CLIMATE CHANGE THREATS TO BIRDS’ MIGRATION

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By Bibhuti Pati

It is not only scientists and environmentalists have been raising their concerns about the impact of climate change on human life but also bird watchers and lovers around the globe have come out with the conclusion after extensive research on the movement and behaviour of migratory birds that climate change has the potential to cause harm to the existence of birds during their migration period.

This happens in three stages. Firstly, migratory species require suitable conditions throughout their annual journey from one place the place of their origin to far reaching places where climate suit them. They need suitable climate on their breeding grounds, in their non-breeding range, and along migratory routes between the two. Climate change has the potential to disrupt conditions in all three stages as it effects whether, making it unpredictable at times.

Because of a worldwide global warming, birds migrating during spring are probably going to pass certain stops prior now than they would have 20 years back, says a first-of-its-sort study looking at the effect of environmental change on the planning of avian journey.  They investigated 24 years of radar information from the US National Oceanic and Atmospheric Administration (NOAA) to discover about nocturnal birds migration. The discoveries of the examination, published in the journal Nature Climate Change, uncovered that planning shifts were less evident in fall, than during spring.

A study has revealed that birds suffer higher mortality on migration, because of increased risk of predation and starvation resulting from higher energetic requirements and unpredictable food supplies. Longer journey increase these risks, and may therefore lead to fall in population. The study has come out with credible evidence that long-distance migrants may be hit particularly hard by climate change. Birds migrate in search of food, habitat and suitable season. The observation and recording has a history that goes as back as to 3000 years, when ancient Greeks had done so.

The migration of birds is generally not confined to areas of their origin but at times they fly to long distance or altitudinal. Altitudinal migration is common on mountains. A study says around 1800 of the world’s 10000 bird species are long distance migrants. However, climate change on large scale has affected the timings of migration, breeding as well as population variations.

The major impacts of climate change on migratory birds are loss of habitats due to increasing temperature, flooding or desertification affected patterns of migration, competition for breeding places due to warm weather, food shortage due to earlier arrival of many birds adaptation difficulties due to global warming, warming will decrease survival rate of many birds species. According to IPCC (2007), if the average temperature of the earth increased by 2.5 °C then 20-30 percent of the species will be at the risk of extinction. The climate is changing over the years and it is affecting our environment but perturbation of anthropogenic activities has threatened many migratory bird species. Despite concerns raised by scientists and environmentalists and suggestions made by them to concerned authorities frequently, the governments have failed to formulate a proper policy that could help bring down survival rate of migratory birds.

A science and environment specific journal, in a report dealt with the problem in details and found out that some species of fungi that are resistant to existing treatments may be on the rise as a result of global warming. The report further said several species of fish may become more toxic as a result of warming waters, and malaria may spread to an unprecedented extent. The report explores the ways in which birds may have been affected by rising global temperatures.

The night-time migratory behaviours of hundreds of species — representing billions of birds is critically important to understand the shifting migration patterns. “To see changes in timing at continental scales is truly impressive, especially considering the diversity of behaviours and strategies used by the many species the radars capture,” maintained Kyle Horton from Colorado State University in the US in a study conducted on the behaviour of migratory birds.

As per the impact of climate change, the timing of blooming vegetation, or the emergence of insects may be out of sync with the passage of migratory birds. They cautioned that even subtle shifts could have negative consequences for the health of migratory birds.

The bird flight records utilized in the examination were procured over many years of always filtering climate radars by the US National Weather Services’ system. The information had been for the most part distant for bird specialists, in view of the sheer greatness of data, and the absence of instruments to break down it. The scientists at long last conquered this obstruction with another scientific equipments (ML) apparatus called “MistNet” which they created to extricate bird information from the radar record.

MistNet, whose name consign to the fine, practically undetectable, “mist nets” that ornithologists use to catch migratory songbirds, likewise enables specialists to appraise flying speed and traffic rates of relocating birds. As per the examination, MistNet utilizes PC vision systems to separate winged animals from the downpour on the radar pictures – a significant obstacle that had tested scientists for a considerable length of time. “Verifiably, an individual needed to take a gander at every radar picture to decide if it contained cloudburst or birds. We created ‘MistNet,’ a computerized reasoning framework to identify designs in radar pictures and evacuate cloudburst consequently,” clarified by Dan Sheldon from the University of Massachusetts Amherst, who built up the tools.

“For many species, the areas with suitable climate are expected to move towards the poles. Some species that breed in northern temperate zones and winter further south will therefore need to undertake longer migratory journeys. However, no-one has previously looked at what this might mean in relation to the time and energetic costs of migration. We collaborated with experts to address this issue,” writes Dr. Stuart Buthchart who heads BirdLife International’s science team that provide the scientific basis for conservation programmes across the Partnership.

The study says over 80 percent of European long-distance migrants, there will be significant increases in both the distance and time taken to travel between their breeding and non-breeding ranges. For example, Thrush Nightingales Luscinia luscinia will have to travel nearly 800 km further on average by 2070, adding at least five days to the duration of their journey. European Bee-eater Merops apiaster migrations are projected to increase by over 1,000 km and at least 4.5 days by 2070.

Migratory birds are responding to the effects of climate change by arriving at their breeding grounds earlier as global temperatures rise. The University of Edinburgh in a study, which looked at hundreds of species across five continents, found that birds are reaching their summer breeding grounds on average about one day earlier per degree of increasing global temperature.

The main reason birds take flight is changing seasonal temperatures and food availability. The time they reach their summer breeding grounds is significant, because arriving at the wrong time, even by a few days, may cause them to miss out on vital resources such as food and nesting places. This in turn affects the timing of offspring hatching and their chances of survival.

The research conducted by Dr Stuart included species that travel huge distances, such as the swallow and pied flycatcher, as well as those with shorter migrations, such as the lapwing and pied wagtail. British swallows fly through western France, across the Pyrenees, down eastern Spain into Morocco, and across the Sahara, to spend their winter in South Africa from around September or October. Migrating swallows can cover 200 miles a day at speeds of 17-22 miles per hour, with a maximum flight speed of 35mph.

The earth’s climate has been changing throughout time. Some of the earth’s bird species were able to adapt to these changes, while others could not and have become extinct as a result. This is a natural process. However, the climate change being experienced today is different: human-induced global warming is happening at an accelerated speed and it is becoming increasingly difficult for many bird species to keep up with the resulting shifts.

The migratory bird species also suffer from barriers like wind farms or competition from newly introduced alien species. Species that are already on the decline due to these factors are especially vulnerable to climate change. In other words, for some species, climate change may give these already very vulnerable species the final push towards extinction.

As far as different threats migratory birds have to face, one thing becomes apparent: climate change is already happening and it endangers migratory birds. Especially long distance migrating birds feel the effect; as they are less flexible than other birds, they suffer most. Climate change is in progress, and it is clear that it is affecting our environment, by adding to the disarrangement of ecological balances. It is not only in the interest of migratory birds, but also in our own interest to protect all species on the planet earth against the impact of climate change.

The largest inland saltwater lake in Asia, Chilika, world famous for migratory birds winter home, also has affected by climate change.  20 years back, Chilika lake of Odisha was a lot cooler than at present. This helped birds’ migration and relocating from the Arctic, bit by bit acclimate to the warm atmosphere as they flew from below zero temperatures to modestly cold regions of the world to spend their winters. Today, things are not the equivalent. Environment and climate change has shockingly ransacked the birds of this slow changeover.

This depleting patter of winter affects migratory birds was reported in Chilika along with important coastal wetlands along the east coast of India are Gulf of Mannar, Point Calimere, and Pulicat. The outcome is, lesser and lesser migratory birds are comings to India throughout their winter relocation. Naturally Chalice’s water temperature has changed and it is gradually warm, also the winter weather temperatures suddenly rise and fall, it is most unpredictable. It is seriously affect birds’ migration. The ideal habitat for these birds is also being destroyed due to change in rainfall pattern.

The arrival patterns of several birds had changed like that of the greater flamingos and water birds like plovers and spoonbill sandpipers. Some birds are arriving earlier and some are coming later. Chilika is not being flooded properly and there is a choking of mouths these factors have also contributed to reduced spaces and it is affecting due to climate change. It is a pathetic condition for migratory birds.

Mother Earth’s environment has its own ways of giving out notice and gesture to human being. Undoubtedly the altering prototype of birds’ migration is one which is running over boisterous and clear. It is dependent upon us to notice these and make action to save our mother earth’s mankind. Although the process cannot be stopped completely, we have the possibility to interfere. Everyone can join the fight against climate change every day.

Climate change threat to Chilika

Chilika needs a life not global warming. Chilika Lake in India, are heating up quickly due to climate change, infers a recent study. Chilika, the brackish marine lagoon in Odisha, is the only lake from India to be included in this global study. Chilika is the largest lagoon in India and the second largest in the world. The 25-year-long study is the first to use a combination of satellite temperature data and long-term ground measurements for monitoring impact of climate change on lakes.

Fluctuations in rainfall, in addition to climate change impacts of temperature rise, are the other major disruptor for migratory birds. Due to the absence of winter rainfall, the brackish water can become too saline, resulting in freshwater-feeding birds not finding adequate food. On the other hand, intense rainfall would infuse too much freshwater through rivers draining into the lake, leaving brackish water feeders with insufficient food. With climate change, some species could benefit, while many will not.

Winter temperatures in Chilika are higher today by 3 – 4 degrees Celsius compared with two decades back. Winter days were (earlier) severely cold, and foggy, and the season was spread over a longer period. The main finding is that on average, water temperature of lakes worldwide is going up by 0.34 degree Celsius every 10 years, with the Chilika Lake rising 0.39 degree Celsius in a decade. The rate of rising temperatures in the lakes is much higher than ocean and air temperature rise rate.

Birds are beautiful, but climate change will bring mass extinction. Climate change is already exacerbating many of the factors that have put one in eight of the world’s birds at risk of extinction, according to Britain-based BirdLife International. One of its global studies said 15-37% of species could face extinction by 2050 as a consequence of climate change. Another study assesses that with each degree of temperature rise, 100-500 bird species could go extinct. The present rate of change for wildlife is faster than that in the last 1,000 years and would be beyond the in-built threshold of many species to adapt.

Birds will be faced with the combined threat of habitat loss and climate space, according to an earlier study titled Impact of Climate Change and Habitat Degradation on the Avifauna. There is already a disruption in timing of insects’ emergence, a major source of bird food. Consequently, breeding and egg-laying timings of shore birds are changing. Breeding of birds should synchronise with the abundance of food prey whose larvae development should in turn match the growth of leaves in a plant. For example, the Great Tit has to time its reproduction so that its babies have an abundance of caterpillars’ species to feed on. While resident birds, which also winter in Chilika in large numbers, have more time to adapt to the changing life-cycles of their prey, migrant birds do not have this advantage.

The Black-winged Stilt, a ground-nester from northern Asia, used to head straight for the Nalabana bird sanctuary, but not any more since the island’s mudflats have been invaded by tall grass after the new mouth opening in 2000. Similarly in Chilika, Northern Pintail ducks but their arrivals are declining. Often undertaking transoceanic journeys from Alaska, Canada, Mongolia and Poland to Odisha’s lagoon, these waterfowls are an excellent indicator of climate and developmental projects’ impacts on their habitats

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