{'fraction_non_alphanumeric': 0.019097222222222224, 'fraction_numerical': 0.006944444444444444, 'mean_word_length': 5.165775401069519, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Stable isotopes in adipose tissue fatty acids as indicators of diet in arctic foxes (Alopex lagopus)

The key to successful nutrition of captive animals is understanding the species’ natural diet. Simply observing which foods the animals accept and what can sustain non-breeding adults are often not sufficient to establish the dietary requirements for a permanent breeding population. Diet is particularly important for reproduction, and may be a cryptic cause of infertility or unsuccessful breeding. The lactation habit enables mammals to nourish their offspring from body stores of lipid, protein and minerals, thereby freeing them from dependence on local food sources and enabling them to breed in a wider range of habitats than is usually possible for birds or reptiles. But in the long term, diet is just as important; the reserves of the nutrients necessary for reproduction have to be built up for some time. Obtaining a comprehensive picture of wild animals’ diets is difficult. Direct observation of foraging behaviour and food choice for short periods (Nielsen, 1991; Stickney, 1991) or the examination of crop or stomach contents (Unander