[obol] blackberry

[Pat Waldron]

Dear Dan,
    Excellent information. I unfortunately, being naive one time, 
actually transplanted Armenian Blackberry to our property. I dug up 
plants and moved them home for bird cover and for the bee hives... and 
had a very difficult time getting them to survive. I am a Master 
Gardener, but they did not take to my transplanting. After 10 years, I 
now cut them back for control.
    The California blackberry that you speak of, does it have serrated 
leaves? The common name I know it by is Evergreen blackberry. Have you 
heard that name? Wild grape? Do you mean our native Oregon Grape or 
something else.
    I could replace the Armenian Blackberry. I have MOUNTAIN and 
CALIFORNIA QUAIL that use it for cover, as I feed them on the edge of 
it. Do you have any suggestions for a substitute? 
    Thank you.

    Pat Waldron
    East of Scio
    Linn Co.

Dan Gleason wrote:

> I have posted much of this information in years past but since this 
> discussion has come up again, and there are more people on OBOL now, I 
> thought I would resend some of my thoughts about blackberry and what 
> they do or do not provide for birds.
>
> I have often found myself disagreeing with other birders about the 
> value of blackberry. Its value for food and shelter is often touted 
> but I believe that both of these are of minimal value and then only to 
> a few species. I strongly encourage removing blackberry wherever and 
> whenever possible AND replacing it with a diversity of brushy natives, 
> not simply leaving a void in a grassy field (most likely of non-native 
> grasses as well.) Here are some points to consider about this invader.
> ?
> Himalayan Blackberry is now better known as Armenian Blackberry (Rubus 
> armeniacus). It is not native to North America and is a very invasive 
> species that can easily dominate open fields and, once established, 
> can be very difficult to eradicate. It does provide some food and 
> cover for birds, so many birders believe that removal efforts should 
> often be minimized in the best interest of the birds. It is nice to 
> see the birds but the overall health of the local ecosystem should 
> take precedence. A healthy, native ecosystem also provides the best 
> diversity of native birds, unlike blackberry where only a few species 
> are routinely found. Birds found in blackberry are found mostly around 
> its periphery as the dense cover deep within a blackberry thicket 
> offers little that is attractive to birds.
> ?
> If you examine Internet sites about birds and blackberries, you will 
> mostly find simple statements like: "birds use blackberry thickets in 
> this area" or something similar but containing very little real data. 
> One report on Yellow-breasted Chat (California Partners in Flight 
> Riparian Bird Conservation Plan) indicates that, at least in parts of 
> California, chats use blackberry thickets for food. In late summer, up 
> to 1/2 of the diet may consist of a variety of berries, including 
> Armenian blackberry. There is also limited use of blackberry for 
> nesting by chats and the report gives some cautions about disrupting 
> nests. The report also indicates that there is a lack of extensive 
> nest data so it is difficult to make statements about strict habitat 
> requirements. They suggest as an action to "Include native, 
> thicket-forming shrub species (i.e., California blackberry, wild 
> grape) in restoration plantings, while retaining existing tall, mature 
> trees for song perches." The use of blackberry is documented in other 
> parts of the country as well, but again, these are mostly in disturbed 
> habitats that lack native brushy thickets attracting a greater variety 
> of birds.
> ?
> On the negative side, the list is very long. Blackberry thickets can 
> produce 7,000-13,000 seeds per square meter! Seeds require 90 days of 
> warm temperatures, followed by 90 days of cold (perfect conditions in 
> the Willamette Valley) and seeds can remain viable for several years. 
> The main method of seed dispersal is via birds and some mammals that 
> eat the seeds and pass them through their digestive tracts. 
> Apparently, this also greatly improves the germination rate. Young 
> seedlings require strong sunlight to grow but the developing stalks 
> cannot spread into areas with much less than 50% full sunlight. Once 
> established, the stalks can grow as much as 7 meters in a single 
> growing season. Over 95% of these stalks will have daughter plants 
> growing at the apices, ready to begin growing as the stalks bend over 
> and touch the ground. Most lateral branches also form daughter plants. 
> An individual stalk may only live 2-3 years but the density of stalks 
> is often over 500 per square meter. Even short pieces of stalk or root 
> will readily propagate, so the reproductive potential of these plants 
> is enormous.
> ?
> In addition to choking out native vegetation (including some native 
> blackberries), these plants often form a barrier along stream 
> corridors that prevent some mammals from getting to sources of water. 
> One mammal that does do well in blackberries is the black rat (Rattus 
> rattus) also known as roof rat. This is a non-native, and often rather 
> destructive animal that, in large populations, can serve as a vector 
> for diseases including some human diseases. (See note below).
> ?
> While I do enjoy its fruit, I can't really think of any good reason 
> not to eradicate Armenian blackberries. Unfortunately, they are here 
> to stay, despite our best efforts. I think that we should control 
> these plants wherever they grow as best we can. They do not belong in 
> native grasslands, wetlands or other fields and I advocate their 
> removal. In riparian corridors, we should encourage their removal 
> along with replacement of native plants that can provide the food and 
> shelter needed by native fauna (from invertebrates, to birds and mammals).
> ?
> ---
> ?
> As a side issue:? There is much misunderstanding about rodents and 
> disease. In this country, Norway rat and black rat, both introduced, 
> do not carry plague. Many native rodents do carry plague but their 
> fleas tend to be very host specific, rarely biting humans, and so 
> cases of plague are quite rare. (Fleas found on cats and dogs are 
> generalists and do bite humans.) Also, contrary to popular belief, 
> rodents do not carry rabies and no human cases of rabies have ever 
> been linked to bites by any rodent species. Because of misinformation 
> and ignorance, some people needlessly are given rabies shots after 
> being bitten by a rodent (of any kind). Typhus and other diseases have 
> been attributed to introduced rats.
> ?
> ?
> Dan Gleason
>
> -------------
> Dan Gleason
> dan-gleason at comcast.net <mailto:dan-gleason at comcast.net>
> 541 345-0450
>
>
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