Eideard

The northward and inland movement of North American birds, confirmed by thousands of citizen-observations, has provided new and powerful evidence that climate change is having a serious impact on natural systems, according to a new report by Audubon (BirdLife in the USA). The findings signal the need for dramatic policy changes to combat pervasive ecological disruption.

Analyses of citizen-gathered data from the past 40 years of Audubon’s Christmas Bird Count reveal that 58% of the 305 widespread species that winter on the continent have shifted significantly north since 1968, some by hundreds of kilometres. Movement was detected among species of every type, including more than 70% of highly adaptable forest and feeder birds. Only 38% of grassland species mirrored the trend, reflecting the constraints of their severely-depleted habitat and suggesting that they now face a double threat from the combined stresses of habitat loss and climate adaptation.

Population shifts among individual species are common and can have many causes. However, Audubon scientists say the ongoing trend of movement by some 177 species—closely correlated to long-term winter temperature increases—reveals an undeniable link to the changing climate.

“Birds are showing us how the heavy hand of humanity is tipping the balance of nature and causing ecological disruption in ways we are just beginning to predict and comprehend”, said report co-author Dr Greg Butcher. “Common sense dictates that we act now to curb the causes and impacts of global warming to the extent we can, and shape our policies to better cope with the disruptions we cannot avoid.”

I couldn’t agree more. Friends in northern California tell me of dramatic increases in purple finch arrivals and numbers – while here in northern New Mexico we’re seeing population of bluebirds that traditionally pass through – southbound in late autumn, northbound in spring – wintering over. We’ve picked up a new species or two of doves which I haven’t seen, yet – but, hear on my daily walks.

I joke about the last-noted. It sounds like a 10lb mourning dive with a sore throat!

“Arid aquaculture” using ponds filled with salty, undrinkable water for fish production is one of several options experts have proven to be an effective potential alternative livelihood for people living in desertified parts of the world’s expanding drylands.

Researchers with the United Nations University, the International Centre on Agricultural Research in Dryland Areas (ICARDA), and UNESCO’s Man and the Biosphere (MAB) Program say alternatives to traditional crop farming and livestock rearing will need to be put in place in drylands in order to mitigate human causes of desertification.

While it may sound far-fetched, researchers say using briny water to establish aquaculture in a dry, degraded part of Pakistan not only introduced a new source of income, it helped improve nutrition through diet diversification. The researchers also showed it possible to cultivate some varieties of vegetables with the same type of brackish water.

And there are many other promising alternative livelihoods, successfully tested in eight countries.

Because they do not primarily depend on land productivity, these options have the potential to reduce the pressure on the fragile resource base in marginal drylands, says the report. “At the same time, these strategies proved to yield significantly higher income per investment than traditional land-based livelihoods.”

Look through the article. It offers hope to those with the courage and forethought to step out ahead of their ancestors, the limitations of their history.