Weights and measures of Ugandan pelicans with some seasonal variations

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Abstract
Summary: Samples of White and Pink‐backed Pelicans from the Rwenzori National Park, Uganda were weighed and measured. The results are given below as mean values in the order of male and female White Pelicans and male and female Pink‐backed Pelicans. Only a few measurements were taken of female White Pelicans. Further details given in the Tables include sample size, standard deviation and range. Linear measurements (cm): total body length:— 177.3, 136.7, 146.9, 134.0; tail length:—18.1, ‐, 17.2, 16.6; tarsometatarsus:— 14.2, ‐, 9.6, 8.7: cu1men:— 41.8, 31.4, 35.7, 30.5; lower mandible:— 49.3, ‐, 40.3, 34.6; wing span:— 285.8, 246.4, 233.9, 224.2; wing length:— 136.5, ‐, 112.9, 105.8; standard wing length:— 70.2, ‐, 60.5, 56.0; chord:— 70.8, ‐, 35.5, 34.3; aspect ratio:— 4.0, ‐, 6.6, 6.6; weights (gm unless stated otherwise): total weight (kg);— 11.45, 7.59, 5.97, 4.92; adrenal (mg):— 647.2, 531–0, 401.2, 352.4; heart:— 100.1, ‐, 49.9, 39.5; kidney:— 40.9, ‐, 23.6, 23.4; liver:—258.2, 176.5, 128.5, 110.4; lung:— 60.3, –, 29.1, 30.0; pancreas:— 15.2, ‐, 7.1, 5.3; pectoralis major:— 731.9, ‐, 389.0, 313.9; pectoralis minor:— 51.8, ‐, 27.6, 24.3; pituitary (mg):— 40.6, 39.1, 37.4, 37.5; spleen:— 12.7, ‐, 12.3, 10.1. There was no significant difference between the species in the proportional weights of the organs. Seasonal variations were found in the weights of testes, ovaries, oviducts and fat deposits. Changes in weight of the reproductive organs of the Pink‐backed Pelican showed a clear correlation with the breeding cycle. The testes of the migratory White Pelican appeared to be inactive while the birds were in the park. The amount of fat laid down could be directly related to seasonal fluctuations in the food supply. The degree of development of the head crest was greatest during the breeding season in the Pink‐backed Pelican and during the second quarter of the year in the White Pelican. 58.6% of the White Pelicans showed traces of colouration on the breast.