A new study showed that migration isn’t easy for most of the birds. More than 90% migratory bird species face troubles when they are on their way of migration, according to the study published in the journal Science.

Loss of habitat and hunting are some of the common problems that most migratory birds face on their journeys. Study researchers are calling for international efforts to prevent extinction risks that these birds face.

In last three decades, more than 50% migratory birds travelling the world's main flyways have experienced decline in their populations, says Claire Runge, a researcher from the University of Queensland and lead author of the study that compared the migration paths of over 1,400 migratory birds with the protections given to them in different nations.

Runge said the population decline is mainly due to ineffective protection given to migratory bird species across their routes of the migration. The problems are very serious in countries like India, China, Africa and some regions of South America, Runge explained.

She said long-distance migrations usually put strain on migratory birds. During the voyage, they lose significant amount of body weight. “So even if we protect most of their breeding grounds, it's still not enough — threats somewhere else can affect the entire population. The chain can be broken at any link”, Runge added.

During the study, the researchers collected data on migratory bird species and then compared it with maps of protected regions in different habitats. The study concluded that only 9% migratory birds are protecting during the journey.