Literaturdatenbank |
Najbar, B., & Szuszkiewicz, E. (2005). Reproductive ecology of the european pond turtle emys orbicularis (linnaeus, 1758) (testudines: emydidae) in western poland. Acta Zoologica Cracoviensia, Series A - Vertebrata, 48(1-2), 11–19.
Added by: Admin (14 Aug 2008 20:31:53 UTC) |
Resource type: Journal Article BibTeX citation key: Najbar2005 View all bibliographic details |
Categories: General Keywords: Emydidae, Emys, Emys orbicularis, Habitat = habitat, Osteuropa = Eastern Europe, Schildkröten = turtles + tortoises Creators: Najbar, Szuszkiewicz Collection: Acta Zoologica Cracoviensia, Series A - Vertebrata |
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Abstract |
From May 1999 until June 2003, 48 nests of the European pond turtle Emys orbicularis were observed in the valleys of Ilanka and Pliszka rivers (western Poland). 33 nests dug by turtles were found in the vicinity of the Ilanka river, where 15 marked females laid 373 eggs. A further 13 nests were completely damaged by predators. In 2 cases (in the valley of the Pliszka river) ploughed nests were found with 19 undamaged eggs. The earliest date of egg laying was May 24th and the latest was on June 13th. Digging a chamber, egg laying and burying the nest took between 60-145 minutes, 97.7 minutes on the average. Most females started egg laying 19.20-20.30 and finished 20.55-0.55. The number of eggs varied between 5-17 (av. 11.3). The average length of the eggs was 33.8 mm, the width 19.8 mm and weight 7.8 g. 210 turtles hatched from 392 eggs (from 35 clutches) (53.58%). 160 were subsequently reared in artificial conditions. 50 young turtles were left in natural conditions. Lack of snow and low temperatures probably caused their death. 65 eggs (16.58%) were dug up and destroyed by predators, 22 eggs (young individuals during hatching) (5.61%) were damaged underground by ants. Embryos died in 38 eggs (9.69%) at different, mainly final, stages of development, 30 eggs (7.65%) had shells damaged mechanically, the remaining 27 eggs (6.89%) were not fertilized.
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