Monday, December 30, 2019

Disappearing Birds

A study published recently in the journal Science reveals that since 1970, bird populations in the United States and Canada have declined by 29 percent, or almost 3 billion birds. The results show tremendous losses across diverse groups of birds and habitats – from iconic songbirds such as meadowlarks to long-distance migrants such as swallows, as well as backyard birds including sparrows. In fact, three out of every four Meadowlarks have vanished.

“Multiple, independent lines of evidence show a massive reduction in the abundance of birds,” said Ken Rosenberg, the study’s lead author and a senior scientist at the Cornell Lab of Ornithology and American Bird Conservancy. “We expected to see continuing declines of threatened species. But for the first time, the results also showed pervasive losses among common birds across all habitats, including backyard birds.”

Of nearly 3 billion birds lost, 90 percent belong to 12 just families, including sparrows, warblers, finches, and swallows – common, widespread species that play essential roles in food webs and ecosystem functioning, from seed dispersal to pest control. If we lose these species, it won’t just be bad for birds – it will be disastrous for humankind.

“The connection between birds and humans is undeniable—we share the same fate. This is a bird emergency with a clear message: the natural world humans depend on is being paved, logged, eroded and polluted. You don’t need to look hard for the metaphor: birds are the canaries in the coal mine that is the earth’s future,” said David Yarnold, president of the National Audubon Society.

Within these results, certain groups of birds were particularly hard hit. Grassland birds saw a 53-percent reduction in population – more than 720 million birds – since 1970. Shorebirds, most of which frequent sensitive coastal habitats, were already at dangerously low numbers and have lost more than one-third of their population. Furthermore, the volume of spring migrations, measured by radar in the night skies, has dropped by 14 percent in just the past decade.

Since birds are indicators of environmental health, these worrying findings suggest that natural systems across the U.S. and Canada are now being so severely impacted by human activities that they no longer support the same robust wildlife populations.

With these facts in mind, we should all plan to feed our birds this winter while their food source is scant, avoid pesticides in our gardens, and thoughtfully consider our actions which adversely affect the environment. A world without birds is unimaginable.

*The Audubon Society, founded in 1905, is the oldest non-profit environmental organization dedicated to conservation. It is named in honor John James Audubon who observed, painted, cataloged, and described the birds of North America in 1827-38. 

Monday, December 2, 2019

Apple Trees and Cedar Apple Rust

For all of those who are planning an orchard, there are a few facts about apple trees, junipers, and cedars which are odd, interesting and important to review before the purchase. The combination of any of the aforementioned may result in the formation of Cedar-Apple rust, which is a most interesting fungus. It is necessary for the rust to have both the apple and the cedar to complete its life-cycle so purchase of resistant apples is paramount considering the numbers of cedars infecting our environment.

In the warm days of early spring, the galls associated with the rust appear on infected Cedar trees following a rain. The galls are golf ball size, bright orange, and any kind of moisture will cause the formation of tendrils which secrete a gooey gelatinous substance that actually drips from the tree. Our patio Cedar was infected after we planted several Jonathan and Golden Delicious apples trees in the orchard, both of which are highly susceptible to the fungus. As the galls grew on the Cedars and began to drip, the children often complained of being 'slimed'. The slime secreted is actually a fungal spore which can travel up to two miles on the wind looking for a susceptible apple or crab apple host.

Upon arrival on the apple cultivar, the spore settle in and the apple becomes infected. The first sign of infection is the formation of small yellow spots which appear rather suddenly in the uppermost branches of the apple tree shortly after flowering. The spots begin to enlarge and turn a vivid orange making the condition easy to identify. In late summer, small tube-like structures appear on the underside of the leaves spores from these tubes are released into the wind and settle on susceptible cedars or junipers thus completing the cycle. Oftentimes as the disease progresses, the apple trees lose almost all of their leaves making their appearance quite pitiful.

Fortunately, there are new disease resistant varieties of apples which are readily available. Redfree, Liberty, William's Pride, and Freedom are extremely disease resistant and provide ample fruit. Additionally, they show resistance to powdery mildew, apple scab, and fire blight as well.

The newest apple to be introduced in 2017 is the Cosmic Crisp, which has been in the lab at the University of Washington State since 1997. The fruit is a cross between the Enterprise and Honeycrisp apple varieties, is GMO free, and bred to feature naturally higher levels of acidity and sugar. They scientists claim that it’s naturally slow to brown when cut and maintains its texture and flavor in storage for more than a year. Research about its resistance to Rust is inconclusive and since I am as old fashioned as a McIntosh I am uncertain… however out of curiosity I will give Miss Cosmic Crisp a try!

Photo credit Cornell Research