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Summary

Thesis: Ecology and genetic variation of fallow deer (Dama dama) on Rhodes

The present thesis is concerned with the study of ecological and genetic parameters of the population of fallow

deer (Dama dama) on the island of Rhodes. Rhodian fallow deer is the only free-ranging population in Greece

and the law protects it. Also, this population, which is believed to have an ancient origin, has been recognised by

IUCN as a significant population for which special conservation measures have to be taken. Besides its biological

value, Rhodian fallow deer has a cultural value as well; it is the symbol of the island, much beloved by Rhodian

people.

The current study deals with interdisciplinary research approaches which are associated with fallow deer long-

term conservation. The research approaches include: a. deer distribution, present and past, b. deer food habits

and c. genetic variation of the deer population.

Temporal and spatial distribution of the Rhodian Fallow deer

Prior to this study, records of fallow deer distribution on the island of Rhodes were rather occasional and

produced by no systematic survey. However, species distribution constitutes the fundamental unit of their

biogeography. Moreover, given that species distribution changes through time and space, because of the natural

and/or human reasons, it is more informative, in terms of species conservation and management, to explore the

temporal history of a species and the parameters that formed it, rather than its distribution at a specific time. This

study has two objectives: a. to assess the present and past distribution of fallow deer on the island of Rhodes and

b. to explore the reasons that are associated with the distribution change.

For determining present deer distribution (2002 2005), information provided by local people was combined with

field work, while past distribution (1935-1943) was defined based only on the information provided by local

people. In total, 194 local people were interviewed for the present distribution and 31 old local people over the

age of 75 for the past one. For the current distribution, field work consisted of track counts along forest roads

located within 466 quadrats of 1 km2, selected based on information provided by the local people. Track counts

were conducted in two seasons: the wet and dry season over the period of three years. Based on the records

derived from the interviews (for both distributions) and field work (only for the present distribution), the quadrats

were classified as quadrats with permanent presence of fallow deer and quadrats with occasional presence of

deer. Overall deer range for each period was defined based on minimum concave polygon method. Spatial

analysis with ArcGis and Patch Analyst followed for revealing the quantitative and qualitative aspects of deer

distribution in two periods, present and past. The reasons for the change of deer range between the two periodswere determined by information provided by 159 local people.


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The data analysis revealed that the present distribution (2002-2005) is greatly limited and less contiguous than

the distribution of species during the latter part of the Italian Occupancy (1935-1943). The past distribution (1167

km2) occupied 83.6% of the island and corresponded almost totally to quadrats of permanent deer presence

(1126.9 km2). On the contrary, present distribution (619.6 km2) occupied only 44.2% of the island and

corresponds partly to permanent presence areas (388.5 km2) and partly to occasional deer presence areas

(231.1 km2). Furthermore, the present distribution presents gaps of deer presence, which are absent to the past

distribution. Also, the changes in range size and pattern seem to represent the changes in population size: during

the latter part of the Italian Occupancy, fallow deer numbered a few thousand individuals, which, after the Second

World War, started to decline gradually, and it is only since the beginning of 21st century that deer population

shows clear signs of recovery. The restriction of the fallow deer distribution and the population decline seem to be

the result of poaching, and the big fires that burned on the island during the last three decades.

Food habits of the Rhodian fallow deer during mid-dry and early-wet season

Food is one of the basic parameters that define the relationships between animals and their habitat, since it

affects the distribution pattern of the animals and their preference for particular habitat types. Rhodian fallow deer

lives in a changing Mediterranean environment, with a distinct seasonality of food resources in terms of

availability and quality; food is abundant and of high quality during the wet season, while it becomes scarce and

of low quality as summer progresses. This study has two objectives: a. to define deer food habits during mid-dry

and early-wet season, and b. to associate food habits with food availability and quality.

For both seasons, food habits were assessed by fecal microhistological analysis. The study was conducted in a

protected area in the centre of the island (near Laerma village), a heterogeneous landscape of forestland ( Pinus

brutia), shrubland (maquis) and agricultural land (mainly olive trees and a few wheat fields). A reference collection

of plant epidermis of more than 130 taxa which occurred in the study area was created. 20 fecal samples per

season were collected and microhistological analysis was followed. Plant fragments were classified into three

categories, graminoids, forbs and woody plants, and their percentage frequency was calculated. Vegetationsampling took place in August 2005 (mid-dry season) and January 2006 (early-wet season), and a modified

Daubenmire technique was used along 19 transects, spread out among the three habitat types.

Based on the analysis of the results, fallow deer proved to be an intermediate feeder, consuming both woody and

herbaceous vegetation during both seasons. However, while during the mid-dry season fallow deer consumes

equivalent quantities of woody and herbaceous vegetation, during the early-dry season woody plants dominate in

deer diet. Graminoids, olive leaves and bulbous plants seem to be the main food categories consumed by deer

during the mid-dry season, and olive leaves and bulbous during the early-wet season. Forbs contribute slightly todeer diet in both seasons, while seed consumption was observed only during the mid-dry season. Deer diet


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seems to be associated with food availability and quality. The high consumption of woody plants in both seasons

seems to be associated with their constant availability and their high nutritional value. On the contrary, the

significant decline of graminoids consumption during the early-wet season has to be affected by their reduced

availability. Finally, early-wet season seems to be also a crucial period for satisfying deer dietary needs, as is

well-recognized for the dry season.

Spatial and temporal genetic variation of the Rhodian fallow deer by the use of microsatellite markers

Genetic variation is considered to be a crucial component for the survival of species and populations, as it is a

prerequisite for their evolution and adaptation to the environmental challenges. Under the concept of conservation

genetics, two tasks have to be accomplished: to preserve high genetic variation within the populations and to

prevent genetic introgression incidences that set at risk their genetic integrity. Rhodian fallow deer is a protected

species of deer in Greece with a reference for its conservation on IUCN Red List. Based on a preliminary mtDNA

analysis, this population seems to be genetically distinct compared with Italian, Bulgarian and Turkish populations

of fallow deer. This study has four objectives: a. to define the genetic polymorphism and pattern of fallow deer

population, past (1945 1990) and present (1990 2007), and to detect the genetic bottleneck which occurred

over the last decades as a result of population decline, b. to explore the genetic value of a captive population of

Rhodian fallow deer as a genetic stock in terms of conservation genetics, c. to give a preliminary insight about

fallow deer differentiation from fallow deer of non-Rhodian origin based on microsatellite DNA analysis.

Fallow deer genetic variation was assessed based on 9 microsatellite loci. Samples included mainly antlers

coming from the current free-ranging population (sampling period: 1990 2007, N: 80), the past free-ranging

(sampling period: 1945 1990, N: 42), the captive population of Rhodian fallow deer (sampling period: 2006

2007, N: 30), and three samples from deer of non-Rhodian origin. Almost all of the samples from the free-ranging

population (present and past) had been collected by the local people within different time periods, and their

geographic position and chronology were determined based on information provided by the local people as well.

Statistical analysis included the assessment of basic population genetic parameters (average number of alleles,heterozygosity, test for departure from linkage disequilibrium and deviations from Hardy-Weinberg equilibrium),

quantitative genetic differentiation (Fst and exact tests), spatial genetic differentiation (visual comparison by GIS,

Principal Coordinate Analysis, and Spatial Autocorrelation Method), and bottleneck testing.

Rhodian fallow deer genetic polymorphism was found to be low and, this seems to be in accordance with the low

genetic polymorphism found in other populations of fallow deer in Europe. Although genetic bottleneck was

detected in the present free-ranging population, this differentiation seems to be associated mainly with spatial

qualitative criteria rather than quantitative ones. No significant decline of alleles number was observed in thecurrent population, but it was found that the current population presents less spatial homogeneity compared to


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the population a few decades ago. Furthermore, the spatial genetic heterogeneity of the current population is

favored more by the existence of fine scale genetic structure, which is related to the dispersal of young

individuals. Also, Rhodian fallow deer kept in an enclosure in the city of Rhodes can not be considered as genetic

stock, as this population contains significantly less genetic variation than the free-ranging population does.

Finally, although the sample size of non Rhodian deer was very low and did not permit a detailed analysis, it

seems that Rhodian fallow deer is differentiated from other non-Rhodian deer: non-Rhodian deer contained 6

alleles that were not observed in any of the 152 Rhodian deer.


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