Good parents..
“Life history theory suggests that parents should balance their current investment in young against their chance of survival and reproduce in the future.”(Erikstad) This comprises of two things, guaranteeing the survival of their offspring while maximizing the offspring’s reproductive chances and maintaining the adult’s survival to reproduce again. Erikstad et al studied puffins adjustment when their 20-day-old chicks were randomly switched with younger or older than chicks. The puffin is an interesting species to study because it is a long-lived seabird species that lay only one egg per breeding season. Erikstad studied “whether parental effort in the puffin is regulated b y the parent’s body condition and also whether parents adjusted their effort according to the size of the chick, which may indicate the chick’s prospects of survival and recruitment to the population.”
Erikstad and team studied a population of puffins on Hornoya, a small island in north-eastern Norway from May until August 1994. Twenty days later, chicks were randomly replaced and the parental effort change and whether the parent puffin deserted the chick. The body condition of each parent puffin was recorded and known. If parents regulate their effort in raising young according to their own body condition, then it would be expected that there would be “a positive correlation between body condition of parents and the growth rate of their chick before manipulation; and growth of foster chicks should be positively related to the body condition of foster parents, but not to that of their own parents before switching.”(Erikstad) They found that parents who deserted their nest had received chicks that were smaller than their previous chick. Chicks with parents in good body condition early on were larger than those with chicks who had parents in poor body condition. The results indicate that there is a positive correlation between parent’s body condition and mass gain, but there is a negative correlation between size of foster chick and parental body condition.
I found that this research asked a perplexing question about parental effort in caring for their offspring. I automatically assume that a parent would give it their all, but that is a very humanistic quality and even all humans don’t exert the most effort into child rearing. I wonder what psychologists would find if this experiment was applied to them…
---happyfeet
posted by PWH @ 10:41 PM
4 comments
4 Comments:
This was a very interesting blog entry topic! I liked the inquiry posted at the bottom... it makes you think about the double standards between animals and humans. Animals are looked at as 'not as intelligent' yet they master the essentials to life more often than humans.
It was interesting to find out that the puffins only left the foster chicks when they were smaller than the original chicks.
A factor that could have been brought up was the environment... maybe food was not supplied readily enough for the mother's to have a good body condition, which would lead to a smaller chick size as well.
Overall, this blog was informative, and followed the scientific method well (hypothesis, data). Good job.
-Danielle Bushey
i see your point, and i agree with you it is a humanisitc quality, but when you say " I wonder what psychologists would find if this experiment was applied to them…"
i m not sure that directly relate the same concept here, foster parents in human societies only effect the social conditions and not the physical as we believe they are inherited from the original family with contrast to the chicks that aquire better physical conditions because it is being taken better care of.
but that is only my point if view!
SAmer Ead
22540701
I enjoyed reading your article; I found it interesting and funny. I thought to myself the same thing; doesn’t it make sense for parents to give it their all to further the development of their offspring? I was thinking that maybe because the puffins do not consciously, but rather instinctively, do what they do that it would be different in humans. Humans would be more aware of this and may have a different correlation as in the puffins. Also, humans have an age where they stop the ability to reproduce which may change the out look of the situation. I like the points you made and your quotes with resources to back them up made it a stronger article.
combsj7
Interesting study, I had never thought of parents in the wild abandoning their child if it was smaller than expected, especially if it was the only child they would be raising that breeding season. The idea that a chicks size would be dependent on the health of their parents is sort of expected, as a stronger/healthier adult would be able to better provide for their young. All in all, a very interesting study, one that could probably lead to studies in other species, to look at rates of survival/abandonment/development of offspring with regard to their parents (possibly in humans??).
--Burkej6
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