Adelie Penguins: "Partners For Life"
Adelie Penguins generally tend to be very good couples but suffers from separation due to their migratory behaviors. They are usually monogamous but pair up with their partner from the last season at the same place to breed. Adelie penguins are known very well for their ability to find their way back to exactly where they mated. They usually mate at their natal breeding ground. It is still unknown how Adelie penguins are so good at finding their way back to the breeding grounds but it had been suggested that they follow the direction of the sun to navigate.
The male Adelie penguin usually returns to their natal mating ground at first. Upon arrival, they create a breeding nest with mostly stones and sometimes feathers and bones. Stones become scarce during mating time since they are used to build walls. Thus it becomes common for Adelie penguins to steal stone from one another when they are not looking. Male penguins express their choice to mate with a female by rolling a stone at her feet.
Each year, the male recognizes their female mate from thousands of other mates by their voices and cries. If the female cannot find its male mate at the colony, then she goes for another male. But if the male mate ends up showing up later, the female will go back to mating with her original partner. On the other hand, if a female is late to show up at her colony and finds her mate with another female, she will attack and drive the intruder away.
-Loba Alam (Group A)
I really think its amazing that some species have monogamous relationships. However, instead of getting separated when its time to migrate, why don't they just migrate together? What advantage is there to migrate on a different path from your spouse? Also, what kinds of research have been done on recognition by vocalizations?
ReplyDeleteAbbie Lamarre-DeJesus
Will the females actually copulate with multiple males? If they cannot find their partner and mate with a new male, will they abandon their previous offspring?
ReplyDeleteJen Kodela
Hmm I wonder what the evolutionary advantage is for the penguins to get back with their old mates even if their mates have already paired up with another bird. What if the female finds a better mate? Why would she go back to the old mate?
ReplyDelete-Alex Sprague
What about the stone determines whether a female chooses that particular male? How round? How big? And when they build this wall to shield the eggs, what if it falls? or worse, falls on the egg? Wind's must be strong and it is a stone wall after all.
ReplyDelete-Vince Tieu
For a female penguin to distinguish the call of their male partner after a year's separation is amazing given the time span. I wonder if there's a wide range of variation in penguin calls or a very advanced call-recognition ablity (maybe both?) that allows the female penguins to find their male partners.
ReplyDelete-Kevin Tse
how was this study done? will the male mate with multiple females?
ReplyDeleteIt's pretty crazy that they can still find and recognize each other after so long. Do you know if there is a hormone or something that strengthens a penguin bond?
Leah Salloway
Abbie,
ReplyDeleteThere has been a lot of study done on the calls of penguins. Since penguins migrate a lot and do not live in fixed sites, there is no other way for them to recognize their mate or offspring other than recognizing their individual vocalizations. They use a complex set of calls that is critical to individual recognition between parents, offspring and mates. Vocalizations are usually complex with two frequency bands occurring simultaneously.
Jen,
When a female does not find its original mate and it has already been past its mating season, it will copulate with a new male and take care of its offspring. Males and females both contribute in caring for the offspring until they are all set to be on their own. When the female finds its original male, and it has already laid eggs with a different father, it will still take care of its offspring but eventually go back to mating with their original partner.
Alex,
You have a interesting question, what if the female finds a new mate that is better than its "life partner".. Well prior research has shown that when penguins go back to mating with the same partner year after year, their offspring have better chances of being reproduced and usually ends up being fitter and stronger. I think it has to do with the fact that both males and females contribute to taking care of the young and rearing the young. As the mates keep reproducing and rearing the young year after year, they might become more experienced and develop better strategies of team work to rear the young.
Vince,
You are right, the wind could definitely knock down a few eggs. But most of the time, the female is sitting on top of the eggs and protecting it until the infants are hatched. Also the stones must usually be strong enough to defend the wind or the penguins would have come up with a better strategy by now. Nevertheless, research has shown that about 20% eggs get destroyed before they get a chance to hatch.
As for the stone rolling event, when a male choses a particular female to mate with, he usually expresses his intentions by taking a stone and rolling it under her feet. If the female takes welcomes this gesture as an invite, they shall mate.
Kevin,
You are right. Penguins have very advanced call recognition strategies. For example, infants start calling from the time they are born so their parents can learn to recognize their infants voice. All penguins use a complex set of calls that is critical to individual recognition between parents, offspring and mates. Vocalizations are usually complex with two frequency bands occurring simultaneously. Among the different types of penguins, Empire penguins are known to be the ones with the most specialized individual recognition vocalization patterns.
Leah,
A male will usually find a female at their previous mating site. They initially recognize each other among thousands of other penguins by recognizing their vocalizations. A penguin bond is perhaps solely strengthened by mating together, rearing their infants together and most importantly learning to recognize their individual vocalizations for recognition. Previous studies on the calls of penguins have shown that penguins have specific calls for infant, partner and mating recognition.
-Loba