Grouping behaviour, tail-biting behaviour and sexual dimorphism in the armadillo lizard (Cordylus cataphractus) from South Africa

1999 ◽  
Vol 249 (1) ◽  
pp. 1-10 ◽  
Author(s):  
P. le F. N. Mouton ◽  
A. F. Flemming ◽  
E. M. Kanga
PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7240 ◽  
Author(s):  
Kimberley E.J. Chapelle ◽  
Paul M. Barrett ◽  
Jennifer Botha ◽  
Jonah N. Choiniere

Our knowledge of Early Jurassic palaeobiodiversity in the upper Elliot Formation of South Africa has increased markedly in recent years with the discovery of new fossils, re-assessments of previously collected material and a better understanding of Stormberg Group stratigraphy. Here, Ngwevu intloko, a new genus of upper Elliot basal sauropodomorph is named on the basis of a complete skull and partial skeleton (BP/1/4779) previously assigned to Massospondylus carinatus. It can be distinguished from all other basal sauropodomorphs by a combination of 16 cranial and six postcranial characters. The new species is compared to a small ontogenetic series of M. carinatus as well as to a range of closely related taxa. Taphonomic deformation, sexual dimorphism and ontogeny are rejected as possible explanations for the morphological differences present between BP/1/4779 and other taxa. Osteohistological examination reveals that BP/1/4779 had nearly reached adult size at the time of its death at a minimum age of 10 years.


2004 ◽  
Vol 31 ◽  
pp. 165-168
Author(s):  
H. A. Van de Weerd ◽  
C. M. Docking ◽  
J .E. L. Day ◽  
K. Breuer ◽  
S. A. Edwards

AbstractThe development of adverse behaviour in group–housed growing/ finishing pigs with intact tails was studied in a straw–flow housing system and in a part–slatted system with a commercial enrichment object. Food intake, body weight and behaviour were monitored over the finishing period, with tail biting outbreaks defined as an occasion where three or more pigs within a group had freshly damaged tails and tail biting behaviour was ongoing. Data from the two systems were analysed to identify tail–biting outbreaks and behavioural changes over time. Levels of pig manipulation were higher in the part–slatted system. Over time, pigs in both systems showed reduced interest in the enrichment provided, but not in each other. Despite the presence of the enrichment device, tail biting occurred in all groups in the part–slatted system, but only 1/12 groups in the straw–flow system. The amount of time occupied by manipulation of the enrichment provided was very significantly higher for straw than for the commercial object. Better design of enrichment strategies is therefore needed and should be based on species–relevant requirements.


1964 ◽  
Vol 54 (4) ◽  
pp. 649-656 ◽  
Author(s):  
L. P. Lefkovitch

Cryptolestes pusilloides (Steel & Howe) has, since 1944, become a regularly occurring pest of stored cereals in South America, Australia, South Africa, and to a lesser extent, East Africa, and apparently occurs also in North America as well as in Portugal (where it has recently been found on stored almonds), but has not established itself in flour mills in the U.K., notwithstanding its frequent introduction. Prior to that time it appears to have been very rare. Its life-cycle resembles that of C. ugandae Steel & Howe, and in common with that species and with C. turcicus (Grouv.), it is unable to breed successfully at relative humidities below 50 per cent. Its temperature range is 15–35°C., the optimum for development and fecundity being at about 30°C. at 90 per cent. R.H. Survival was greatest at 27·5°C. and newly formed adults weighed most at 22·5°C. In general, males weighed more than females and their developmental period under any one set of conditions was slightly longer than that of females. The biological information now available shows that C. ferrugineus (Steph.) and C. capensis (Waltl), which are taxonomieally associated by exhibiting sexual dimorphism in the structure of the mandibles, are species that can withstand dry conditions, whereas C. ugandae, C. turcicus, C. pusillus (Schönh.) and C. pusilloides, all of which show sexual dimorphism in the antennae, are unable to breed at relative humidities much below 50 per cent.


2012 ◽  
Vol 53 (4) ◽  
pp. 449-456 ◽  
Author(s):  
Kaitlin Wilson ◽  
Ricardo Zanella ◽  
Carlos Ventura ◽  
Hanne Lind Johansen ◽  
Tore Framstad ◽  
...  

2015 ◽  
Vol 92 ◽  
pp. 25-44 ◽  
Author(s):  
Maria F. Norup ◽  
Gitte Petersen ◽  
Sandie Burrows ◽  
Yanis Bouchenak-Khelladi ◽  
Jim Leebens-Mack ◽  
...  

2016 ◽  
Vol 32 (4) ◽  
pp. 1254-1271 ◽  
Author(s):  
Danielle S. Conry ◽  
Pierre A. Pistorius ◽  
Stephanie Plön ◽  
G. J. Greg Hofmeyr

Ostrich ◽  
2011 ◽  
Vol 82 (2) ◽  
pp. 135-139 ◽  
Author(s):  
Włodzimierz Meissner ◽  
Magdalena Remisiewicz ◽  
Lucyna Pilacka

2014 ◽  
Vol 156 ◽  
pp. 22-36 ◽  
Author(s):  
Winanda W. Ursinus ◽  
Cornelis G. Van Reenen ◽  
Bas Kemp ◽  
J. Elizabeth Bolhuis

2021 ◽  
Vol 29 (3) ◽  
Author(s):  
Collette H. Mwanangombe ◽  
Deon Durholtz ◽  
Dawit Yemane ◽  
Jean Githaiga-Mwicigi ◽  
Warwick H. H. Sauer ◽  
...  

Growth of adult chokka squid Loligo reynaudii d’Orbigny was modelled using mantle length and age data derived from samples collected over two years (2003 and 2004) from a single, large cohort of mature and spawning squid. A total of 588 statoliths were examined (310 males, 278 females) from individuals of 71–425 mm mantle length (ML). The maximum size of chokka squid was 425 mm ML for males and 263 mm ML for females. The Francis Growth Model and Linear Growth model were selected for further analysis from six models considered. Males and females attain similar ages, although mantle length-based daily growth rates ranged from 0.75 to 1.02 (0.88 quantile _50) mm/day for males and 0.32–0.45 (0.38 quantile _50) mm/day for females, explaining the sexual dimorphism apparent in the sizes of individuals of this species.


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