Hello Bryan and The Rest of Tweeterdom

Bryan and I have had a wee discussion about introduced species.

Many of these have been a huge boon, at least to certain species.

If one reads Jewett et al, it is hard to believe that the sparrow increase
isn't real. Swamp Sparrows, perhaps, are recorded more due to increased
observers, but how about the increases in wintering WC Sparrows, GC Sparrows,
Lincoln's Sparrows? I think blackberry brambles play a large role. A whole host of
species utilize Russian Olives, and I've no doubt that wintering YR Warblers,
Hermit Thrushes, solitaires, and eastside Varied Thrushes would be far less
common were it not for this plant. Bewick's Wrens also seem dependent on it in many
places e. of the Cascades. Finally, Eurasian Milfoil has been a huge benefit
to scaup, coots, wigeon and other waterfowl/birds.

I am certain these species have some detrimental effects, but they grow in
many places so incredibly altered that "restoring" them is impossible. And when
one says "restore," one must ask to when? Before white man, before humans,
before the ice ages? I am not being silly. This world is not static, especially
over the last 2 million years.

I've a friend high up in WDFW and another high up in the NWR system who think
the real answer is a high diversity of quality habitats. Some of these would
include introduced species such as Russian Olive, and some would have these
introduced species removed. It is better to try to preserve/improve the high
quality more pristine areas than try to take out every blackberry bramble and
Russian Olive tree. Indeed, for many birds, the latter would be detrimental.
Unfortunately, the government has currently taken a "if its not native, it needs
to go" stance. Such as squashed the Russian Olive woodland that provided so
much habitat for so many birds on the totally artificial habitat created by ag
runoff at Wahluke Slope. Ideally, such an area would be a mix of willow and
olive. Maybe someday it will, but right now, a number of Song Sparrows, WC
Sparrows, towhees, Hermit Thrushes, etc have lost their wintering grounds. If it
grows back solid willow, maybe the Song Sparrows will use it, but none of the
others will.

Similarly, the move to destroy every artificially created freshwater/brackish
wetland in w. Washington to re-establish "natural" tidelands would be a huge
blow to shorebirds, many of whom depend on these created wetlands as high tide
feeding areas/roost sites. The enormous numbers and diversity of shorebirds
that use Crockett Lake and Port Susan Bay are no accident. Same for Iona Island
in BC. Shorebirds are particularly dependent on high quality areas for
refeuling, or they don't make it to the next stop hundreds of miles away. The amount
of salmon habitat would be increased by a tiny fraction if these areas are
eliminated, yet a huge percentage of w. Washington's non-tidal shorebird habitat
would be erased.

Sadly, this topic is exceptionally complicated. Those espousing complete
eradication of introduced species are ignoring real life realities. Those
suggesting we abandon rehabilitation of "natural" habitats are equally misled.

An interesting example was given in the book that I cited in a much earlier
post. It was by a guy whose specialty was, yes, the feces of extinct mammals.
He suggested that the non-native burro and horse populations are replacing
species wiped out by humans about 10000 years ago. Burros were removed from part
(all?) of the Grand Canyon National Park because they were supposedly
detrimental to the mesquite. He studied the situation and found that mesquite declined
after the burros were removed. He looked at their feces and they weren't
predominantly eating branches/foliage, but were eating seed pods and actually
spreading the mesquite.

I am not suggesting we introduce Monk Parakeets throughout Washington or
plant Russian Olives in pristine habitats, but I am suggesting that we re-evaluate
our knee-jerk reaction to non-natives.

Some of the species we discussed that are on the increase are increasing, I
believe, because of an increasingly milder climate. Others, however, are the
beneficiaries of some of these introduced plants. And I am not just talking Eur
Starlings, but birds like Greater Scaup.

Cheers
Steven Mlodinow
Everett WA