# Ornithology Question **URL:** \ **Category:** Factual Questions\ **Created:** [July 30, 2022, 11:48pm UTC](https://boards.straightdope.com/t/ornithology-question/968849 "2022-07-30T23:48:50Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [July 30, 2022, 11:48pm UTC](https://boards.straightdope.com/t/ornithology-question/968849/1 "2022-07-30T23:48:50Z")
I’ve heard since I was a kid that when a mated pair of birds is tending to a restful of eggs, the mama bird will sit on the eggs and incubate, and the papa bird will bring food to the mama bird (I’m pretty confident that not ALL species of bird behave this way). But here’s my question: Is the papa bird motivated by the need to keep his offspring viable, or by the desire for the mama bird to mate with him again? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [July 30, 2022, 11:55pm UTC](https://boards.straightdope.com/t/ornithology-question/968849/2 "2022-07-30T23:55:33Z")
In my (very limited) experience with birds, none behave that way. With chickens, the hen will incubate the eggs, and she will get up and leave for short periods to get food. The rooster is off doing rooster-stuff (like impregnating other hens). With hummingbirds, the female incubates the eggs and the male is nowhere to be found. She also leaves the nest periodically to eat. Harris’ Hawks often have two generations tending the nest. But although the female is doing the brooding, both sexes hunt and feed the young. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [July 31, 2022, 12:03am UTC](https://boards.straightdope.com/t/ornithology-question/968849/3 "2022-07-31T00:03:11Z")
Courtship feeding is common in birds. I think this most often _precedes_ egg laying, when the female will benefit from the extra nutrition, and when she may be less able to feed herself. [Courtship Feeding](https://web.stanford.edu/group/stanfordbirds/text/essays/Courtship_Feeding.html) > Courtship feeding is frequently seen in terns. For instance, in an effort to lure females to their territories in the nesting area, a male Common Tern carries a fish around the breeding colony and displays it to prospective mates. After a pair bond is formed, during the “honeymoon period” the male tern actually feeds the female, and soon thereafter they begin to copulate. During the following five to ten days, both sexes feed themselves, but the male also frequently feeds the increasingly dependent female. For the few days prior to egg laying the female is fed almost exclusively by the male, but this activity declines rapidly as the second and third eggs are laid. … > [@kaylasdad99](#): > > …when a mated pair of birds is tending to a restful of eggs, the mama bird will sit on the eggs and incubate, and the papa bird will bring food to the mama bird… After the eggs are laid, I’m not sure if it’s quite so common for one bird to incubate the eggs and the other to feed it, but that article does mention it. ETA: here you go > **[The effect of male incubation feeding on female nest attendance and...](https://link.springer.com/article/10.1007/s10336-016-1427-2)** > > The incubation of eggs plays a key role in avian parental care. To ensure embryo development, incubating parents have to keep their eggs within the appropriate temperature limits. To do so, incubating individuals allocate substantial energy to the... > In species with female-only incubation, > males can help their partners by providing them with food > on the nest, a behavior which may enable females to spend > more time incubating and could, consequently, lead to > improved reproductive performance. In the study reported > here, we first investigated whether incubation feeding by > males affects nest attendance by females in Blue Tits > (Cyanistes caeruleus) and subsequently determined how > this incubation feeding affects reproductive performance. > We found that the female nest attendance tended to > increase with increasing amounts of food supplied by their > male partner. Thus, males may enable females to incubate > more when needed, as suggested by our observation that > male incubation feeding was more frequent when the > ambient temperature was lower, and especially so when > females incubated later in the breeding season (during the > study period the ambient temperature decreased rapidly > over the breeding season, which is exceptional). Although > female nest attendance did not result in a shorter time until > the eggs hatched or in higher hatching success, females that > attended the nest more produced heavier nestlings. We > suggest that the trade-off between self-maintenance and > meeting the demands of egg incubation likely tends to be > less when females received more assistance from their > partner during the egg incubation period, resulting in a > higher investment in offspring. ---
**Author:** ![Tamerlane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tamerlane/32/7602_2.png) [@Tamerlane](https://boards.straightdope.com/u/Tamerlane)\ **Post date:** [July 31, 2022, 12:13am UTC](https://boards.straightdope.com/t/ornithology-question/968849/4 "2022-07-31T00:13:38Z")
> [@kaylasdad99](#): > > Is the papa bird motivated by the need to keep his offspring viable, or by the desire for the mama bird to mate with him again? I think motivation for the male (sex or viable offspring) is a bit of chicken or the egg situation and probably can’t be teased apart. Natural selection works on successful reproduction and both of those factors are important to achieve that. Raptors, to take that example, just aren’t that bright - they have learned behaviors, but mostly they are operating on pure instinct. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [July 31, 2022, 12:26am UTC](https://boards.straightdope.com/t/ornithology-question/968849/5 "2022-07-31T00:26:13Z")
More: [https://www.sciencedirect.com/science/article/abs/pii/S0003347288801453](https://www.sciencedirect.com/science/article/abs/pii/S0003347288801453) > Male marsh tits, _Parus palustris_ , regularly feed their mates from the beginning of nest building until hatching… There was a significant negative relationship between the frequency with which the male fed the female in the nest during incubation and the length of the incubation period…feeding of the female by the male is a nutritional contribution and that the shorter incubation period and increased hatching success enhance the fitness of both parents…the male’s provisioning rate increased when ambient temperatures decreased. [https://onlinelibrary.wiley.com/doi/full/10.1111/ibi.12614](https://onlinelibrary.wiley.com/doi/full/10.1111/ibi.12614) > …during the incubation phase in passerines, females perform most or all of the incubation, while the male cares for the brood indirectly by feeding the female…The frequency of male incubation feeding varied between 0 and 74 times per day with an average of 12 feeds per day…males fed their females more often at the nest when ambient temperatures were low. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [July 31, 2022, 12:38am UTC](https://boards.straightdope.com/t/ornithology-question/968849/6 "2022-07-31T00:38:50Z")
> [@kaylasdad99](#): > > Is the papa bird motivated by the need to keep his offspring viable, or by the desire for the mama bird to mate with him again? As to this specific question, that research shows that there’s a fitness advantage from incubation feeding to both parents in keeping the eggs warm. In addition to the male having an instinct for the behavior, we’d expect the female to be instinctively attracted to a male who exhibits the behavior - these are surely complementary, not mutually exclusive alternatives. ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [August 2, 2022, 12:28am UTC](https://boards.straightdope.com/t/ornithology-question/968849/7 "2022-08-02T00:28:26Z")
Apparently emperor penguin fathers brood the egg while the females are at sea, eating. [\> When the females finally return to the colony in July the males have lost nearly half their body mass and look quite skinny.](https://www.antarctica.gov.au/about-antarctica/animals/penguins/emperor-penguins/breeding-cycle/) ---
**Author:** ![Ulfreida](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ulfreida/32/8014_2.png) [@Ulfreida](https://boards.straightdope.com/u/Ulfreida)\ **Post date:** [August 2, 2022, 12:44am UTC](https://boards.straightdope.com/t/ornithology-question/968849/8 "2022-08-02T00:44:17Z")
Emu females just lay the eggs and their job is done; the males incubate the eggs and raise the chicks. ---
**Author:** ![Tamerlane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tamerlane/32/7602_2.png) [@Tamerlane](https://boards.straightdope.com/u/Tamerlane)\ **Post date:** [August 2, 2022, 1:06am UTC](https://boards.straightdope.com/t/ornithology-question/968849/9 "2022-08-02T01:06:06Z")
> [@Ulfreida](#): > > Emu females just lay the eggs and their job is done; the males incubate the eggs and raise the chicks. Cassowaries, rheas, most kiwis and tinamous as well. In fact ostriches are kinda the exception to the rule among ratites and their close taxonomic kin (tinamou) and even with them the male still regularly participates in brooding (they cover the night shift). ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [August 2, 2022, 12:47pm UTC](https://boards.straightdope.com/t/ornithology-question/968849/10 "2022-08-02T12:47:16Z")
The papa bird feels a biological urge to feed the chicks. There’s no compelling reason to believe complicated webs of motivation are involved. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 2, 2022, 8:22pm UTC](https://boards.straightdope.com/t/ornithology-question/968849/11 "2022-08-02T20:22:21Z")
Yeah, from the broader perspective, they do it because males who do that tend to have more descendants, who carry on the instinct-genes. From the perspective of an individual bird, if you were to somehow ask him, he’d probably just say “because that’s what you do”, or something similarly non-descriptive. “Motivation” is something that’s reserved for higher mental function, and even we probably lie to ourselves about it as often as not.