Bioavailability of freeze-dried and spray-dried grapefruit ...
Preliminary assessment of feeding ecology of a Golden...
1
Preliminary assessment of feeding ecology of a Golden jackal (Canis aureus) population in South Eastern Samos Island, Greece, through post mortem examination and scat analysis W33P Dr. Guido Pietroluongo, [email protected] 2nd International Symposium on jackals and related species 31st of October - 2nd of November 2018 Marathon Bay - Attica, Greece References 1 Giannatos, G. (2004). Conservation action plan for the golden jackal Canis aureus L. Greece WWF Greece 47. 2 Radović, A., and Kovačić, D. (2010). Diet composition of the golden jackal (Canis aureus L.) on the Pelješac Peninsula, Dalmatia, Croatia. Periodicum biolo- gorum 112, 219-224. 3 Raichev, E.G., Tsunoda, H., Newman, C., Masuda, R., Georgiev, D.M., and Kaneko, Y. (2013). The Reliance of the golden jackal (Canis aureus) on anthropogenic foods in winter in Central Bulgaria. Mammal study 38, 19-27. Introduction Samos Island, North-Eastern Aegean Sea, is one of the few Mediterranean islands and the only one in Greece where the Golden Jackal (Canis aureus) is considered native. Previous studies estimated 13 to 20 groups on the island with 8 to 15 individuals each; most of them found in the Eastern side 1 . This study focuses on the diet composition of the C. aureus population living on the South-Eastern region (Fig. 1), based on scat analyses and post mortem analyses of stomach contents. Pietroluongo G. 1 , Leggett J. 2 , Falquina Fernández F. J. 1 , Linardaki I. 1 , Parker W. 1 , Miliou A. 1 , Tsimpidis T. 1 Conclusion The samples collected during the necropsies demonstrate that the diet of C. aureus is highly diverse. Further analyses should be carried out in order to study a potential relation of the population with anthropic settlements and regional agricultural habits. In addition to this, higher sampling numbers and systematic surveys are underway to assess the feeding ecology of the overall population living on the island and make comparisons based on seasonal and geographical variations. Conservation measures are needed to prevent road-kill, especially during the touristic season (Fig. 6). Necropsies were conducted (Fig. 3) on 15 specimens between April 2017 and September 2018. The stomach of each individual was isolated. The content was collected and categorised into organic (vegetal; animal) and non-organic components (Fig. 4). Archipelagos Institute of Marine Conservation, Marine Research Base: P.O. Box 42, Pythagorio, Samos 83103, Greece www.archipelago.gr Layout by Lilly Gothe – [email protected] Fig. 3: C. aureus necropsy. 1 Archipelagos Institute of Marine Conservation 2 University of the West of England Materials & Methods 30 scat samples were collected (Fig. 2) between June and September 2018 along transects set in areas habituated by C. aureus. The samples, after being soaked in water, were rinsed through a sieve (0.5 mm) in order to separate fecal matter from identifiable content. The collected content was dried and divided into the same categories as the stomach content of the dead jackals. Frequency of occurrence (FO) and Relative Frequency of Occurrence (RFO) were calculated for each category 2, 3 . In all the 15 stomachs vegetal matter was found : leaves, grass, mulberries ( Morus alba ), olives (Olea europaea), grapes (Vitis vinifera ), figs ( Ficus carica ), carob (Ceratonia siliqua). 5 stomachs contained animal remains (bones, arthropods, feathers). An unusual case of a hook with a nylon line was found. Discussion The scat analyses showed similar results to those of the post-mortem ones. The studied population is composed of opportunistic omnivores , with seasonal dependency on the food sources. The samples collected have shown the preference for natural food sources instead of anthropogenic food subsidies. Even though the population is living in a synanthropic environment, no evidence of feeding on anthropogenic materials, such as domestic waste, was recorded. Diet composition shows seasonal variations associated with the availability of different prey and food sources. During the summer season, the diet was mostly composed by fruits (i.e. figs, carobs, grapes, berries, olives, etc.) while in the winter season the composition showed presence of bones belonging to small mammals (rodents, birds, etc.). Scats were primarily collected during spring and summer, when they are better preserved due to good weather conditions. Although necropsies were conducted throughout the year, most animals were victims of car accidents during the touristic season (May-October). 10% 9% 12% 7% 21% 6% 1% 6% 2% 13% 13% Total Vegetal Total Animal Non-Organic 13% 27% 60% Fig. 2: C. aureus scat sample. Fig. 4: Stomach content: grapes. Results Plant matter was the primary dietary component in all scats analysed (χ 2 = 47.206, df=10, p-value=8.661e-07). Olives (FO: 16/30), figs (FO: 13/30), grapes (FO: 11/30), seeds (FO: 9/30) and berries (FO: 1/30) were the most commonly items found (Fig. 5). Fig. 6: Design draft for a street warning sign. Figs Berries Grapes Seeds Plant Matter Olives Animal Matter Bones Arthropods Non-Organic Matter Feathers Fig. 5: RFO of the food categories. Fig. 1: Land use map of Samos Island, modified after Corine 2012. Legend Agriculture Airports Anthropogenic Bare rocks Beaches, dunes, sands Mineral extraction sites Natural vegetated Non-irrigated arable land Port areas Salt marshes and salines Sea and ocean
Transcript of Preliminary assessment of feeding ecology of a Golden...
Preliminary assessment of feeding ecology of a Golden jackal (Canis aureus) population in South Eastern Samos Island, Greece, through post mortem examination and scat analysis
W33P Dr. Guido Pietroluongo, [email protected] International Symposium on jackals and related species31st of October - 2nd of November 2018Marathon Bay - Attica, Greece
References1Giannatos, G. (2004). Conservation action plan for the golden jackal Canis aureus L. Greece WWF Greece 47. 2Radović, A., and Kovačić, D. (2010). Diet composition of the golden jackal (Canis aureus L.) on the Pelješac Peninsula, Dalmatia, Croatia. Periodicum biolo-gorum 112, 219-224. 3Raichev, E.G., Tsunoda, H., Newman, C., Masuda, R., Georgiev, D.M., and Kaneko, Y. (2013). The Reliance of the golden jackal (Canis aureus) on anthropogenic foods in winter in Central Bulgaria. Mammal study 38, 19-27.
Introduction Samos Island, North-Eastern Aegean Sea, is one of the few Mediterranean islands and the only one in Greece where the Golden Jackal (Canis aureus) is considered native. Previous studies estimated 13 to 20 groups on the island with 8 to 15 individuals each; most of them found in the Eastern side1. This study focuses on the diet composition of the C. aureus population living on the South-Eastern region (Fig. 1), based on scat analyses and post mortem analyses of stomach contents.
Pietroluongo G.1, Leggett J.2, Falquina Fernández F. J.1, Linardaki I.1, Parker W.1, Miliou A.1, Tsimpidis T.1
Conclusion The samples collected during the necropsies demonstrate that the diet of C. aureus is highly diverse. Further analyses should be carried out in order to study a potential relation of the population with anthropic settlements and regional agricultural habits. In addition to this, higher sampling numbers and systematic surveys are underway to assess the feeding ecology of the overall population living on the island and make comparisons based on seasonal and geographical variations. Conservation measures are needed to prevent road-kill, especially during the touristic season (Fig. 6).
Necropsies were conducted (Fig. 3) on 15 specimens between April 2017 and September 2018. The stomach of each individual was isolated. The content was collected and categorised into organic (vegetal; animal) and non-organic components (Fig. 4).
Archipelagos Institute of Marine Conservation,Marine Research Base: P.O. Box 42, Pythagorio,
Samos 83103, Greecewww.archipelago.gr
Layo
ut b
y Li
lly G
othe
– li
lly.g
othe
@ou
tlook
.de
Fig. 3: C. aureus necropsy.
1 Archipelagos Institute of Marine Conservation 2 University of the West of England
Materials & Methods 30 scat samples were collected (Fig. 2) between June and September 2018 along transects set in areas habituated by C. aureus. The samples, after being soaked in water, were rinsed through a sieve (0.5 mm) in order to separate fecal matter from identifiable content. The collected content was dried and divided into the same categories as the stomach content of the dead jackals. Frequency of occurrence (FO) and Relative Frequency of Occurrence (RFO) were calculated for each category2, 3.
In all the 15 stomachs vegetal matter was found: leaves, grass, mulberries (Morus alba), olives (Olea europaea), grapes (Vitis vinifera), figs (Ficus carica), carob (Ceratonia siliqua). 5 stomachs contained animal remains (bones, arthropods, feathers). An unusual case of a hook with a nylon line was found.
Discussion The scat analyses showed similar results to those of the post-mortem ones. The studied population is composed of opportunistic omnivores, with seasonal dependency on the food sources. The samples collected have shown the preference for natural food sources instead of anthropogenic food subsidies. Even though the population is living in a synanthropic environment, no evidence of feeding on anthropogenic materials, such as domestic waste, was recorded.
Diet composition shows seasonal variations associated with the availability of different prey and food sources. During the summer season, the diet was mostly composed by fruits (i.e. figs, carobs, grapes, berries, olives, etc.) while in the winter season the composition showed presence of bones belonging to small mammals (rodents, birds, etc.).
Scats were primarily collected during spring and summer, when they are better preserved due to good weather conditions. Although necropsies were conducted throughout the year, most animals were victims of car accidents during the touristic season (May-October).
10%
9%
12%7%
21%6%
1%
6%
2%
13%
13%
Total Vegetal Total Animal Non-Organic
13%27%60%
Fig. 2: C. aureus scat sample. Fig. 4: Stomach content: grapes.
Results Plant matter was the primary dietary component in all scats analysed (χ2 = 47.206, df=10, p-value=8.661e-07). Olives (FO: 16/30), figs (FO: 13/30), grapes (FO: 11/30), seeds (FO: 9/30) and berries (FO: 1/30) were the most commonly items found (Fig. 5).
Fig. 6: Design draft for a street warning sign.
Figs
Berries
Grapes
Seeds
Plant Matter
Olives
Animal Matter
Bones
Arthropods
Non-Organic Matter
Feathers
Fig. 5: RFO of the food categories.
Fig. 1: Land use map of Samos Island, modified after Corine 2012.
LegendAgriculture
Airports
Anthropogenic
Bare rocks
Beaches, dunes, sands
Mineral extraction sites
Natural vegetated
Non-irrigated arable land
Port areas
Salt marshes and salines
Sea and ocean
