Kelly, (and all)

On generalizing Salmonberry - Rubus spectabilis as "Rubus" and on generalizing from species to genus in general and a discussion on the adaptation of R. spectabilis to hummingbird pollination for anyone interested:

Kelly wrote:
"I'm not an expert in Rubus biology, but I consider it interesting that hummingbirds are one of their pollinators..."

Please don't take this personally, but In your post you express curiosity that hummingbirds pollinate "Rubus" (blackberry / rasberry / salmonberry / thimbleberries etc.). I confess you touched a bit of a button for me. I often see people generalizing about an organism, by referring to its genus, not its species, when the observer knows what species is referred to or is readilly able to identify it. For me it is especially frustrating when I am studying herbarium labels of plants to learn more about the ecology of a given species, but the botanist, who recorded associated taxa growing with the plant they collected, only records the genus of the associated species, thus throwing away most of the ecological data that listing that associated taxon would give. This is even when they likely recognize the associated species that is in an easy genus (e.g. Cornus - the dogwoods, with one creeping herb-like plant, one shrub and one tree). The essence of speciation is adaption to a different niche from the parent species.

It is not Rubus in general that are highly attractive to hummingbirds, but that our bright magenta flowered species, Rubus spectabilis - Salmonberry, that is among our earliest blooming plants in the late "winter" or early spring, is particularly attractive to them. (We don't have a real "winter" in western Washington lowlands).
Again, an image of our striking Salmonberry bloom:
http://biology.burke.washington.edu/herbarium/imagecollection.php?Genus=Rubus&Species=spectabilis
Though I'm sure they attract other pollinaters also, these striking bright magenta flowers are adapted to attract hummingbirds, even if they aren't tubular. The lack of a tubular shape, is both a function of the family they come from and presumably a way to allow pollination by a greater diversity of pollinators that don't all have long tongues / proboscises. That is, they are not specialists. I don't remember noting other Rubus species attracting hummingbirds, but as far as I know the other, mostly white flowered species, are not particularly adapted to attract hummingbirds. You also mention that you are quite familiar with hummingbirds using (white) cherry blossoms for nectar. Rubus and Prunus (the genus of the cherry) are both members of the Rose family - Rosaceae with very similar flower types, so knowing that hummers nectar on Cherries - Prunus sp., you might expect them to nectar on Rubus also, especially a member of the genus that both has magenta flowers and blooms at a time when relatively few other nectar sources are available. Similarly, you might expect our earliest blooming Rubus species to have red flowers if they bloom at a time when insect pollinators are relatively uncommon and fly mostly at warmer and sunnier moments, but the hummers are nectaring whether it is sunny and warm or cloudy and cool. R. spectabilis is also a shade lover, but pollinating insects, on the whole, especially in the late winter / early spring are not shade loving.

On the danger of being destroyed by frost, I have never noted R. spectabilis blossoms damaged by frost. I expect that they have enough antifreeze in them to survive the light frosts that are reasonably common in western Washington lowlands at this time of year (like last night).


-Stewart

Stewart Wechsler
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----- Original Message -From: Kelly Cassidy
To: 'Tweeters'
Sent: Wednesday, February 25, 2009 5:52 PM
Subject: RE: [Tweeters] salmonberries and red-flowering currants


I'm not an expert in Rubus biology, but I consider it interesting that hummingbirds are one of their pollinators. On this side of the mountains, the hummingbirds that come through Pullman on the way uphill in late March and April seem to rely heavily on fruit tree flowers. We have a big (~35 ft tall) old cherry tree that is usually a heavy bloomer and a hands-down favorite with the hummers and insect-pollinators of all types. Neither Rubus nor apple, plum, or cherry trees are "typical" hummingbird flowers. Hummer-specialist plants tend to have pink or red tubular flowers with no landing platform for insects.



Rubus and some of the flowering fruit trees may be pinkish, but are often white. They are not tubular. I think these early flowering plants are trading off the danger of early flowering (late frost killing the flower buds, etc.) for the advantage of having no competition for pollinators. The pollinators have few choices and must work any flowers they can find. I've often wondered if these early flowerers can be stingier with the nectar, the price they have to pay for the pollination service.



Kelly Cassidy

Pullman



From: tweeters-bounces at mailman2.u.washington.edu

Behalf Of Dennis Paulson
Sent: Wednesday, February 25, 2009 1:10 PM
To: Tweeters
Subject: [Tweeters] salmonberries and red-flowering currants



Hi, tweets.



I know these aren't birds, but they came up in the discussion of Rufous Hummingbird arrival times.



I've always found it interesting that these two species of Rubus and Ribes, respectively, were reddish pink in two genera of plants that feature mostly white-flowered species. They are also early bloomers. They still attract and are probably pollinated by bumblebees, like others of their genera, but I think they evolved the red color to take advantage of the fact that hummingbirds are much more dependably active during the commonly wet and chilly spring weather, just as we're having today, than bumblebees are. Being conspicuous to the hummers, the plants have expanded their options greatly. They are also both Pacific Northwest plant species, coinciding with an area in which Rufous is a common (and early) spring migrant and breeder. But note that neither of them is a classical hummingbird flower, bright red to red-orange with a long, tubular corolla.



Rufous also breeds well to the east of the range of these two plant species, and I don't know if there are other plants east of the Cascades that have taken advantage of spring hummingbird migration. Scarlet gilia serve the birds well where it occurs, but later in the summer.



Most of the "classical" hummingbird flowers in the PNW bloom in late summer and early fall and coincide with the southbound migration of Rufous and Calliope through the mountains. Mother Nature plans well!

-----

Dennis Paulson

1724 NE 98 St.

Seattle, WA 98115

206-528-1382

dennispaulson at comcast.net