Taphonomy of Yellow-legged Gull (Larus …...10 E-mail: [email protected]; [email protected] 11 c Unité Histoire naturelle de l’Homme préhistorique (HNHP), Muséum national

Draft

Taphonomy of Yellow-legged Gull (Larus michahellis Naumann, 1840) pellets from the Chafarinas Islands

(Spain)

Journal: Canadian Journal of Zoology

Manuscript ID cjz-2018-0139.R1

Manuscript Type: Article

Date Submitted by the Author: 16-Jul-2018

Complete List of Authors: Guillaud, Emilie; Museum National d'Histoire Naturelle, Morales-Muñiz, Arturo ; Universidad Autonoma de Madrid Facultad de Ciencias Economicas y Empresariales, Dept. BiologiaRosello Izquierdo, Eufrasia; Universidad Autonoma de Madrid Facultad de Ciencias Economicas y Empresariales, Dept. Biologia Calle Darwin 2Béarez, Philippe; Museum National d'Histoire Naturelle, UMR 7209 55 rue Buffon

Is your manuscript invited for consideration in a Special

Issue?:Not applicable (regular submission)

Keyword: Yellow-legged gull, Larus michahellis, Pellet, Fish bone, Taphonomy, Chafarinas Islands

https://mc06.manuscriptcentral.com/cjz-pubs

Canadian Journal of Zoology

Draft

1

1 Taphonomy of Yellow-legged Gull (Larus michahellis Naumann, 1840) pellets from the

2 Chafarinas Islands (Spain)

3 Emilie GUILLAUDa,c, Arturo MORALES-MUÑIZb, Eufrasia ROSELLÓ-IZQUIERDOb,

4 Philippe BÉAREZa

5

6 a Unité Archéozoologie, archéobotanique: sociétés, pratiques et environnements (AASPE),

7 Muséum national d’histoire naturelle, CNRS. CP 56, 57 rue Cuvier, 75005 Paris, France .

8 E-mail : [email protected]; [email protected]

9 b Laboratorio de Arqueozoología, Universidad Autónoma de Madrid, E-28049 Madrid, Spain.

10 E-mail: [email protected]; [email protected]

11 c Unité Histoire naturelle de l’Homme préhistorique (HNHP), Muséum national d’histoire

12 naturelle, CNRS. 1 rue René Panhard, 75013 Paris, France.

13

14 Abstract

15 Fish are consumed by many predators in addition to humans. Identifying the agent responsible for

16 an archaeological fish bone accumulation is a crucial yet far from straightforward task in the

17 absence of diagnostic criteria. It is for this reason that exploring the features of fish bone

18 collections produced by animals constitutes a key issue of archaeozoological research. In this

19 paper one such study is presented for the Yellow-legged Gull (Larus michahellis Naumann,

20 1840). A total of 48 pellets were collected in a colony of the species on two islands of the

21 Chafarinas archipelago (Mediterranean Sea). The analyses demonstrate that fish remains,

22 represented by 13 species and one genus, made up 93% of the 2,789 identified remains. Most

23 assemblages were dominated by the European pilchard (Sardina pilchardus (Walbaum, 1792)).

Page 1 of 39



Draft

2

24 Our study indicates that digestive processes modify skeletal elements through abrasion and

25 fragmentation. Based on the modifications that were recorded, a set of diagnostic criteria is

26 proposed to serve as proxies for spotting fish bone deposits produced by gulls on archaeological

27 assemblages.

28

29 Résumé

30 En dehors des populations humaines, les poissons sont inclus dans l'alimentation d'un large

31 éventail de prédateurs. Pour cette raison, l'identification de l'agent responsable des accumulations

32 d'os de poisson, en contexte archéologique, est une tâche cruciale mais souvent loin d'être simple

33 en l'absence de critères diagnostiques. L'observation des informations diagnostiques produits par

34 des accumulateurs non humains, sur des ossements de poissons, constitue donc une question clé

35 de la recherche archéozoologique. Dans cet article, est présenté l’étude taphonomique de pelotes

36 provenant d’un rapace diurne opportuniste : le Goéland à pattes jaunes (Larus michahellis

37 Naumann, 1840). L'analyse de 48 pelotes collectées sur deux îles de l'archipel des Chafarinas

38 (mer Méditerranée), a montré que les restes de poissons -13 espèces et un genre- représentaient

39 93% des 2789 restes identifiés sur l’ensemble des assemblages. Le spectre est dominé par la

40 sardine (Sardina pilchardus (Walbaum, 1792)). Notre étude a démontré que les processus

41 digestifs modifient souvent les éléments du squelette par abrasion et fragmentation. En se basant

42 sur les modifications de surface, un ensemble de critères a pu être identifié concernant le goéland

43 à pattes jaunes. Ces critères peuvent servir de d’indicateurs pour repérer l’impact de cette espèce

44 sur les assemblages archéologiques.

45

46 Keywords

Page 2 of 39



Draft

3

47 Yellow-legged gull, Larus michahellis, pellet, fish bone, taphonomy, Chafarinas Islands.

Page 3 of 39



Draft

4

49 Introduction

50 In zooarchaeology, the identification of species is not restricted to anatomy and taxonomy.

51 Determining the origin of an archaeological deposit, for example, requires the accumulating

52 agent to be identified and that task, in turn, requires taphonomic criteria. For fishes, preyed by

53 many animals in addition to humans, an improvement in excavation and retrieval techniques has

54 generated a large number of sites where fish bones are found. Yet the origin of their deposits

55 remains unspecified more often than not due to a lack of taphonomic criteria. On caves, the

56 problem is compound by a spatio-temporal coexistence of fish predators such as carnivores,

57 raptors and humans, whose meal leftovers get mixed in the archaeological deposits. To

58 complicate matters further, the remains of those predators may not appear in the deposits so that

59 their presence can only be inferred through criteria such as the size range of the fish taxa present,

60 marks recorded on fish bones, etc. Under such circumstances, only a taphonomical analysis will

61 manage to correctly infer the accumulating agent (Andrews 1990; Fernández-Jalvo and Andrews

62 2016).

63

64 Actualistic studies are a fundamental tool for taphonomical analysis since the baselines they

65 provide allow zooarchaeologists to correctly interpret data from the past. In the case of birds,

66 dietary studies based on ocular inspection of pellets are often biased since remains tend to be

67 digested to the extent that even complete bones can be difficult to identify. Here lies the

68 importance of evaluating fish remains modifications under closer scrutiny. Comparative analyses

69 of diets, however, are rarely carried out from a taphonomical standpoint. To date, few studies

70 exist that allow one to set apart fish accumulations produced by humans (Jones 1986) from those

71 produced by predators (Russ and Jones 2011; Guillaud et al. 2017) or those of mixed origin (Russ

Page 4 of 39



Draft

5

72 2016; Morales in press). Previous taphonomical analyses of bird meal leftovers have focused on

73 the Eurasian eagle owl (e.g. Nicholson 1991; Le Gall 1999, Russ 2010; Russ and Jones 2011),

74 barn owl (Broughton et al. 2006), bald eagle (Erlandson et al. 2007) and common kingfisher

75 (Frontin 2017). Although gulls at large (i.e. Laridae) are regular fish-eaters on marine, lacustrine

76 and riverine habitats, the marks they leave on fish bones have not been investigated from a

77 taphonomical standpoint.

78

79 In this paper, we provide an overview of the range of species consumed by the Yellow-legged

80 gull (Larus michahellis Naumann, 1840) in the Strait of Gibraltar area and the traces it leaves on

81 fish bones. An opportunistic and eclectic predator, the Yellow-legged gull’s diet is still poorly

82 documented no study existing that addresses the issue of traces left on fish bones (Ramos et al.

83 2006; 2009). A vicariant species of the European herring gull (Larus argentatus Pontoppidan,

84 1763), we also targeted the Yellow-legged gull with the aim of developing a taphonomical

85 baseline for gull diet studies in the Northern Atlantic in general (Del Hoyo et al. 1996; Collinson

86 et al. 2008).

87

88 Study area

89 The Chafarinas Islands (Fig 1) are located in the southern Alborán Sea, off the eastern

90 Mediterranean coast of Morocco, facing the city of Melilla (35o 11’ N, 2o 26’ W). The main

91 islands of this volcanic archipelago are Congreso, Isabel II and Rey. Only Isabel II Island has

92 been permanently inhabited since 1848 by a Spanish garrison. In 1982, the islands were classified

93 as a National Hunting Refuge Area (Royal Decree 1115/82). Later, in 1989, they were declared a

94 Special Protection Area for Birds (SPA; Directiva 79/409/EEC) and in 2006 they became a Site

Page 5 of 39



Draft

6

95 of Community Importance (SCI) of the Natura 2000 network (EEC Habitats Directive 92/43)

96 (Guallart Furió and Afán Asensio 2013).

97

98 Figure 1: Location of sites mentioned in the text.

99

100 Several gull species are found on the Chafarinas, some confusion existing when distinguishing

101 the Yellow-legged Gull and the endangered Audouin's Gull (Ichthyaetus audouinii Payraudeau,

102 1826), whose largest nesting colony in the Mediterranean is found on Congreso island. The two

103 species feature similar life histories and their breeding colonies lie adjacent to each other despite

104 the Yellow-legged gull being a major predator of Audouin’s gull’s eggs and chicks (Oro et al.

105 1999).

106

107 Material and methods

108 A total of 56 regurgitation pellets were collected at Congreso and Rey islands in June 1965, June

109 1968, and April-June 1969. At Congreso, pellets were collected around Yellow-legged gull nests

110 lying close to the breeding colony of Scopoli's shearwater, Calonectris diomedea (Scopoli, 1769).

111 On Rey Island pellets were collected around the nests. The identification of pellets as belonging

112 to the Yellow-legged Gull was carried out in the field by Varela and De Juana (1986) (Fig 2).

113

114 Figure 2: Pellet of Yellow-legged Gull.

115

116 Each pellet was cleaned through a 0.5 mm mesh sieve with fresh tap water and 70% alcohol, and

117 then air-dried on filter paper. Each bone was identified through anatomic and taxonomic

Page 6 of 39



Draft

7

118 comparison using one of the authors’ (AMM) reference collection housed at the Laboratorio de

119 Arqueozoologia, Universidad Autonoma de Madrid (UAM). Remains were inspectioned both

120 macroscopically and microscopically. A binocular microscope was used for the identification of

121 small skeletal elements and for the observation of marks. For quantitative purposes, the number

122 of identified specimens (NISP) and the minimum number of individuals (MNI) were used (Reitz

123 and Wing 2008). MNIs were estimated based on the number of first vertebrae and paired bones,

124 taking into account side (left/right) and size (Poplin 1976). Specimen size was inferred through

125 direct comparison with modern reference specimens. Surface modification was recorded

126 following Nicholson’s method (1991), the percentage of visible surface present adapted from

127 Villa and Mahieu (1991). Bone digestion was recorded according to a five category scale,

128 namely: absent (0), minimal (1), moderate (2), heavy (3) and extreme (4-5) (Fernández-Jalvo and

129 Andrews 2016). Percentage of bone representation follows Dodson and Wexlar (1979) (PR =

130 FO/FT x MNI, where FO is the number of elements in the sample and FT the number of elements

131 in the prey’s skeleton excluding fin rays, pterygiophores, ribs and scales). This formula also

132 provided an overview of skeletal representation, as frequencies from each element were pooled

133 from all pellets.

134

135 Results

136 A total of 48 pellets from the islands of Congreso (N = 34) and Rey (N = 14), representing 2,789

137 identified remains, were analyzed for this study (Table I).

138

139 Table I. Number of identified remains in the Yellow-legged gull pellets. NISP: number of

140 identified specimens; (%): percentage of identified specimens

Page 7 of 39



Draft

8

141

142 Fish represented 93% (NISP = 2,602) of the total sample (Table I), most pellets containing the

143 bones of just one individual. Detailed counts for Congreso Island (NISP = 1,505) and Rey Island

144 (NISP = 1,097) are given in Tables II and III. Several pellets also contained remains of birds

145 (chicken), mammals (mice, rabbit, sheep), crustaceans (crabs), molluscs (cuttlefish), insects

146 (Tenebrionidae) and seeds for a total non-fish NISP of 170 (17 remains could not be identified

147 taxonomically).

148 Thirteen species and one genus of fish were identified. These include Eel, Anguilla anguilla

149 (Linnaeus, 1758); Bogue, Boops boops (Linnaeus, 1758); White sea bream, Diplodus sargus

150 (Linnaeus, 1758); European anchovy, Engraulis encrasicolus (Linnaeus, 1758); grouper,

151 Epinephelus sp.; Sand steenbras, Lithognathus mormyrus (Linnaeus, 1758); European hake,

152 Merluccius merluccius (Linnaeus, 1758); Axillary sea bream, Pagellus acarne (Risso, 1827);

153 Common pandora, Pagellus erythrinus (Linnaeus, 1758); Red porgy, Pagrus pagrus (Linnaeus,

154 1758); European pilchard, Sardina pilchardus (Walbaum, 1792); Round sardinella, Sardinella

155 aurita Valenciennes, 1847; Salema, Sarpa salpa (Linnaeus, 1758 ) and Atlantic horse mackerel,

156 Trachurus trachurus (Linnaeus, 1758).

157

158 In decreasing order of importance, the most frequently represented family was Clupeidae

159 (Sardine; NISP = 1476; MNI =50), followed by Sparidae (Sea breams; NISP = 218; MNI = 16),

160 Engraulidae (Anchovy; NISP = 100; MNI = 6), Anguillidae (Eel; NISP = 58; MNI = 4);

161 Carangidae (Horse mackerel; NISP = 35; MNI = 5); Merlucciidae (Hake; NISP = 15; MNI = 2)

162 and Serranidae (Groupers; NISP =1; MNI = 1). Estimated mass ranged from less than 10 g to

163 200g (10 to 30 cm TL) and up to 2000 g (40 cm TL) for the White sea bream.

Page 8 of 39



Draft

9

164

165 Table II. Number of identified and unidentified remains per Yellow-legged gull pellet. NISP:

166 number of identified specimens; (%): percentage of identified specimens.

167 Table III. Number of identified remains per species and per pellets of Yellow-legged gull pellet.

168

169 Anatomical representation

170 Only 42% of the remains have been identified both anatomically and taxonomically. Among

171 these, 7% (169) belonged to the cranial skeleton and 35% (915) to the axial skeleton.

172 Unidentified vertebrae fragments, including neural or haemal processes and scales, represented

173 58% (1518) of the remains.

174

175 Sardine was represented by the entire skeleton, with caudal vertebrae being the most frequent

176 category. Caudal vertebrae also dominated the anchovy, eel, hake and horse mackerel samples.

177 For sea breams, the dentary was the most frequently represented bone. The maxilla was the only

178 element present for grouper.

179

180 Bone modification

181 Bone surface damage was recorded with a stereoscope. Only 3% of the elements lack traces of

182 digestion. The frequencies of those that do include 9% altered to a light degree (1), 6%

183 moderately affected (2), 41% featuring heavy modification (3), and 22% extremely damaged (4-

184 5) (Table IV). Eel, sea bream and grouper exhibited no digestion traces or else minimal digestion.

185 Horse mackerel remains exhibited moderate digestion for the most part whereas sardine, anchovy

186 and hake bones were all heavily altered by digestion. Within a single pellet, the intensity of

Page 9 of 39



Draft

10

187 digestion can vary from bone to bone, as this may depend on the type of bone and on how long

188 ingestion lasted.

189

190 Table IV. Percentage and classes of digestion for fish taxon by number of remains (NISP) and

191 percentage

192

193 Deformation of skeletal elements was infrequent. The rounding and polishing of articulation

194 edges observed under the scanning electron microscope (SEM) allowed us to recognize advanced

195 degradation along with digestion pits (Fig 3). Several types of alteration were visible, including

196 fissures (NISP = 37), exfoliation (NISP = 34), and abrasion/polishing marks (NISP = 1,141).

197 Otoliths and eye lenses were well preserved and showed no evidence of alteration.

198

199 Figure 3: Modification of a precaudal vertebra of Anguilla anguilla (scanning electron

200 microscope).

201

202 Survival rate, fragmentation and loss of skeletal elements

203 Yellow-legged gull pellets were characterized by the presence of complete and fragmented

204 elements within the same pellet. The elements that were retrieved exhibited a moderate degree of

205 integrity. The frequency of broken elements reached to 40% of the remains. Three fish specimens

206 were almost intact but were missing the head (Fig 4).

207

208 Figure 4: Degrees of digestion.

Page 10 of 39



Draft

11

209 a) Undigested Boops boops, b) Sardine bones (loss absent); c) Precaudal vertebra of sardine

210 (minimal digestion); d) Caudal vertebra of sardine (moderate digestion); e) Sardine vertebra

211 exhibiting intensive digestion; f) and g) From the same pellet, two patterns of digestion of

212 precaudal vertebra of eel (lack of and heavy digestion); h) and i) From the same pellet, two

213 patterns of digestion of opercula of sardine (lack of and moderate digestion).

214

215 Only 29 skeletal elements from approximately 200 bones composing the entire skeleton were

216 recovered after the digestive process (Fig 5, Table V). The percentage of representation as per

217 Dodson and Wexlar (1979) evidenced good preservation for caudal vertebrae (PR = 98.5% for

218 Anchovy, 62.4% for Sardine; 40.9% for Hake and 28% for Eel). The basioccipital was best

219 preserved in Sea breams (PR = 37.5%), and so were the maxilla and the quadrate in the Horse

220 mackerel (PR = 12.5%). For Grouper, only one maxilla was recovered. Within the Sea breams,

221 the dentary was well preserved in White sea bream (PR = 50%) and Common pandora

222 (PR = 100%), whereas the maxilla was well preserved in Sand steenbras and the premaxilla in the

223 Axillary sea bream (PR = 75%). In Red porgy, the dentary and maxilla were present with

224 identical proportions (PR = 50%) whereas for Salema the samples included articular, cleithrum,

225 coracoid, parasphenoid, scapula, subopercle and supracleithrum (PR = 100%). The bones least

226 represented include the precaudal vertebrae of Bogue (PR = 5%) and Salema (18%), the caudal

227 vertebrae of the Axillary sea bream (PR = 2%), and the premaxilla (Red porgy) and articular plus

228 dentary for Sand Steenbras (PR = 25% in all cases). Bones were best preserved in specimens

229 weighing either around 200-300 g (Hake and Sea breams) or 20-60 g (Eel, Horse mackerel,

230 Sardine and Anchovy).

231

Page 11 of 39



Draft

12

232 Figure 5. Skeletal elements before and after digestion in Yellow-legged gull pellets (Common

233 carp skeleton, modified from Tercerie et al. 2016 (osteobase.mnhn.fr) and Archaeological Fish

234 Resource (http://fishbone.nottingham.ac.uk/). For abbreviations see Table V.

235

236 Discussion

237 Generalist and opportunistic habits have been reported on other Yellow-legged gull colonies from

238 the Western Mediterranean. Examples include Bosch et al. (1994), who analyzed 85 pellets from

239 the Medes Islands and the Ebro Delta on the northeastern coast of Spain; Vidal et al. (1998), who

240 studied 350 chick regurgitates on colonies from those two localities plus others on the

241 Columbretes and Mazarrón islands; and Duhem et al. (2003a, b), who analyzed 1,192 pellets

242 from 6 colonies in southeast France (Ratonneau, Pomègues, Plane, Riou, Porquerolles, and

243 Bagaud). Consistent with the results of our analysis, these studies evidenced that fish were the

244 main prey of the Yellow-legged gull’s diet, and Anchovy and Sardine its favored species (Fasola

245 et al. 1989; Gonzáles-Solís et al. 1997). Fish nevertheless constituted a significantly smaller

246 percentage of food remains (65-85%) in those studies than appears to be our case. This might be

247 due to a combination of factors, the absence of substantial (human) dumpyards on the Chafarinas

248 being probably a crucial item. Failure to carry out taphonomic analyses on those samples does

249 not allow one to decide whether the fish retrieved derived from active fishing or from

250 scavenging. Studies from other regions do not exhibit such consistency in the dietary spectra.

251 López et al. (2016) studied 529 pellets and 465 fecal samples from the island of El Hierro in the

252 Canary Islands and found that fish represented only slightly over 30% of the identified remains.

253 Pellets consisted of 5% of marine invertebrates (including Crustacea) which frequencies rose to

254 19% in the fecal samples. Terrestrial invertebrates, including Pulmonata, Araneae, Isopoda,

Page 12 of 39



Draft

13

255 Julida, Orthoptera and Coleoptera, represented 60% of preyed items in pellets and 84% on fecal

256 samples. Terrestrial vertebrates (reptiles, mammals and birds) represented less than 5% of all

257 prey. These spectra hint at the presence of substantial vegetation on El Hierro island, and this

258 contrasts with the essentially barren landscape characterizing the Chafarinas archipelago. Also,

259 given that terrestrial invertebrates tend to be more frequent in gull pellets when scavenging is the

260 preferred feeding strategy, the data from El Hierro island stress the scavenging (i.e. generalist and

261 opportunistic) component in the feeding behavior of this species (Bernhardt et al. 2010; Matias

262 and Catry 2010).

263

264 The presence of a broad size range for eel and sardine indicates no selectivity of prey size. Fish

265 body size can also be interpreted in terms of season of capture. Seasonality may not only hold the

266 key to the shifting abundances of fish in pellets and fecal samples of the Yellow-legged gull, but

267 may also explain the dominance of sardine and snchovy that our study and the aforementioned

268 western Mediterranean ones reveal. The study by López et al. (2016) concluded that prey

269 abundances were linked not only to environment but also season. Apparently, when colonies are

270 located next to a continental platform, the proportion of marine prey is higher during autumn-

271 winter and decreases at other times of the year (Moreno et al. 2010). These differences in prey

272 composition can be explained by the availability of specific food resources for each colony.

273 When marine resources, in particular fish, diminish, gulls will tend to focus on alternative, easier

274 to obtain, foodstuffs (Bertellotti et al. 2001). The absence of a continental platform around the

275 volcanic Chafarinas Islands may help explain why, even during spring, fish made up such a high

276 proportion of the diet. But the time of the year when pellets were collected is also important.

277 June-July, for example, are the months when sardines and anchovies reach surface waters in the

Page 13 of 39



Draft

14

278 Alborán Sea during their spawning migrations. Under such circumstances, the abundance of these

279 Clupeiformes within the pellet samples makes a lot of sense.

280 In terms of dietary spectrum then, the results from our analysis appear essentially consistent with

281 the data that have been thus far published for this species. The food spectra of the Yellow-legged

282 gull in the Chafarinas islands reflect a combination of active fishing and scavenging of human

283 refuse deposits. Although no people are presently stationed on Congreso or Rey Islands, where

284 the breeding colonies of the species are located, the remains of birds and mammals, as well as

285 those of fish such as the White sea bream, appear to derive from a regular scavenging of garbage

286 dump yards of the garrison stationed at the island of Isabel II. On the other hand, most of the

287 fishes that made up the bulk of the spectra, in particular sardine and anchovy, appear to represent

288 active fishing on the part of gulls.

289

290 The general pattern of modification recorded in our samples was characterized by extensive

291 damage and evidence of bone digestion. The analyses indicated variations in terms of bone

292 modification, depending on the species but also even within the same species.

293

294 It is interesting to compare the Yellow-legged gull data with that from other fish predators.

295 Among the nocturnal raptors, the Eurasian eagle owl, Bubo bubo (Linnaeus, 1758), long

296 recognized as a recurrent accumulator of fish in archaeological deposits, has been the species

297 most intensively studied. Among the works of zooarchaeological relevance, in addition to Le Gall

298 (1999) who analyzed pellets from southeastern France and Guillaud et al. (in prep.) who analyzed

299 pellets from Tautavel (France), one needs to consider the trace analysis of a controlled feeding

300 experiment carried out by Russ (2010). The skeletal spectra from the latter analysis evidenced

Page 14 of 39



Draft

15

301 that almost complete fish skeletons were retrieved. Digestion traces were minimal and bone

302 deformations rare. Digestion damage included fissures, exfoliation, perforation, twisted bones

303 and beak impact marks. In the case of the Barn owl, Tyto alba (Scopoli, 1769), a study of 14

304 pellets from Homestead Cave (Utah, USA) also evidenced a high level of conservation and low

305 damage including feeble digestion traces (Broughton et al. 2006). Such facts notwithstanding,

306 rounding, pitting and deformation were recorded on a few bones.

307 Fewer studies of fish bone remains from pellets exist in the case of diurnal raptors. The common

308 kingfisher, Alcedo atthis (Linnaeus, 1758), was studied by Frontin (2017), yet her taphonomic

309 study covered only 10% of the available sample (NISP = 5868) and focused on vertebrae (no

310 cranial remains were analyzed). Frontin (2017) did not find any visible traces of manipulative

311 marks on her samples. Engström and Johnsson (2003; L. Johnsson pers. comm.) studied pellets

312 from the Great cormorant, Phalacrocorax carbo (Linnaeus, 1758) whose fish bones featured

313 intensive digestion marks, similar to those reported by Andrews (1990), and the most superficial

314 of the cranial bones were completely dissolved. Otoliths in cormorant pellets survived longer

315 than either bone or eye lenses.

316 As far as gulls are concerned, the most important study is that of Nicholson (1991), who collected

317 pellets from the European herring gull (Larus argentatus Pontoppidan, 1763) and the Greater

318 black-backed gull (Larus marinus Linnaeus, 1758) on Eileans and Skate Point in the Great

319 Cumbrae Islands (Scotland). In this case, out of a total of 84 pellets, only six contained fish

320 bones. The majority of pellets contained mollusk shells, crabs, beetles, algae and human

321 consumption waste. Fish bones exhibited a wide range of damage, including fragmentation and

322 digestive erosion. Cranial bones showed little damage whereas some vertebrae featured rounded

323 and lightly polished margins, a result of erosion by acids. Rarely were fish remains from one

Page 15 of 39



https://en.wikipedia.org/wiki/Erik_Pontoppidan

Draft

16

324 pellet homogeneously corroded, some being polished/rounded others not. Not surprisingly, given

325 the taxonomical proximity of these species to the Yellow-legged gull, the results from

326 Nicholson’s study appear fully consistent with ours.

327 Few fish bone studies have been carried out on carnivores, the spraints of the Eurasian otter,

328 Lutra lutra (Linnaeus, 1758), being the most appropriate analogue. The studies that have been

329 carried out report intensive modifications including chewed and crushed bones, along with

330 dissolution, pitting and rounding marks (Nicholson 2001, Guillaud et al. 2017). Fish bones

331 consumed by otters tend to be broken and digested to a degree that corresponds mostly with

332 category no. 5 (Andrews, 1990).

333

334 Several studies report that the variability of taphonomic marks, even within the same species,

335 may depend on factors such as age, size of the predator, size of the prey, prey availability and the

336 histological structure of the bones (Denys et al. 1995; Fernández-Jalvo et al. 2002). The time it

337 takes for a pellet to be produced depends on the type of prey ingested by the gull. Brown and

338 Ewins (1996) estimated that pellets can take several days to form but an experimental study on

339 the Great skua (Stercorarius skua Brunnich, 1764) evidenced that pellets took only 6-24 hours to

340 form after feeding (Votier et al. 2001). It appears that pellets are produced faster when they

341 contain an excess of non-digestible material. All these contingencies may help explain why in our

342 samples bones from the same species exhibited different intensities of digestion even within the

343 same pellet (e.g., some may have been immediately regurgitated, others later) and why some fish

344 were still almost intact. These studies also highlight variations in bone modification among the

345 different types of predators. Bone fragmentation and skeleton completeness in pellet assemblages

346 may also depend on the feeding habits of a bird (e.g., fisher or scavenger). These differences in

Page 16 of 39



Draft

17

347 feeding behaviour may also imply that preyed fish MNIs calculated for the total assemblage can

348 be far lower than the actual number of consumed fish.

349

350 The importance of recognizing non-human predators in archaeological assemblages is crucial for

351 the correct interpretation of any bone accumulation. Archaeological sites were often shared by

352 human groups, raptors and carnivores, thus their recognition enables researchers to access various

353 kinds of information. Spatial distribution can also potentially inform the analyst about the

354 specific fish accumulator at a given deposit. Nocturnal raptors bone accumulations tend to

355 concentrate next to their nests whereas diurnal raptors, including gulls, tend to concentrate their

356 food remains around or below roosting sites. This is also the case of otters which use spraints to

357 mark their territory, being thus prone to place meal leftovers on top of rocks and prominences

358 around their dens.

359

360 Conclusions

361 The available taphonomic studies of fish accumulations made by predatory birds and otters

362 provide evidence that traces of digestion vary among species. These studies also suggest that

363 archaeological fish deposits can be characterized by a combination of features, including the

364 variety of skeletal elements present, as well as by differing amounts of fragmentation and quite

365 specific bone surface alterations.

366 In this paper, we provide the first taphonomic study of pellets from the Yellow-legged gull. This

367 opportunistic species consumes a variety of live prey, including those around human refuse

368 grounds, as well as a variety of meal leftovers. Based on selected digestion traits on the skeletal

369 elements, heavy digestion and polishing rather than fragmentation appear to constitute the most

Page 17 of 39



Draft

18

370 relevant features of fish accumulations produced by this gull. Some pitting and rounded bones

371 may also be diagnostic. These results are consistent with those carried out previously on other

372 gull species.

373 To set up reliable baselines taphonomic analyses must be implemented for as many species of

374 fish accumulators as possible to develop a robust comparative frame for the potential recognition

375 of the specific accumulator agent, or agents, that operated at any given site.

376

377 Acknowledgements

378 This study was funded by a fellowship granted by the LabEx BCDiv of the Muséum National

379 d’Histoire Naturelle (Paris) and by the project “Ictioarqueologia de la prehistoria cantábrica:

380 Modelos para la caracterización de las primeras pesquerías europeas” (HAR 2014-55722-P) from

381 the Spanish Ministerio de Economía y Competitividad. We would like to particularly thank

382 Yolanda Fernández-Jalvo and Leif Jonsson for their advice, Arlene Fradkin for copy-editing, and

383 Christine Lefèvre, François Poplin and Jean-Bernard Huchet for their help with the identification

384 of birds and insects. Michel Lemoine is acknowledged for making the SEM pictures with the

385 neoscope of the “plateau archéobotanique de l’UMR 7209 équipement programme CoBota-IdF”

386 and Marie-Hélène Moncel for post-doctoral co-supervision.

387

388 References

389

390 Andrews, P. 1990. Owls, Caves and Fossils. University of Chicago Press (Chicago).

391

Page 18 of 39



Draft

19

392 Archaeological Fish Resource [en ligne]. Available from http://fishbone.nottingham.ac.uk/

393 [consulté le 16 avril 2018].

394

395 Arizaga, J., Jover, L., Aldalur, A., Cuadrado, J.F., Herrero, A., and Sanpera, C. 2013. Trophic

396 ecology of a resident Yellow-legged Gull (Larus michahellis) population in the Bay of Biscay.

397 Mar. Environ. Res. 87–88 : 19–25. Available from

398 http://dx.doi.org/10.1016/j.marenvres.2013.02.016

399

400 Bernhardt, G.E., Kutschbach-Brohl, L., Washburn, B.E., Chipman, R.B., and Francoeur, L.C.

401 2010. Temporal variation in terrestrial invertebrate consumption by Laughing Gulls in New

402 York. Am. Midl. Nat. 163 : 442–454. Available from http://www.jstor.org/stable/40730938

403

404 Bertellotti, M., Yorio, P., Blanco, G., and Giaccardi, M. 2001. Use of tips by nesting Kelp Gulls

405 at a growing colony in Patagonia. J. Field Ornithol. 72 : 338–348.

406

407 Bosch, M., Oro, D., and Ruiz, X. 1994. Dependence of yellow-legged gulls (Larus cachinnans)

408 on food from human activity in two Western Mediterranean colonies. Avocetta, 18 : 135–139.

409

410 Broughton, J.M., Cannon, V.I., Bogiatto, R., Arnold, S., and Dalton, K. 2006. The taphonomy of

411 owl-deposited fish remains and the origin of the Homestead Cave ichthyofauna. Journal of

412 Taphonomy, 4(2) : 69-95.

413

Page 19 of 39



Draft

20

414 Brown, K.,. and Ewins, P.J. 1996. Technique-dependent biases in determination of diet

415 composition: an example with Ring-billed gulls. The Condor, 98 : 34-41. Available from

416 http://www.jstor.org/stable/1369505

417

418 Collinson, J.M., Parkin, D.T., Knox, A.G., Sangster, G., and Svensson, L. 2008. Species

419 boundaries in the Herring and Lesser Black-backed Gull complex. British Birds, 101(7) : 340–

420 363.

421

422 Del Hoyo, J., Elliot, A., and Sargatal, J.1996. Handbook of the Birds of the World. Vol. 3:

423 Hoatzin to Auks. Lynx Editions. (Barcelona).

424

425 Denys, C., Fernández-Jalvo, Y., and Dauphin, Y. 1995. Experimental taphonomy: preliminary

426 results of the digestion of micromammal bones in the laboratory. C.R. Acad. Sci., Ser. IIa: Sci.

427 Terre Planetes. 321(9) : 803-809.

428

429 Dodson, P., and Wexlar, D. 1979. Taphonomic investigation of owl pellets. Paleobiology, 5 :

430 275-284. Available from http://www.jstor.org/stable/2400260

431

432 Duhem, C., Vidal, E., Roche, P., and Legrand, J. 2003a. Island breeding and continental feeding:

433 how are diet patterns in adult yellow-legged gulls influenced by landfill accessibility and

434 breeding stages? Ecoscience, 10 : 502–508. Available from

435 https://doi.org/10.1080/11956860.2003.11682798

436

Page 20 of 39



Draft

21

437 Duhem, C., Vidal, E., Legrand, J., and Tatoni, T. 2003b. Opportunistic feeding responses of the

438 Yellow-legged Gull Larus michahellis to accessibility of refuse dumps. Bird Study, 50(1) : 61-

439 67. doi: 10.1080/00063650309461291

440

441 Engström, H., and Johnsson, L. 2003. Great cormorant Phalacrocorax carbo sinensis diet in

442 relation to fish community structure in a freshwater lake. Vogelwelt, 124(Suppl.) : 187–196.

443

444 Erlandson, J.M., and Moss, M.L. 2001. Shellfish feeders, carrion eaters and the archaeology of

445 aquatic adaptations. American Antiquity, 66(3) : 413-432. Available from

446 http://www.jstor.org/stable/2694242

447

448 Erlandson, J.M., Rick, T.C., Collins, P.W., and Guthrie, D.A. 2007. Archaeological implications

449 of a bald eagle nesting site at Ferrelo Point, San Miguel Island, California. J. Archaeol. Sci. 34

450 (2) : 255-271. Available from https://doi.org/10.1016/j.jas.2006.05.002

451

452 Fasola, M., Bogliani, G., Saino, N., and Canova, L. 1989. Foraging, feeding and time-activity

453 niches of eight species of breeding seabirds on the coastal wetlands of the Adriatic Sea. Bolletino

454 di zoología, 56 : 61–72. Available from https://doi.org/10.1080/11250008909355623

455

456 Fernández-Jalvo, Y., and Andrews, P. 2016. Atlas of taphonomic identifications. Vertebrate

457 Paleobiology and Paleoanthropology Series, Springer. 359p. doi: 10.1007/978-94-017-7432-1

458

Page 21 of 39



Draft

22

459 Frontin, D. 2017. Economie de pêche au Mésolithique et diversité piscicole à l’Holocène ancien

460 dans le bassin hydrographique du Doubs. Unpublished PhD thesis, Paris I Panthéon-Sorbonne

461 University, Paris (France).

462

463 González-Solís, J., Oro, D., Pedrocchi, V., Jover, L., and Ruiz, X. 1997. Trophic niche width and

464 overlap of two sympatric gulls in the southwestern mediterranean. Oecologia, 112 : 75–80.

465 Available from https://doi.org/10.1007/s004420050285

466

467 Guallart Furió, J., and Afán Asensio, I. 2013. Los sistemas naturales en el archipiélago de las

468 islas Chafarinas. Aldaba, 37 : 39-94.

469

470 Guillaud, E., Béarez, P., Denys, C., and Raimond, S. 2017. New data on fish diet and bone

471 digestion of the Eurasian otter (Lutra lutra) (Mammalia: Mustelidae) in central France. The

472 European Zoological Journal, 84(1) : 226–237. Available from

473 https://doi.org/10.1080/24750263.2017.1315184

474

475 Jones , A.K.G. 1986. Fish bone survival in the digestive system of the pig, dog and man: some

476 experiments. Edited by D. C. Brinkhuizen and A. T. Clason. Oxford: BAR International

477 Archaeopress Series 294 : 53-61.

478

479 Le Gall, O. 1999. Ichtyophagie et pêches préhistoriques. Quelques données de l’Europe

480 occidentale. Unpublished Doctorat d'état thesis, Bordeaux I University, Bordeaux (France).

481

Page 22 of 39



Draft

23

482 López, H., Pérez, A.J., Rumeu, B., and Nogales, M. 2016. Trophic strategies of Yellow-legged

483 Gull Larus michahellis on oceanic islands surrounded by deep waters. Bird Study, 63(3) : 337-

484 345. doi: 10.1080/00063657.2016.1194804

485

486 Matias, R., and Catry, P. 2010. The diet of Atlantic Yellow legged Gulls (Larus michahellis

487 atlantis) at an oceanic seabird colony: estimating predatory impact upon breeding petrels. Eur. J.

488 Wildl. Res. 56 : 861–869. Available from https://doi.org/10.1007/s10344-010-0384-y

489

490 Morales, A. in press. Review of “People with Animals. Perspectives and Studies in

491 Ethnozooarchaeology". Edited by L.G. Broderick. Oxbow Books. Orbis Terrarum

492

493 Moreno, R., Jover, L., Munilla, I., Velando, A., and Sanpera, C. 2010. A three-isotope approach

494 to disentangling the diet of a generalist consumer: the yellow-legged gull in northwest Spain.

495 Mar.Biol. 157 : 545–553. Available from https://doi.org/10.1007/s00227-009-1340-9

496

497 Nicholson, R.A. 1991. An investigation into variability within archaeologically recovered

498 assemblages of faunal remains: The influence of pre-depositional taphonomic factors.

499 Unpublished PhD thesis, York University, York (UK).

500

501 Oro, D., Pradel, R., and Lebreton, J.D. 1999. Food availability and nest predation influence life

502 history traits in Audouin’s Gull, Larus audouinii. Oecologia, 118 : 438–445.

503

Page 23 of 39



Draft

24

504 Poplin, F. 1976. A propos du Nombre de Restes et du Nombre d’Individus dans les échantillons

505 d’ossements. Cahiers du Centre de Recherches Préhistoriques, 5 : 61–74.

506

507 Ramos, R., Ramírez, F., Sanpera, C., Jover, L., and Ruíz, X. 2006. Feeding ecology of Yellow-

508 legged Gulls in four colonies along the western Mediterranean: an isotopic approach. J. Ornithol.

509 147 : 235–236.

510

511 Ramos, R., Ramírez, F., Sanpera, C., Jover, L., and Ruiz, X. 2009. Diet of Yellow-legged Gull

512 (Larus michahellis) chicks along the Spanish Western Mediterranean coast: the relevance of

513 refuse dumps. J. Ornithol. 150(1) : 265-272. Available from https://doi.org/10.1007/s10336-008-

514 0346-2

515

516 Reitz, E.J., and Wing, E.S. 2008. Zooarchaeology. Second edition. Cambridge University Press

517 (Cambridge).

518

519 Russ, H. 2010. The Eurasian eagle owl (Bubo bubo): a fish bone accumulator on Pleistocene cave

520 sites? Journal of Taphonomy, 8 : 281-290.

521

522 Russ, H., and Jones, A.K.G. 2011. Fish remains in cave deposits; how did they get there? Cave

523 and karst science, 38(3) : 57-60.

524

525 Russ, H. 2016. To fish or not to fish? Using observations of recent hunter-gatherer fishing in the

526 interpretation of Late Pleistocene fish bone assemblages. In People with Animals: Perspectives

Page 24 of 39



Draft

25

527 and Studies in Ethnozooarchaeology. Edited by L.G. Broderick. Oxbow Books Oxford. pp. 87-

528 102.

529

530 Tercerie, S., Béarez, P., Pruvost, P., Bailly, N., and Vignes-Lebbe, R. 2016. Osteobase. World

531 Wide Web electronic publication. [en ligne]. Available from http://osteobase.mnhn.fr/ [cité le 16

532 avril 2018]

533

534 Varela, J.M., and De Juana, E. 1986. The Larus cachinnans michahellis colony of Chafarinas

535 islands. In Mediterranean Marine Avifauna. Edited by NATO ASI Series, Mediterranean Marine

536 Avifauna. MEDMARAVIS and X. Monbailliu. Springer-Verlag Berlin Heidelberg G. 12 : 231-

537 244

538

539 Vidal, E., Medail, F., and Tatoni, T. 1998. Is the yellow-legged gull a superabundant bird species

540 in the Mediterranean? Impact on fauna and flora, conservation measures and research priorities.

541 Biodivers. Conserv. 7 :1013–1026. Available from https://doi.org/10.1023/A:1008805030578

542

543 Villa, P., and Mahieu, E. 1991. Breakage patterns of human long bones. J. Hum. Evol. 21 : 27–

544 48. doi: 10.1016/0047-2484(91)90034-S.

545

546 Votier, S.C., Bearhop, S., Ratcliffe, N., and Furness, R.W. 2001. Pellets as indicators of diet in

547 Great skuas Catharacta skua. Bird Study, 48 : 373-376. doi:10.1080/00063650109461237

548

Page 25 of 39



Draft

26

549 Witt, H.H., Crespo, J., De Juana, E., and Varela, J.M. 1981. Comparative feeding ecology of

550 Audouin’s gull Larus audouinii and the herring gull L. argentatus in the Mediterranean. Ibis, 123

551 : 519-526.

Page 26 of 39



Draft

27

553 Figure 1. Location of sites mentioned in the text.

554 Figure 2. Pellet of Yellow-legged Gull.

555 Figure 3. Modification of a precaudal vertebra of Anguilla anguilla (scanning electron

556 microscope).

557 Figure 4. Degrees of digestion. a) Undigested Boops boops, b) Sardine bones (loss absent); c)

558 Precaudal vertebra of sardine (minimal digestion); d) Caudal vertebra of sardine (moderate

559 digestion); e) Sardine vertebra exhibiting intensive digestion; f) and g) From the same pellet, two

560 patterns of digestion of precaudal vertebra of eel (lack of and heavy digestion); h) and i) From the

561 same pellet, two patterns of digestion of opercula of sardine (lack of and moderate digestion).

562 Figure 5. Skeletal elements before and after digestion in Yellow-legged gull pellets (Common

563 carp skeleton, modified from Tercerie et al. 2016 (osteobase.mnhn.fr) and Archaeological Fish

564 Resource (http://fishbone.nottingham.ac.uk/). For abbreviations see Table V.

Page 27 of 39



Draft

28

566 Table I. Number of identified remains from pellets of Yellow lugged gull. NISP: number of identified

567 specimens; (%): percentage of identified specimens

Congreso IslandNISP (%)

Rey IslandNISP (%)

TotalNISP

Total%

Fish 1505 (90.2) 1097 (97.9) 2602 93.3

Birds 87 (5.2) 7 (0.6) 94 3.4

Mammals 29 (1.7) 9 (0.8) 38 1.4

Seeds 15 (0.9) - 15 0.5

Crustaceans 10 (0.6) - 10 0.4

Molluscs 5 (0.3) - 5 0.2

Insects - 4 (0.4) 4 0.1

Rodents 1 (0.1) 3 (0.3) 4 0.1

Unidentifed remains 17 (1.0) - 17 0.6

Total 1669 (60) 1120 (40) 2789 100

568

Page 28 of 39



Draft

29

570 Table II. Number of identified and unidentified remains per Yellow lugged gull pellet. NISP: number of

571 identified specimens; (%): percentage of identified specimens.

Pellets Skeletal remainsIdentifiedNISP (%)

UnidentifiedNISP (%)

4 5 - 5 (0.2)

6 1 1 (0.04) -

9 1 1 (0.04) -

14 13 12 (0.5) 1 (0.04)

19 18 18 (1) -

29 3 - 3 (0.1)

30 43 43 (2) -

48 103 79 (3) 24 (1)

50 15 15 (1) -

52 6 2 (0.1) 4 (0.2)

56 4 4 (0.2) -

66 1 1 (0.04) -

69 10 10 (0.4) -

71 51 48 (2) 3 (0.1)

75 118 98 (4) 20 (1)

82 1 1 (0.04) -

83 121 110 (4) 11 (0.4)

84 99 99 (4) -

86 9 9 (0.3) -

101 1 1 (0.04) -

104 13 13 (0.5) -

110 16 16 (1) -

119 13 8 (0.3) 5

121 76 76 (3) -

122 384 370 (14) 14 (1)

128 14 - 14 (1)

142 15 - 15 (1)

144 1 1 (0.04) -

146 1 - 1 (0.04)

156 5 5 (0.2) -

159 10 10 (0.4) -

161 138 124 (5) 14 (1)

170 194 177 (7) 17 (1)

Cong

reso

isla

nd

173 2 2 (0.1) -

Page 29 of 39



Draft

30

Total 1505 1354 (52) 151 (6)

43 1 1 (0.04) -

46 11 11 (0.4) -

90 602 160 (6) 442 (17)

93 114 94 (4) 20 (1)

94 5 5 (0.2) -

95 69 47 (2) 22 (1)

97 42 34 (1) 8 (0.3)

182 2 2 (0.1) -

184 154 98 (4) 56 (2)

227 25 25 (1) -

276 1 1 (0.04) -

A 23 23 (1) -

B 24 24 (1) -

Rey

islan

d

D 24 24 (1) -

Total 1097 549 (21) 548 (21)

General total 2602 1903 (73) 699 (27)

Page 30 of 39



Draft

31

573 Table III. Number of identified remains and the minimum number of individuals per species and per pellets of Yellow lugged gull. 574

Anguillidae Carangidae Clupeidae Engraulidae Merlucciidae Serranidae SparidaePellets Anguilla

anguillaTrachurustrachurus

Sardinapilchardus

Sardinellaaurita

Engraulisencrasicolus

Merlucciusmerluccius

Epinephelussp.

BoopsBoops

Diplodussargus

Lithognathusmormyrus

Pagellusacarne

Pagelluserythrinus

Pagruspagrus

Sarpasalpa

4 - - - - - - - - - - - - - -6 - - - 1 (1) - - - - - - - - - -9 - - - - - - - - - - - - 1 (1) -

14 - - 12 (1) - - - - - - - - - - -19 - - - - - - - - - - - - 18 (1) -29 - - - - - - - - - - - - - -30 - - - - - - - - - - 43 (1) - - -48 - - 79 (1) - - - - - - - - - - -50 - - 4 (1) - - - - - - - 11 (1) - - -52 - - - - - - - 2 (1) - - - - - -56 - - 1 (1) - - - - 3 (1) - - - - - -66 - - 1 (1) - - - - - - - - - - -69 - 8 (1) 1 (1) - 1 (1) - - - - - - - - -71 - - 48 (1) - - - - - - - - - - -75 - - 98 (2) - - - - - - - - - - -82 - - 1 (1) - - - - - - - - - - -83 - - 110 (2) - - - - - - - - - - -84 - - 99 (2) - - - - - - - - - - -86 - - 5 (1) - - - - - - 4 (1) - - - -

101 - - - - - - - 1 (1) - - - - - -104 - - 8 (1) - - - 1 (1) - - 3 (1) 1 (1) - - -110 - - 16 (1) - - - - - - - - - - -119 8 (1) - - - - - - - - - - - - -121 - - - - - - - - - - - - - 76 (1)122 - - 370 (6) - - - - - - - - - - -128 - - - - - - - - - - - - - -142 - - - - - - - - - - - - - -144 - - - - 1 (1) - - - - - - - - -146 - - - - - - - - - - - - - -156 1 (1) - - - - - - - - - 4 (1) - - -159 - - - - - 10 (1) - - - - - - - -161 - 1 (1) 118 (2) - - 5 (1) - - - - - - - -170 - - 177 (3) - - - - - - - - - - -

Cong

reso

isla

nd

173 - 2 (2) - - - - - - - - - - - -Total 9 11 1148 1 2 15 1 6 - 7 59 - 19 76MNI 2 3 28 1 2 2 1 3 - 2 4 - 2 1

43 - - 1 (1) - - - - - - - - - - -

Re y

46 - - 11 (1) - - - - - - - - - - -

Page 31 of 39



Draft

32

90 31 (1) - 129 (6) - - - - - - - - - - -93 - - 94 (5) - - - - - - - - - - -94 - 1 (1) 4 (1) - - - - - - - - - - -95 - - 47 (3) - - - - - - - - - - -97 - - 32 (2) - - - - - 2 (1) - - - - -

182 - - 1 (1) - - - - - - - - 1 (1) - -184 - - - - 98 (4) - - - - - - - - -227 17 (1) - 8 (1) - - - - - - - - - - -276 1 (1) - - - - - - - - - - - - -

A - 23 (1) - - - - - - - - - - - -B - - - - - - - 24 (1) - - - - - -

i s l a n dD - - - - - - - 24 (1) - - - - - -Total 49 24 327 - 98 - - 48 2 - - 1 - -MNI 3 2 21 - 4 - - 2 1 - - 1 - -

General total 58 35 1475 1 100 15 1 54 2 7 59 1 19 76MNI total 5 5 49 1 6 2 1 5 1 2 4 1 2 1

Page 32 of 39



Draft

33

576 Table IV. Percentage and classes of digestion for fish taxon by number of remains (NISP) and

577 percentage

Total remainsnumber

Bone lossabsent

Minimal digestion

Moderatedigestion

Heavy digestion

Extremedigestion

Taxon NISP NISP % NISP % NISP % NISP % NISP %

Anguillidae 58 - - 32 1,68 9 0,47 17 0,68 4 0,21

Carangidae 35 - - 10 0,53 16 0,84 9 0,47 - -

Clupeidae 1476 45 2,36 76 3,99 388 20,39 967 32,48 349 18,34

Engraulidae 100 - - 1 0,05 2 0,11 97 5,1 - -

Merlucciidae 15 - - - - - - - - 15 0,79

Serranidae 1 1 0,05 - - - - - - - -

Sparidae 218 18 0,95 54 2,84 46 2,42 50 2,63 50 2,63

578

Page 33 of 39



Draft

34

580 Table V: Number of identified specimens (NISP) by bones and fish family in the Yellow-legged gull 581 pellets.582

583

Abbrevation Bones Anguillidae Carangidae Clupeidae Engraulidae Merlucciidae Serranidae Sparidae TOTAL

ar Articular 1 5 8 14

boc Basioccipital 3 1 1 5

bpq Basipterygium 2 2

c Caudal vertebra 37 3 343 65 9 1 458

ceh Ceratohyal 5 5

co Coracoïd 2 2

cl Cleithrum 1 11 2 2 16

dn Dentary 4 11 15

eph Epihyal 4 1 4 9

fr Frontal 2 2

hy Hyomandibula 1 9 2 12

iop Interopercle 2 1 3

mx Maxilla 1 1 2 1 9 14

neu Neurocranium 1 1

op Opercle 13 13

oto Otolith 5 2 7

pl Palatine 1 1

psp Parasphenoid 2 1 1 4

pha Pharyngeal bone 1 1

ptp Posttemporal 5 5

pc Precaudal vertebra 14 303 29 6 5 357

pmx Premaxilla 10 10

pu Preural vertebra 22 22

pop Preopercle 9 2 11

qd Quadrate 1 1 2 4

ec Scale (unidentified) 756

sc Scapula 2 2

sop Subopercle 2 1 3

scl Supracleithrum 2 2

ub Unidentified bones 2 7 10 1 54 74

ver Vertebra (unidentified) 72

vo Vomer 1 1

TOTAL 58 35 1476 100 15 1 218

Page 34 of 39



Draft

Figure 1. Location of sites mentioned in the text.

151x148mm (300 x 300 DPI)

Page 35 of 39



Draft

Figure 2. Pellet of Yellow-legged Gull.

203x148mm (300 x 300 DPI)

Page 36 of 39



Draft

Figure 3. Modification of a precaudal vertebra of Anguilla anguilla (scanning electron microscope).

200x170mm (300 x 300 DPI)

Page 37 of 39



Draft

Figure 4. Degrees of digestion. a) Undigested Boops boops, b) Sardine bones (loss absent); c) Precaudal vertebra of sardine (minimal digestion); d) Caudal vertebra of sardine (moderate digestion); e) Sardine vertebra exhibiting intensive

digestion; f) and g) From the same pellet, two patterns of digestion of precaudal vertebra of eel (lack of and heavy digestion); h) and i) From the same pellet, two patterns of digestion of opercula of sardine (lack of

and moderate digestion).

208x313mm (300 x 300 DPI)

Page 38 of 39



Draft

Page 39 of 39



Documents

Taphonomy of Yellow-legged Gull (Larus …...10 E-mail: [email protected]; [email protected] 11 c Unité Histoire naturelle de l’Homme préhistorique (HNHP), Muséum national