Abstract The blood bacterial microbiota of the Texas tortoise (Gopherus berlandieri) in Tamaulipas, Mexico, was characterized by next-generation sequencing. In 2019, blood was collected from 6 free-living tortoises. DNA was extracted, the V3-V4 region of the 16S rRNA gene was amplified, and Illumina sequencing was performed. The results showed 9 phyla, 20 classes, 42 orders, 81 families, 176 genera and 299 bacterial species. Firmicutes was the most abundant phylum in the blood of G. berlandieri; this taxon has been recorded as predominant in the intestine, excrement, nasal exudates and saliva of other species of the genus Gopherus. The dominant bacterial genera were Caldalkalibacillus, Anaerobacillus, Nesterenkonia and Bacillus. These taxa have been recorded in alkaline and halophilic soils, such as those found in G. berlandieri burrows. All of these bacterial taxa can enter the bloodstream of G. berlandieri via intestinal, oral and nasal translocation. Likewise, 3 bacterial taxa (Coxiella sp., Ehrlichia sp. and Anaplasma phagocytophilum) that are transmitted by arthropod vectors, as well as the potentially pathogenic Salmonella enterica were recorded. This information is the first bacteriological reference for the blood of G. berlandieri, and is expected to be useful for health and conservation programs.

Resumen La microbiota bacteriana sanguínea de la tortuga texana (Gopherus berlandieri) en Tamaulipas, México, fue caracterizada mediante secuenciación de siguiente generación. En 2019 se colectó sangre de 6 tortugas silvestres. Se extrajo el DNA, se amplificó la región V3-V4 del gen 16S rRNA y se realizó secuenciación con Illumina. Los resultados mostraron 9 phyla, 20 clases, 42 órdenes, 81 familias, 176 géneros y 299 especies bacterianas. Firmicutes fue el phylum más abundante en la sangre de G. berlandieri; este taxón ha sido registrado como predominante en intestino, excremento, exudados nasales y saliva de otras especies de Gopherus. Los géneros bacterianos dominantes fueron Caldalkalibacillus, Anaerobacillus, Nesterenkonia y Bacillus. Estos taxa se encuentran en suelos alcalinos y halófilos como los que se presentan en las madrigueras de G. berlandieri. Todos estos taxa bacterianos podrían ingresar al torrente sanguíneo vía translocación intestinal, oral y nasal. En la sangre de esta tortuga se registraron 3 taxa (Coxiella sp., Ehrlichia sp. y Anaplasma phagocytophilum) que se trasmiten por artrópodos y el patógeno potencial Salmonella enterica. Esta información es una primera referencia bacteriológica de la sangre de G. berlandieri y se espera que sea de utilidad en programas de salud y conservación.

Abstract The exploited mangrove crab Ucides cordatus, an important ecosystem engineer in South American mangroves, has a biphasic lifecycle with pelagic larvae developing offshore. Megalopae return to the mangrove forest to settle, i.e., metamorphose into benthic juveniles but its environmental drivers remain poorly understood. We postulate that conspecific crabs facilitate recruitment. In the field, we investigated whether the number of recruits is higher near conspecific burrows than in areas without conspecific bioturbation. Recruit sampling was conducted monthly from April 2008 to May 2009 along an environmental gradient. First, U. cordatus recruits of that year emerged from March to July. Intraspecific facilitation was indicated by significantly higher recruit numbers in bioturbated than in non-bioturbated substrates. Recruits were most abundant in zones with intermediate conditions of inundation, leaf litter standing stock, sediment consistency, luminosity, temperature, salinity, and pH. Avoidance of more inundated zones likely reduces predation by fishes and of less inundated zones helps individuals escape more stressful, drier environmental conditions. The observed habitat-specific recruitment pattern must be considered when designing field assessments of the population structure of U. cordatus (which should include sampling recruits) and enhancing stocks by releasing laboratory-cultivated larvae and first juveniles into the wild. mangroves offshore settle ie i e i.e. understood bioturbation 200 gradient First U July nonbioturbated non substrates inundation stock consistency luminosity temperature salinity pH stressful habitatspecific habitat specific which laboratorycultivated laboratory cultivated wild i.e 20 2

Abstract The domestic cat is not considered a primary host for any specific tick species; however, it can be affected by some Ixodidae species, such as Rhipicephalus sanguineus sensu lato and Amblyomma spp. The study reports parasitism by Amblyomma auricularium and the detection of anti-Rickettsia spp. antibodies in domestic cats from a rural property in the Afrânio municipality, Pernambuco, Brazil. Amblyomma auricularium (24 nymphs, six females, and four males) and Amblyomma sp. (42 larvae) parasitized three cats, and 73 free-living ticks were captured in armadillo burrows: A. auricularium (36 nymphs, six females, five males) and Amblyomma sp. (26 larvae). Blood samples from cats were collected and the obtained plasma were subjected to indirect immunofluorescence assay (IFA) to detect antibodies against Rickettsia antigens. Thus, anti-Rickettsia spp. antibodies were determined (titers ranging from 128 to 512) and showed a predominant antibody response to Rickettsia amblyommatis or a very closely related genotype. This study reports the first infestation of nymphs and adults of A. auricularium on cats in a new area of occurrence in the semi-arid region of Northeastern Brazil and reports for the first time the presence of anti-Ricketsia antibodies in cats in the region, with R. amblyommatis as the probable infectious agent. species however spp antiRickettsia anti municipality Pernambuco 24 (2 females males sp 42 (4 larvae 7 freeliving free living burrows A 36 (3 26 larvae. . IFA (IFA antigens Thus titers 12 512 genotype semiarid semi arid antiRicketsia Ricketsia R agent 2 ( 4 3 1 51 5

Resumo O gato doméstico não é considerado hospedeiro para nenhuma espécie de carrapato. Pode, entretanto, ser afetado por algumas espécies de Ixodídeos, como Rhipicephalus sanguineus e Amblyomma spp. Este estudo relata o parasitismo por Amblyomma auricularium e detecção de anticorpos anti-Rickettsia spp. em gatos domésticos, em uma propriedade rural no município de Afrânio, Pernambuco, Brasil. Amblyomma auricularium (24 ninfas, seis fêmeas e quatro machos) e Amblyomma sp. (42 larvas) parasitavam os gatos, e 73 carrapatos de vida-livre foram capturados em tocas de tatus: A. auricularium (36 ninfas, seis fêmeas, cindo machos) e Amblyomma sp. (26 larvas). Amostras de sangue dos três gatos foram coletadas, e os plasmas obtidos foram submetidos à reação de imunofluorescência indireta (RIFI) para a detecção de anticorpos contra antígenos de Rickettsia. Dessa forma, anticorpos anti-Rickettsia spp. foram determinados (títulos variando de 256 a 512) e demonstraram uma resposta predominante para Rickettsia amblyommatis ou genótipo próximo. Este estudo relata, pela primeira vez, infestação de ninfas e adultos A. auricularium em gatos em uma nova área de ocorrência na região semiárida do nordeste do Brasil. E, também relata, pela primeira vez, a presença de anticorpos anti-Ricketsia em gatos na região, com R. amblyommatis como agente provável pela infecção. carrapato Pode entretanto Ixodídeos spp antiRickettsia anti domésticos Afrânio Pernambuco Brasil 24 (2 machos sp 42 (4 larvas 7 vidalivre vida livre tatus A 36 (3 26 larvas. . coletadas RIFI (RIFI forma títulos 25 512 próximo vez E antiRicketsia Ricketsia R infecção 2 ( 4 3 51 5

Abstract The sedimentary basins in the Continental Rift of Southeastern Brazil (CRSB) provide an opportunity for ichnological analyses due to its well-known facies relationships and paleoenvironmental interpretations. This study reports invertebrate trace fossils from the Neogene fluvial deposits (Floriano Formation) and applies integrated ichnological and facies analyses to reconstruct the environmental conditions recorded in this lithostratigraphic unit. Fieldworks revealed a rich ichnofauna in the Floriano Formation, whose facies associations have been interpreted as indicative of meandering river environments. Four sedimentary facies were identified, including bioturbated sandstone, horizontally stratified sandstone, laminated sandstone, and mudstone. Six ichnogenera were identified, Arenicolites, Beaconites, Camborygma, Palaeophycus, Skolithos, and Taenidium. Those ichnogenera occur as Skolithos, Taenidium, and Beaconites ichnocoenoses. The Skolithos ichnocoenosis is primarily represented within sand bar deposits, indicating arthropod colonization in abandoned channels. The Taenidium ichnocoenosis, which is observed within mudstone layers and presents Camborygma burrows, suggests transitional environments between aquatic and subaerial conditions, locally with high water table levels. The Beaconites ichnocoenosis indicates changes in substrate consistency associated with progressive desiccation and extended exposure time. Therefore, the identified ichnocoenoses, combined with the analysis of physical sedimentary structures, suggest generally humid conditions during colonization by invertebrates of the meandering river deposits of the Floriano Formation. CRSB (CRSB wellknown well known interpretations Formation unit sandstone Arenicolites Palaeophycus ichnocoenoses channels burrows levels time Therefore structures

Abstract The ecology of movement is an expanding area, marked by the diversity of analytical methods and protocols, which enables this integrative reading. We investigated movement ecology aspects of Coleodactylus meridionalis in southern Bahia, northeastern Brazil, using fluorescent powder with mineral oil to track individuals. We monitored 69 individuals of C. meridionalis that walked an average distance of 148 cm in 2h. We identified this movement as foraging due to the orientation of the step sequence and microenvironments used. We find no significant differences between walking distance and weight. However, we found a decrease in activity over the follow-up period. Most of the lizard’s movements were directed north, while south, east, and west were followed equally. The individuals stayed predominantly on the ground (leaf litter), but it was possible to observe the use of other surfaces, such as trunks and burrows on the ground. Therefore, we studied the movement in three dimensions (ground height, distance traveled, and orientation of steps). We observed the lizard’s foraging, one of the most common and least investigated movements in small lizards like C. meridionalis. This involves not only the species’ activity schedule but other intrinsic and extrinsic factors that shape the movement decisions of individuals. area protocols reading Bahia Brazil 6 C 14 2h h used weight However followup follow up period lizard s north south east equally leaf litter, litter , litter) surfaces Therefore height traveled steps. steps . steps) species 1

Abstract The presence of humans frequently modifies the behavior of animals, particularly their foraging patterns, compromising energetic demands. The fiddler crab Leptuca leptodactyla inhabits mangroves with high degrees of anthropogenic influence. Thus, we tested if populations living in highly anthropized mangroves respond differently from those living in more protected areas. We predict that individuals from touristy areas will be more tolerant to humans and will resume their activities sooner after disturbance. To do so, we conducted an experiment that consisted in the approach of an observer to the burrows, recording the response of individuals to the stimuli. The experiment took place in July 2022, in Ubatuba, São Paulo, Brazil. We analysed the duration and latency of various behaviors of a total of 80 adult males from two populations (high and low anthropogenic influence). Contrary to our predictions, individuals from the anthropized population were less tolerant, spending more time inside their burrows and taking longer to resume their activities. Therefore, fiddler crabs were not habituated to human presence. These results help us understand the learning process in invertebrates and their ability to select stimuli, contributing to understanding the impacts of human-wildlife interactions. animals patterns demands influence Thus disturbance so stimuli 2022 Ubatuba Paulo Brazil 8 . influence) predictions Therefore humanwildlife wildlife interactions 202 20 2

BACKGROUND: Much of the Grassland Biome in South Africa is prone to shrub encroachment, leading to loss of ecosystem services, habitat heterogeneity and species diversity. Burrowing mammals are an important component of grasslands as these animals create microhabitats for other taxa, including smaller mammal species, birds, reptiles and invertebrates. However, our understanding of how shrub encroachment affects burrowing mammals is poor OBJECTIVES: Here we assessed the relationship between burrow abundance and bankrupt bush, Seriphium plumosum, encroachment as well as burrowing mammal diversity in bankrupt bush encroached and non-encroached grasslands METHOD: Shrub density, medium and large mammal burrow abundance and density were measured in 24 encroached and 24 non-encroached areas randomly selected in the Telperion Nature Reserve, Mpumalanga, South Africa. In addition, burrowing mammal diversity was assessed using camera traps in a subset of six encroached and six non-encroached areas RESULTS: Our results show that the abundance and density of medium and large burrows were significantly lower in encroached areas than in non-encroached areas (p = 0.011 and p < 0.001, respectively). The relationship between burrow abundance and bankrupt bush encroachment was negative (rho = -0.456, p = 0.001). However, burrowing mammal diversity had no significant difference between encroached and non-encroached areas CONCLUSION: Our data, therefore, suggest that with increasing bankrupt bush encroachment and a decreased abundance in burrowing mammal ecosystem services, a negative effect will occur on burrowing mammal communities, leading to the reduction in species-specific habitat heterogeneity and possibly animal biodiversity

Abstract This study evaluated the effects of biogenic structures (tree roots and crab burrows) on sediment carbon (C), sulfur (S), and iron (Fe) biogeochemistry during the wet season in the Olaria mangrove forests near the city of Cananéia, São Paulo state, Brazil and the Nobrega mangrove forest approximately 2 km from the city. Anaerobic C oxidation pathways were assessed from sediment profiles and anaerobic incubations and related to the abundance of biogenic structures in the form of pneumatophores and crab burrows. Porewater depth profiles of dissolved inorganic carbon (DIC) and SO42- were less steep in the presence than absence of biogenic structures. While Fe(II) appeared unaffected by biogenic structures, Fe(III) levels were significantly higher in the upper 4 cm of the sediment in the presence than absence of vegetation and bioturbation. Surprisingly, the concentration of Fe(III) in this layer was 2-6 times higher in the Nobrega forest (6-13 µmol cm-3) than in the Olaria forest (1.5-6.5 µmol cm-3). Accordingly, depth integrated sulfate reduction (SR) tended to be highest at Olaria, while iron reduction (FeR) was highest at Nobrega. SR accounted for 54-83% of DIC production, with no diference between forested sites, while FeR accounted for 8-24% of DIC production, with a 2-3 times higher contribution in the Nobrega versus the Olaria forest. The results suggest that mangrove roots and crab burrows in mangrove sediments only promote FeR at the expense of SR in the Nobrega forest. It appears that anthropogenic discharge from Cananéia city may have overridden the impact of biogenic structures on sediment redox conditions at Olaria, thereby diminishing the role of FeR without strong stimulation of overall C oxidation rates.

Resumen Introducción: Los camarones mantis son organismos ecológica y económicamente importantes en los ecosistemas marinos. Sin embargo, aún falta información sobre su hábitat, en particular sobre sus madrigueras. Objetivo: Analizar cómo difieren las madrigueras de los camarones mantis en su abundancia, tamaño, tamaño de grano de los sedimentos y calidad del agua. Métodos: Contamos las madrigueras en parcelas de 10 x 10 m2 al azar (diez parcelas por densidad) en pastos marinos densos y poco densos, alrededor de la isla de Barrang Lompo, Sulawesi del Sur, Indonesia. Resultados: Se observaron dos especies de camarones mantis: Lysiosquillina maculata y L. sulcata. El tamaño de grano de las paredes de las madrigueras y los parámetros de agua, tanto dentro y fuera de la madriguera no variaron (P > 0.05). Tampoco hubo correlación entre la profundidad y el diámetro de las madrigueras, tanto en praderas densas (P > 0.05; r= 0.27), como no densas (P > 0.05; r= 0.33). Sin embargo, las madrigueras más grandes tienden a aparecer en las praderas densas, además había más madrigueras en pastos densos (t-test, P < 0.05). Conclusiones: Parece haber una preferencia por las praderas marinas densas, especialmente en los camarones mantis de mayor tamaño. La correlación entre la abundancia de madrigueras de camarones y la densidad de pastos marinos pone de manifiesto la importancia de conservar la calidad del hábitat de los pastos, así como su extensión.

Abstract Introduction: Mantis shrimps are ecologically and economically important organisms in marine ecosystems. However, there is still a lack of information about their habitat, in particular, their burrows. Objective: To analyze how dense and sparse mantis shrimp burrows differ in abundance, size, sediment grain size, and water quality. Methods: We counted burrows in 10 x 10 m2 random plots in sparse and dense seagrass (ten plots per density), around Barrang Lompo Island, South Sulawesi, Indonesia. Sampling took place at spring low tide from August to September 2017. Results: Two mantis shrimp species were observed: Lysiosquillina maculate and L. sulcata. Dense and sparse seagrass burrows did not differ in wall grain size or water parameters, both inside and outside of the burrows (P > 0.05). Similarly, there was no correlation between burrow depth and diameter in either dense (P > 0.05; r= 0.27) or sparse (P > 0.05; r= 0.33) seagrass. However, larger burrows tend to occur in denser beds, but there were more burrows in denser seagrass (t-test, P < 0.05). Conclusions: There seems to be a preference for dense seagrass beds, especially by larger mantis shrimps. The correlation between shrimp burrow abundance and seagrass density highlights the importance of conserving the quality as well as the extent of seagrass habitat.

Resumen La Lechucita de las Vizcacheras (Athenecunicularia) es un ave estrigiforme muy conspicua en las planicies de Sudamérica. Se caracteriza por ser una especie estacionalmente oportunista que consume una amplia diversidad de vertebrados y artrópodos. En este trabajo se evalúa la variabilidad estacional en la dieta de este predador y se brinda una caracterización tafonómica de los restos ingeridos y restos presa de anuros que ayudará a identificar al predador en contextos fósiles. Los trabajos de campo se llevaron a cabo en un sector periurbano de la ciudad de Olavarría, provincia de Buenos Aires. Se recolectaron semanalmente las egagrópilas y restos no ingeridos hallados en asociación a cuatro nidos delechucita. Los resultados obtenidos muestran que, entre los vertebrados,las presas principales eninvierno fueron los roedores y en verano los anuros. Esta especie de estrigiforme produce modificaciones leves a moderadas sobre los especímenes óseos de anfibios. Entre los efectos digestivos identificados predominan el pulido, el adelgazamiento, astillamiento y el colapso.

Abstract The Burrowing Owl (Athenecunicularia) is an Strigiformes bird widely distributed throughout the plains of South America. This species is seasonal opportunist and consumes a wide range of vertebrates and arthropods. This work evaluates the seasonal diet of the burrowing owl. Besides, we provide a taphonomic characterization of the anuran bone prey remains that will help to identify the predator in fossil contexts. The study was conducted in a peri-urban sector in Olavarría city, Buenos Aires Province. Pellets and uneaten remains scattered around four owl burrows were weekly collected. Our results show that, among vertebrates, rodents were the main prey in winter and anurans in summer. Burrowing owls produced little to moderate modifications on amphibian bone remains. The more frequent modifications of bone surface due to the digestive effects were polishing, thinning, splitting and collapsing.

RESUMO Com as próprias patas: Como e onde o Sapinho-de-Jardim Rhinella dorbignyi constrói seus abrigos. Neste estudo, observamos que tocas de Rhinella dorbignyi (Duméril & Bibron, 1841) são distribuídas de uma forma não-aleatória no habitat, sugerindo que esta espécie seleciona sítios para cavá-las. Esta conclusão foi baseada em uma caracterização de 36 tocas e do micro-habitat que as cerca. Estabelecemos um quadrante de 1 m x 1 m com a toca como seu ponto central (n=36) para medir a porcentagem (densidade) e a altura média de gramíneas, plantas herbáceas e arbustos. Todas as medidas foram repetidas em dois quadrantes não utilizados (sem tocas), para avaliar o micro-habitat disponível ao anfíbio (n=72). As tocas são construídas em áreas específicas do habitat com maior porcentagem de gramíneas, ervas mais altas, menos arbustos presentes e pouca área sombreada. Baseado em modelos tridimensionais do interior das tocas (n=15), observamos que todas elas são construídas com uma abertura elíptica que se abre para um canal estreito, perpendicular ao chão. Os canais têm diâmetro máximo médio de 38 mm e diâmetro mínimo médio de 18 mm. O comprimento médio das tocas é de 182 mm, e o volume médio é de 95 mL.

ABSTRACT In this study, we observed that burrows of Rhinella dorbignyi (Duméril & Bibron, 1841) are distributed in a non-random manner in the habitat, suggesting a microhabitat selection for digging. This conclusion was based on a characterization of 36 burrows and surrounding micro-habitat. We established a 1 m x 1 m quadrat with the burrow in its central point (n=36) to measure the percentage (density) and the average heights of grasses, herbs, and shrubs. All measurements were repeated in two unused quadrats (without burrows) to evaluate the available microhabitat (n=72). The burrows are built in specific areas of the habitat with a higher percentage of grass, taller herbs, lower density of shrubs and low shaded sites than the founded at control sites. Based on three-dimensional models of the interior of the burrow (n=15), we observed that all of them were constructed with an elliptical opening that opens into a narrow channel perpendicular to the ground. Channels had a mean maximum diameter of 38 mm and a mean minimum diameter of 18 mm. The mean length of the burrows is 182 mm, and the mean volume is 95 mL.

ABSTRACT The white-toothed woodrat (Neotoma leucodon) inhabits the arid zones of north-central Mexico and it is important for rural communities for food and economic income. The objective was to characterize the habitat of the white-toothed woodrat in the Potosino-Zacatecano Plateau. In 44 sites with burrows and 44 random sites, the altitude, slope, slope exposure, ground cover: shrubs, grasses, rock, woody material and bare soil, as well as the density of prickly pear cactus, agave, shrubs and palms were recorded. In addition, 21 hunter-gatherers (H-G) were surveyed about woodrat habitat conditions. The woodrat builds its burrows in agaves (40.4 %) and 47.6 % of the H-Gs stated that the woodrat was more frequent in prickly pear cactus. Ninety % of the burrows were located on terrain with low slopes (≤ 4 %), where shrub density and cover were dominant (2085.6 ± 1825 ha -1, 36.1 ± 17.5%, respectively). Rat burrows are associated with shrubs and cactus, as they provide them with food and protection from predators. The H-G consider that in order to conserve the woodrat it is necessary to allow them to reproduce, establish hunting seasons and maintain the vegetation.

RESUMEN La rata nopalera (Neotoma leucodon) habita las zonas áridas del centro-norte de México y es importante para las comunidades rurales como alimento e ingreso económico. El objetivo fue caracterizar el hábitat de la rata nopalera en el Altiplano Potosino-Zacatecano. En 44 sitios con madrigueras y 44 aleatorios, se registró la altitud, la pendiente, exposición de la pendiente, la cobertura del suelo: arbustivas, gramíneas, roca, material leñoso y suelo desnudo, así como la densidad de nopal, maguey, arbustos y palmas. Asimismo, se encuestaron 21 cazadores-recolectores (C-R) acerca de las condiciones del hábitat de la rata. Ésta construyó sus madrigueras en maguey (40.4 %) y el 47.6 % de los C-R aseguran que la rata es más frecuente en los nopales. El 90 % de las madrigueras se ubicaron en terrenos con pendientes bajas (≤ 4 %) donde la densidad y la cobertura de arbustivas fueron dominantes (2085.6 ± 1825 ha -1, 36.1 ± 17.5%, respectivamente). Las madrigueras de rata se asocian con arbustos y nopales, ya que les brindan alimento y protección contra depredadores. Los C-R consideran que para conservar la rata es necesario dejar que se reproduzcan, establecer temporadas de caza y mantener la vegetación.

Abstract The Burrowing Owl, Athene cunicularia, is distributed from Canada to Tierra del Fuego in America. It occupies a wide variety of natural habitats, urban-rural environments, and agro-ecosystems. Three subspecies reside in Peru: A. c. nanodes (Berlepsch and Stolzmann, 1892), A. c. juninensis (Berlepsch & Stolzmann, 1902) and A. c. cunicularia (Molina, 1782). The present work constitutes a bibliography review, supplemented with our own data, to identify the current state of knowledge about the biology and conservation status of A. cunicularia; with special emphasis on the populations that inhabit Peru.

Resumen La lechuza de los arenales Athene cunicularia (Aves: Strigidae) se distribuye desde Canadá hasta Tierra del Fuego en América. Ocupa una gran variedad de hábitats naturales, ambientes urbanorurales y agroecosistemas. En el Perú residen tres subespecies A. c. nanodes, (Berlepsch y Stolzmann, 1892), A. c. juninensis (Berlepsch y Stolzmann, 1902) y A. c. cunicularia (Moliln, 1782). El presente trabajo, constituye una revisión de la bibliografía complementada con datos propios, con la finalidad de identificar el estado actual del conocimiento de la biología y estado de conservación de A. cunicularia con especial énfasis en las poblaciones que habitan en el Perú.

ABSTRACT Extreme climate events cause major disturbances to the fauna of sandy beaches. For abiotic-controlled species, storm waves play a significant role in controlling populations. Considering the projected increase in the frequency of extreme climate events and the consequential influence on benthic macrofauna, there is a need to adjust the time-scale of observations. In this context, we conducted weekly monitoring of the ghost crab Ocypode quadrata on an urbanized sandy beach in southeast Brazil to evaluate the effect of storm waves on population dynamics. The effect of storm wave events was not as strong as expected, but two of the 8 registered storm events provoked an increase in density of O. quadrata. Although not significant, after events 4-5, the population suffered a decrease in density and burrows were concentrated in the upper supralittoral, probably because of contiguous effect of habitat reduction by trampling and the storm waves. It is probable that the combination of storm wave events in conjunction with urbanization could have prevented the population recovery by reducing the overall recruitment or even causing mortality or migration towards safer areas. Multi-factor approaches are needed to better understand the dynamics of O. quadrata in urbanized beaches, however, our study showed that weekly monitoring allowed us to record subtle variations in population dynamics that would go unregistered with other approaches but might reveal long-term changes.