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قراءة كتاب Natural History of the Salamander, Aneides hardii

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Natural History of the Salamander, Aneides hardii

Natural History of the Salamander, Aneides hardii

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دار النشر: Project Gutenberg
الصفحة رقم: 6

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21 100:75 Sacramentos, 1958 23 20 100:121 Sacramentos, '56-'57 34 43 100:126 All 120 123 1:1

Table 4.—Sex Ratios in Aneides hardii, Adults

Locality Number
of
males		 Number
of
females		 Ratio of
males to
females
Capitan Mountains 35 19 100:54
Sierra Blanca 22 7 100:32
Sacramentos, 1958 15 14 100:93
Sacramentos, '56-'57 22 16 100:73

Age-ratio

The data in Table 5 show adult salamanders to outnumber young at each collecting locality. This is probably not an accurate reflection of actual age composition in this species. Yet, we obtained the same general result in all three years of the study. We assume, therefore, that young were located where we could not catch many of them; probably they were underground. Sites of hatching and of the activities of early life would thus occur where we think the bulk of eggs are laid.

Table 5.—Age Ratios, Adults-juveniles

Locality Number
of
adults		   Number
of
juveniles		 Ratio of
adults to
juveniles
Capitan Mountains 57 15 100:26
Sierra Blanca 30 22 100:73
Sacramentos, 1958 42 30 100:71
Sacramentos, '56-'57 46 35 100:76
All 175 102 100:58

For purposes of this study we had only to age the individuals into adult and subadult classes. The criterion for adult status was breeding capability. A five-millimeter testis was the smallest size found in individuals that probably bred, and all of these were 40 mm. or more in snout-vent length.

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