blue poison dart frogs (dendrobates tinctorius azureus).	blue poison dart frogs (dendrobates tinctorius azureus) are commonly maintained in zoological institutions and are becoming popular in the pet trade industry. sedation or light anesthesia is required for safe and effective handling of this species. in this study, the sedative effects of subcutaneously administered alfaxalone-midazolam-dexmedetomidine (amd) (20, 40, 5 mg/kg, respectively) and ketamine-midazolam-dexmedetomidine (kmd) (100, 40, 5 mg/kg, respectively) were compared in a prospective, ...	2020	31926517