Featured Research

from universities, journals, and other organizations

Bird-pollinated plant mixes it up when it comes to sex

Date:
September 6, 2011
Source:
Oxford University Press (OUP)
Summary:
Across the western Cape of South Africa can be found small plants in the Iris family called Babiana. Flitting between them are sunbirds, small colourful birds like the African version of hummingbirds, that drink the nectar of flowers and in doing so pollinate them. New research shows that while birds are important for plant reproduction, when it comes to sex Babiana don't put all their eggs in one basket.

Sunbird feeding.
Credit: Image courtesy of Oxford University Press (OUP)

Across the western Cape of South Africa can be found small plants in the Iris family called Babiana. Flitting between them are sunbirds, small colourful birds like the African version of hummingbirds, that drink the nectar of flowers and in doing so pollinate them. New research to be published early next year in a special edition on plant mating in the Annals of Botany by De Waal, Anderson and Barrett shows that while birds are important for plant reproduction, when it comes to sex Babiana don't put all their eggs in one basket.

Babiana interest biologists because they seem to have a very specialised adaptation. Spencer Barrett of the University of Toronto said: "Sunbirds fill a similar evolutionary niche to hummingbirds, but there's a key difference. Hummingbirds feed on the wing by hovering. In contrast, sunbirds prefer to perch when they feed. What makes Babiana special is that some species have evolved a specialised bird perch, so what we did was set out to investigate how this functions."

The research consisted of fieldwork across the western Cape, examining Babiana and making observations of the sunbirds that pollinate them. Barrett said: "What we found is when sunbirds visit Babiana ringens, they always land on this perch and then turn upside down to feed on nectar from the the ground-level flowers. In contrast Babiana carminea doesn't have a perch, and here we found that sunbirds land on the ground and probe flowers to feed on nectar. Ground level flowers are highly unusual in bird-pollinated plants because of the likely predation risk and to find two contrasting feeding strategies among related species is remarkable."

"Babiana avicularis has a perch, but these plants are only visited by the southern double collared sunbird. This is a smaller sunbird, and it looks like Babiana avicularis may have evolved a specialised relationship with it. Larger malachite sunbirds don't visit this plant but are the exclusive pollinators of Babiana ringens which has larger flowers. No one had seen birds pollinate this plant before and it's now one of the smallest bird-pollinated plants known."

Another important discovery was the finding that in "Babiana ringens perch size and flower size were of different sizes depending on the geographical location of populations. We found that the bigger the perch, the more birds visited the plant. If that's the case, then why do some Babiana ringens plants have small perches?"

To find out what happened if no birds visited, the team experimented with self-pollination. "If you're a plant that's adapted for cross-pollination we might not expect self-pollination to be very successful: it's better for a species if genes are spread around, whereas self-pollination can lead to severe inbreeding. Indeed one of the Babiana species that were investigated B. hirusta was largely self-sterile but the remaining species that were investigated could set seed from self-pollination.

"What we also found with Babiana ringens is that the perch length was smaller in the east of our survey area. This is the region where we saw fewest sunbird visits to plants. So with fewer pollinators around there's less natural selection to maintain large perches, and it also makes sense to have self-pollination as a back-up when the alternative may be no pollination at all."

Barrett is pleased that the work provides insight into the most specialized bird perch in the plant kingdom, but warns that there is still much that we do not know about how the perch evolved in the first place: "Our research shows a clear functional basis between perches and bird pollination, but that's not all it shows. At the same time we're also seeing self-pollination and it's clear Babiana can adopt different mating strategies in different locations depending on the availability of sunbirds."


Story Source:

The above story is based on materials provided by Oxford University Press (OUP). Note: Materials may be edited for content and length.


Journal Reference:

  1. C. de Waal, B. Anderson, S. C. H. Barrett. The natural history of pollination and mating in bird-pollinated Babiana (Iridaceae). Annals of Botany, 2011; DOI: 10.1093/aob/mcr172

Cite This Page:

Oxford University Press (OUP). "Bird-pollinated plant mixes it up when it comes to sex." ScienceDaily. ScienceDaily, 6 September 2011. <www.sciencedaily.com/releases/2011/09/110906085143.htm>.
Oxford University Press (OUP). (2011, September 6). Bird-pollinated plant mixes it up when it comes to sex. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2011/09/110906085143.htm
Oxford University Press (OUP). "Bird-pollinated plant mixes it up when it comes to sex." ScienceDaily. www.sciencedaily.com/releases/2011/09/110906085143.htm (accessed July 25, 2014).

Share This




More Plants & Animals News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Boy Attacked by Shark in Florida

Boy Attacked by Shark in Florida

Reuters - US Online Video (July 24, 2014) An 8-year-old boy is bitten in the leg by a shark while vacationing at a Florida beach. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Dogs Appear To Become Jealous Of Owners' Attention

Dogs Appear To Become Jealous Of Owners' Attention

Newsy (July 23, 2014) A U.C. San Diego researcher says jealousy isn't just a human trait, and dogs aren't the best at sharing the attention of humans with other dogs. Video provided by Newsy
Powered by NewsLook.com
Professor Creates Site Revealing Where People's Cats Live

Professor Creates Site Revealing Where People's Cats Live

Newsy (July 23, 2014) ​It's called I Know Where Your Cat Lives, and you can keep hitting the "Random Cat" button to find more real cats all over the world. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins