Louisiana State University LSU Digital Commons
LSU Historical Dissertations and Theses Graduate School
Spring 3-30-1999 Diets of White-Tailed Deer at Avery Island, Louisiana Nathan D. Rains
Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Part of the Life Sciences Commons DIETS OF WHITE-TAILED DEER AT AVERY ISLAND, LOUISIANA
A Thesis
Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Master of Science
in
The School o f Forestry, Wildlife, and Fisheries
by Nathan D Rains B.S., Texas A&M University, 1994 May 1999 MANUSCRIPT THESES
Unpublished theses submitted for the Master's and Doctor’s
Degrees and deposited in the Louisiana State University Libraries are available for inspection. Use of any thesis is limited by the rights of the author. Bibliographical references may be noted, but passages may not be copied unless the author has given permission.
Credit must be given in subsequent written or published work.
A library which borrows this thesis for use by its clientele is expected to make sure that the borrower is aware of the above restrictions.
LOUISIANA STATE UNIVERSITY LIBRARIES ACKNOWLEDGMENTS
I thank Dr Mark K Johnson who served as my major professor and provided guidance and support throughout my graduate tenure I thank Drs Alan D Afton and Robert H. Chabreck for serving on my graduate committee and providing useful and timely advice. I also thank Ms. Stacy Robinson for her assistance in preparing reference slides for my project.
I am indebted to the Mclhenny Company for allowing use of their facilities
and properties at Avery Island, Louisiana I am especially thankful to Mr Raleigh
Rogers for his assistance in collections at Avery Island
I am grateful to Mr Kerney Sonnier and others at the Louisiana Department
of Wildlife and Fisheries for their continued support thoughout my research
Finally, l thank my family. Their help, support and encouragement enabled
me to fulfill my goal of obtaining a masters degree in wildlife
ii TABLE OF CONTENTS
ACKNOWLEDGMENTS...... 11
LIST OF TABLES lv
ABSTRACT...... v
INTRODUCTION...... 1
LITERATURE REVIEW...... 2 Louisiana Deer Food Habits...... Microscope Technique......
STUDY AREAS...... ••••;...... General Location and Description...... ^ Vegetation......
METHODS...... Fecal Pellet Collection ' Laboratory Procedure...... g Statistical Analysis......
RESULTS...... Diet Composition Chi-square Test...... ^ Kulczynski’s Similarity Index
DISCUSSION...... 1 20 SUMMARY AND CONCLUSION 21 LITERATURE CITED ...... 25 APPENDIX...... 30 VITA......
iii LIST OF TABLES
Table Page
1. Estimated botanical compositions (% dry weight) of fecal pellets from white-tailed deer at Avery Island, Louisiana, during spring, summer, fall, and winter, 1997...... 12
2 Calculated Chi-square values of plant taxa based upon frequency of occurance in seasonal diets of white-tailed deer at Avery Island, Louisiana, 1997...... 14
3 Kulczynski’s similarity index (S I.) for spring, summer, fall, and winter diets of white-tailed deer at Avery Island, 1997...... 16
4. Observed values (frequency of occurance) for plant taxa in seasonal diets of white-tailed deer at Avery Island, Louisiana, 1997...... 26
5 Expected values (frequency of occurance) for plant taxa in seasonal diets of white-tailed deer at Avery Island, Louisiana, 1997...... 27
6. Plant species collected for forage reference material from Avery Island, Louisiana, 1997...... 28
iv ABSTRACT
I conducted a food habits study of white-tailed deer (Odocoileus virginianus) at Avery Island, Louisiana, to determine if deer diets differed among seasons In
1997,1 randomly collected 25 seasonal fecal pellet groups in January, April, August and October respectively I also collected reference forage plant samples in conjunction with fecal pellet collections I estimated botanical composition of deer diets based on a microscopic analysis of fecal pellets I compared diets using a chi- squared contingency table to assess significant seasonal variation 1 also used
Kulczynski’s similarity index to determine degree of similarity among seasonal diets
I found significant differences in diet composition among seasons
4 Differences primarily occurred because several plant taxa were available only during select seasons. Woody browse and fruits dominated diets regardless of season
Callicarpa americcma and Quercus virginiana made up substantial proportions of diets in all seasons sampled Many other taxa were consumed only in trace amounts
My results indicate that food plots were used extensively in the winter when wheat was available. I determined that food plot plant taxa were an important dietary
component apparently because other plant taxa were not available during winter
v INTRODUCTION
Analysis of white-tailed deer (Odocoileus virginianus) diets, though greatly
studied, is an invaluable tool for deer management Knowledge of their diet and
habitat enables wildlife managers to evaluate habitat quality as well as monitor deer
health and population fitness Diet studies can provide important information used in
determining whether deer populations are below, at, or above the carrying capacity
of their habitat
In 1990, the deer population at Avery Island was determined by Dr Mark K
Johnson (pers comm.) to exceed the nutritional carrying capacity of the habitat The
deer had below normal body weights and low reproductive success Subsequent
management was established by McIIhenny Co personnel to aid the population
Supplemental feeding, one of these actions, had positive effects on deer body size,
yielding more questions about the effect o f diet quality on the unique physical
characteristics of the deer During my study, there were 3 food plots at Avery Island
consisting of 1 -2 hectares each of wheat and clover
The objective of my research was to compare deer diets among seasons of the year at Avery Island With this information, I was able to determine how plant taxa diet percentages varied among seasons I also was able to estimate the contribution that forages from food plots contributed to deer diets at Avery Island
1 LITERATURE REVIEW
Louisiana Deer
The white-tailed deer at Avery Island are of the subspecies Odocoileus virginianus mcilhennyi. This subspecies inhabits most of coastal Louisiana interbreeding with O. v. texanus in southeastern Texas, with (). v. macrounis in southern Louisiana, and with O. v. osceola in southern Mississippi (Lowery 1974)
This subspecies of the white-tail deer is characterized by small body size, large dentition (in relation to other cranial measurements) and large hooves (Miller 1925,
Lowery 1974). Lowery and Hines (1974) do, however, question whether they are truly a subspecies or their unique physical characteristics can be attributed to poor
quality habitat and diet.
In 1925, Frederic W. Miller, of the Colorado Museum of Natural History,
studied five white-tailed deer collected from Avery Island, Louisiana Upon study,
he found that these deer have a small skull (in all essential measurements) relative to
other Odocoileus virginianus subspecies (Miller 1925) Their rostrums and nasals
were much reduced as compared to other Odocoileus virginianus subspecies
However, he also found that they have a heavier dentition The teeth were larger and
more massive than their races to the north. Miller concluded that these deer were a
small southern race of the virginianus group, most nearly related to the subspecies
Odocoileus virginianus virginianus (Miller 1925). He gave them the subspecies
name mclhennyi named for Mr E A. Mcllhenny of Avery Island, Louisiana, through
2 3 whose courtesy the material was obtained (Miller 1925) Valuable information was gained from Mr. Miller’s research yet his sample size of five individuals was
extremely small to base taxonomic classifications upon
In 1974, George H. Lowery and George Hines released the book “The
Mammals of Louisiana and it’s Adjacent Water” where they describe the Odocoileus
virginianus mcilhennyi subspecies They hypothesize that the smaller size of this
deer may be “nothing more than a consequence of nutritional deficiencies in the food
available to the marsh deer in coastal Louisiana ” They also address the larger
hooves of the mcilhennyi subspecies noting that it was said to be an adaptations to
its marsh habitat (Lowery and Hines 1974). The authors, however, say that through
personal communication with John D Newsom, the deer he observed maintained
their large foot size after being transplanted from the marsh habitat to hard ground
Their offspring also developed the larger hooves (Lowery and Hines 1974)
However, there was no scientific data upon which to base this conclusion
Food Habits
White-tailed deer are browsers As opposed to grazing animals, they move
from place to place selecting the succulent portions of woody plant species, grass
and shrub species, and agricultural crops where available Weckerly and Kennedy
(1992), studying deer in Tennessee, found diets to be characterized by agricultural
crops, browse and acorns in autumn and winter, and browse, forbs and agricultural
crops in spring and summer Acorns were common in autumn and winter diets 4
Spring and summer diets were high in browse and forbs and, to a lesser extent, agricultural crops (Weckerly and Kennedy 1992). They found that deer less selective in their diet during seasons when plants had lower dietary fiber and higher forage abundance In south Texas, Meyer et al (1984) found browse comprised 50-70% of the fall diet Meyer et al also found that forbs comprised > 50% of the diet in
January through April and September In their study, grasses comprised 35-42% of the May and June diet (Meyer et al 1984) Sowell et al (1985), also studying deer in
Texas, found that deer consumed on an annual basis, 62% browse, 34% forbs, 1%
grasses, and 3% unknowns in one study area In another study area, Sowell et al
found deer diets were comprised of 56 % browse, 28% forbs, 11% grasses and 5%
unidentified annually (Sowell et al 1985) The increase in grass intake was
attributed to the availability of winter wheat and rye grass in the second study area
Sowell et al. also found that these forages improved the quality of deer diets in
winter as compared to areas where these crops were unavailable (Sowell et al 1985,
Johnson et al 1987).
Microscope Technique
1 used procedures described by Sparks and Malechek (1968) for
microhistological examination of fecal material Sparks and Malechek identified
plant species in fecal material based on epidermal characteristics. They determined
that histological features such as size and shape of epidermal hairs, presence or
absence of hairs, cell shapes, and crystals included in epidermal cells provide 5
diagnostic characteristics for identification of forb species Grass species were
identified by Sparks and Malechek by the occurrence and position of specialized
epidermal cells such as cork cells, silica cells, and asperities The size and shape of
the guard and subsidiary cells of the stomata also were reliable diagnostic features
(Sparks and Malechek 1968).
Johnson et al (1987), studied deer in Louisiana and further described this
microscope procedure They determined that any fecal group, collected randomly
and consisting of at least five pellets, would be considered a sample After material
was ground and dried, a 50:50 household bleach-water solution was used to remove
plant pigment.
Sowell et al. (1985) also used this microhistological technique to study mule
deer in Texas One hundred power magnification was used as opposed to 125 power
as outlined by Sparks and Malechek (1968) to examine sample slides and estimates
were averaged across seasons In Sowell’s study, plant parts (leaves and new
growth) were collected to simulate observed deer feeding behavior Johnson et al
(1987) used this technique to collect plant material to be made into reference slides
using the same laboratory procedure used to make fecal material slides
. STUDY AREA
General Location and Description
Avery Island is a salt dome surrounded by coastal marsh habitat located in
Iberia Parish, south of Lafayette, Louisiana Soil is of the Memphis-Frost association These loamy soils often are associated with salt domes Avery Island is
home to the Mcllhenny Coorporation, maker of Tobasco brand products The
Mclhenny Co and its shareholders own most of the property at Avery Island
Vegetation
Although located in the coastal marsh area, vegetation on Avery Island is
typical of bottomland hardwood habitat due to the slightly higher elevation of the salt
dome Some of the area has been altered for asthetic purposes This includes
mowing open fields and plantings of ornamental flora
Scientific nomenclature of plant taxa on Avery Island is from Radford et al
(1968). Overstory taxa on Avery Island includes live oak (Quercus virginiana),
sweetgum {Liquidambar styraciflua), black willow (Sahx nigra), black cherry
(Prunus serotina), baldcypress (Tax odium distichum), and winged elm (Ulmus
alata) Woody midstory species were American beautyberry {Calhear pa
americana), eastern redeedar {Junipenis virginianus), youpon {Ilex vomitoria),
swith cane {Arundtnaria gigantea), red maple {Acer rubrum), waxmyrtle {Myrica
cerifera), and Chinese tallowtree {Sapium sebiferum) Herbaceous understory
included Japanese honeysuckle {Lonicera japonica), wild dewberry and blackberry
{Rubus spp), wild grape {Vitis spp ), trumpet creeper {Campsis radicans),
6 7 greenbriar (Smilax spp ), morning glory (Ipomea spp ), poison ivy (Rhus radicans), common privet (Ligustrum spp ), cross vine (Anisostichus capreolata), and various grasses and forbs A complete list of plant species I collected for reference is provided in the appendix (Table 6). METHODS
Fecal Pellet Collection
I collected fecal pellets in February 1997, April 1997, August 1997, and
October 1997 as representative of winter, spring, summer, and fall samples, respectively. Twenty-five random samples were collected during each season A group of five or greater pellets was considered a sample (Johnson et al 1987) 1 also
collected forage plants simultaneously with the fecal pellet collections for reference
material The most succulent plant portions were removed to simulate feeding of
white-tailed deer (Johnson 1987),
Laboratory Procedure
I dried fecal and plant samples at 100 C for 9-12 hours and then ground each
in a Wiley mill (40 mesh screen) 1 then placed the samples in a 50:50 household
bleach-water solution, heated them for approximately thirty seconds in a microwave
oven, and left samples to stand for approximately five minutes to remove plant
pigments. I then rinsed the samples through a 100 mesh sieve
1 removed the fecal samples from the sieve with a standard biological scalpel
and placed about 0. lg of material on each of 5 standard microscope slides for each
sample 1 used a mounting medium of soapy water for the sample slides and
dispersed the fecal material evenly on the microscopes slides for easiest viewing 1
made reference slides of plant material in the same manner but used a mounting
medium of Clerium to provide a more permanent medium
8 9
I examined fecal sample slides with a Labrolux binocular microscope, using lOx ocular and lOx objective lenses (lOOx) The microscope was equipped with a mechanical stage for focusing Twenty fields per slide were examined systematically to obtain 100 fields for each pellet group (Johnson 1987) I established a field as the area of the slide delineated by a microscope field using 100-power magnification
Identification of each plant species was based on epidermal characteristics
(Davies 1959, Brusven and Muldern 1960, Storr 1961, Sparks and Malechek 1968)
Histological features such as size and shape of epidermal hairs, presence or absence of hairs, cell shapes, and crystals included in epidermal cells provided diagnostic characteristics for identification of plant species The size and shape of the guard and
subsidiary cells of the stomata were reliable diagnostic features (Sparks and
Malechek 1968) I recorded only fragments recognized as epidermal tissue (other
than trichomes) as positive evidence of the presence of a plant species in a field on
the slide (Sparks and Malechek 1968)
Statistical Analysis
Frequency of occurrence (number of fields in which each taxa occurred) was
tabulated for each plant taxa in each pellet group (Sparks and Malechek 1968) I
summed these frequencies for each season and calculated relative frequencies
(percentages) for all taxa present in each season by dividing frequencies of each plant
taxa by total number of fields in each season (100 fields X 25 samples=2500 fields)
These percentages provided seasonal estimates of dry weight diet compositions 10
I used a Chi-square test to discern if diet composition differed significantly
among seasons. The null hypothesis was that diet composition did not differ
significantly among seasons I used a 4 (seasons) X 23 (plant taxa) chi-square
contingency table and calculated chi-square values in the table with the formula
(Observed-Expected)2 / Expected 1 used frequency of occurrence of recorded plant
taxa for observed values and calculated expected values from observed values with
the formula (row total X column total) / grand total (Freund and Wilson 1993) The
calculated chi-square test statistic used for significance was the sum of all chi-square
values for individual plant taxa within the contingency table 1 only included plant
taxa with frequency of occurrence >8 1 chose an alpha level of 0 05 for statistical
significance with 66 degrees of freedom, the critical X2 values was 84 82
I also used Kulczynski’s similarity index (Oosting 1956) to compare diet
composition among seasons. This index provided proportion of similarity among
seasonal diets. I used this test to discern if there was substantial difference in diet
composition among seasons. 1 used this information to determine whether diets
change substantially among all four season or only between warm months (spring,
summer and fall) and cold months (winter)
: RESULTS
Diet Composition
I found that woody browse and fruits dominated deer diets regardless of season (Table 1). Woody browse and fruits comprised >75% of diets in all seasons
sampled Forbs and grasses and grass-likes each comprised < 15% of seasonal diets
I also found that many plant taxa comprised very little (<1%) of spring, summer, fall,
and winter diets.
1 found that American beautyberry, live oak, honeysuckle, and rubus spp
comprised highest dietary percentages of plant taxa found in spring, summer and fall
diets American beautyberry, live oak, youpon, and acorns comprised the highest
dietary percentages of plant taxa found in winter diets Wheat and clover, food plot
plant taxa, comprised approximately 15 % (combined) of winter diets Winter diets
were comprised of higher percentages of grasses and grass likes and smaller
percentages of forbs as compared to diets from other seasons
Chi-square Test
1 found that diet composition differed among seasons (Table 2). 1 also found
large differences among chi-square values for individual plant taxa As expected,
some plant taxa were used more in certain seasons and little, if at all, in others I
found that winter diets had more plant taxa with high chi-square values than diets of
other seasons It appears the decreased consumption of honeysuckle, St John’s
wort, sweetgum and greenbriar in winter diets contributed much to significant
11 12
Table 1. Estimated botanical compositions (% dry weight) of fecal pellets from white-tailed deer at Avery Island, Louisiana, during spring, summer, fall, and winter, 1997.
Plant taxa Spring Summ er Fall W inter
Grasses and Grass-likes Arundinaria gigantea 0.60 0.40 1.60 0.50
Echinochloa colonum — — — —
Paspalum urvillei — — — — Tillandsia usneoides 7.60 5 60 3.70 2.60
Tricticum aestivum — — — 8.80 Uniola spp. 0.08 0 40 0.10 0.50 total 8.28 6.40 5.40 12.40
Forbs
Aster spp — — — —
Desmodium spp — — 0.10 004
Eupatorium capillifolium — — — —
Hydrocotyle spp 0.12 0.10 — — Hypericum virginianus 5.36 4 90 4 80 020 lpomea spp 0.36 0.20 1.00 0 10
Lespedeza spp. — — — — Trifolium repens 3.72 4 4 0 3.60 5 30
Verbena spp — 0 10 — 0.10 total 9.56 9.70 9.50 5.74
Woody browse / fruits Acer rub rum 860 1 40 8.00 0 9 0
Ampelopsis arborea — 1 50 — —
A nisostichus capreolata — 004 0 0 4 — Callicarpa americana 14 88 1900 6.50 17.00 Campsis radicans 1.60 2 20 1.50 0.50
Daubentonia spp — — — ___ Ilex vomitoria 4.96 3.90 3.40 17.20 Juniperus virginianus — — 0.10 .. Lantana spp — — __ Ligustrum spp 4.32 6 3 0 2.60 0 6 0 13
Table 1 cont
Plant taxa Spring Summer Fall Winter
Liquidambar styraciflua 0.16 0.04 — 0 60 Lonicera japonica 10.56 5.90 11.00 0.40
Myrica cerifera — 0.30 0.30 — Quercus virginiana 10.80 14.00 15 80 20.10
Q. virginiana acorns 0.24 — 8.20 9 60 Rubus spp 11.04 10.20 9.90 3.40 Salix nigra 4.16 1.20 5.40 2.00
Sapium sebiferum — 0.10 — — Smilax spp. 3.64 5.50 4.40 0.30 Ulmus alata 0.24 0.20 0 50 0.10
Vitis spp. — — 0.10 — Zea mays 3.44 5.40 3.60 3.00 total 78.64 77.18 81.34 75.70
unidentified 3.52 8.20 3.80 6.70
Grand total 100 100 100 too 14
Table 2. Calculated Chi-square values of plant taxa based upon frequency of occurance in seasonal diets of white-tailed deer at Avery Island, Louisiana, 1997
Plant Taxa Spring Summer Fall Winter Total
Callicarpa americana 0.001 0.023 0.409 0.278 0.711 Quercus virginiana 0.001 0.023 0.409 0.278 0.711 Lonicera japonica 0.338 0.462 1.866 8.141 10.807 Ilex vomitoria 0.091 0.038 2.411 1.500 4.040 Salix nigra 1.006 2.561 0.701 0.110 4.378 Hypericum spp. 1.815 1.515 0.205 10.253 13.788 Acer rubrum 1.818 0.384 0.205 1.639 4.043 Liquidambar styraciflua 0.016 1.467 3.690 12.575 17.748 Rubus spp. 0.036 0.009 0.076 0 0.121 Tillandsia usneoides 0.038 0.019 0.001 0.001 0.059 Ampelopsis arborea 3.230 30.801 3.690 2.930 40.651 Ipomea spp. 0.031 1.736 5.912 1.388 9.067 Zea mays 0.198 0.092 0.428 0.787 1.505 Ligustrum spp. 1.030 0.178 0.081 1.411 2.700 Trifolium repens 0.372 0.259 0 1.366 1.997 Tricticum aestivum 6.210 6.070 7.100 66.642 86.022 Smilax spp. 0.001 2.561 0.701 6.934 10.197 Ulmus alata 0.017 0.081 1.252 1.215 2.565 Uniola spp. 0 2.187 0.032 1.800 4.019 Arundinaria gigantea 2.336 0.640 2.952 0.238 6.166 Quercus virginiana acorns 6.149 12.620 5.768 12.931 37.468 Campsis radicans 0.356 2.141 0.202 2.693 5.392 Unidentified 0.014 0.039 0.590 0.613 1.256
Total 25.101 65.906 38.681 135.723 265.411
chi-square test statistic = 265.41
Critical value = 84.82 with 66 c //
P value < 0.0001 15 differences among seasonal diets. The increased consumption of wheat and acorns in winter diets also contributed high chi-square values. The majority of plant taxa in seasonal deer diets, however, contributed small chi-square values Observed and expected frequency of occurrence of plant taxa among seasons are located in the appendix (Tables 3-4).
Kulczynski’s Similarity Index
Based upon Kulczynski’s similarity index, I found that spring, summer and fall diets were more similar to each other than to the winter diet (Table 4) Similarity of diet composition between spring, summer, and fall diets ranged from
73 % to 81%. However, 1 found that spring, summer and fall diets were each less than 60% similar to the winter diet The high percentages of wheat, acorns and youpon found in the winter diet attributed most to the difference in diets From this index, only substantial change in diet compositions is apparent between warm months
(spring, summer, and fall) and cold months (winter). 16
Table 3. Kulczynski’s similarity index (S I ) for spring, summer, fall, and winter diets of white-tailed deer at Avery Island, Louisiana, 1997.
Seasonal Diet Comparison S.I.
Spring vs. Summer 81%
Spring vs. Fall 83%
Spring vs Winter 53%
Summer vs. Fall 73%
Summer vs. Winter 60%
Fall vs. Winter 58% DISCUSSION
My analysis revealed that woody browse and forbs dominated spring, summer, fall, and winter diets. I found that woody browse comprised >70 % of seasonal diets. My results are consistent with similar white-tailed deer food habits studies in Louisiana. Thrill et al. (1983), studying deer in Grant Parish, Louisiana, found that woody browse dominated yearlong diets. Thrill also determined that deer only select fruits of American beautyberry and stated that deer seldom consume leaves or twigs of this species (Thrill et all. 1983). 1 found, however, that American beautyberry foliage comprised approximately 7 -19% of seasonal diets William
Sheffield (1957), studying deer in Tensas Parish, found that woody browse
comprised > 86% of deer diets, however, his study only examined summer diets
Patrick Murphy, also studying deer in Tensas Parish, also found seasonal diets
dominated by woody browse (Murphy 1974).
Additionally, similar deer food habits studies in Texas (Warren et al 1983,
Sowell et al. 1985) also found deer diets primarily comprised of woody browse
However, Kie et al. (1980), studying deer in south Texas, found that forbs comprised
76 % of deer diets. Deer habitat in south Texas, however, is dominated by gulf
prairie marshes and plains, and woody browse diversity is low (Kie et al 1980).
I found that diets differed among seasons, however, spring, summer, and fall
diets were similar Winter diets differed from other seasons presumably because this
is when plant diversity is lowest (Keegan et al. 1989, Murphy 1974). Weckerly
17 18 et al.(1991) also found differences in deer diets among seasons and that spring, summer and fall diets were similar Thrill et al. (1983) and Murphy (1974) report similar results of seasonal diet differences in white-tailed deer Murphy also found spring and summer diets similar and Thrill et al found spring, summer and fall diets
similar.
Zielinski (1999), studying deer in southeast Louisiana, also found that diets
differed among seasons. Zielinski found that forbs dominated spring and summer
diets. However, fall diets were mostly comprised of woody browse Winter diets
were comprised of both woody browse and grasses and grass-likes. Spring and
summer diets appear similar in Zielinski’s study, however, fall and winter diets differ
Zielinski, however, did not classify plant taxa as grasses, forbs and woody browse as
found in most previous deer food habit studies, causing difficult study comparisons
Decreases in plant availability and diversity are generally found in winter
(Thrill et al. 1983, Murphy 1974, Keegan et al 1989). Supplemental food plots also
have been shown to improve deer diets in winter (Johnson et al. 1987, Keegan et al
1989). I found that many plant taxa in winter comprised small diet percentages
(<1%) and that wheat and clover (food plots) comprised approximately 15 % of
winter diets. The increased use of food plot plant taxa apparently resulted from
decreased plant taxa availability and the availability of wheat in the winter This is
generally consistent with previous white-tail deer diet studies (Johnson et al 1987,
Johnson et al. 1993, Zielinski 1999) in Louisiana. Johnson et al (1993), studying 19 deer in west-central Louisiana, found that wheat and clover comprised 15 % of deer diets from October through May. Johnson et al. (1987), also found approximately
40% of cool season diets of white-tailed deer comprised of forages from food plots which totaled < 1 % of the habitat The increase in food plot forage consumption in
Johnson’s study also coincided with a decrease in woody browse in winter diets
(Johnson et al 1987). Based upon my results, I conclude that diet composition differs primarily in winter, presumably due to decreases in plant availability and diversity, and that forages ffom food plots are important to diets of white-tailed deer at Avery Island SUMMARY AND CONCLUSION
I found that diets of deer at Avery Island, Louisiana, differ significantly among seasons. The greatest seasonal difference in diet composition was found in the winter diet I primarily attributed this difference to the availability of wheat and to low plant diversity in the winter, although I present no data on plant taxa diversity or abundance. From Kulczynski’s similarity index, I found spring, summer, and fall diets to be similar, with spring and fall diets being most similar (83%). Winter diets, however, were less than 60% similar to other seasonal diets.
From the results of my research, I conclude that there are only two seasons that differ substantially in diet composition Differences in deer diets primarily occur
between warm months (spring, summer and fall) and cold months (winter). I
primarily attribute similarity among deer diets in spring, summer, and fall to a long
warm season Avery Island apparently has a long growing season probably due to its
location near the coast of Louisiana. 1 also conclude that food plot plant taxa are
important to diets of deer at Avery Island Food plot plant taxa at Avery Island
apparently supplement plant taxa not available or abundant in winter.
20 LITERATURE CITED
Allen, G M. The Louisiana Deer The American Naturalist, pp 449-454
Burt, W H , and R R Grossenheider 1980 Mammals. Peterson Field Guide pp 218
Causey, M.K 1964 Nutritional analysis and seasonal variation of some herbaceous deer brouse plants in the pine-hardwoods areas of Winn and Union Parishes, Louisiana M S Thesis. Louisiana State University, Baton Rouge, Louisiana.
Crawford, H.S and D.H. Handinson 1984 White-tailed deer vs bovine innocula for in vitro digestibilities. J. Wildl Manage. 48:649-651
Delany, B W. 1985 Effects of cool-season food plots on white-tailed deer M S Thesis, Louisiana State Univ., Baton Rouge 46pp.
Ensinger, M E , and C.G. Oentine, Jr. 1987 Feeds and nutrition: complete: First ed Ensminger Publ Co., Clovis, Calif 1417pp.
Everitt, J.H., and C L Gonzalez. 1981 Seasonal nutrient content in food plants of white-tailed deer on the South Texas plains J Range Manage 34: 506-510
Freund, R.J. and W J Wilson Statistical Methods. Academic Press, Inc , Boston MA. 644 pp
Halls, Lowell K 1984 White-Tailed Deer. Ecology and Management Stackpole Books, Harrisburg, PA. 870 pp
Hoveland, C.S , G.A. Buchanan, SC Boswith, and I J Bailey 1986 Forage nutritive quality of weeds in Alabama Alabama Agr Exp Sta Bull 577 pp
Howery, L.D., and J.A. Pfister 1990. Dietary and fecal concentrations of nitrogen and phosphorus in penned white-tailed deer does. J. Wildl Manage 54 383- 389.
Johnson, J.K., H. Wofifort, and J.A. Pearson 1983. Microhistological techniques for food habits analysis. U S. Forest serv., South, Forest Exp Sta Res Pap AO-199, New Orleans, La.
21 22
Johnson, M K., and K.D. Dancak. 1993. Effects of food plots on white-tailed deer in Kisatchie National Forest. J Range Manage. 46 110-114.
Johnson, M K. , B W Delany, S P Lynch, J.A Zeno, S.R. Scholtz, T.W. Deegan, and B E Nelson 1987 Effects of cool-season agronomic forages on white tailed deer. Wildl Soc. Bull. 15 330-339.
Keegan, T.W., M.K. Johnson, and B.D. Nelson. 1987. American Jointvetch improves summer range for white-tailed deer. J. Wildl. Manage. 42:128-134
Kie, J.G., D L. Drawe, and G. Scott 1980. Changes in diet and nutrition with increased herd size in Texas white-tailed deer. J. Range Manage. 33. 28-34
Klein, B 1971. Deer and turkey managemant on Idlewild Experiment Station, East Feliciana Parish, Louisiana. M S. Thesis, Louisiana State Univ., Baton Rouge. 77pp.
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Table 4. Observed values (frequency of occurance) for plant taxa in seasonal diets of white-tailed deer at Avery Island, Louisiana, 1997
Plant Taxa Spring Summer Fall Winter Total
Callicarpa americana 25 25 25 25 100 Quercus virginiana 25 25 25 25 100 Lonicera japonica 19 19 25 4 67 Ilex vomitoria 23 22 17 25 87 Salix nigra 21 10 23 14 68 Hypericum spp. 25 24 24 4 77 Acer rubrum 25 16 24 12 77 Liquidambar styraciflua 3 1 0 9 13 Rubus spp. 24 23 25 21 93 Tillandsia usneoides 22 20 24 19 85 Ampelopsis arborea 0 13 0 0 13 Ipomea spp. 6 3 14 3 26 Zea mays 20 23 22 24 89 Ligustrum spp. 23 20 20 12 75 Trifolium repens 19 19 25 25 88 Tricticum aestivum 0 0 0 25 25 Smilax spp. 17 23 23 5 68 Ulmus alata 5 4 8 2 19 Uniola spp. 2 4 2 0 8 Arundinaria gigantea 4 6 15 9 34 Quercus virginiana acorns 4 0 24 24 52 Campsis radicans 18 21 16 8 63 Unidentified 23 24 23 25 95
Total 353 345 404 320 1422 27
Table 5. Expected values (frequency of occurance) for plant taxa in seasonal diets of white-tailed deer at Avery Island, Louisiana, 1997
Plant Taxa Sorina Summer Fall Winter
Callicarpa americana 24 8 2 2 4 2 6 28.41 22.50 Quercus virginiana 24.82 24.26 28.41 22.50 Lonicera japonica 16.63 16.26 19.04 15.08 Ilex vomitoria 21.60 21.11 24.72 19.58 Salix nigra 16.88 16.50 19.32 15.30 Hypericum spp. 19.11 18 68 21.88 17 33 Acer rubrum 19.11 18.68 21.88 17 33 Liquidambar styraciflua 3.23 3.15 3.69 2.93 Rubus spp. 23.09 22.56 26.42 20.93 Tillandsia usneoides 21.10 20.62 24 15 19 13 Ampelopsis arborea 3.23 3.15 3.69 2.93 Ipomea spp. 6.45 6.31 7.39 5 8 5 Zea mays 22.09 21.59 25.29 20.03 Ligustrum spp. 18.62 18.20 21.31 16 88 Trifolium repens 21.85 21.35 25.00 19 80 Tricticum aestivum 6.21 6.07 7.10 5 63 Smilax spp. 16.88 16.50 19.32 15 30 Ulmus alata 4 79 A C l "T. » £ . 4 . 0 I O.40 4.28 Uniola spp. 1 QQ 1 OA n 0 7 1.80 Arundinaria gigantea 8.44 8.25 9.66 7 65 Quercus virginiana acorns 12.91 12.62 14 77 117 Campsis radicans 15.64 15.28 17.90 14.18 Unidentified 23.58 23.05 26.99 21.38 28
Table 6 Plant species collected for forage reference material from Avery Island, Louisiana, 1997.
Plant Species Common Name
Grasses and Grass-likes Arundanaria gigantea Cane Echinochloa colomm N/A Paspalum urvi/lei N/A Tillcmdsia usneoides Spanish Moss Tricticum aestivum Wheat Uniola spp. N/A
Forbs Aster spp. N/A Desmodium spp Begger lice Eupatorium capillifolium Dog-fennel Hydrocotyle spp. Pennywort Hypericum spp. St. John’s-wort Ipomea spp. Morning Glory Lespedeza spp. Clover Trifolium repens White Clover Verbena sp. Verbena
Woody Browse / Fruits Acer rubrum Red Maple Ampelopsis arborea Pepper-vine Anisotichus capreolata Cross Vine Callicarpa americana American Beautyberry Campsis radicans Trumpet Creeper Daubentonia punicea N/A Ilex vomitoria Youpon Juniperus virginianus Eastern Redcedar Lantana spp. Lantana Ligustrum spp Privet Liquidambar styraciflua Sweetgum Lonicera japonica Honeysuckle Myrica cerifera Wax Myrtle Prunus serotina Black Cherry Quercus virginiana Live Oak Quercus virginiana acorns Acorns Rubusspp Blackberry/Dewberry Salix nigra Black Willow 29
Table 6 cont
Plant Species Common Name
Sapium sebiferum Chinese Tallowtree Smilax spp Greenbriar Ulmus alata Winged Elm Vitis spp. Wild Grape Zea mays Corn VITA
Nathan D Rains was born on 14 June 1972 in Oklahoma City, Oklahoma
He graduated from Pampa High School in Pampa, Texas, in May 1990. He received
a bachelor of science degree in wildlife biology from Texas A&M University, College
Station, Texas, in December 1994. While an undergraduate student at Texas A&M,
he received an academic outstanding achievement award.
He and his wife, the former Elizabeth Faye Riggs, were married 16 December
1995 have one child, Madison Grace, born 8 February 1997, and are expecting
another in October 1999.
In September 1996, Nathan entered graduate school at Louisiana State
University, and is now a candidate for the degree of Master of Science in wildlife
30
i MASTER’S EXAMINATION AND THESIS REPORT
Candidate: Nathan D. Rains
Major Field: Wildlife
Title of Thesis: Diets of White-tailed Deer at Avery Island, Louisiana
Approved:
Date of Examination:
3/ 30/99