BREEDING ECOLOGY OF NIGHT HERON (Nycticorax nycticorax Linne,1758) IN THE
LAKE VAN BASIN, TURKEY
A. Durmuş and O. Adizel
Yuzuncu Yil University Faculty, Science and Art, Dept. of Biology. 65080 Van-Turkey
Corresponding author e-mail: atilla@yyu.edu.tr
ABSTRACT
A study on breeding ecology of night heron (Nycticorax nycticorax) was conducted in the Lake Van Basin between 16
February 2006 and 04 October 2007 on four big islands inside the lake and sorrounding wetlands.The night heron only
breeds on islands inside the lake in this region because it finds food in wetlands. Trees which numbers had been given
previously were observed and, starting from pre-breeding period into March and June, data on nests and breeding were
taken. The breeding period was about seven months (March – September). During this period, it was frequently
observed that nests from the previous year were repaired and re-used. Both the male and the female repair the
nest.Average dimensions of eggs laid on nests were measured as 49.33±3.2 mm in length, 32.19±1.35 in width, and with
a weight of 29.66±5.01 grams. The number of eggs laid ranged from 1 to 6 per nest. In 1364 active nests observed within
the entire breeding region, 4206 (92 %) of 4576 eggs hatched and 3923 (93 %) of all chicks managed to leave the nest.
Brooding periods in 50 nests were observed separately in each breeding season. In 2006, average brooding period during
the first period was 25.62±2.03 and it was 26.22±1.18 during the second period; in 2007, average brooding period during
the first period was 26.10±1.69 and it was 25.60±1.76 during the second period. Juvenile growth periods for N.
nycticorax have been observed as follows: in 2006, average 39.98±2.47 days during the first breeding period and
32.68±1.25 days during the second breeding period; in 2007, average 42.18±2.60 days during the first breeding period
and 34.64±1.15 days during the second breeding period. A significant statistical difference has been observed between
years and even periods in question (P < 0.01).
Key words: Nycticorax nycticorax, The Night Heron, Ecology, Birds, Breeding, Lake Van, Turkey. |