Accra — The theme for this year's World Migratory Bird Day: "Migratory Birds - Ambassadors for Biodiversity" draws attention to the link between migratory birds and wider biodiversity as well as the overall state of our environment.

Birds are considered to be some of the best indicators for the status and trends of wider biodiversity as they connect, and are inhabitants of, virtually all ecosystems in the world.

Birdwatchers and conservationists in dozens of countries marked World Migratory Bird Day on the weekend of 10-11 May 2008 with film shows, bird watching and other public events to draw attention to the rising threat to migratory birds and global biodiversity.

The events focused on one of the world's most magnificent natural phenomena - bird migration and the birds' journeys of thousands of miles between their breeding and wintering grounds. However, the global celebrations are being overshadowed by a series of recent reports indicating that the numbers of migratory birds are declining globally.

The decline in numbers is currently being recorded for many of the migratory bird species along all of the world's major flyways - the main migration systems, or corridors, used by various groups of migratory birds in different parts of the world.

While the exact reasons for the global declines are complex and vary from species to species and from flyway to flyway, the overall decline in bird numbers may be signaling a wider environmental problem linked to the climate change, loss of habitats and biodiversity worldwide.

Migratory birds and in particular long distance migrants are very vulnerable to environmental changes. To complete their annual migrations, they require breeding and wintering areas but also a network of stop-over sites along their flyways where they can rest and refuel before continuing on their journeys. Yet these important natural habitats such as the five coastal Ramsar Sites and many other coastal lagoons in Ghana, which also host numerous other threatened species of plants and animals, are increasingly being lost with agricultural, urban, infrastructural and industrial development. For migratory birds, this means fewer sites are left for them to use throughout their migration cycle and that the network of sites they depend on to complete their annual journeys is getting thinner.

The loss and fragmentation of essential habitats is being further compounded by the effects of climate change - rising global temperatures lead to expanding deserts and more frequent storms which impact on bird migration and subsequent sea-level rise threaten tidal and wetland areas which are important for many migratory birds. Scientists are also linking all these factors to their decline.

Both the theme and the timing of this year's World Migratory Bird Day coincide with the forthcoming 9th Conference of the Parties of the Convention on Biological Diversity (CBD) to be held in Bonn, Germany later this month. In this context, the message of this year's World Migratory Bird Day is a clear signal to our leaders, planners, and in fact, every one, that birds are useful natural indicators for the status and trends of biodiversity and environmental change. More is thus needed to be done to increase national and international efforts at protecting the network of sites required by birds and halting the loss of biodiversity as well.