Analisis Morfometrik Kepala Pada Beberapa Subspesies Burung Dara Laut (Laridae)

Abstract

This experiment was conducted to determine the size and body shape score of terns using Principal Component Analysis (PCA). The measurement taken were bill length, bill width, bill depth, head width and head length. A total of 168 specimen of terns consisted of 79 specimen males and 89 specimen females were measured. There were differences in linear bill and head measurements among subspecies of terns (P<0.01). The discriminator of head size for all subspecies terns being examined was bill length. The Eigen vectors of the discriminator of head size in subspecies Anous minutus worcesteri was 0,975; Anous stolidus pileatus was 0,917; Chlidonias hybrida javanica was 0,746; Sterna albifrons sinensis was 0,931; Sterna anaethetus anaethetus was 0,983; Sterna bergii cristatus was 0,879; Sterna fuscata nubilosa was 0,875; and Sterna sumatrana sumatrana was 0,985. The discriminator of head shape of subspecies A. s. pileatus, C. h. javanica and S. a. anaethetus were head width, while the subspecies A. m.s worcesteri, S. a. sinensis, S. b. cristatus, S. f. nubilosa and S. s. sumatrana were head length. The Eigen vectors of the discriminator of head shape in subspecies A. s. pileatus, C. h. javanica and S. a. anaethetus were 0,882; 0,714 and 0,975 respectively. The Eigen vectors of the discriminator of head shape in subspecies A. m. worcesteri, S. a. sinensis, S. b. cristatus, S. f. nubilosa and S. s. sumatrana were 0,956; 0,742; 0,757; 0,922 and 0,728 respectively. Descriminator of size is influenced by the environment. Bill length as descriminator of shape indicates that the bill length is affected by habitat. Head width and head length are influenced by genetics. The Minimum D Mahalonobis distance showed the classification of terns into two group at the branching point of 3.6004, group A and B. Group A consisted of A. s. pileatus, C. h. javanica, S. a. anaethetus, S. f. nubilosa and S. b. cristatus. Group B consisted of S. a. sinensis, A. m. worcesteri and S. s. sumatrana.