aquatic mammal
Recently Published Documents


TOTAL DOCUMENTS

69
(FIVE YEARS 19)

H-INDEX

13
(FIVE YEARS 2)

2023 ◽  
Vol 83 ◽  
Author(s):  
D. S. Silva ◽  
M. V. Ribeiro ◽  
F. H. Soares

Abstract Brazil is the world's richest country in biodiversity, including mammal species. In the Brazilian Cerrado biome, mammalian diversity is vast, with about 251 species, 32 of them are endemic and 22 listed as threatened species. In this work, we investigated species diversity of medium- and large-sized mammals in the private protected area RPPN Pontal do Jaburu (RPPN-PJ) and its surroundings, which is a flooded area located in an important biological corridor in the Cerrado-Amazon ecotone zone, a priority area for biodiversity conservation in Brazil. We used camera-trapping, active search (night and day), and track survey during dry season (Apr – Aug 2016). We recorded 29 mammal species, being the Carnivora order the most representative with 11 species. Regarding threat status, 35.7% of the recorded species were listed as threatened in Brazil and 32.1% worldwide. We highlight the high relative frequency of threatened species records such as Tapirus terrestris, Panthera onca, Blastocerus dichotomus, Pteronura brasiliensis, Priodontes maximus, and other, as well as the presence of the newly described aquatic mammal species Inia araguaiaensis. We stress the importance of RPPN-PJ and its surroundings for mammal conservation, which include complex habitats (wetlands) located in an important ecotone zone.


2021 ◽  
Author(s):  
Camila Duarte Ritter ◽  
Giorgi Dal Pont ◽  
Paula Valeska Stika ◽  
Aline Horodesky ◽  
Nathieli Cozer ◽  
...  

Metabarcoding of environmental DNA is based on primers that are specific to the target taxa (e.g. bacteria, zooplankton, fishes). However, due to the nature of the commonly used protocols, regardless of the chosen primers, several sequences of non-target species will inevitably be generated, but are usually discarded in commonly used bioinformatics pipelines. These non-target sequences might contain important biological information about the presence of other species in the studied habitats and its potential for ecological studies is still poorly understood. Here, we analyzed the presence of mammal and bird species in aquatic environmental samples that were originally amplified targeting teleost fish species. After all cleaning and checking steps, we kept 21 amplicon sequence variants (ASVs) belonging to mammals and ten to birds. Most ASVs were taxonomic assigned to farm/domestic animals, such as cats, cows, and ducks. Yet, we were able to identify a native semi-aquatic mammal, the capybara, in the samples. Four native bird species and a non-native potentially invasive bird (Corvus sp.) were also detected. Although the data derived from these samples for mammals and birds are of limited use for diversity analyses, our results demonstrate the potential of aquatic samples to characterize non-aquatic birds and highlight the presence of a potentially invasive species that had not been recorded before in the region.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Rasmus Mohr Mortensen ◽  
Stefanie Reinhardt ◽  
Marina Eraker Hjønnevåg ◽  
Rory Paul Wilson ◽  
Frank Rosell

Abstract Background Semi-aquatic mammals exploit resources both on land and in water and may require both to meet their habitat requirements including food- and building resources, refuges, and for social interactions with conspecifics. Within this, the specific availability of both terrestrial and aquatic resources is expected to impact individual fitness. Beavers are highly dependent on water for movement and protection from predators. They are central place foragers and mostly forage on woody vegetation near water although aquatic vegetation may also be an important food resource. However, little is known about their use of aquatic habitats. We aimed to address this knowledge gap by dead-reckoning fine-scale movement tracks and classifying fine-scale diving events, which we then related to the spatial distribution of aquatic vegetation and habitat components within the territory. Results Overall, there was a statistically clear decrease in probability that diving would occur at dawn and with increasing distance from territory borders. In addition, the distance from the lodge at which animals dived decreased through the night and during the spring/early summer. There was strong selection for diving habitats located closer to the riverbank, with stronger selection for these areas being observed in individuals with larger home ranges. We saw a higher selection for diving above clay sediment, and within 150 m from the lodge, presumably because mud and clay sediment tended to be located closer to the lodge than sand and rock sediment. Furthermore, we found a clear selection for diving in the presence of quillwort (Isoetes spp.), shoreweed (Littorella uniflora), and stonewort (Nitella spp.). Selection for these focal species was stronger among subordinate individuals. Individuals with lower body condition dived closer to the beaver lodge, and dives located further from the lodge were associated with high densities of aquatic vegetation. Conclusion We provide new knowledge on the aquatic habitat use in a semi-aquatic mammal and show how energetic constraints may shape how beavers spatially use the aquatic environment, whereby short and shallow dives appear most beneficial. We show how aquatic habitats may have great importance for both foraging, building materials and safety, and discuss to how they may affect the fitness of individuals.


2021 ◽  
Author(s):  
Gina L. Lonati ◽  
Amber R. Howell ◽  
Paul Schueller ◽  
Charles J. Deutsch

Author(s):  
Artur Lagoia Fonseca de Miranda ◽  
Andréa Soares de Araújo ◽  
Carlos Eduardo Costa Campos

Sotalia fluviatilis is known as “tucuxi” is endemic to the rivers of the Amazon basin, with aggregations of individuals at the mouths of rivers and canals, it is an almost endangered species and information about it is lacking in the state of Amapá. This study was aimed at monitoring the social behavior of S. fluviatilis in the northern channel of the Amazon River, Amapá, Brazil. Monitoring was carried out from a fixed point on the bank of the northern channel of the Amazon River, located in a Private Reserve of Natural Heritage. Ninety-six days of monitoring were carried out from a fixed point of observation, totaling 480 hours of sample effort. S. fluviatilis was frequently observed throughout the year in predominantly small groups formed mostly by two to three adult animals. Young individuals were observed in larger groups of four to six individuals, formed during activities such as feeding or for protection. Behavioral activities included slow and fast travel, which were in most cases associated with other behaviors, mainly foraging and socializing. The largest number of sightings of socialization occurred in the months of January and February, when river water levels are high. Studies on key species are essential for decision making, in order to optimize conservation strategies for this aquatic mammal in the Amapá. As a suggestion for conservation measures, it would be the distancing of vessels when they perceive a group of porpoises using the region, thus stimulating the conservation of the species.


2021 ◽  
Author(s):  
Wesley Williams Boone ◽  
Audrey A Albrecht ◽  
Jeremy R Conrad ◽  
Chris J Lechowicz ◽  
Eric C Hellgren ◽  
...  

Abstract Shrub encroachment is altering the structure and species composition of freshwater wetlands across the globe. These changes are likely to be particularly detrimental for threatened wetland vertebrates. However, little research has focused on how shrub encroachment influences threatened wetland vertebrates. We sought to determine how vegetative structure and shrub cover influenced the occurrence of a threatened semi-aquatic mammal species, the Sanibel Island rice rat (Oryzomys palustris sanibeli). Using aerial photography from across the Sanibel Island rice rat’s range, we found a 5.5-fold increase in shrub cover over a 71-year period. To link these changes to the current distribution of the species, we evaluated the influence of vegetation and metrics of inundation on probability of occurrence and localized colonization and extinction rates over a three-year period. We found Sanibel Island rice rats on 18 (33.3%) of our 54 sites. Their occurrence was positively associated with elevated sand cordgrass (Spartina bakeri) cover and increased elevation, but negatively associated with elevated shrub cover. Their probability of colonization was negatively associated with increased shrub cover. Extinction probabilities for Sanibel Island rice rats were positively associated with increased rainfall totals in the preceding three months and increased shrub cover. Increases in shrub cover reduce sand cordgrass cover, which additively may be driving the decline of this once ubiquitous species. We conclude that shrub encroachment of freshwater wetlands requires greater attention due to its potential to imperil wetland endemic wildlife species.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tahneal Hawke ◽  
Gilad Bino ◽  
Richard T. Kingsford ◽  
Dion Iervasi ◽  
Kylie Iervasi ◽  
...  

AbstractThe platypus is a semi-aquatic mammal, endemic to freshwater habitats of eastern Australia. There are gaps in the understanding of platypus movement behaviour within river systems, including spatial and temporal organization of individuals. We tracked movements of 12 platypuses on the regulated Snowy and Mitta Mitta Rivers for up to 12-months, the longest continuous tracking of platypus using acoustic telemetry. Platypuses remained relatively localized, occupying 0.73–8.45 km of river over 12 months, consistent with previous tracking studies over shorter periods. Males moved further than females, and larger males had higher cumulative movements, suggesting a possible relationship to metabolic requirements. Platypuses moved greater distances on the Mitta Mitta River, possibly associated with impacts of altered flow regimes to their macroinvertebrate diet. Increased movements and diurnal activity during winter were primarily driven by males, possibly attributable to breeding behaviours, rather than increased costs of winter foraging. Evidence for relatively small movements has implications for declining populations, given areas of localised declines are unlikely to be supplemented by migrating platypuses, especially when dispersal is restricted by dam walls. Understanding platypus movement behaviour is pertinent for their conservation, as water resource development and habitat modification continue to reduce connectivity between populations across their distribution.


Author(s):  
Carrie Sadowski ◽  
Jeff Bowman

The muskrat (Ondatra zibethicus) is an iconic species in Canada, valued for both its fur and its integral role in wetland ecosystems, and widely regarded for its perseverance. However, the resilience of this semi-aquatic mammal seems to be in question now as increasing evidence points to widespread population declines. Recent analyses of harvest data across North America suggest a reduction in their numbers, but this has not been widely corroborated by population surveys. In this study we replicated historic muskrat house count surveys at two large Great Lakes coastal wetlands and present confirmation that declines in muskrat harvest correspond to actual declines in muskrat abundance. At the Point Pelee National Park marsh and the Matchedash Bay-Gray Marsh wetland we found that mean muskrat house counts declined by 93% and 91% respectively between historic surveys 40-50 years ago and contemporary surveys over the past five years. The factors responsible for these dramatic declines remain unclear but there may be a relationship with changes in the habitat quality of these wetlands that have occurred over the same time frame. Not only is the loss of muskrats an issue for the resulting loss of the wetland ecosystem services they provide, but it may be an indication of broader marsh ecosystem degradation. As such, a scarcity of muskrats should be considered a red flag for the state of biodiversity in our wetlands. Continued surveys and ongoing research are needed to shed more light on the current status of muskrat populations and their marsh habitats across their native range. Keywords: Fur harvest; Muskrat; Ondatra; Population decline; Typha; Wetlands


2021 ◽  
Author(s):  
Mikhail Butko ◽  
◽  
A. Gerasimov ◽  
Tatyana Poskonnaya ◽  
Petr Popov ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document