Vol. 16, No. 1 The Coevolution of and

March, 2011 in the Eastern Caribbean By W. John Kress and Ethan J. Temeles

A major goal of systematic, evolu- cordingly, studies of co-adaptation tionary, and ecological studies is between species require an analy- to understand the processes that sis of populations across the broad shape adaptations of organisms to geographic distribution of the spe- their environment. One approach cies. Some populations across this towards this goal is to use patterns geographic landscape are hotspots of morphological variation among of reciprocal selection and others closely related species to make are coldspots with little coevolu- inferences about the kinds of eco- tion. We have recently described logical processes, such as competi- an interaction between a and tion, predation, parasitism, or mu- its pollinator found tualism, through which these char- in the Eastern Caribbean that pro- acteristics have evolved. This type vides an ideal tropical system to of study traces back to Charles test Thompson’s theory. Both the Darwin and his classic observa- pollinators and the exhibit tions in the Galapagos Islands of character polymorphisms, which beak variation and food types can be readily linked to fitness among species of ground finches measures, throughout their ranges. in the genus Geospiza. Over the last several years and probably for a number of years to Since Darwin’s time, interactions come we plan to study co- between flowering plants and their adaptations in this plant- pollinators have provided model hummingbird association through

PUERTO RICO, INC. examples of hypothesized feeding extensive observations of both flo- adaptations, species specialization, ral and sexual dimorphisms across and coevolution. However, some the island archipelago in the East- investigations suggest that such ern Caribbean. interspecific interactions are sel- dom constant throughout a spe- The focal system of this research cies’ range and that populations involves the purple-throated carib differ in the traits shaped by the hummingbird, Eulampis jugularis, interaction. These observations and its food plants (Fig. have resulted in the John Thomp- 1), considered one of the strongest son’s proposed “Geographic Mo- examples of ecological causation saic Theory of Coevolution.” Ac- of sexual dimorphism to date and a

Inside this issue: Dates to Remember Coevolution of Heliconias and Hummingbirds 1  HSPR Meeting, 9:30 a.m., Sunday, March HELICONIA SOCIETY OF 13, 2011. Amphitheater of the Auxilio Mu- From Our Last Meeting 5 tuo Hospital (9th floor of the main hospital building), Hato Rey, PR. President’s Corner 6 43rd Aibonito Flower Festival, June 24- July 3, 2011, Aibonito, PR. The HSPR Newsletter Coevolution of Heliconias and Hummingbirds (continued)

tical in plum- age, but dis- play some of the most ex- treme sexual dimorphisms of any hum- mingbird species. First, bills of males aver- Fig. 1. From left to right, red Heliconia caribaea and the purple-throated carib hummingbird, distribu- age 24.8 mm tion of the hummingbird throughout the Eastern Antilles, and the yellow form of H. caribaea. in length, whereas bills well-documented plant – pollinator mutualism. of females average 29 mm in length, a difference of Many biology textbooks note that flowers polli- 15 percent. Moreover, bills of males are relatively nated by hummingbirds have long, tubular corollas straight, curving downwards at a 15 degree angle, matching the size and shape of the birds’ beaks. whereas bills of females are highly curved, curving Darwin himself stated that bills of hummingbirds downwards at a 30 degree angle. These differences are specially adapted to the various kinds of flow- in bill morphology were associated with differences ers they visit. Our work has provided evidence for in the use of the two Heliconia species on the is- co-adaptation by demonstrating that the purple- land. Males were associated with a red-bracted throated carib hummingbird is the primary pollina- morph of H. caribaea, which they defended against tor of H. caribaea and H. bihai, with flowers of the other males and females. In contrast, females in- former corresponding to the short, straight bills of truded onto male territories to feed and also fed at males (the larger sex) and flowers of the latter to undefended patches of H. caribaea, but more im- the longer, curved bills of females (Fig. 2). Further portantly they were the predominant visitor to the evidence for co-adaptation comes from a reversal in other Heliconia, a green-bracted morph of H. bihai. the floral dimorphism of the Heliconia food plants The morphology of the flowers of the two helico- on two islands: on St. Lucia, the female-pollinated nias reflected this sexual preference by the hum- H. bihai develops a second morph with shorter, mingbirds. Flowers of H. caribaea were short and straighter flowers matching the bills of males, straight, measuring 38 mm in length and 20 degrees whereas on Dominica the male-pollinated H. cari- in curvature, which approximates the short, straight baea develops a second morph with longer, curved bills of male purple-throats, their primary pollina- flowers matching the bills of females. The nectar tor. In contrast, flowers of the green-bracted H. bi- rewards of all Heliconia morphs on both islands are hai were long and curved, measuring nearly 44 mm consistent with each sex’s choice for the morph in length and 31 degree in curvature, which is al- corresponding to its bill morphology and energy most identical to the 30 degree curvature of female requirements, supporting the hypotheses of ecologi- bills. The close correspondence between bills of cal causation of sexual dimorphism and co- male and female purple-throats and the sizes and adaptation. shapes of the Heliconia flowers they visit argues strongly for reciprocal adaptation. This hypothesis Our work started nearly a decade ago when one of receives additional support from our discovery of a us (EJT) initiated studies of the purple-throated second, red-green morph of H. bihai on the island. carib hummingbird, Eulampis jugularis, on the is- This red-green morph acts as a geographic replace- land of St. Lucia. The males and females are iden-

Page 2 THE HSPR NEWSLETTER Coevolution of Heliconias and Hummingbirds (continued)

ment of H. caribaea and is defended and visited low stripe. Similarly, whereas there was only a sin- primarily by male purple-throated caribs. Its flow- gle, red color morph of H. caribaea on St. Lucia, on ers are both significantly shorter and straighter than Dominica there are now two: a red morph and a flowers of the green-bracted morph visited by fe- yellow morph. males, which is what you would expect given its As on St. Lucia, males associate primarily with H. visitation by males. caribaea. Females also visit H. caribaea and are the sole pollinator of H. bihai. Once again, flowers of We then extended our investigations of this plant- the two heliconias correspond closely to the bills of pollinator system to the island of Dominica, located their primary hummingbird visitor. Flowers of H. 100 miles north of St. Lucia. Bills of both sexes of caribaea are short and straight, measuring 36 mm purple-throated caribs on this island are slightly in length and 20 degrees in curvature, which longer and slightly less curved than on St. Lucia. roughly corresponds to the 15-degree bill curvature As on St. Lucia, however, the primary food plants of males. In contrast, flowers of H. bihai measure of these birds are H. caribaea and H. bihai. But in 48 mm in length and 30 degrees in curvature, a per- contrast to St. Lucia which has two morphs of H. fect match for the 30 degree bill curvature of fe- bihai, green and red-green, on Dominica there is males. The flowers of H. bihai are 4 mm longer only one morph of H. bihai which is red with a yel- than on St. Lucia which we interpret as a coevolu- tionary re- sponse to the exclusive visi- tation by fe- male purple- throats with their long bills.

Vinita Gowda, a graduate stu- dent at George Washington University working with us on this pro- ject, has pro- vided an im- portant tem- poral compo- nent to our observations. As part of her dissertation, she monitored the flowering Fig. 2. Polymorphisms in bills of purple-throated carib hummingbirds and inflorescences and flowers of times of the Heliconia species in Dominica, W.I. heliconias and the visitation

VOL. 16, NO. 1 Page 3 Coevolution of Heliconias and Hummingbirds (continued) rates of the hummingbirds on three islands: Domin- results from character release associated with a de- ica, St. Kitts to the north, and St. Vincent to the crease in the number of species on islands as one south. On Dominica flowering patterns of Helico- moves north farther and farther from the mainland. nia bihai and Heliconia caribaea were significantly The number of endemic Heliconia species de- different: H. bihai flowers throughout the year but creases from five on Trinidad to two on St. Lucia has a distinct peak flowering season in April, and Dominica, whereas the number of humming- whereas H. caribaea has a distinct flowering sea- bird species decreases from twelve on Trinidad to son from March until September (with a peak in three on St. Lucia and four on Dominica. This re- May) and does not produce any flowers the rest of duction in species diversity may permit H. bihai the year. The peak flowering season of the two spe- and H. caribaea to undergo character displacement cies did not overlap. With respect to pollinator where the two heliconias overlap. Similarly, a re- visitation patterns H. bihai shows a clear female duction in competing hummingbird species com- dominated interaction throughout the flowering bined with two abundant and rewarding Heliconia season while H. caribaea inflorescences are always food plants may drive the evolution of sexual di- strictly defended as territories by males with fe- morphism within purple-throated caribs. Our avail- males often allowed to enter the territories to feed able evidence supports this hypothesis. on the flowers during the mating season. Other pollinators that were rarely observed on H. cari- These results indicate that a geographic approach baea are Green throated Carib hummingbirds can identify populations of plant-pollinator spe- (Eulampis holosericeus) and Antillean Crested cialization and generalization. Highly-specialized Hummingbirds (Orthorhyncus cristatus). Both of populations may represent hotspots of reciprocal these visitors are aggressively chased away by terri- evolution. In this regard, it is significant that the torial males. longest flowers of H. bihai and the longest bills of female purple-throated caribs occur where it is pol- As our studies and observations have spread linated exclusively by females. Whether such asso- throughout the archipelago we have tracked the ciations represent coevolutionary arms races re- long-distance transition between generalized and quires future study. specialized plant-pollinator interactions in this heli- conia-hummingbird system. What we have found We have much more to understand about the mo- is that one species of plant, Heliconia bihai, saic of interactions between the species of heliconia changes from a generalist strategy in the southern and their hummingbirds pollinators in the Lesser range of the island chain (Trinidad) where its flow- Antilles. Through a grant from the National Sci- ers are pollinated by many hummingbird species to ence Foundation we have funding support to con- a highly specialized pollination strategy in the core tinue our investigations in the Eastern Caribbean of the archipelago (St. Lucia and Dominica) where for several more years. Like the Galapagos Islands its flowers are pollinated by one sex of one hum- off the coast of Ecuador, the Eastern Caribbean ar- mingbird species. We are only now beginning to chipelago is an ideal natural laboratory for under- understand the floral and pollinator traits associated standing the evolutionary processes of adaptation with the transition from generalization to speciali- and coevolution. zation. Where H. bihai is pollinated by many hum- mingbird species with bills of many different HSPR thanks collaborators W. John Kress, PhD, Re- lengths, the flowers are 30% shorter in length than search Botanist and Curator, Department of Botany, MRC-166, National Museum of Natural History, Smith- on the islands where the flowers are only visited by sonian Institution, P.O. Box 37012, Washington, DC female purple throated Carib hummingbirds with 20013-7012, USA, and Ethan J. Temeles, PhD, Professor long-curved bills. We hypothesize that this transi- in the Department of Biology, Amherst College, Amherst, tion across 300 miles in the Caribbean archipelago MA 01002, USA, for this interesting article. Page 4 THE HSPR NEWSLETTER From Our Last Meeting

Close to 55 persons attended our traditional HSPR Christmas Dinner, held at the charming country house of Gildreth and Bob Castro. This farm is located at Cerro Guilarte, in Adjuntas, and is one of our pre- cious HSI / HSPR Conservation Centers. Bob gave us the official welcome to Siberia –the name by which he calls his farm, among the close friends-, which is situated at 3,200 feet above sea level.

Judy Nelson, from Marín Alto Tropicals, told us of a cheerful anecdote from her last visit to this farm (the June 2008 HSPR meeting). Here is where she found and adopted an adorable stray puppy, which she later named Kathy. She sadly informed us that after 29 years in the tropical cut flower business she, Kelly From left to right, HSPR President José R. Abreu, HSPR and Susan plan on retiring to the States. The legen- Vice President Héctor Méndez Caratini, and HSI Presi- dary Marin Alto Tropicals (a heliconia nursery dent W. John Kress, at the 2010 Heliconia Society Interna- tional Conference, held in Singapore. founded by Dr. Harold Kelly Brooks in 1981) is up for sale, including over 200 varieties of heliconias Hato Rey. This conference was originally scheduled and gingers, which they are currently growing. The to be held at the University of Puerto Rico’s May- 131 cuerdas, located next to Torrecilla peak in the aguez Campus. But, due to the uncertainties related to mountains of Patillas, are located at 2,300 feet above a possible future student’s strike and campus closing, sea level. From the farm you can see an impressive to solve the impasse HSPR member Jorge Matta gra- panoramic view of the turquoise-blue waters of the ciously offered the facilities of the institution where Caribbean. Interested buyers should contact her at he works at, as an alternative site. A Special Fund was 787-839-2040 or 787-237-8128. immediately established to help cover the costs asso- ciated with Dr. Kress’ visit to Puerto Rico. The Our Treasurer, Reily Rodríguez, provided us with the amount of one hundred and twenty dollars was col- report of HSPR’s finances. We initially had $2,730.00 lected from our members. in the account. But after paying $1,155.00 for current expenses, we are left with a projected balance of Dr. Abreu and myself read the names of the three doz- $1,575.00 in the bank. During today’s activities, ens heliconias and more than a dozen different palms $895.00 was collected. These monies came from: (and other precious plants, such as bromeliads) that $405.00 from the Raffle, $350.00 from membership were available at the Raffle. Among the heliconias dues, $120.00 from a Special Fund and $20.00 from that were up for grabs were: H. penduloides Perfect the special invited guests to the dinner. Therefore, we Darling, H. griggsiana Harvest Moon, H. chartacea now have approximately $2,470.00 in the bank. Columbine, H. temptress, H. curtispatha, H. caribaea Manoa Midnight, H. champneiana Maya Blood, H. The members were reminded that for our next quar- orthotricha yellow, H. hirsuta, H. bihai red (from terly meeting (to be held the second Sunday of March Trinidad), H. bihai Giant Lobster Claw, white torch 2011), our invited Guest of Honor is going to be Dr. ginger (also the pink variety) and many, many more. W. John Kress –world authority on heliconias. Dr. The excitement generated from the Raffle accrued Kress is Research Botanist and Curator at the Botany $405.00 for the society. Our sincere thanks goes out Department of the National Museum of Natural His- to all members who donated plants for the Raffle. tory, Smithsonian Institution, in Washington, D.C. He is also the President of Heliconia Society Interna- We would like to publicly acknowledge the conta- tional. The Meet the Experts Conference will be held gious enthusiasm of young Aaron Jr, who decided to at the Amphitheater of the Auxilio Mutuo Hospital, in celebrate his eighth birthday among the members of

VOL. 16, NO. 1 Page 5 HELICONIA SOCIETY OF PUERTO RICO, INC. HSPR

Promoting in www.heliconiasocietypr.org Puerto Rico since 1996. President: Dr. José Abreu Deliz Past President: Mr. Héctor Méndez Caratini Vice President: Mr. Héctor Méndez Caratini Treasurer: Mr. Reily Rodríguez Secretary: Mrs. Yarisa Montes Officer: Ms. Judy Nelson The Heliconia Society of Puerto Rico, Inc. was founded in 1996. The objec- Officer: Dr. Bryan Brunner Editor/Webmaster: Dr. Bryan Brunner tives of the society are to stimulate and promote the enjoyment and under- Assistant Editor: Mr. Bob Castro standing of Heliconia and related plants of the order Zingiberales through Juan J. Jimenez 554 Hato Rey, P.R. 00918 education, research and communication, and to interact with the Heliconia Phone: 787-792-5081 Society International and other institutions which share similar interests, pur- Fax: 1-240-238-7366 Email: [email protected] poses or objectives.

From Our Last Meeting (continued) President’s Corner

HSPR, instead of with his friends of the same age. He Greetings in this New Year 2011. The year 2010 was was the lucky winner of eight heliconias in the Raffle, one of persistent “bad weather”, according to those to augment his rapidly growing collection. Be on the who make a living at announcing showers and sprin- look out for this kid, who one day promises to be a kles around the Island on radio and TV. To us helico- future leader in our organization. We all wished him a nia enthusiasts I wish 2011 to be another “bad ¡Feliz Cumpleaños! weather” year.

The members then proceeded uphill, to tour the farm Early this week I was notified by our mutual friend and see the heliconias, gingers and costacaea growing and greatest heliconia enthusiast Héctor Méndez there. Afterwards, a delicious dinner was served with Caratini, that Dr. John Kress had confirmed his visit the traditional lechón asao, pasteles, arroz con gan- to Puerto Rico in March. So, during our March 13th dules, roasted chicken, guineitos en escabeche and meeting we will have the very special, perhaps unique other gourmet Christmas time delicacies. opportunity of enjoying the presence and wise lectur- ing by the most knowledgeable scientist involved During our visit to Siberia we were able to greet old with Zingiberales: Dr. John Kress. friends, we had not seen in many years, and welcome the new ones. It was an unforgettable meeting, full of Since this meeting is inside an institution (9th floor camaraderie, enjoyed by those who ventured to drive Conference Room of the Hospital Auxilio Mutuo, the tortuous roads of the Cordillera Central and toler- Ponce de Leon Avenue in Hato Rey), please bring ate the coolness of the climate. We are ALL very clean, containerized rhizomes and plants for the raf- grateful for our hosts’ hospitality, and the great time fle. We want to avoid soiling the space made avail- we had. ¡Muchas Gracias Bob and Gildreth! able to us by the generosity of our member Mr. Jorge Matta. Snacks and eatables are welcome! Héctor Méndez Caratini Vice President, HSPR See you next March 13th.

José R. Abreu, President, HSPR

Page 6 THE HSPR NEWSLETTER