PIC OF THE MONTH
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Parental Care Redux
Feeding her young?
This photograph was taken in the Siamese crocodile exhibit at the St Augustine Alligator Farm, fascinating in itself because the young were hatched within the enclosure and allowed to live with both parents for nearly a year. In mid-July, the adult female was fed a skinned nutria (a type of South American rodent) as normal, but instead of eating it immediately she moved away from the male and allowed one hatchling to approach it and begin to feed. The following week she was fed another nutria, and a remarkable piece of behaviour was observed. John Brueggen, General Curator of the Alligator Farm, explains:
"This week, the male did not make any effort to take the meat away from her in the beginning. She sat for more than an hour letting the hatchlings feed from the meat. In the past, if the male was coming for her meat, she would move away from him and gobble the meat up quickly. About a half hour into this, the male did come out of the pool and try to take the meat. The female moved away, in fact into the pool, and then crawled back on to land to allow the juveniles to feed again. The entire thing ended when she sat up in an attempt to shake the meat into pieces and the meat happened to swing into the males mouth and he ran off with it and ate it ... This is the second time it has happened, and she is very deliberate about it. She makes sure the male does not get the meat, but sits with her mouth slightly open while the babies tear off pieces. They have waited almost an entire year to demonstrate this behavior."
So, what is really happening here? Are we seeing a remarkable extension of parental care in crocodilians, feeding of the young - a behaviour typically associated with birds and mammals? St Augustine is not the only place to have reported this behaviour: an experienced private keeper in Florida has reported parental feeding in captive broad-snouted caiman (Caiman latirostris), and a researcher in South America has reported seeing it in wild Orinoco crocodiles (Crocodylus intermedius).
Of course I would love to believe that we're seeing a new type of parental care in crocodilians, but let's be analytical for a moment. This is only the second time in a year that this behaviour has been observed, which doesn't suggest that it's a typical behaviour, nor one that is essential to the survival of the young during a critical period of their life. Perhaps the female only feeds juveniles once they attain a certain size (eg. too small to tear off pieces of meat) but by this stage they are normally established and capable of capturing a variety of live prey for themselves.
Let me postulate an alternative scenario:
It is typical for an adult crocodilian, once it has food in its mouth, to retreat from other adults to prevent the food from being stolen. Perhaps this is what happened here, and the female happened to move towards her juveniles (that were also keeping out of the male's way) and sat immobile for several minutes. Such behaviour is quite normal, as crocodilians often sit with food in their mouths (a few minutes to over half an hour). During this time, the juveniles would have detected the food (smell, sight) and taken the opportunity to approach and begin eating. The female ignored them because of their size, and possibly because she recognised them as her juveniles.
The male approached before she was ready to swallow the meat, so she moved away into the water. Upon leaving the water, she prepared to break the meat into more manageable pieces for swallowing. She whipped her head quickly from one side to another - a behaviour perfect for ripping large prey items into several smaller pieces. This resulted in the food landing in the male's mouth, which was his cue to steal it. Once the meat was eaten, the juveniles lost their opportunity to scavenge.
So, the behaviour seen was either a rare example of parental feeding of juveniles, or the juveniles were exercising their opportunistic nature while the female dawdled.
Which scenario is more likely? It is tempting to view this as an example of parental feeding, but such behaviour has been so rarely observed that its selective or intrinsic value is difficult to see. Of course, it cannot be discounted, and that's what makes it interesting. There's so much we don't know about crocodilians - they can inspire a person for their entire life, and still leave questions unanswered. Truly, crocodilians never cease to amaze me!
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