Archbold Biological Station, Biennial Report 1997-1998


 


Research Affiliates

Curtis S. Adkisson, Virginia Polytechnic Institute;
James E. Carrel, University of Missouri-Columbia;
William E. Conner, Wake Forest University;
Rebecca E. Dolan, Butler University;
Hugh I. Ellis, University of San Diego;
Daniel Gagnon, University of Quebec at Montreal;
Doria R. Gordon, The Nature Conservancy;
Jack P. Hailman, University of Wisconsin;
Margaret A. Hodge, College of Wooster;
David S. Maehr, University of Kentucky;
Samuel D. Marshall, Miami University;
Walter E. Meshaka, Jr.,
Everglades National Park;
Ronald L. Mumme, Allegheny College; and
William A. Watts, Trinity College, Dublin

[Biennial Contents | Biennial 95-96]

In 1997, Archbold Biological Station established a new administrative category, Research Affiliate, for scientists with a close association to the Station. This title may be conferred on persons of recognized scientific standing who are actively engaged in original research, at or near the Station, that contributes significantly to the scientific mission of the Station. Such persons normally hold an earned doctoral degree. Research Affiliates may establish grant accounts at the Station for funded research. Research Affiliate appointments are made for two-year periods, and must be renewed. Appointments are offered by the Executive Director, following review of the candidate's application and qualifications by the scientific staff. We highlight research by 11 Research Affiliates below.


Blue jay (Cyanicitta cristata); photo by Henry Comstock
top   Curtis Adkisson. Blue jays, Cyanocitta cristata, are common edge-habitat birds in North America, and are successful in many disturbed habitats. Blue jays cache nuts of the Fagaceae, especially acorns, in their home ranges. They appear to cache mainly near ecological boundaries or near distinctive features, like bushes or saplings, especially where the ground vegetation is short or missing. Near the Archbold Biological Station, blue jays are abundant in citrus groves within 500 m of oak-dominated woods or scrub habitats. Prior to 1997, Adkisson established that many blue jays; live full-time in the groves, fly up to 2 km to gather acorns, and return to cache them in their home ranges where they nest, roost at night, and also winter. During 1997, he placed radio transmitters on 12 birds and tracked their movements from mid-July until late November. Each of these birds cached an estimated 5,000 acorns from Archbold’s Red Hill, and from areas west of Old State Road 8, in its home range in the grove. Future plans include; color-banding as many grove jays as possible, using radio transmitters to learn more about their movements within the groves, to and from the oak woods, obtaining better estimates of numbers of acorns transported to the groves, and measuring acorn germination under citrus trees, to better estimate oak recolonization should agriculture cease in that grove in the future.

Red-widow spider (Lactrodectus bishopi), a Florida scrub endemic; photo by Nancy Deyrup
top   James Carrel currently works on four projects at the Station. One is a study of the chemical ecology of blister beetles, particularly their use of the toxin cantharidin for defense against predation. In collaboration with Thomas Eisner (Station Research Associate) and others he has staged encounters between the large blister beetle, Lytta polita, and various spiders, shrikes, raccoons, and other potential enemies. The second, conducted annually since 1987, is on the population biology of four scrub-endemic spiders. The third is on the sociality and feeding behavior in the southern house spider. In the coming years he hopes to make this spider a model species because it is very amenable to manipulation in the laboratory and field, plus its bite is not a threat to humans. Finally, in collaboration with his wife, Jan C. Weaver, Carrel has initiated an inventory of the arachnids at the Station.

Scarlet-bodied wasp moth, Cosmosoma myrodora (Lepidoptera: Arctiidae)
top   Bill Conner is studying the behavior of the scarlet-bodied wasp moth, Cosmosoma myrodora. The larvae of this wasp moth are white woolybear caterpillars that feed on leaves of the composite Mikania scandens which grows in the ditches on and near the Station. Adult male Cosmosoma have an unusual behavior. During several nights of their early adult life they visit plants rich in secondary chemicals called pyrrolizidine alkaloids (PAs). The males regurgitate on the PA plants, extract the alkaloids, and reimbibe them. In collaboration with Thomas Eisner (Station Research Associate), Conner hopes to discover the fate of the pyrrolizidine alkaloids and their role in the natural history of the moth. So far it is clear that the males use the alkaloids to protect themselves from predators like the orb-weaving spider, Nephila clavipes. Males also concentrate the alkaloid in a special fiber-filled gland on the ventral side of the abdomen. During courtship the male’s gland explodes showering the female with alkaloid-laden fibers. The fibers apparently convince the female of the quality of the male as a potential mate. Next, Conner wants to determine if males then transfer the defensive alkaloids to the female in a nuptial gift. The female may use them as protection for herself and her offspring.

Lake Wales balm (Dicerandra christmanii), an endangered mint endemic to central Florida's Lake Wales Ridge; photo by Tom Eisner
top   Rebecca Dolan’s research interest is using molecular markers as indicators of individual, population, and species-level genetic variation. In collaboration with Eric Menges (Station Research Biologist), and with her undergraduate students, Dolan has documented isozyme variation in many if not all populations of six federally listed plant species from Florida’s Lake Wales Ridge (Dicerandra christmanii, D. frutescens, Eryngium cuneifolium, Hypericum cumulicola, Liatris ohlingerae, Nolina brittoniana, and Warea carteri). These species generally have very low levels of variation, although some clines in allele frequency were found, indicating geographic structuring of variation does exist in Warea and Nolina. Hypericum has very highly differentiated populations, supporting pollinator and breeding system research by Margaret Evans (see Archbold Biennial Report 1995-1996) that indicates very localized pollen flow. This research was supported by a grant from The Nature Conservancy. Using methods developed during the TNC study, Dolan also assisted Pedro Quintana-Ascencio (see Plant Ecology) by using genetic markers to document the parentage of seedlings of Hypericum that had been transplanted into suitable, but previously unoccupied habitat. These studies produced one publication, two articles in press, and several manuscripts still in development over the last two years. Future research will focus on within-population gene flow in H. cumulicola, with emphasis on the effects of fire on seed bank dynamics.

Florida scrub-jay (Aphelocoma coerulescens) at a drop-door trap; photo by Glen Woolfenden
top   Hugh Ellis is working with Glen Woolfenden (Station Research Associate) and Reed Bowman (Station Research Biologist) on the energetics of Florida scrub-jays. They are looking at resting metabolism, thermoregulation, and energy budgets. The emphasis has been on the latter, particularly early in the breeding season when females are incubating eggs or caring for small nestlings. During 1997-98, they compared breeding males with breeding females both at Archbold (natural habitat) and in nearby suburban Placid Lakes Estates (fragmented habitat with supplementary food provided by people) by measuring Field Metabolic Rates (FMR’s).
     Ellis used the doubly labeled water technique to measure FMR which varied significantly by sex and location. The most striking result of the FMR study is that male scrub-jays in the suburbs have an FMR 100% higher than males at Archbold. This was a surprise considering that suburban scrub-jays have much smaller territories than Archbold scrub-jays. Smaller territory size may be related to supplemental feeding by people, or it may be a result of habitat fragmentation. In any event, smaller territory size does not translate into lower FMR’s. The suburban birds, already demonstrating lower reproductive rates and life spans than Archbold birds, have one more problem that does not occur in unfragmented, natural habitat.

Scrubby flatwoods along Lake Annie Road, Tract 7, Archbold Biological Station; photo by Nancy Deyrup
top   Daniel Gagnon. Spatial variation in scrub vegetation is assumed to be associated with small variations in soil moisture availability, but this has never been shown directly, as critical differences may appear only briefly during certain periods. On sabbatical leave from Univ. Quebec at Montreal during 1998-99, Gagnon collaborated with Eric Menges (Station Research Biologist) to detect differences in soil moisture patterns in three Archbold scrub communities; rosemary scrub, scrubby flatwoods (SF), hickory scrub (HS), and to assess the effects of recent prescribed burns (vs unburned) and aboveground vegetation gaps (vs shrub cover) on soil moisture. Soil moisture data were recorded one day per week, at 3 depths (10, 50 and 90 cm) in 78 PVC tubes inserted into the soil. A probe instantaneously and directly measures soil moisture, using Frequency Domain Reflectrometry. Sampling began 1 October 1998 and will continue as a long term monitoring effort by Menges, who is also concurrently measuring pre-dawn water potential on two common shrubs and two endangered herbs. Preliminary soil moisture results show that SF soils have the highest soil moisture at 90 cm, and that HS soils are the driest. In all data analyzed so far, soil moisture was significantly different at all depths (increasing with depth). Recent burning increased soil moisture in all scrub types, whereas gaps had no influence. Prolonged dry periods may alter these patterns. Precipitation events are clearly identifiable in the data.
  top   Doria Gordon collaborated on two projects with Archbold scientists. The first, with Hilary Swain (Station Research Biologist) and Leonard Brennan (Tall Timbers Res. Sta.), identified the highest priority research needs for conservation of biodiversity in Florida. Four regional meetings (panhandle, central, south, and coastal Fla.) were convened, attracting more than 50 academic and agency biologists. The database developed from these meetings will be available to the research and management communities and, hopefully, will be used for development of new research projects. This project reveals that applied conservation research needs are a fairly narrow subset of the broader theoretical research agenda for biodiversity, and we found a large emphasis on various aspects of disturbance ecology. Additionally, Gordon collaborated with Eric Menges (Station Research Biologist) and Rebecca Dolan (Butler Univ.) to study the demography, breeding system, genetics, and conservation of seven rare scrub endemic plant species (see Dolan above). The reserve design currently being implemented across the Lake Wales Ridge will protect the majority of genetic diversity that we sampled in these seven species.

Archbold oak (Quercus inopina) is distinguished by its vertical, curled leaves and round acorns. This scrub endemic is the dominant shrub in scrubby flatwoods at Archbold Biological Station; photo by Nancy Deyrup.

top   Jack Hailman and his students have been studying cognitive problems in the Florida scrub-jay. Cognition is involved when an animal has some sort of mental representation guiding its behavior, such as a mental map of where a scrub-jay buries its acorns. Studies of captive corvids indicate such a map exists, but no one has shown that individuals in the wild actually dig up their own caches. Douglas Kramer dug up acorns he watched jays bury, numbered the acorns, replaced them, and noted the locations. Weeks of watching and some luck were required to see a marked acorn dug up, but results show that birds do retrieve their own caches. Peter Midford studied another mental map by teaching jays to dig in the center of a plastic ring on the sand in order to find peanut bits that he buried there. Naive jays can learn this task by watching experienced birds, so the behavior could potentially spread in the population as a novel foraging tradition. Finally, Hailman has studied how jays learn the concept of an object. A hand-tame jay removes the nut from half a peanut, and while the bird is watching, the empty shell is turned over. Naive jays try to tear open the empty shell, but with experience stop such useless effort, presumably having come to understand that it is the same shell they just emptied. A few individuals never learn, however, suggesting that the object concept is near the cognitive limits of the Florida scrub-jay.

A scrub wolf spider, Geolycosa xera archboldi, endemic to the Lake Wales Ridge; photo by H.K.Wallace
top    Sam Marshall and Walter Hoeh (Kent State University) have been searching Florida for burrowing wolf spiders. This project began at the Station and has expanded into a biogeographic study. Demanding special habitats, and incapable of long-range dispersal, burrowing wolf spiders easily become divided into isolated populations and species. Burrowing wolf spiders are usually easy to find, because they leave their neat, silk-rimmed burrows open and visible. In Florida, there are six species of burrowing wolf spiders (Geolycosa) restricted to scrub and sandhill habitats. Results indicate that two species, xera and hubbelli, appear to be confined to the central ridges of the Peninsula, and. patellonigra and micanopy range through the coastal scrubs and the interior ridges peripheral to the central ridges, and are less common (or absent) in the central ridges. Within these species pairs, xera and patellonigra make their burrows in open sand, while hubbelli and micanopy occur where there is ground litter. The remaining two species are in north Florida uplands, their ranges apparently separated by the Apalachicola River. Marshall and Hoeh are now attempting to work out the phylogeny of Geolycosa spiders using DNA analysis.

Narrowmouth toad (Gastrophryne carolinensis), photo by James Layne
top  Walter E. Meshaka, Jr. reported on the status of four projects in progress at the Station. A manuscript, with James Layne (Station Research Biologist Emeritus) and Gerald Johnston (Broward Community College) on the herpetofaunal community in long-unburned (60-years) habitats on Archbold’s Red Hill, approaches completion. Results indicate that a long absence of fire did not adversely affect the species diversity or evenness of the entire herpetological community or a segment (lizards) of that community. A manuscript, with Glen Woolfenden (Station Research Associate), relating weather to reproductive activity in the narrowmouth toad (Gastrophryne carolinensis), is in press (Florida Scientist). Results show that threshold values for rainfall and minimum temperatures predict a geographic trend in reproductive season for this species, whereby breeding season remains generally long in all but the northern edge of its geographic range where breeding is restricted to the mid-summer months. With Layne, Meshaka began a herpetological monograph that analyzes the long-term ecological data on the reptiles and amphibians of the southern end of the Lake Wales Ridge. Meshaka assisted in curating the Station’s collection of fish and herp specimens in preparation for computerizing the catalog data.

Florida scrub-jay (Aphelocoma coerulescens); photo by Reed Bowman

top Ronald Mumme, a regular visitor to Archbold since 1986, continued his research on the behavioral ecology and conservation biology of the Florida scrub-jay. He has primary responsibility for color-banding, censusing, and maintaining records of the scrub-jay population in the "experimental tract" [called the south tract since 2000] on portions of the Station south of the main scrub-jay study area (the "demography tract"). During 1997-98, Mumme's conservation-related research focused on the demographic consequences of roadside mortality, and the viability of translocation as a management technique. A manuscript on the demographic consequences of roadside mortality, co-authored by Stephan Schoech (Indiana Univ.) Glen Woolfenden (Station Research Associate), and John Fitzpatrick (Cornell Univ.), was provisionally accepted by Conservation Biology in November 1998. The translocation research, conducted in collaboration with Theodore Below (National Audubon Soc.) and funded by awards from the Florida Nongame Wildlife Program, was completed in 1998. A manuscript describing its findings is now in press in the Journal of Wildlife Management. In addition, Mumme continues to collaborate with Schoech. During 1998, Schoech and Mumme (along with Ellen Ketterson (Indiana Univ.) investigated the hormonal mechanisms that mediate alloparental (helping) behavior in the jays, work that was funded by a one-year "proof of concept" award from the National Science Foundation.

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Archbold Biological Station, 4 April 2000
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