migratory birds
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2022 ◽  
Vol 13 (1) ◽  
pp. 153-159
Author(s):  
Karla Mildred Cigarroa-Alonso ◽  
Gladys Linares-Fleites ◽  
Miguel Ángel Valera-Pérez

Mangroves are the most productive ecosystems in the world, since they provide ecosystem services, are biological filters, stabilize the coastline and are the habitat of important fishing species and migratory birds nest. However, the inadequate implementation of agricultural, livestock and tourism development policies has implied the loss of biodiversity, habitat fragmentation and deforestation. The objective of this work is to evaluate the dynamics of changes in mangrove cover and land use in Barra San José, Chiapas, Mexico, in the period 1978-2017. The detection of the changes was carried out by means of a post-classificatory multitemporal study, through the superposition of digital cartographic bases of land use of the series III and VI of the INEGI. Maps of change processes, deforestation rates, and change matrices were obtained. The results indicate a loss of 574 ha of Mangroves in 39 years, with a deforestation rate of -0.41%, where human settlements and agriculture accounted for 90% of the changes. The conversion of Mangroves to grasslands was very marked, showing the fragmentation and loss of habitat to which the forests are exposed in the study area. The results of this analysis should be considered in the establishment of management and conservation policies for this ecological region.


Author(s):  
Giuseppe Bianco ◽  
Robin Clemens Köhler ◽  
Mihaela Ilieva ◽  
Susanne Åkesson

AbstractSpontaneous magnetic alignment is the simplest known directional response to the geomagnetic field that animals perform. Magnetic alignment is not a goal directed response and its relevance in the context of orientation and navigation has received little attention. Migratory songbirds, long-standing model organisms for studying magnetosensation, have recently been reported to align their body with the geomagnetic field. To explore whether the magnetic alignment behaviour in songbirds is involved in the underlying mechanism for compass calibration, which have been suggested to occur near to sunset, we studied juvenile Eurasian reed warblers (Acrocephalus scirpaceus) captured at stopover during their first autumn migration. We kept one group of birds in local daylight conditions and an experimental group under a 2 h delayed sunset. We used an ad hoc machine learning algorithm to track the birds’ body alignment over a 2-week period. Our results show that magnetic body alignment occurs prior to sunset, but shifts to a more northeast–southwest alignment afterwards. Our findings support the hypothesis that body alignment could be associated with how directional celestial and magnetic cues are integrated in the compass of migratory birds.


2022 ◽  
Vol 43 (1) ◽  
pp. 1-10
Author(s):  
A.S. Dixit ◽  
◽  
R. Chetri ◽  
N.S. Singh ◽  
◽  
...  

Migratory birds undergo physiological and behavioral changes to fuel their high energy demanding migratory flights. They increase their food intake as a part of the preparation for migration which results in increase in their body mass. Fat, carbohydrate and protein acquired from food are stored mainly in the adipose tissue (triglycerides), muscle and liver (glycogen) and body organs (protein) in migratory birds. These stored foods act as fuels to support birds’ migratory flights. Dietary carbohydrates and lipids not only provide energy for migration but also help in fattening as carbohydrates can be converted into fat and lipids which can be stored. Lipolysis of adipose-stored fats leads to the production of triglycerides, fatty acids and glycerol, which provide energy for migration. Fats are depleted after long migratory flights and replenished during refueling at the stopover sites. Being chemically reduced and hydrophobic in nature, fat releases more energy on oxidation as compared to carbohydrate and protein. Due to its high energy-yielding nature, the fat is the preferred fuel to support migration in birds. Migratory birds deposit fat and deplete it during the course of migration. Though, the stored fat acts as the primary source of energy, metabolism of body protein also provides energy for migratory flights. Uric acid in plasma is elevated when protein is catabolized. The metabolism of carbohydrate, stored as glycogen in liver and muscle in migratory birds, produces glucose which also fuels migration. Glucose in migratory birds is maintained at stable levels in plasma and it provides energy only for a flight of short period. Further, catabolism of carbohydrate and protein results in release of metabolic water which helps the migratory birds to maintain their water balance during long dehydrating flight conditions. Different levels of plasma metabolites in migratory birds act as significant indicators of their physiological and metabolic state. Plasma metabolites also give an idea of feeding, fasting and refueling during migration in birds. The available information is scanty and fragmented about how birds meet their migratory requirements and overcome the physiological challenges encountered during migration. The present review article, therefore, focuses on the biomolecules and their plasma biochemistry during migration in birds.


2022 ◽  
Vol 50 ◽  
Author(s):  
Renata Farinelli de Siqueira ◽  
Viviane Soares Hansen ◽  
Maria de Fátima Monteiro Martins ◽  
Marta Lizandra Do Rego Leal ◽  
Eduardo Fernandes Bondan

Background: The West Nile virus (WNV) antibodies were reported in Brazil in the serum samples taken from horses and birds in the Midwest region and Paraíba state in 2008 and 2013, respectively. In 2014, the first human case was confirmed in a rural worker in the state of Piauí and, in 2018, the virus was isolated from the central nervous system of a horse with nervous symptoms in the state of Espírito Santo. The virus is a member of the Flaviviridae family of the genus Flavivirus (neurotropic), infecting several mammalian species, with humans and horses being the most susceptible. Approximately 35% of horses develop clinical signs, thus they are considered the best sentinels for this disease. The aim of this case report is to describe the first confirmed cases of West Nile Fever (WNF) in two horses in the state of São Paulo.Cases: Two horses with neurological symptoms were treated at the Veterinary Hospital of Cruzeiro do Sul University (São Paulo, SP), in 2019. Both horses came from neighboring regions that have a large Atlantic Forest preservation area and are also routes for migratory birds, known to be competent hosts for transmitting the West Nile Fever virus, such as the swallow, the falcon and the hawk. The first one had symptoms, such as weakness and sporadic seizures; however, after recovering, it was hospitalized a few days later due to kidney failure and laminitis. The second one showed incoordination, pelvic limb weakness, and was walking in circles, evolving to seizures. Both animals were euthanized, and their central nervous system samples and total blood samples were tested for rabies, herpes virus, and WNV; the first 2 tests showed negative results. Ribonucleic acids (RNA) were extracted from erythrocytes using the polymerase chain reaction (PCR) technique in-house. The WNV-specific reverse transcription-polymerase chain reaction amplification products were obtained using the nested PCR-multiplex PCR combination.Discussion: Since the 1940s, several WNF outbreaks have been reported around the world (Africa, Europe, Asia and Middle East). In the 2000s, the USA had the most amount of WNF cases reported; cases started being reported in Central and South America in the following years. The virus was identified for the first time in Brazil in 2014. Since then, our country is a route for migratory birds, with many states still having forests, several arboviruses are found such as WNF, which could become a public health problem. Both horses in the present study showed neurological signs and the horse that recovered had renal failure. Such signs are inconclusive, however, similar to those that occur in humans infected by the virus in its neurotropic form. The emergence of new diseases is an important aspect of public health. The literature is vast regarding the description of the pathogenesis, clinical signs, diagnosis, viral persistence and sequelae of WNF in humans, however, it is scarce regarding the viral persistence and sequelae of the disease in horses. Future studies are needed to understand the post-infection period in horses, as they are the most sensitive animals along with humans to this virus. Here, we report the first confirmed cases of WNF in the city of São Paulo to bring awareness about considering this disease while diagnosing horses with nervous system disorders.Keywords: encephalitis, horses, flavivirus, mosquito.Título: Infecção pelo vírus da Febre do Nilo Ocidental em equinos no Estado de São PauloDescritores: encefalite, equinos, flavivírus, mosquito.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260339
Author(s):  
Bryan D. Watts ◽  
Fletcher M. Smith ◽  
Chance Hines ◽  
Laura Duval ◽  
Diana J. Hamilton ◽  
...  

Many long-distance migratory birds use habitats that are scattered across continents and confront hazards throughout the annual cycle that may be population-limiting. Identifying where and when populations spend their time is fundamental to effective management. We tracked 34 adult whimbrels (Numenius phaeopus) from two breeding populations (Mackenzie Delta and Hudson Bay) with satellite transmitters to document the structure of their annual cycles. The two populations differed in their use of migratory pathways and their seasonal schedules. Mackenzie Delta whimbrels made long (22,800 km) loop migrations with different autumn and spring routes. Hudson Bay whimbrels made shorter (17,500 km) and more direct migrations along the same route during autumn and spring. The two populations overlap on the winter grounds and within one spring staging area. Mackenzie Delta whimbrels left the breeding ground, arrived on winter grounds, left winter grounds and arrived on spring staging areas earlier compared to whimbrels from Hudson Bay. For both populations, migration speed was significantly higher during spring compared to autumn migration. Faster migration was achieved by having fewer and shorter stopovers en route. We identified five migratory staging areas including four that were used during autumn and two that were used during spring. Whimbrels tracked for multiple years had high (98%) fidelity to staging areas. We documented dozens of locations where birds stopped for short periods along nearly all migration routes. The consistent use of very few staging areas suggests that these areas are integral to the annual cycle of both populations and have high conservation value.


2021 ◽  
Vol 14 (4) ◽  
pp. 1885-1889
Author(s):  
Muhammad Wasim Tasleem

Patisar lake is an important wetland for migratory birds in mid-winter which is located in the center of the Lal Suhanra National Park of Bahawalpur, Pakistan. In this study Patisar lake has been explored to find out the endangered bird species. We used a map, a pencil, a notebook, a watch that is used to show seconds and binoculars for the census. Point counting system is used for the monitoring of birds and their habitat requirement was also measured. Result of the study indicated that these population belonging to 6 different orders, 10 different families, 18 genera and 32 different species of waterfowl were observed (1) Podicipediformes iPodicipedidae; iTachybaptus iruficollis), (2) Pelecaniformes (Family: Phalacrocoridae; Phalacrocorax iniger; P. carbo; Family; Anhingidae, Anhinga melanogaster), (3) Ciconiiformes (Family: Ardeidae, Ardea cinerea, A. purpurea, Ardeola grayii, Bubulcus ibis, Egretta alba, E. garzetta, E. intermedia), (4) Anseriformes (Family: Anatidae; Anas acuta, A. crecca, A. platyrhynchos, A. strepera, A. penelope, A. clypeata, Aythya ferina, A. fuligula, A. nyroca), (5) Gruiformes (Family: Rallidae: Fulica atra, Porphyrio porphyrio, Gallinula chloropus) and (6) Charadriiformes (Family: Recurvirostridae, Himantopusi himantopus; Family: Charadridae, Vanellusi indicus, V. vanellus, V. leucurus, Charadrius dubius; Family: Scolopacidae, Tringa tetanus, T. nebularia, Actitis hypoleucus; Family: Laridae,Sterna aurantia). According to They all preferred fresh water layer of the lake and marshes near the lake as their habitat. It was concluded that Patisar lake is a prodigious natural resource for the migratory waterfowl and the number of waterfowl declining with the passage of time.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12669
Author(s):  
Heraldo V. Norambuena ◽  
Reinaldo Rivera ◽  
Rodrigo Barros ◽  
Rodrigo Silva ◽  
Ronny Peredo ◽  
...  

Migratory birds are threatened by habitat loss and degradation, illegal killings, ineffective conservation policies, knowledge gaps and climate change. These threats are particularly troubling in the Procellariiformes (Aves), one of the most endangered bird groups. For “storm-petrels”, their cryptic breeding behavior, asynchrony between populations, and light pollution pose additional threats that contribute to increased mortality.Markham’s Storm-Petrel (Hydrobates markhami), a poorly known migratory species, is a pelagic bird that breeds in dispersed colonies in the Sechura and Atacama Deserts, with asynchronous reproduction between colonies, and is highly affected by artificial lights. Considering its complex conservation scenario and singular breeding, we expected to find narrow habitat distribution conditions, strong geographic genetic structure, and spatially differentiation related to human population activities (e.g., light pollution) and the climate global change. To evaluate these predictions, we analyzed the phylogeography, current and future potential distribution based on mitochondrial gene ND1 and geographic records.The phylogeographic analyses revealed three well-supported clades (i.e., Paracas, Arica, and Salar Grande), and the geographical distribution modeled using an intrinsic conditional model (iCAR) suggests a positive relationship with the mean temperature of the wettest quarter and of the driest quarter, solar radiation, and anthropogenic disturbance. The future predictions under moderate and severe scenarios of global change indicated a drastic distribution area reduction, especially in the southern zone around Tarapacá and Antofagasta in Chile. These suggest a potential loss of unique genetic diversity and the need for conservation actions particularly focused at the edges of the H. markhami distribution.


2021 ◽  
Vol 10 (1) ◽  
pp. 31
Author(s):  
Alina Matsvay ◽  
Marina Dyachkova ◽  
Ivan Mikhaylov ◽  
Daniil Kiselev ◽  
Anna Say ◽  
...  

Discovery and study of viruses carried by migratory birds are tasks of high importance due to the host’s ability to spread infectious diseases over significant distances. With this paper, we present and characterize the first complete genome sequence of atadenovirus from a tern bird (common tern, Sterna hirundo) preliminarily named tern atadenovirus 1 (TeAdV-1). TeAdV-1 genome is a linear double-stranded DNA molecule, 31,334 base pairs which contain 30 methionine-initiated open reading frames with gene structure typical for Atadenovirus genus, and the shortest known inverted terminal repeats (ITRs) within the Atadenovirus genus consisted of 25 bases. The nucleotide composition of the genome is characterized by a low G + C content (33.86%), which is the most AT-rich genome of known avian adenoviruses within Atadenovirus genus. The nucleotide sequence of the TeAdV-1 genome shows high divergence compared to known representatives of the Atadenovirus genus with the highest similarity to the duck atadenovirus 1 (53.7%). Phylogenetic analysis of the protein sequences of core genes confirms the taxonomic affiliation of the new representative to the genus Atadenovirus with the degree of divergence from the known representatives exceeding the interspecies distance within the genus. Thereby we proposed a novel TeAdV-1 to be considered as a separate species.


2021 ◽  
Vol 91 (2) ◽  
pp. 13-28
Author(s):  
Alessandro Franzoi ◽  
Simone Tenan ◽  
Paula Lorenzo Sanchez ◽  
Paolo Pedrini

Introduction: Bird migration across mountainous regions has been studied usually at single sites due to the difficulty in employing and support a multi-site sampling effort. This may affect inference on migration whose scale is larger that a single site. The Progetto Alpi has been monitoring post-breeding bird migration through the Italian Alps with a network of several ringing stations since 1997. Until 2017, 666,471 ringing data of 191 different species were collected. Methods: Phenology of bird migration in terms of date of capture and the related elevational distribution during the sampling season (August-November) were analysed for 69 species. For a subset of 45 species the inter-annual variation in phenology along with trends in the number of ringed birds and in the ratio between the number of juveniles and adults ringed, were also analysed. Results: Migration through the Italian Alps occurred differently between species, with heterogeneity across species in the median date of capture and their elevational distribution. No linear trends in phenology were detected. For four species an annual linear increase of the ringed individuals was detected, while for other four species an annual linear decrease of the captures was detected. For two species, an increase of the ratio between the number of the juveniles and the number of adults ringed was detected. Conclusions: The long-term standardized monitoring of post-breeding migration allowed us to consolidate and increase knowledge of bird migration through Italian southern Alps. The information gathered allowed us to define the temporal and elevation distribution of passerine birds crossing the mountainous area, and to test interannual trends in the number of captures. The main purpose of this work was to report on the information collected in twenty years of field activity, providing a contribution to the understanding this complex phenomenon. Further investigations and more in-depth analyses are necessary to understand how environmental factors and species-specific eco-physiological traits interact and affect migratory strategies of passerine birds in the Italian Alpine region.


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