Krokodile: Alligatoren, Kaimane, echte Krokodile und Gaviale.

Die Neue Brehm Bücherei Bd. 593.
Westarp Wissenschaften Magdeburg. isbn 3-89432-420-1

Verlagstext:

Nur wenige Menschen wissen, daß die heute noch lebenden Krokodile enger mit den ausgestorbenen Dinosauriern oder den Vögeln verwandt sind als mit anderen Reptiliengruppen. Ihre isolierte Stellung ist durch viele Besonderheiten in der Biologie gekennzeichnet. Von den 22 noch lebenden Krokodilarten sind 21 in ihrer Existenz bedroht*. Die Verwendung ihrer Häute als überflüssige Lederwaren, die Zerstörung der Lebensräume und die Jagd auf sie als vermeintlich gefährliche Konkurrenten um Nahrung und Raum haben zu dieser dramatischen Situation geführt. Auf der anderen Seite werden Farmen errichtet, um die kommerziellen Interessen zu steuern und die Wildbestände zu schonen. Der Verfasser greift diese Themenvielfalt auf. Er beschreibt in einem allgemeinen Teil auf der Grundlage der Biologie der Tiere diese Gegensätze und behandelt auch Fragen zu Haltung und Nachzucht. In einem speziellen Teil werden alle Arten mit Abbildungen und Verbreitungskarten vorgestellt. Angaben zu Färbung und Aussehen, Verbreitung und Lebensraum sowie zur Ökologie runden diese Besprechungen ab.

* NB: Das trifft heute nicht mehr zu!

Yacare Caiman - Caiman yacare.

In: Crocodiles.Status Survey and Conservation Action Plan: 23-28.
Third Edition, ed. by S.C. Manolis and C. Stevenson. Crocodile Specialist Group: Darwin

Aus dem Inhalt:

The  Yacare  caiman  is  found  in  the  lowlands  of  northern and  eastern  Bolivia  and  western  Brazil,  from  the Amazon southwards  through  the  Guaporé/Madeira  and  Paraguay/Paraná  River  systems  and  into  northern  Argentina. Morphologically and ecologically, this species is similar to
the  common  caiman  (Caiman  crocodilus  crocodilus), and integrates with that subspecies along a large area (probably more  than  1000  km)  of  the  Madeira  River  in  Amazonia. As with the common caiman, C. yacare is found in a wide spectrum  of  habitat  types.  Most  ecological  studies  have been carried out in the Pantanal region of southern Brazil.

Resolution of the systematic relationships within the very widespread C. crocodilus complex  is needed. Extensive surveys and specimen collection in southern Brazil, northern Bolivia and  Paraguay suggest a  ery  complex gradient of morphological features between C. c. crocodilus and the C. yacare. As there are no fixed differences between the two taxa, they have to be defined geographically,  rather than morphologically, which obviously poses legal difficulties if an individual crosses the  hypothetical line and changes “species”.

Morphological and genetic analyses to resolve the relationships between these taxa are incomplete and inconclusive, mainly because  data  from  the zone of hybridization between the two taxa was not included.

Caiman yacare is still, and always has been, listed technically as a full species. Some authors do  not recognize it as  being distinct from the common caiman and use the subspecies C. c. yacare.  Recent  molecular data provide evidence for long-term biological separation of large populations of caimans in  Central and South America.

Breeding the Broad-nosed caiman, Caiman latirostris, in captivity.

Int. Zoo Yearb. 24/25: 226-230. ISSN 0074-9664.

Conclusions:

From our observations, Broad-nosed caimans are easily bred in captivity as long as adequate materials for nest building are provided together with a relatively secluded area close to a reasonably large body of water. Co-operative nest building commences some days before the start of mating, which takes place under water, and eggs are laid just over a month later; incubation has been found to  last 70 days. There appear to be four well-defined phases  in the behaviour of the adults during incubation an rearing:

1. although both adults build the nest, the male plays no part in guarding it and ignores or avoids the female who becomes increasingly aggressive;
2. when the young hatch, only the female carries them to the water where they are guarded by the male; either adult will attack anything, apart from their own young, which approaches too closely;
3. both adults watch the neonates  which do not move far from the nest site, and protect them for several months;
4. once a new clutch has hatched the adults lose all interest in the previous year's young, although they are never aggressive towards them.

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