Morphometrics, sex ratio, sexual size dimorphism, biomass, and population size of the Nile crocodile (Crocodylus niloticus) at its southern range limit in KwaZulu-Natal, South Africa

Australia’s prehistoric ‘swamp king’: revision of the Plio-Pleistocene crocodylian genusPallimnarchusde Vis, 1886

“…That ties with the continual growth in combination with the longevity experienced by living crocodylians ( Cott, 1961 ; Grigg & Kirshner, 2015 ). Additionally, intraspecific sexual dimorphism in adult crocodylians is expressed in size differences that are commonly biased towards males being the much larger sex ( Fitch, 1981 ; Hall & Portier, 1994 ; Platt et al, 2009 , 2011 ; Barrios-Quiroz, Casas-Andreu & Escobedo-Galván, 2012 ; Warner et al, 2016 ; Grigg & Kirshner, 2015 ; Edwards et al, 2017 ). However, the difference observed between P. gracilis and P. vincenti does not conform with the variability seen in extant taxa.…”

A Body Condition Score for Crocodilians

“…With BCS, only technical experience is required and, while the validation is subjective, experience is not an important factor in BC categorization (Edmonson et al, 1989). However, the possible effects of sexual dimorphism have been not South American Journal of Herpetology, 16, 2020, 10-15 A Body Condition Score for Crocodilians Ricardo Adrián Ojeda-Adame, Helios Hernández-Hurtado, María Magdalena Ramírez-Martinez, Luis Ignacio Iñiguez-Davalos extensively researched and, therefore, require special attention (Platt et al, 2011;Barrios-Quiroz et al, 2012;Warner et al, 2016), although it has been observed that males have a larger head and body than females in some size classes (Barrios-Quiroz et al, 2012). Despite this, no differences in shape per se have been found between males and females, so we assume that this attribute should not affect the BCS assessment.…”

Accumulation of organochlorine pesticides in fat tissue of wild Nile crocodiles (Crocodylus niloticus) from iSimangaliso Wetland Park, South Africa

“…The sampled population consisted of nine adults (≥ 2.5 m) and 6 sub-adults (˂ 2.5 m), with a male biased female-to-male sex ratio of 0.4:1. The skewed sex ratio was likely due to the small sample size, as a recent study at Lake St Lucia reported a 1:1 sex ratio based on 104 individuals (Warner et al, 2016a). Capture success at Kosi Bay and Lake Sibaya was limited by the low population density of crocodiles present within these systems, while low water levels following a prolonged drought severely hindered capture operations at Nsumo pan.…”

“…Lake St Lucia hosts the largest population with a minimum of 684 adult and sub-adult crocodiles, while Lake Sibaya (26), Kosi Bay (<10) and Nsumo pan (<10) are estimated to contain substantially lower numbers (EKZNW unpublished 2015 aerial survey data). Trend analysis based on aerial count data for the last decade indicates a decline in all four populations (EKZNW unpublished data 2015 aerial survey data) and is attributed largely to direct and incidental anthropogenic pressures, including illegal killings, fish-trap and gillnet mortalities, destructions of nesting sites and eggs, alien plant infestation at nesting sites, boat-collision mortalities, and severe droughts (Kyle, 1999;Leslie and Spotila, 2001;Combrink et al, 2011;Combrink et al, 2013, Warner et al, 2016a.…”