Participants:

Katharina Dittmar De La Cruz, Ph.D., SUNY @ Buffalo

Megan Porter, Ph.D., University of Maryland, Baltimore County

Bruce D. Patterson, Ph.D., The Field Museum of Chicago

Carl W. Dick, Ph.D., The Field Museum of Chicago

A preliminary trip to Vieques Island was carried out in July of 2008 to assess the diversity of bats and their parasites.  Our team consisted of Drs. Bruce D. Patterson and Carl W. Dick of Field Museum, Dr. Katharina Dittmar of State University of New York – Buffalo and Dr. Megan Porter of the University of Maryland.  We had earlier obtained authorization of the Puerto Rican Department of Natural Resources and the FCPR, and consulted with Johanna Santiago Torres and Neida Pumarejo-Cintrón of the FCPR, as well as Dr. Armando Rodriguez-Duran of the Inter-American University of Puerto Rico - Bayamón. 

During this visit, we accessed bunkers owned and managed by the FCPR and began studies of the bats roosting there and in surrounding areas.  During this time, the team gained preliminary information on the bats and ectoparasites roosting inside the bunkers, and documented the existence of two new bat species for Isla Vieques (Monophyllus redmani and Lasiurus borealis). Clearly, much remains to be learned from Vieques bats.

Specifically, we visited the following bunkers:

Bunker 416 (FCPR) – This bunker was used by a small colony of Molossus molossus.

Bunker 241 (FPCR) – This bunker contained 31 Artibeus jamaicensis, and 1 Monophyllus redmani. Bats in this bunker were tagged with the following numbers: PSU 1202 – PSU 1222. Bunker 241 was visited twice again, and it was clear that (a.) fewer bats roosted in the bunker after initial capture, but (b.) some new bats had moved into the bunker. It is likely that bats frequently move between roosting sites. Recapture of bats in this bunker showed an increased parasite load per bat.

Power Plant Ruin (not FPCR) – This ruin contains a maternity colony of Artibeus jamaicensis. The estimated size of the colony is 60 – 80 individuals. Although not yet within the properties of the FPCR, it is recommended to incorporate this structure into future conservation plans. Bats captured in this structure were tagged with PSU 1223 – 1241.

Bunker 256 (not FPCR) – This municipal bunker contained a maternity colony of Artibeus jamaicensis. The estimated colony size is 50 individuals. Captured bats were tagged with numbers PSU 1242 – PSU 1310.

Bunker 241 (FPCR) – This bunker housed 3 Artibeus jamaicensis bats.

Bunker 235 (FPCR) – This bunker contained a mixed colony of Artibeus jamaicensis bats, 24 bats were captured. None were tagged.

Bunker 226 (property rights unknown to us) – We captured 14 Molossus molossus from the door slots of the bunkers. None were tagged.

Bunker 223 (FPCR) – This bunker contained a mixed colony of Artibeus jamaicensis. All individuals from the bunker were captured and tagged with numbers PSU 1311 – PSU 1341. Recapture of bats in the bunker again showed a significantly higher parasite load per individual, as fewer individuals had to absorb the parasites.

Mist Net capture – Mosquito Beach: We captured 4 Noctilio leporinus and 1 Artibeus jamaicensis.

Mist Net capture – road to Green Beach: We captured 11 Artibeus jamaicensis, 16 Stenoderma rufum, and 1 Lasiurus borealis. 8 Artibeus jamaicensis were tagged with numbers PSU 1341 – PSU 1349.

In total we confirmed the occurrence of the following bats on Vieques Island:

Artibeus jamaicensis, Molossus molossus, Monophyllus redmani, Lasiurus borealis, Stenoderma rufum, and Noctilio leporinus.

147 Artibeus jamaicensis bats were tagged with numbers PSU 1202 – PSU 1349.

The parasites captured in the process were: Trichobius intermedius, Paradyschiria lineata, Megistopoda aranea, polyctenid bugs, bat mites, ticks.

Immediate suggestions to the FPCR Management:

1.It is abundantly clear that abandoned bunkers are attractive and important roost sites for island bats; management plans should consider those bunkers to be of the highest priority for conservation and research purposes.

2.We noticed that many bunkers along the main road were closed and locked. This does not facilitate the roosting of bats, and alternative entry points to the bunkers should be considered if the purpose of the bunkers were to serve as bat roosts.

3.Additionally, some conservation efforts should be focused on the steel doors of the small bunkers, as the door slots seem to be a preferred roosting spot for Molossus molossus.

4.The planting of trees and shrubs known to be a food source for fruit eating bats may help to maintain colony sizes, although Artibeus jamaicensis colonies seem to be doing well on the island.

Judging from our preliminary data, the ectoparasite load of Vieques bunker roosting bats is high, however, the bats health does not seem to be affected by this.