Studii şi Cercetări Mai 2011 Biologie 20/2 44-47 Universitatea”Vasile Alecsandri” din Bacău THE COMPARATIVE BIOMETRICAL ANALYSIS OF THE ROOK, CORVUS FRUGILEGUS (L.) AND THE EUROPEAN JACKDAW, CORVUS MONEDULA (L.) REALIZED IN THE CITY OF IAŞI AND ITS SURROUNDINGS (THE IAŞI COUNTY) Emanuel Târnoveanu Key words: emancipation, predators, exhaustion, cries, feeding, flight, feathering establish the location of the research sample. Rooks were collected from Copou and from the sides of the Vasile Lupu and Aurel Vlaicu Streets. The captured birds were taken to be metrically and weightily analyzed, using a sliding caliper, a measuring tape and, of course, a 5kg/1 g Tefal Easy balance. The values gathered by applying this ecological method was statistically analyzed with Microsoft Excel and graphically reproduced by confidence intervals. When the measurements ended all the birds were released in the wild. For studying the exterior features of the two Corvids species I used a Panasonic LUMIX DMC/FZ35 Photo Camera with a width angle of 27 mm, an 18x optic zoom, LEICA DC lens with F2.8 brightness. INTRODUCTION Gache (2004) and Croitoru (2009) realized studies on the seasonal dynamics of the Corvus frugilegus species in the city of Iaşi and PiticanMunteanu (2009) studied the same phenomenon, in the Someşul Mic Valley. The length of the wing represents an indicator regarding the size of the body (Gloser et al., mentioned by Laiolo & Rolando, 2003) of the Corvus species representatives. Their long, pointed wings are used for flying long distances (Ion et al. 2009). During the feather growth period, the young birds leave the colony and join their parents in search for trophic resources. The complete moult of the adult birds occurs in the autumn, while in case of the young individuals, the only feathers that are replaced are the covering ones. Outside the breeding season, mixed flocks of Corvus frugilegus and Corvus monedula make two great displacements – in the morning – from roosting places to feeding places and, in the evening – all the way back. The birds pass the night in well-known “roosts” (Ciochia, 2002), placed, in all studied cases, near towns or villages. The two species of Corvids (biological family Corvidae) prefer to gather to upper parts of tree canopy, from where they can fly again, very easily, in the morning, when go searching for food or during the night time, if something or somebody disturb their rest. RESULTS AND DISCUSSIONS A characteristic feature of the juvenile rook is the white feather patch located under the inferior mandible (C tuneanu, 1953). However, inside the Corvus frugilegus sample we studied I noticed two types of birds – with and without the white submandibular feathers. Typical for the juveniles is the stimulative behavior in order to obtain food from their parents. This consists in open beak long cries accompanied by the tremble of their wings. During the emancipation period, the juvenile replacing feathers loose their horny sheaths, by meansofexfoliation. We noticed a connection between the presence of the subcutaneous adipose deposits and metallic brilliance of the plumage. During the process of emancipation, the mortality incidence in juveniles is high. In case of Corvus frugilegus the early entrance of the male bird in the moult season causes the abandon of the nest, while the chicks are still young, which stops their growing process for lack of food (Richards, 1976). MATERIAL AND METHODS In the nesting season area, the unity between the Corvids population members is maintained by means of resounding signals. The adult birds mark acoustically the presence of the fledged chicks outside the nest. According to the direction from which the communication sounds between parents and fledgelings came we could 44 - another bird experienced feathering depreciation before reaching the age of 6 months when the moult usually starts out; - other three individuals reported a weak response to the environmental factors, as a consequence of the exhaustion; - in case of a vigorous individual, consistent under skin fat deposits were noticed. This can cause supraponderability. The aspects regarding the „flight qualities” of the European jackdaw, Corvus monedula, were emphasized as follow: - five individuals had missing feathers in different regions of their bodies (on the back, on the forehead, back head, chin, around the eyes, around the ears, etc), being exposed to predator attacks; - two individuals were well developed, presenting under skin fat deposits but they manifested disorientation while flying or walking; - a single individual could make displacements through flying and it had well coordinated prehensile gestures when feeding itself; - two individuals had been attacked by predators (one by a cat and the other by a dog); - from the rest of 7 captured individuals, none could fly. They could only climb in the bushy vegetation from the nesting area. After the statistic analysis of metrical and weight related data gathered for Corvus frugilegus (fig. 1; table 1) and Corvus monedula (fig. 2; table 2) resulted that the values corresponding to the size indicators (Andriescu, 1982) – the total length of the body, the length of the wing, the amplitude of the wing and the length of the tail – alter between the most wide limitsof the confidence interval. In the first days after leaving the nest, when they are still beginners in flying method, the chicks are highly exposed to predators. When this situation occurs, the jackdaw resorts to a misleading strategy in order to escape from predators by pretending it cannot fly. Among the forms of defensive aggression I noticed, one refers to the bird sprinkling when flying with regurgitated food and fecals towards the enemy, and then harassing it with the claws and the beak. During the period dedicated to the ecological study of Corvus frugilegus species (between 11.05.2010 and 05.06.2010). I noticed an analogy between the early abandon of the nest by the male bird and the tendency of the chicks to leave their origin colonies as well. In a physiological plan, the consequences were spending the energetic resources and exhaustion, and, in the end, the death of the chicks as the result of loosing the chance of being fed. The sample of 17 birds, studied in the nesting environments inside the area of the city of Iaşi, was descriptive analyzed and the following conclusions were drawn (all showing the deficiency in power of flight): - two individuals didn’t complete the flight feather growth period, the moment they left the nest; from two, one couldn’t eat nor fly due to some malformations of the beak and remiges; the other hurt itself during the flying maneuvers; - nine individuals presented subnutrition signs, materialized by showing a pronounced keel of the breast-bone under the tegument; - an individual had an accident at the left wing, after starting its emancipation flight; 9 0.08 9 9 0.35 8 10 17 Weight Tarsus scale number The third toe length Tarsus width Tarsus length Tail length Carina length Prim aries length Wing width Wing length Wingspan 2.08 0.07 2 2 0.32 1.5 2.7 17 Body width Bill height 2.5 0.2 2.5 2.5 0.7 2 5 17 Total body length Bill width 5.2 0.08 5 5 0.35 5 6 17 Head width Bill length Mean Standard Error Median Mode Standard Deviation Minimum Maximum Count Head & bill legth Table 1. The values of the metrical and weight related analysis of the rook, Corvus frugilegus 4.64 31 11 31.23 23.61 6.97 3.89 5.23 10 5.68 1.51 3.105 6.94 289.05 0.12 0.53 0.18 0.45 1.14 0.16 0.12 0.18 0.4 0.12 0.02 0.06 0.05 12.7 4.5 31 11 32 21.5 7 4 5.5 10 5.7 1.5 3 7 260 4.5 31 11 32 20 7 3.5 6 10 6 1.5 3 7 260 0.52 2.18 0.75 1.8 4.72 0.67 0.52 0.7 1.67 0.52 0.08 0.26 0.24 52.45 3.5 28 9.5 28 20 5.5 3 3.5 5.5 4.5 1.3 3 6 240 6 37.5 12 36 32 8 5 6 13 6.5 1.7 4 7 435 17 17 17 17 17 17 17 17 17 17 17 17 17 17 45 Table 2. The values of the metrical and weight related analysis of the jackdaw, Corvus monedula Standard Error 0.051 0.04 0.05 0.07 0.492 0.12 0.39 0.25 0.13 0.11 0.07 0.28 0.09 0.05 6.54 Mean Bill length Bill width Bill height Head width Total body length Body width Wingspan Wing length Wing width Primaries length Carina length Tail length Tarsus length The third toe length Weight 3.35 1.825 1.6 3.45 25.7 8.4 24.6 16.6 5.08 3.16 3.8 8.51 4.72 2.65 155.31 Standard Deviation 0.2 0.16 0.2 0.28 1.9 0.51 1.59 1.02 0.54 0.45 0.31 1.14 0.36 0.2 26.17 Sample Variance 0.04 0.02 0.04 0.08 3.87 0.2 2.54 1.05 0.29 0.2 0.09 1.3 0.13 0.04 684.89 Minimum Maximum Count 3 1.5 1.3 3 23 8 22.5 15 4 2.5 3.2 5 4 2.3 115 3.8 2 2 4 31 9.5 27.8 19 6 4 4.5 9.7 5.3 3 205 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 Confidence Level (95.0%) 0.11 0.09 0.11 0.15 1.04 0.27 0.84 0.54 0.28 0.24 0.16 0.6 0.19 0.1 13.94 35 30 25 20 15 10 w id th W in gs pa n W in g le ng th W in g w P i rim dt h ar ie s le ng th C ar in a le ng th T ai ll en T gt ar h su s le ng T th ar su T s he w th id ird th T ar to su e s le sc ng al th es nu m b er le ng th B od y w id th bo dy T ot al H ea d he ig ht bi ll H ea d & w id th B ill Bi ll B ill le ng th 0 le ng th 5 Fig. 1. The confidence interval of Corvus frugilegus populations in the city of Iaşi and surroundings (Iaşi County) obtained for metrical and weight related data 30 25 20 15 10 5 ng th le to e le ng th Ta rs us th ird T he Ta il le n gt h W in g w id th Pr im ar ie s le ng th C ar in a le ng th le ng th W in g W in gs pa n le ng th w id th B od y w id th bo dy To ta l H ea d he ig ht Bi ll w id th Bi ll Bi ll le ng th 0 Fig. 2. The confidence interval of Corvus monedula populations in the city of Iaşi and surroundings (Iaşi County) obtained for metricaland weight related data 46 REFERENCES CONCLUSIONS 1. In the present study, we tried to evaluate the reproductive success of both Corvus frugilegus and Corvus monedula species, in the context of exploring their nesting areas. As far as the feeding territories visited by the adults are productive, consequently, the energetic resources of the chicks would correspond, in the height stage of post embryonic development, to an ecological optimum. Spreading and flying far away from their origin/home colonies is possible only in case of healthy individuals. In the metrical and weight related analysis we made, the physical decompensate individuals that could not leave the nesting territories during the emancipation period, prevailed. ABSTRACT 2. 3. 4. 5. We present the results of the biometrical analysis made on a sample of 17 juvenile rooks, Corvus frugilegus (L.), captured in the city of Iaşi, during the emancipation period, between 11th of May 2010 and 5th of June 2010. Thirteen of these birds came from a nesting area situated in the northern part of the city, along the Boulevard Carol 1st, between the buildings of Romanian Academy, Iaşi Branch and the Super Copou Store, where old trees are predominant. The rest of four individuals were captured from two poplar plantations, located in southeastern part of the city. Willing to gather metrical and weight related data, we captured 16 European jackdaw chicks, Corvus monedula (L.) from T t raşi, the neighborhood situated in the eastern part of the city of Iaşi, between 26th of May 2010 and 30th of the same month. This species usually build their nests inside the ventilation holes of the apartment houses. We choose to study Corvus frugilegus and Corvus monedula species together because the last one joins the first when looking for food, defending from predators and night aggregation. 6. 7. 8. 9. ANDRIESCU, D. C., 1983 - Studiul bioecologic la st ncuţa (Corvus monedula L.) din Moldova, Tez de doctorat, Universitatea “Alexandru Ioan Cuza” Iaşi C TUNEANU, ION I., 1953 - Ciorile şi celelalte corvide: metodele de combatere a celor d un toare, Editura Agro-Silvic de Stat, Bucureşti CIOCHIA, VICTOR, 2002 - Dicţionarul p s rilor, Editura Pelecanus, Braşov CROITORU MARIA-MAGDALENA, 2009 - P s rile din zonele verzi ale oraşului Iaşi, Editura Universit ţii „Alexandru Ioan Cuza” Iaşi GACHE CARMEN, 2004 - Ornithological observations in Ciric area – Iaşi county, Analele Ştiinţifice ale Universit ţii „Al.I.Cuza” Iaşi, s. Biologie animal , Tom L: 343–349 ION, C., DOROŞENCU, AL., BALTAG, E., BOLBOAC , L., 2009 - Migraţia paseriformelor în estul României, Editura Universit ţii „Alexandru Ioan Cuza” Iaşi LAIOLO PAOLA, ROLANDO A., 2003 The evolution of vocalisations in the genus Corvus: effects of phylogeny, morphology and habitat, Evolutionary Ecology 17: 111– 123 PINTICAN-MUNTEANU CLAUDIA, 2009 - Studiul ecologiei şi etologiei populaţiilor de Corvus frugilegus (Aves) din Valea Someşului Mic, Tez de doctorat, Universitatea „Babeş-Bolyai”Cluj-Napoca RICHARDS PETER R., 1976 - The Onset of Moult in the Rook, Bird Study, 23: 3, 212 AUTHORS’ ADDRESS TÂRNOVEANU EMANUEL – “Al. I. Cuza” University of Iaşi, Faculty of Biology, Bl. Carol I 20A, 700505, Iaşi, Romania e-mail: emantarn@yahoo.com ACKNOWLEDGEMENTS The research activities that are the subject of this article were carried out with financial support POSDRU/88/1.5/S/47646 project, financed by European Social Fund, the Human Resources Development Operational Programme 2007-2013". 47