Abundance and Population Structure of Podocnemis erythrocephala (Testudines, Podocnemididae) in the Unini River, Amazonas

Virginia Campos Diniz Bernardes, Camila Ferrara, Richard Vogt

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

We studied the population structure, sex ratio, and abundance of a locally endangered species of freshwater turtle, the red-headed river turtle (Podocnemis erythrocephala), in the Unini River in Negro River Basin in Brazil with capture–recapture of marked individuals in 1 yr, including both dry and rainy seasons. We used trammel nets of 3 different inner mesh sizes in the lakes. The nets were revisited at 3-hr intervals from 0600 to 1800 hrs each day. All turtles were released after being marked, measured, and sexed. During the study, 352 individuals were marked including 162 males, 150 females, and 40 immatures. The majority of the turtles (79%) were captured in the dry season when the water level of the river was declining. Mean ± standard deviation straight-line carapace length was 210 ±?14 mm?(range 163–262 mm) for males and 251 ±?18 mm?(221–303) for females. Most turtles captured were in the intermediate size classes: 200–210 mm for males and 230–270 mm for females. The sex ratio of adults in this population was 1.05 males per female, not significantly different from 1:1. Only 12 turtles were recaptured, each once: 5 males, 5 females, and 2 immatures. The population showed recruitment and the adults are in equilibrium; however, few turtles were captured in the smallest or largest size classes.
Original languageEnglish
Pages (from-to)89-95
Number of pages7
JournalChelonian Conservation Biology
Volume13
Issue number1
DOIs
Publication statusPublished - 2014
Externally publishedYes

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Testudines
turtle
turtles
population structure
Brazil
rivers
river
sex ratio
dry season
immatures
mesh size
African Americans
Podocnemididae
Podocnemis
endangered species
surface water level
wet season
water level
river basin
lakes

Cite this

Bernardes, Virginia Campos Diniz ; Ferrara, Camila ; Vogt, Richard. / Abundance and Population Structure of Podocnemis erythrocephala (Testudines, Podocnemididae) in the Unini River, Amazonas. In: Chelonian Conservation Biology. 2014 ; Vol. 13, No. 1. pp. 89-95.
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abstract = "We studied the population structure, sex ratio, and abundance of a locally endangered species of freshwater turtle, the red-headed river turtle (Podocnemis erythrocephala), in the Unini River in Negro River Basin in Brazil with capture–recapture of marked individuals in 1 yr, including both dry and rainy seasons. We used trammel nets of 3 different inner mesh sizes in the lakes. The nets were revisited at 3-hr intervals from 0600 to 1800 hrs each day. All turtles were released after being marked, measured, and sexed. During the study, 352 individuals were marked including 162 males, 150 females, and 40 immatures. The majority of the turtles (79{\%}) were captured in the dry season when the water level of the river was declining. Mean ± standard deviation straight-line carapace length was 210 ±?14 mm?(range 163–262 mm) for males and 251 ±?18 mm?(221–303) for females. Most turtles captured were in the intermediate size classes: 200–210 mm for males and 230–270 mm for females. The sex ratio of adults in this population was 1.05 males per female, not significantly different from 1:1. Only 12 turtles were recaptured, each once: 5 males, 5 females, and 2 immatures. The population showed recruitment and the adults are in equilibrium; however, few turtles were captured in the smallest or largest size classes.",
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Abundance and Population Structure of Podocnemis erythrocephala (Testudines, Podocnemididae) in the Unini River, Amazonas. / Bernardes, Virginia Campos Diniz; Ferrara, Camila; Vogt, Richard.

In: Chelonian Conservation Biology, Vol. 13, No. 1, 2014, p. 89-95.

Research output: Contribution to journalArticle

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KW - threats

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