by Mark E. Hostetler

INTRODUCTION

Ecologists, in general, have conducted very little research in human-impacted areas, and urban landscapes provide a unique opportunity to analyze the ecological effects of "human-induced" disturbances. Urban areas are becoming the dominant landscape in North America and in terms of biological diversity, it is important to understand which animals will be most affected by an urban development. Knowledge gained from urban ecological studies will provide managers and developers alike with the information to design and promote wildlife diversity in urban areas.

In Gainesville, the expansion of urban environments affects a variety of animal species; however, little research to date has specifically studied the impact of development on a broad collection of species associated with areas under construction. Although ecological theory can hypothesize which animals will be adversely affected, actual data is needed to test these theories. The Landings apartment complex provides an excellent opportunity to learn more about how animal communities in Gainesville are influenced by development.

The objective of this study is to estimate the abundance and diversity of animals and plants on the "Landing property" and on the western edge of Bivens Arm Nature Park before the development and to monitor the abundance of animals after the development for a period of 3?5 years. Many different taxa of animals (see list of taxa below) will be monitored, and a vegetation survey will be conducted to study the effects on species of plants bordering the property and those that reside on the property. In cooperation with the developers of the Landing and the Bivens Arm Nature Park management, a team of professors, graduate students, and undergraduate students will conduct the surveys on the property and on the western edge of Bivens Arm Nature Park. Although the thrust of this study is to gather data, this research also provides an opportunity for undergraduates, graduates, and even citizens to get a "hands-on" approach to wildlife and conservation issues. I think this study will benefit the Gainesville community and a whole host of young students that will get a degree from the University of Florida. Below I have listed four goals (and some objectives of each of the goals) for this project.

1. Conservation Ecology: One goal is to learn more about the ecological impacts of development on animal and plant communities. As most of us know, urban sprawl is becoming the dominant landscape feature in the U.S. (especially in Florida).I heard one talk that estimated that when the baby boomers retire, they will have (collectively) over 600 billion dollars to spend on their retirement; most of these baby boomers want to purchase a piece of property in the country (not in dense urban areas) ? thus increasing urban sprawl quite dramatically in the near future.

As mentioned previously, ecologists have conducted very little research in the urban/suburban matrix, and this paucity of knowledge will greatly hurt the goal of preserving biological diversity in North America. Understanding the impact of development on animal and plant communities is important for several reasons; (1) although we know about the importance of large preserves to save a variety of species, the matrix (i.e., residential areas) that surround these reserves is critical in terms of the dispersal of animals from one area to another and also in terms of the direct impact on the reserve itself. Whether animals move through a landscape is contingent on what in the landscape. Thus, urban/suburban areas are becoming a critical feature in terms of promoting healthy "meta-populations.; (2) It is quite possible that many species of plants and animals could actually thrive in urban/suburban areas (given the right management).For example, the pileated woodpecker has been suggested by Robbins et. al. that this woodpecker requires over 3000 hectares of wooded habitat to breed. Well, in Gainesville, I know of pileated woodpeckers that are breeding near my backyard (in plots less than 40 hectares).Thus, something about the Gainesville matrix is promoting the successful breeding of woodpeckers in this area. However, more examples of what species are adversely affected by a particular development is needed (especially for other taxa -- e.g., plants, arthropods, herps, etc.).Pretty soon, the urban/suburban matrix may become a critical habitat in which "pockets" of species breed and the offspring colonize more "pristine" reserves (or even primarily breed in suburban areas).Further, not much has been done on the changes in abiotic factors (e.g., changes in soil temperature) in the urban/suburban matrix, and this is important to recognize as processes that could ultimately define what species occur in an area (both plant and animal).In this study, our objectives are (1) to document exactly which species survive or disappear (or decrease in number) near and on the development site, (2) to document how abiotic factors change on the site and on the western edge of Bivens Arm, and (3) to compare (2?3 years in the future) the species diversity (and abiotic factors) on "The Landing" to the apartment complex just north of Bivens Arm.

2. Community Service: A second goal is to provide a service to citizens in Gainesville (architects, homeowners, developers, politicians, etc.), I think this project will enlighten many people within the community on both ecological and developmental issues (and when published ? for urbanites throughout North America).I have a feeling that this will get some play in the press (both from the developers' side and those people concerned with biological diversity), and this project could be a focus point to discuss many of these issues. Gainesville is growing at an alarming rate, and we need to search for "win" "win" solutions that promote biological diversity while maintaining the need for housing. Thus, another objective is to obtain data that developers and environmentalists alike can use in the Gainesville area.

3. Repertoire with Developers: Another goal is to build bridges with developers. Of course, there is some hostility between ecologists and developers, but we need to develop some common ground in which to exchange ideas, problems, misconceptions, etc. Again, this project could be a long-term focal point that permits this kind of communication. I am already learning much about some constraints developers have when developing a site, and I think the owner of the property (from our brief discussions) is learning a little ecology. Thus, another objective is pure communication and developing ties with the developers in order to test ecological theories, ideas, etc.

4.Educational:Lastly, this project is a good study in which undergraduates and even citizens of Gainesville can get involved and learn about ecological/development issues. It can be a good tool to teach people about science, ecological issues, natural history, and even broader issues such as population growth and land use. Because the site is in town, we strongly encourage anyone to come along and help with this study.

Steering Committee

Birds: Mark Hostetler, Eric Tillman, Scott Duncan
Mammals: Kristi MacDonald, Rafael Samudio, Hugo Ochoa-Acuna,
Herps (Snakes, Frogs, Lizards): Kevin Baldwin, Robin Borghton
Soil Invertebrates: Lloyd Davis
Insect/Arachnids (Spiders): Paula Cushing, Mark Stowe, Lloyd Davis
Plants: Debbie Kennard, Kelley McPherson

PROTOCOL AND METHODOLOGY FOR BIVENS ARM/LANDINGS BIRD SURVEY

Scot Duncan & Mark Hostetler

The following is a description of the protocol developed and used for bird censusing at the Bivens Arm/Landings study area. The protocol was developed by Mark Hostetler and Scot Duncan, and used beginning with the first sample day (7 OCT 95).All future censuses should mimic these procedures and accompanying methodology as much as possible to ensure the comparative value the data.

Success of the Study: It will be crucial to the success of this study that accurate notes are taken on the methodologies employed. If their are any changes to the sampling protocol or methods, they should be described in detail, and it should be clear which sampling times are effected

Assume that you will not be present when the study is concluded. Thus, all data and notes should be unambiguously recorded.(Asking other researchers familiar with the study to read your transcribed notes will help in this.)

Goals of the Bird Surveys: To generate a list of bird species and their relative densities as found in the different locational categories or habitats on the study site. This information will be used to compare bird densities for areas of the property and adjacent marsh before and after construction.

Starting Time: Censuses should start 0?30 min. after sunrise as published in the Gainesville Sun newspaper. Initial starting time should be noted on the census day's summary sheet. Observers should try to complete surveys within three hours of initiating surveying. If there are point counts remaining to be surveyed after this time, go ahead and sample them, their data may be usable.

Number of Primary Observers per Day: The number of primary observers conducting point counts should not exceed two. Prior to beginning sampling, they should coordinate who will survey which point counts. They should meet in the morning prior to sampling, and conduct sampling simultaneously, minimizing transit time between point counts and making sure that observers do not visit or cross through point counts not yet surveyed.

Additional Observers: In order to use this study as a means for undergraduates to gain experience in avian censusing techniques, secondary observers may accompany the primary observer during point count surveys. No more than one additional observer may accompany the primary observer while doing surveys. Both parties should take measures to prevent the secondary observer from biasing the census. This means that the secondary observer cannot point out birds. This includes nonverbal cues such as looking through binoculars or visually scanning and subsequently focusing on birds. The best protocol for the secondary observer will be to mimic the primary observer's movements. This is very important if the results of these surveys are ever to be presented in a scientific forum such as publications. Otherwise these data could be heavily criticized.

Approaching the point count: Observers should approach point count in a quiet manner, minimizing movement and communication. Birds flushed from and leaving the point count circles prior to initiating the survey should be recorded with notes explaining that the bird was flushed.

Traveling between point counts: Travel time and distance should be minimized when traveling between point counts. Although observers should move quietly, this is the ideal time for communication between observers, including doing nonsystematic bird observation. Observers should not cross through unsampled point counts unless they are going to sample the point count immediately. Birds noted in transit between point counts should be listed and noted appropriately. Be sure to note in what land/habitat category of the bird was observed.

Initiating the point count: Upon reaching the observation point of the survey area, the observer should wait one minute before starting the survey. This time can be used to locate birds a priori; this should not bias the results if it is consistently done. This is also a good time for arranging the data sheets and writing starting time and point count number.

Clothing color: Clothes worn should be drab and non colorful. Bright colors may attract curious birds, or warn others away.

Interlopers: When the observer is approached by a non-participant during the course of sampling, the point count survey should be fully terminated until the observer is once again left alone. this may mean coming back later during the sampling morning.

Safety: Observers should avoid visiting the study site alone. This should not impose biases on the point count surveys as the participation of additional observers is incorporated into the protocol.

SAMPLING:

Sample Period Duration: Censuses will start within a 1/2 hour of sunrise and end no later than three hours after sunrise. No censuses will be conducted during a rainstorm or otherwise windy conditions. Sampling for each point count will be done within a consecutive 10 minute period. There can be no temporal interruptions during the survey (e.g. pausing your stopwatch to tie your shoe).A bird being observed but not yet identified when the 10 min. are over can continue to be observed for identification, however, the observer cannot move from the observation point during this time. This pertains only to individual birds under direct observation at the exact end of the sample period. If the observer is aware of other birds not yet noted, too bad.

Study area: The study area is the projected construction site for the Landings Apartments and the nearby marsh. Point counts were set up in areas projected to be open spaces after construction. Areas of the point counts will later be under a variety of habitat regimes "including parking areas, lawns, retention pond, and planted native vegetation. Areas that will be vegetated after construction are: parking islands, green spaces, borders of the property, and the buffer zone bordering Bivens arm nature park. As these latter locations will be distinct habitats post construction, we want to compare what is found in them , specifically, before and after construction. Thus during point counts conducted before construction it is important to note if birds observed are in such areas as best can be predicted by the information available. When birds are observed in such areas they should be noted: here are the codes used. Buffer Zone BZ, Core Forest CF, Border BD.

Location and Size of Point Counts: A total of thirteen sites were censused. See map to get exact locations. All point counts had a radius of 100 ft.; thus all birds heard or seen within a 100 ft. from an observer were noted.

Detection Mode: The mode of detection and/or identification is noted: V visual, A audible. Some birds will be both seen and heard; when this is the case it is best if both A and V are listed. This is especially important when the song, or calls are diagnostic of the species: e.g. crows.

Some birds will be observed flying over the point count. These are also listed: Fly over, visual=FOV;Flyover, audible=FOA. If, however they are flying at or below the canopy level, they are listed as A or V depending on the detection mode. We also noted those birds, which have loud calls (e.g., red-shouldered hawk or pileated woodpecker), that were heard during our ten minute count but were over 100 feet away.

Unidentified Birds: Are listed as such with the closest taxonomic affiliation that can be determined, e.g., Unidentified Warbler or in some cases, Unidentified Bird. During the point count sample, try to avoid duplicative listings for unidentified birds. This is helped by noting (mentally or otherwise) at time of observation anything you can about the bird: size, direction last seen, any behaviors, etc. Thus, when confronted with several unidentified birds during a sample period, you can justifiably include or exclude them based on ruling out the possibility of seeing any one of them twice, OR confusing them with any of the identified birds observed. Also, if you record an unidentified warbler, but also saw a black-and-white warbler, notes on general coloration or behavior of the unidentified bird can justify inclusion of it.

Estimating Abundance: When multiple sightings of a species occur within a point count survey, only include multiple entries for a species if you are reasonably certain they are different individuals. For example: if you hear a titmouse to the west, and several minutes later see one to the east, then there is the possibility it is the same bird. However, if the species is a house wren that is unlikely to travels such distances in that amount of time, then they are probably different birds. When listing multiple entries or numbers for a species, make a note that they are considered different birds. That way future interpreters of your notes will not doubt that you have taken this into consideration.

When large flocks of birds are present (e.g. robins, yellow-rumped warblers), estimates will have to suffice. Be sure to note that they are estimates. For the circles that are subdivided into categories (BZ,CF,BD), perhaps the best way to take notes is to estimate total number of birds in the circle, and then estimate the ratio or percentage that utilized, for example, CF, BZ, and the number that visited both.In this case the sum of the percentages would not = 100.From these percentage estimates, we can later calculate density of the birds utilizing each category.

Field Data Transcription: Unless you are a fastidious note taker and/or have a superlative memory, it is best to write up the results of you surveys very soon after sampling. This ensures you will be able to supply information that was not noted during the sampling (e.g. you forgot to note by which detection mode you saw a bird, etc.).It also ensures that you will be able to read you own field notes!

Remember that you may be taking and transcribing notes that other students will be relying on in your absence. Include any and all information that may help later researchers know what you observed.

Avoiding Artificial Densities: We have decided to not use "spishing", "squeaking", owl calls, or any other methods that encourage birds to show themselves or investigate the observer. This would result in artificial densities of birds, and would lose comparative value.

Incidental Observations: Whether traveling between point counts or visiting the study site for any reason, keeping notes on birds observed and their location (BZ, CF, BD, Marsh, etc.) will be very helpful. These may be the only instances when rare or cryptic species are noted. Or they may be the only times birds are noted in a particular location category. These observations will contribute to a total list of species observed on the site, which will undoubtedly represent total diversity better than a cumulative list from the point count surveys.

Categorical Divisions of Point Count Circles: Birds are noted as being in areas expected to be distinct "habitats" after construction. These are as follows: BD=border, the developer will leave a border around the property that will be approx. 20 feet wide. this border will be vegetated. CFis forest now (core forest) and is in the heard of the property, not any border. BZ is the buffer zone bordering the marsh. Tree islands and etc. to be left in the property are too difficult to guess where that will be.

Marsh Sampling: In addition to sampling the forest, we want to observe effects on the marsh bird community. Marsh is designated, by our definition, to begin where the continuous forest canopy drops down to a low canopy originating from the wet soils bordering the marsh. Brush bordering the forest that is not true marsh is counted as marsh. The tree canopy profile is the dividing point.

Note: Although we did not sample all of the seasons, future studies in the Gainesville area should census birds during the following dates. Diurnal bird species should be censused twice a week (or once - see how it goes) for a three week period in the Fall (Sept.29 - Oct. 21), Summer (May 26 - June 16), Spring (April 1 - April 22), and Winter (Jan. 14 - Feb. 4).During the breeding season, the number of singing males will be doubled to account for females on their territories (except for some species that have multiple females on territory). 

Bivens Arm Project: Monitoring Changes in the Plant Community
Debbie Kennnard and Kelly McPherson

Plant Species List

Plant species lists will be compiled pre-development and post-development. The pre-development survey will be conducted in October. Post-development surveys will be conducted in April and October during the 2nd and 5th year following development. The survey area will be divided into manageable units and assigned to flora survey teams. All plant species occurring in the units will be recorded. Samples of unknown species will be collected for identification. Abundance of species will be discussed by teams immediately after the survey and ranked on a scale of 1 to 4 scale [1=extremely rare (1?5 individuals observed), 2=uncommon (5 to 20 individuals), 3=common (20 to 100), 4=abundant (>100)].
Vegetation Structure
Vegetation structure will be characterized pre- and post-development by measuring the density of herbs, shrubs, vines, tree seedlings, tree saplings, and overstory trees. Two transects in the upland area and one transect in the wetland area will be established pre-development. One upland transect will extend northeast from the property edge adjacent to the highway to the 100 year floodplain (starting from utility pole #33691 on 441, 55 degrees).The second upland transect will extend northeast from the parking lot behind IHOP to the 100 year floodplain (location marked on map, also at 55 degrees).The wetland transect will run the length of the property along the marsh's edge in the 100 year floodplain (bearing will vary with the shoreline).
Along each transect, 20 m long nested plots will be randomly located with at least 10 meters between plots. Each nested plot will consist of a 9 x 20 m plot, a 1 x 20 m plot, and a 1 x 1 plot located in the center of the 20 meters (see attached diagram).In the 9 x 20 m plot all trees > 10 cm DBH (diameter at 1.3 meters) will be identified, recorded, and grouped into one of two size classes (10?30 cm DBH or > 30 cm DBH).In the 1 x 20 m plot all trees < 10 cm DBH and > 1 m height will be identified and recorded. In the 1 x 1 m plot all tree seedlings, saplings, shrubs, vines, and herbs will be identified and grouped into categories of percent cover (<20%, 20?40%, 40?60%, 60?80%, 80?100%).The position of vines will also be noted as predominately on the ground, in the shrub layer, or extending to the canopy.
Surveys of vegetation structure post-development will follow the above guidelines using the same transects as above. Additional transects may need to be established along the property edges where vegetation was spared.

Edge Survey for Exotic Plant Species
Two belt transects will be placed along property edges (in phase 2 and in the 100 ft flood plain).All exotic species in the transect will be counted and recorded. One to several control transects will be placed in an similar area that will not be developed, such as Bivens arm park.
Post Development Tree Mortality Survey
Trees left standing on the development site may be damaged during construction and die as a result. We will monitor trees after development to detect increased incidence of damage and mortality associated with development activities and post development conditions. Nested plots will be randomly placed in islands, edges, and other areas where trees were spared. The number and overall size of plots will be determined later, but the sum of their areas should equal approximately 25% of the remaining vegetation. The largest plot will include all trees >10 cm DBH and the smaller plot will include trees <10 cm DBH. Surveyed trees will be tagged and their overall health and any signs of damage will be recorded. A form will be devised to standardize the damage assessments. Damage categories will include crown damage, trunk damage, and root damage. Intensity of damage will be recorded in 5 classes, with 1 representing minor damage and 5 representing severe damage. Pre-existing decay will also be noted when present. An attempt will be made to distinguish between damage incurred during construction and damage present before the development began. Plots will be recensused once a year and trees observed for new signs of damage, increased decay, or mortality. A similar study will be carried out in Biven's Arm Nature Park for purposes of comparison.
Edge Effect Studies
"Edges" usually are areas adjacent to a vegetation clearing or opening where environmental conditions are altered. Even though the edges themselves are not disturbed, the influence of the adjacent disturbance on microsite and habitat conditions can lead to changes in numbers and species composition of plants and animals in the edge area.
Our objective will be to quantify the extent of edge area resulting from the construction of The Landing. Since we define the edge as the area where environmental conditions have changed as a result of construction, we will quantify environmental conditions before and after construction. We will quantify relative air temperature, relative humidity, forest canopy openness, soil density, soil moisture, litter (e.g., dead leaves, decomposed organic matter) depth, and densities of several small-statured plant species.

After construction we will quantify environmental conditions in both the [Phase I] and [Phase II] areas via several transects located in a stratified random manner. All environmental variables will be quantified in each of six to eight plots within each transect. Air temperature and relative humidity will be measured 1 m above the ground with a thermometer and sling psychrometer. Canopy openness will be estimated using a spherical densiometer held 1 m above the ground. Soil density will be quantified on a dry weight per volume basis (bulk density), and soil moisture will be quantified gravimetrically. Densities of several target plant species will be estimated by counting plants present within an area centered on each transect, up to 1 m on either side of the transect.
Data collection after construction will begin during the first fall after vegetation clearing is completed, and will occur annually during the fall for approximately five years following vegetation clearing. We will quantify these variables within transects oriented parallel to the [Phase I ? Phase II] boundary and located at increasing distances from the boundary. We will use the results to identify edges as the area (expected to be relatively close to the construction boundary) where environmental conditions and plant species densities differ.

ANT CENSUS FOR THE BIVENS ARM RESEARCH PROJECT
Lloyd Davis
Ants were sampled with pitfall traps placed at approximately 10 meter intervals around the perimeter of the Landings development site. Each trap consisted of a 5 oz (148 ml) plastic cup placed into the soil so that the upper lip was flush with surrounding soil surface. Each cup was placed in position with a second cup inside to keep soil from the excavation entering the sample. The inner cup was then removed and a mixture of propylene glycol and isopropanol were added to the cups as a preservative and killing solution. This mixture of fluids was made in a 1600 ml container by adding 3 bottles of 473 ml of isopropanol and bringing the total volume to 1600 ml with propylene glycol. It took 3 of these 1600 ml containers to set out the total of 88 traps.
The distance between traps was paced off rather than measured with a tape. This resulted in some inaccuracy in trap placement, as I had estimated that I would use about 14 more traps than I actually did. After setting the pitfalls, they were left for 48 hours and then the fluid in the traps was poured into numbered whirl-pak bags. The contents of the bags were poured through a fine brass screen (fluid kept for re-use) and the sample rinsed with tap water while on the screen and then sorted under a binocular microscope. The specimens were placed in glass vials of 70% isopropanol until they could be identified and counted. Each sample was sorted to two or three vials. One vial contained all the ants, the other contained all other taxa unless too large. The large specimens were kept in the third vial.

BIVEN'S ARM DEVELOPMENT ("The Landing") PROJECT:
ARTHROPOD SAMPLING PROTOCOL

Paula Cushing

I. OBJECTIVES

A. To track changes in biodiversity of arthropod fauna

1. before development
2. immediately following development
3. after the area has had time to reach some stable equilibrium

B. To compare the biodiversity of "The Landing" (after equilibrium) where the landscape architect agreed to use low impact landscaping techniques with "Oak Forest" development where no such attempt was made.

II. SAMPLING SITES

A. Island A: entrance island
B. Island B: first island just east of entrance island. This island is oriented north-south and is approximately 80 ft long.
C. Island C: large interior island between buildings B & C (on the map). It is the largest interior island.
D. Courtyard A: courtyard bounded by two wings of building A.
E. Buffer A: buffer area directly north of the entrance, bordering 441.
F. Buffer C (note Buffer B was on other side of entrance & was omitted from sampling): this area borders the Chiropractor/IHOP parking lot (east of the parking lot).
G. Buffer D: marshy border near the lake; this is the northwest part of this  long buffer area.
H. Buffer E: marshy border near the lake; this is the southeast part of this long buffer area.
I. Buffer F: buffer area east of building A
J. Buffer G: southern buffer area

III. SAMPLING PROTOCOL

A. Ideally, sampling should be done both during the day and at night. If this is not feasible which it probably won't be), then samples should be collected at approximately the same time (e.g., between 12:00 -16:00) and during the same season (Fall).

B. Soil Arthropod Collection: each person assigned to a site (A through J above) should sift through at least one 1 X 1m square area of litter, collecting all arthropods encountered (except for the smallest soil arthropods such as mites and collembolans).If the microhabitats within each site vary, then representative 1 X 1msquare areas should be sampled in each distinct microhabitat.

C. Timed Look and Grab

1. Each person at each site should also search for arthropods by eye for a total of two hours. These visual searches must include beating the branches and the shrubs to knock arthropods from their hiding places (this is a very effective technique).

2. Individual searchers should look under bark, under logs, beneath stones, under leaves, on top of surfaces, etc., etc. Look and Grab searches should be as complete as possible and incorporate any areas above the soil. Use killing jars to collect arthropods (or put them directly into ethanol).

3. Night Collection: at least one night collection should be conducted at the border adjacent to 441 (Buffer A and defunct Buffer B).Use a headlight to spot the eyeshine of the wolf spiders and use the beating technique to find other night-active arthropods.

IV. DATA COLLECTION AND ANALYSIS

A. Preserve all arthropods in 70 - 75% ethanol labeled with the date, the site, the search technique (Timed Search or Soil Sample), and the collector's full name. Samples should be kept in plastic or glass jars or vials until they are sorted. It is probably best to keep all samples until the end of the study, although it may be sufficient to keep only representatives of the different arthropods found that year.

B. The arthropod team as a whole will be responsible for sorting samples and identifying arthropods at the very least to Order – ideally down to Family. Spiders and Ants (see Methods Addendum for Pitfall trapping of ants) should be identified to species if possible – these taxa will be the focal taxa for documenting biodiversity changes.

C. Each year of the study, the arthropod team should be responsible for writing a report (in standard scientific format) summarizing the results for that year. This report will be used by the next year's team for further comparison of changes in biodiversity over time. Raw data should be collected by the instructor and copies also passed on to the next year's team.

D. If this is offered for course-credit, then the course should be offered the same semester each year and collections made at the beginning of the semester so the remainder of the semester can be spent sorting samples, analyzing results and writing the report.

E. The final year of the study, there will be two arthropod teams – one for "The Landing" and the other for "Oak Forest" development.

F. The two teams during the final year will be responsible for summarizing the patterns evident over the entire course of the study.

G. Data collection throughout should concentrate on changes in biodiversity rather than changes in abundance.

Method to Estimate Bat Diversity and Relative Abundance

Rafael Samudio, Jr. and Kristi MacDonald*

Department of Zoology, Department of Wildlife Ecology and Conservation*, University of Florida

The most commonly used method for capturing flying bats is with mist nets. Some of the advantages of using mist nets to capture bats are that they are inexpensive, lightweight, compact, and easily transported and erected in the field. The most successful sites to set mist nets are near roosts, at water holes, across trails that are used as flyways, and at openings to buildings. Other methods that can be used are visual counts of foraging bats and ultrasonic detectors for indirect population density and relative abundance estimates, respectively. In North Central Florida the species of bats belong to the two families: Vespertilionidae with the genera Myotis, Eptesicus, Nycticeius, Lasiurus, and Pipistrellus and Molossidae with the genus Tadarida.

Materials:

• 3 mist nets
• 3 headlamps
• 2 flashlights
• 3 pairs of leather gloves
• 6 cloth holding bags
• 2 forceps

Method:

Three mist nets were set at ground level (3 m) across possible bats flyways on 19 October, 1995.One mist net was set in the ecotone between the marsh and the woodland, a second net was set in the middle of the woodland habitat, and the third mist net was set along the woodland edge in the west side, parallel to the parking lot in front of the chiropractor's office. Mist nets were open from sunset (18:00) to after four hours later (22:00).Nets were checked one every hour. When a bat is captured, it will be placed in an individual cloth bag. If possible, captured bats will be marked and released. For each bat captured the following data should be recorded: species, hour and location of capture, sex, age class, body mass, and forearm length.

Results and Discussion:

We were not able to catch any bat during that night. We can not repeat another netting night because of the climatic conditions and time constrain .But we observed bats foraging outside the forested area at the street lights. Possible reason(s) for the unsuccessful night capture can be that bats when leaving their roosts fly above and/or at the canopy level, because the canopy is not very closed. We recommend for the next study period to set mist nets also at the canopy level (>10 m) and/or conduct visual observations of bats foraging at street lights. All species of bats reported for Gainesville are insectivorous: Myotis austroriparius, Eptesicus fuscus, Nycticeius humeralis, Lasiurus borealis, L. cinereus, L. intermedius, L. seminolus, Pipistrelus subflavus, and Tadarida brasiliensis. Sometimes insectivorous bats can deal very well in habitats in which you find buildings near wild lands. We have the opinion that the bats in this area probably roost in the forested lands around the developing site. Consequently bats seem to be a group of mammals that will not suffer a strong negative impact due to the apartments development. On the other hand bats can take advantage of the building roofs as roosting sites mainly during the winter, due to the low ambient temperatures. This situation can lead to a conflict in which it will be faced the people health against the bats preservation.

Suggested References:

Bonaccorso, F.J. and N. Smythe.1972.Punch marking bats: an alternative to banding.J. Mammal., 53: 389-390.

Kunz, T.H.1988.Ecological and Behavioral Methods for the Study of Bats.Smithsonian Institution Press, Washington, D.C.

Kurta, A. and J.A. Teramino.1992.Bat community structure in an urban park.Ecography, 15: 257-261.

McNab, B.K.1974.The behavior of temperate cave bats in a subtropical environment.Ecology, 55: 943-958

Determining the Relative Abundance of Mammals Using Scent Stations

Kristi MacDonald , Rafael Samudio , Hugo Ochoa-Acuna

Introduction:

Scent-station transects are a common method used to determine the relative abundance of mammalian carnivores and some herbivores (i.e. rabbits).In this region, scent-stations should be useful for obtaining relative abundance data on bobcats (Lynx rufus), coyotes (Canis latrans), grey foxes (Urocyon cinereoargenteus), opossums (Didelphis marsupialis), raccoons (Procyon lotor), striped skunks (Mephitis mephitis), and domestic cats, and dogs.

Materials:

• 5 (70 lb.) bags moist sifted sand
• measuring tape
• scent*
• cottonballs (one for each station)
• Plaster of Paris
• Bucket for mixing plaster
• 1 gallon jug of water
• Track guide

* The most successful scent (i.e. attracted the most animals) was concentrated tuna juice from canned tuna cat food diluted with about 50 mls of water. Use the cheapest no-name brand because it seems to have the strongest scent.

Methods:

Three permanent 20 meter scent station transects were established. Each transect consisted of 3 stations spaced 10 meters apart. The location for each transect was chosen to represent one of the 3 ecotone types of interest: (e.g.) lowland hammock (present)/apartment complex (future), marsh, and buffer zone. Transect 1 was located along the woodland edge in an west to southeast line parallel to the lot behind the chiropractor’s office. Transect 2 was located 30 meters south of transect 1 running north to south. This transect represents interior woodland. Transect 3 was along the marsh edge running northeast to southwest and represents the proposed buffer zone to the marsh. Transects one and three lie in areas which should have remaining trees after site development and, therefore, sampling can be repeated there in 1996.The location of transect 2 will make it difficult to repeat sampling there in 1996.

Stations were prepared in late afternoon and checked the following morning. Each one meter diameter station consisted of a circle of moist sifted sand (1 cm deep).In order to insure the highest quality tracks, the smoothed over sand was often moistened by spraying a fine mist of water over the surface. A cotton ball saturated with scent was then placed at the center.

When the stations were checked the following morning, types and numbers of animal tracks were recorded and plaster casts taken for tracks which could not be identified in the field. This procedure was done 3 times between 28 October and 2 December so the total number of transect nights is 9.In addition, a trial run was conducted using two of the woodland interior stations on 8 October. The results from this can be incorporated into the final analysis.

A visit is defined as > one track of a species/station. Visitation rates will be expressed as the % of stations visited by a species/transect night. Since we did not have the funds to replicate transects in each of the three habitat types, it may not be possible to compare results between ecotones. However, the consolidation of the results from all of the transects can be used to compare species composition at the site between years.

Suggested references:

Conner, M.C., R.F. Labisky, and D.R. Progulske, Jr. 1983. Scent-station indices as measures of population abundance for bobcats, raccoons, gray foxes, and opossums. Wildl. Soc. Bull. 11:146-151.

Halfpenny, J. and E.A. Biesiot. 1986. A Field Guide to Mammal Tracking in North America. Johnson Books, Boulder.

Murie, O.J. 1954. Peterson Field Guide Series: A Field Guide to Animal Tracks. Houghton Mifflin Company, Boston.

Bivens Arm Survey: Amphibians and Reptiles, Fall 1995

Robin Boughton and Kevin S. Baldwin

The objective of this survey was to compile as complete a species list as possible given the limitations of sampling during a single post-breeding season. Given the wide variation in habits of these taxa, several survey techniques were used: aural survey, coverboards, and intensive searching; each described below.

Aural survey consisted of listening at the site during intensive sampling periods. Cover boards were pieces of plywood or roofing metal elevated on sticks or stones to provide moist, shady refugia for various species. Intensive sampling consisted of methodical walking through the area while searching in logs, debris, rocks, leaf litter, and in tree crotches, foliage and trunks. The water’s edge was walked to flush out aquatic species. Low-lying wet areas were surveyed for tadpoles. The following species were found using these various methods:

Amphibians
Hyla cinerea
Hyla squirella
Rana utricularia
Gastrophryne carolinensis
Eleutherodactylus planirostris

Reptiles
Terrapene carolina
Scincella lateralis
Eumeces inexpectatus &/or E. laticeps
Anolis carolinensis
Ophisaurus spp.
Thamnophis sauritus
Opheodrys aestivus

This list indicates a depauperate herpetofauna, which may be in part due to beginning the survey long into the post-breeding season (i.e. October). Thus, this list could easily be an underestimate of the true diversity of the site prior to construction.

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