Mehrjährige Untersuchungen zu Biometrie und Gewässeraufenthalt einer isolierten Population des Teichmolches Lissotriton vulgaris(Linnaeus, 1758) in der Stadt Halle (Saale)

Abstract

Grosse, W.-R., Fritzsche, P.: Perennial studies on biometrics of an isolated population of the smooth
newt Lissotriton vulgaris (Linnaeus, 1758) and their presence in a spawning site in the City of Halle(Saale).
- Hercynia N.F. 49 (2016): 47 – 63.

Between 2009-2016, we investigated a population of smooth newts found in a 4 m² pond in the Eastern
courtyard (Osthof) of the Zoological Institute of the Martin Luther University, Halle/Saale, Germany.
We tested all individuals biometrically for the period of their presence and recognized individuals by
taking photographs of their belly side. We found 52 ± 19.3 individuals in the pond per year. The sex ratio
was 1.5 males : 1 females. Males were slightly larger than females but without statistical significance.
The population showed significant differences in head-body length, body mass and the condition index
between vintages and partly between the sexes. A significant correlation between mean temperatures in
March and body mass of heavier females at warmer temperatures were found, which was not the case
for males. Significant differences of the biometrical data between the years have been found also. The
newts in Osthof were significantly smaller and lighter than similar populations in natural habitats, which
is an indication of unfavourable habitat condition due to the isolated occurrence of the pond in the city.
We found no statistically validated relationship between the number of newts and the duration of their
stay in the pond. With 36.7 ± 12.0 days, females tended to spend more time in the water than males with
34.0 ± 9.1 days. The biometric data of individuals of both sexes only changed slightly during their stay
in the water. To summarize, the occurrence of newts in small ponds is seemingly suboptimal to ensure
their survival in the city.