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Other Projects |
Modeling
the recovery rates of avian populations (completed)
Ecology
and management of feral hogs on Fort Benning, Georgia (completed)
Abundance and habitat use of King Rails
in Eufaula National Wildlife Refuge (completed)
Population status and host plant
population status of the Gulf Coast solitary bee, Hesperapis oraria
Carbon Sequestration and natural longleaf
pine ecosystems
Renesting,
nest depredation, and gosling survival of dusky
Funding
Source:
Principal
Investigator: Barry Grand, Mike Anthony
(USGS), Tom Fondell (USGS)
Duration: January 1997 – December 2004
The
Copper River Delta, Alaska (CRD) contains the largest known concentration of breeding
dusky
Status – Field studies examining the variation in productivity across the Delta
were completed in 2003. Two manuscripts
detailing the variability in nest success, renesting
effort, and variation in clutch size are in
press.
Funding source (s): USDA Forest Service
Principal Investigator (s): Barry Grand
Student (s): David Miller
Duration: August 2001 – August 2004
The decline in dusky Canada goose numbers on the Copper River Delta, Alaska (CRD) coincided with declines in nest success. Apparent nest success for duskies in the CRD was estimated at 88% by Hansen (1961), but had fallen to 43% in the early 1980s and below 10% in the late 1980s. More recent (1997-2000) estimates suggest that nest success in the Alaganik Slough study area varied from 27-35%. These apparent changes in the relative importance of nest predators were correlated with rapid successional changes in the vegetation community subsequent to the 2-3m uplift of the region during the 1964 earthquake. The goal of this project was to examine spatial and temporal variation in productivity of duskies across habitats. The objectives were (1) to identify patterns in spatial and temporal variation in nest success that are related to the abundance and distribution of bald eagles, physical features of the landscape, and vegetative cover types; and (2) to provide a cross-walk to the US Forest Service habitat classification and projection model for habitats on the CRD that could be used to project density and productivity changes in dusky populations.
Status – This project was completed in May 2004 and resulted in one M.S. thesis and several manuscripts for publication. In this work we were able to compare alternative mechanistic models of survival that directly related mortality to predator-prey processes. First, we developed estimating models by extending the maximum likelihood estimator for nest survival to incorporate non-linear relationships. Our results support a threespecies interaction, between eagles, goose nests, and eulachon presence determining intra-annual temporal variation in nest survival. When eulachon, an alternative prey for eagles, was present, results supported prey switching by eagles, leading to high nest survival rates for geese. When alternative prey was not available, eagle abundance at study sites largely determined nest survival. The number of nests consumed per eagle was related to the abundance of both eagles and nests. Second, we examined the relationship of predation probability to vegetation near nests and measures of intra- and inter-species interaction. Nest survival was higher during the early season, when predation by eagles was highest, at nest sites on islands and in tall shrub communities. Nest survival also increased as the density of nesting geese increased. Female survival increased as the proportion of low density shrub vegetation increased within 50 m of nests. Results indicate that the ability of geese to detect predators and thus defend nest sites and themselves may be more important than choosing nest sites that limit detection by predators. Future changes in vegetation on the Copper River Delta may further limit nest success for the population.
Funding
Source:
Principal
Investigator: Barry Grand
Post-doctoral
Researchers: Jennifer Arnold, David Koons
Research
Assistants: Nitin
Yogi, William Trimble, Jeff Baker, Shaun Tanger,
Danielle Warren, Carrie Johnson
Duration: April 2001- March 2006
At
least 29 species of birds are known to use the near shore waters of the
Status – This project has been
completed and the final report has been reviewed by USGS and Minerals
Management Service. The software tool
and the Access database were reviewed and finalized. Manuscripts describing the effect of
catastrophic perturbation on short term population dynamics, the momentum of
populations across vertebrate life histories, and the use of momentum in making
population management decisions have been published in Ecological Applications,
Ecological Modeling, and the Journal of Wildlife Management. Additional publications describing the
sensitivity of momentum and an innovative method for predicting the sensitivity
of animal populations to perturbation or management actions is in preparation. The final report is in preparation for
publication as a monograph. A workshop
describing the modeling tool and database was presented at the North American
Duck Symposium in
Funding
Source:
Principal
Investigator: Stephen S. Ditchkoff (
Students: Laura Hanson, Buck Jolley,
Bill Sparklin
Duration: September 2003 – May 2007
Self-sustaining
populations of feral swine have inhabited
The
goal of this project is to investigate the efficacy of removal for reducing the
impact of feral hogs on threatened populations and sensitive habitats on the
Status – We captured and
marked approximately 300 feral hogs to facilitate mark-recapture efforts. These data indicate that feral hog
populations are likely more sensitive to juvenile recruitment and survival than
adult survival, where effort is normally targeted. We affixed GPS collars to approximately 35
female hogs, and examined aspects of their spatial ecology. These data indicate that female-juvenile
sounders on the study area exhibit spatial patterns that are strikingly similar
to species that are territorial, suggesting that traditional control efforts
(shooting and trapping individuals) may not be the most effective
approach. We also collected food habits
data from over 200 individuals, and documented that feral pigs consume
significant numbers of herpetofauna, and possess the
potential to impact sensitive species.
M.S.
Theses have been completed by Laura Hanson (2006) and Buck Jolley
(2007). Bill Sparklin
will complete his thesis during fall 2007.
Funding
Source:
Principal
Investigator: Gary R. Hepp (
Student: Shannon Allen
Duration: August 2003 – August 2006
Eufaula
National Wildlife Refuge (ENWR; 4526 ha) is located on the northern segment of
Status – In moist-soil managed
wetlands, we tested effects of application rate (high, medium and low) and
timing (April and July) of triclopyr amine and imazapyr on controlling alligator weed and restoring native
plants. In the year of treatment, imazapyr controlled alligator weed better than triclopyr amine when applied in April, but both herbicides
applied in July were equally effective at controlling alligator weed. High application rate of herbicides in April
controlled alligator weed better than the low application rate, but application
rates of herbicides in July did not differ.
In the year of treatment, application of triclopyr
amine resulted in greater native plant biomass than imazapyr. High application rate of herbicides in April
resulted in greater native plant biomass in the year of treatment than low
application rate, but native plant biomass did not differ between application
rates in July. One year after treatment,
high application rate of herbicides resulted in less alligator weed than low
application rate, and July application of either herbicide generally controlled
alligator weed better than the April application. Application of imazapyr
in July resulted in greater biomass of native plants one year after treatment
than either imazapyr or triclopyr
amine applied in April. This study
demonstrates that single herbicide applications can be effective at controlling
alligator weed and restoring native plants to managed wetlands.
Results
were published in the journal Wetlands.
Funding
Source:
Principal
Investigator: Gary Hepp
(
Student: Evan Wheeler
Duration: March 2006 – September 2006
Wetland
losses have affected many bird species that depend on these habitats. Population levels of several species of marsh
birds, including rails and bitterns, for example, appear to be declining. However, little is known about the ecological
requirements of these secretive birds, and monitoring programs to determine
their continental status are currently lacking.
Many of these marsh birds are listed by the U.S. Fish and Wildlife
Service as Birds of Management Concern (BMC).
In fiscal year 2005-2006, the king rail (Rallus elegans) was placed on the focal species
list, identifying this as a species in need of immediate attention by the
conservation community. In this study, we initiated a survey to determine
examine the status of king rail, black rail (Laterallus jamaicensis), least bittern (Ixobrychus exilis), and
common moorhen (Gallinula chloropus) at
Eufaula National Wildlife Refuge, and describe habitats used by these marsh
birds.
Status - Survey points (n= 37)
were established in the Bradley, Houston, and Kennedy Units of Eufaula National
Wildlife Refuge. We conducted two
complete surveys in each of three months (April, May and June) in 2006. Marsh bird sampling protocols established by Courtney
Conway (USGS, Arizona Coop. Fish and Wildlife Research Unit) were used for the
surveys. Morning surveys were conducted
and began 30 min before sunrise and continued for approximately 3 hr. At each
survey point, sampling began with a 5 min passive period followed by a 30 sec
period in which calls of each species were broadcast. Call-broadcast surveys have been shown to
increase detectability of individual marsh bird
species. Each individual observed or
heard during the survey period and estimated distance to the
individual from the survey point were recorded.
Black
rails and least bitterns were not recorded during the survey period. Thirty-nine king rails were observed or heard
during the surveys. Only 10% (n = 4) of king rails were detected
during the passive portion of the survey.
Seventy-five common moorhens were observed or heard during the surveys,
and 29% (n = 22) were detected during
the passive portion of the survey.
Incorporating broadcast calls to the survey substantially increased
detection of these secretive marsh birds.
Data analysis will continue, and the relationships between vegetation
and water depth parameters will be determined.
A
final report was submitted to the U.S. Fish and Wildlife Service.
Funding
Source: U. S. Fish and Wildlife Service
Principal
Investigator: George Folkerts
(
Research
Assistant: Katie Glynn
Duration: March 2006 – March 2007
Hesperapis oraria was described in 1996
(Cane et al. 1996) from specimens ranging from Horn Island off the coast in
Jackson County, Mississippi, eastward to St. Andrews State Park in Bay County,
Florida. This species is the only
representative of its genus east of the Mississippi River and thus represents a
unique geographical disjunct from other species which
inhabit the western
Status – Visits to sites where the bee has been found or could
be present were made August 18, 2007 – October 26, 2007. Because a few bees were seen on October 26, a
final visit was made on November 3, 2007.
No bees were seen on that visit. As
far as is presently known, the only pollen host of Hesperapis oraria is the asteraceous
plant Balduina angustifolia. Pollen loads examined from two bees captured
on October 6, 2007 revealed only pollen from the known host plant. During the 2007 active season of the bee, the
pollen host was far more abundant at all sites visited than it was during the
2006 season.
Funding
Source:
Principal
Investigator: John Kush
(
Graduate
Student(s): Ram Thapa,
John Gilbert, William Whitaker
Student
Technicians: Anshu
Shrestha, Arpi Shrstha
Duration: July 2003 – September 2008
Forested
ecosystems have a significant potential for sequestering large amounts of
carbon through land management. To fully
realize the potential carbon sequestration capabilities of these ecosystems
there is a need to develop strategies and methods for increasing carbon
sequestration. A fire-maintained,
longleaf pine dominated ecosystem may offer one of the best options for carbon
sequestration among the forested ecosystems of the southeastern US while
providing habitat for a number of threatened and endangered plant and wildlife
species, including red-cockaded woodpeckers, gopher tortoises, indigo snakes,
etc … (Hardin and White 1989, Landers et al. 1995, Jackson 1989). Among the southern pines, longleaf may offer
the best opportunity for carbon sequestration.
It is the longest-living of the southern pines, capable of growing to
500 years (Platt et al. 1988). It will
continue to put on growth, even at older ages (West et al. 1993).
Products from longleaf pine will sequester carbon longer than most since
they are likely to be solid wood products like structural lumber and
poles. In addition to the tree itself, a
fire-maintained longleaf pine ecosystem supports a productive understory of grasses and herbaceous plants which
themselves may offer more carbon storage than the trees. Objectives of the study are: Phase I –
Develop a detailed literature review/bibliography of research literature
related to longleaf pine, above and below ground biomass, and carbon
sequestration; Phase II – Determine the relationships between prescribe fire
treatment and above/below ground biomass and carbon sequestration; Phase III –
Determine the relationships between root biomass/carbon sequestration and the
density, site quality, and age of the longleaf pine overstory.
Status – The season of burn study plots on the
Funding
Source:
Principal
Investigator: John Kush
(
Graduate
Student: John Gilbert
Student
Technicians: Anshu
Shrestha, Arpi Shrestha
Duration: September 2004 – December 2006
Mountain
longleaf pine (Pinus palustris
Mill.) forests are a critically endangered component of the once vast longleaf
pine forests of the Southeast.
Stretching from coastal
Most
longleaf pine forests on the refuge are adversely impacted by hardwood
encroachment resulting from lack of fire.
While the reintroduction of prescribed fire will benefit these forests,
many areas have evolved beyond the point in which fire alone can restore the
forest. These lands require
hardwood/mid-story control along with fire.
By implementing a monitoring program in various forest types the overall
effects of this remediation approach can be measured. It also may be possible to recommend slight
modifications to the current methodology that would improve and add benefits to
future forest structure.
Status – The sample of UXO plots on the MLNWR on what are considered longleaf
pine sites, southerly aspects, indicates that there is a considerable amount of
longleaf pine in the overstory. There were very few longleaf pine seedlings
observed on the UXO plots. The major
concern for the MLNWR should be the lack of longleaf pine regeneration. The minimal basal area of longleaf pine for
natural regeneration is 30 square feet/acre.
Less than one-half of the UXO plots have an adequate stocking of
longleaf pine to accomplish that. The further loss of longleaf pine in the overstory across MLNWR would make natural regeneration of
longleaf pine impossible at the stand level.
The only way to get regeneration would be artificial regeneration. Based on the work being done with UXO, it
does not seem plausible to plant longleaf pine on the Refuge.