Introduction
This article focuses on the broody hen, and only incidentally on the chicks they raise. There are already a lot of good articles and threads on BYC about using broody hens to raise chicks, and links to three such articles can be found at the end of this article. What I want to do here is to consider how to assess whether a broody is actually any good at the job. There is very little proper published research on this topic, so this article is based largely on my own experience.
I have had 9 different broody hens raise chicks here since 2019, some of them sitting multiple times a year. As in other aspects of chicken life, they all do it differently, and beyond that, the same hen does it differently as she gains age and experience. In terms of growing the flock, I have gone from just pullets to a mixed flock, and from 3 to 29 (currently). Through that process I have come to consider having broodies as, without doubt, the best part of chicken-keeping; there are few things in life more enjoyable than watching a broody raise her chicks. And yet, this growth and this joy has been accompanied by some failure and sadness.
It is common for keepers with broodies to share their emotional rollercoaster ride on BYC threads, often accompanied by fear or anxiety that some person or broody hen did or might do something wrong. Given that both we and our broodies are usually novices first time round, and we are still learning on the Nth time of going through it, mistakes will surely be made, both by us and by our broodies. I don’t think it helps to remonstrate over it (unless we do not learn from them, and we repeat the same mistakes). Such thinking prompted me to investigate how we might evaluate the success, or otherwise, of broody hens. For just because a hen goes broody, it does not follow that she will make a good job of it, and it can cause real heartache, or financial loss, if she fails badly.
The discussion and statistics that follow omit hidden nests, predated nests and abandoned nests, a few of which I discovered and even photographed, but for which I made and kept no records.
Figure 1: Hidden nest
Measure 1: Hatching
The first obvious metric we could examine is: what proportion of eggs that were set under a broody successfully hatched? This is easy to count. However, failure to hatch is often the result of the eggs being infertile, or old, or shaken, or deficient in some essential nutrient, or a host of other reasons, none of which is necessarily or even likely to be the broody’s fault, so it does not seem rational to judge her on that. Over the years the hatch rate here has improved significantly, most of it attributable to my actions rather than the broodies’ actions, I am sure; I now expect all home-grown eggs to hatch when I set them, and am disappointed if any does not. Purchased hatching eggs are still a lottery, and I am pleased if any of them hatch. Edited to add that I have added a page to this article with the hatching rate statistics against the name, age and breed of the broody, for whatever light it may shed on the topic.
Figure 2: Hatching eggs
What else might we use as a measure of the broody’s abilities?
Measure 2: Fledging
So, we might also ask: what proportion of the chicks that hatched, fledged? That is to say, how many of those that hatched survived to independence? For we might reasonably attribute the chicks’ survival rate, while she is raising them, to her capabilities, or lack thereof.
If we do this, there should be some allowance for brood size: it is a lot easier to look after 2 chicks than it is to look after 10 chicks, for example. On the whole, my broodies have done well by this metric. I typically set between 4 and 8 eggs, and in 10 out of 16 such clutches, all the chicks that hatched, fledged.
Figure 3: Fledge rate: this broody managed 7/7
The 6 other broods lost 1 chick along the way in 5 cases, and 3 along the way in 1 case – a goshawk was probably responsible for at least 2 of the losses in that case, and the broody was a novice.
Here broodies incubate eggs and raise their chicks within the flock; the chicks are on grass as soon as the broody brings them off the nest; and they are free-ranging in a garden of about 1 acre size, from a few days old. My practice has changed in this regard over the years. My first broodies were not separated at all from the flock and the chicks were free-ranging from day 1. I do not know if those first broodies were themselves raised by broody, or by no-one, effectively, in a brooder, since I had acquired them as pullets.
For the last couple of years, just for the last few days of incubation, I have temporarily fenced off the area around the coop that the broody is in (I have 4 small mobile coops) with scaffolding netting, to prevent other birds disturbing the broody during the hatch. Without that, other hens are liable to come in and drive the broody off, if she’s in their favourite nest box and she’s junior to them, or lay their egg among the clutch if she happens to be off the nest for whatever reason. The temporary netting around the coop stays up until the chicks have learned to climb the ramp to get back into the coop at night, because the alternative is a frantic broody torn between staying with the ones that got up the ramp, or leaving them (and them following her out again) to guide in the ones that haven’t made it yet; it also involves me having to try to shoo tiny chicks out of the shrubbery at dusk, which is difficult and stressful for all concerned. As soon as I’ve seen that all the chicks can get up the ramp, the netting comes down and everyone is allowed access everywhere again.
In this free-ranging dawn-dusk environment, the principal lessons that the broody has to teach the young before they fledge are: how to find food in, on, and near the ground; what is and is not edible; what is and is not dangerous; and how to behave with other flock members. I recently observed such a lesson, when a broody spotted a toad crossing the lawn and called the family over to observe and register that this is not for eating (these toads are toxic).
Figure 4: Foraging lesson
As can be seen from the photo, in this case there are 2 broodies co-brooding. These broodies have done well so far, despite both being young and novices; they were raised by different broodies a month apart last year. So these 4 chicks are getting instruction and care from two heads rather than one; it remains to be seen whether this will turn out also noticeably better than having one. For fledging is not the final assessment of a broody’s abilities.
Measure 3: Surviving Independence to maturity
The ‘how many fledged’ metric has one obvious drawback: early fledging can give a false impression of a broody’s success rate, because this metric shifts the responsibility for survival from the broody, to her chicks, sooner. Thus, a broody that dumps her chicks when they are 3 weeks old may appear to have done better than a broody who stayed longer with her chicks, because the broody is then held responsible for any loss over that extra time.
And while their survival after fledging is reasonably considered the chicks’ own responsibility, rather than their broody’s, “the evolutionary success of individuals must ultimately be evaluated in terms of their lifetime contribution of mature young to the breeding population” (Collias et.al. 1994, emphasis added). Thus, in order better to gauge a broody’s success, we need to look beyond the chicks’ fledging, at whatever age that happens; we need to look as far as the chicks’ maturing into breeding adults themselves. We may find that fewer chicks that fledged sooner survived to maturity than those that fledged later, potentially inverting the impression of the broody’s abilities that was given by the fledging metric.
Figure 5: Chicks can eat with adults
Survival through the ‘teen’ months, between fledging and breeding maturity, is not a given. Juveniles are young and inexperienced, and generally are more likely to meet with an accident or fall prey to a predator as a fledgling than they were when they had a broody to look out for them, or will be when they are older and more experienced. Those risks apart, their biggest certain problem is their position in the flock.
Juveniles are at the bottom of the pecking order. They get last dibs of whatever’s going. If there are nutritional shortages, they will suffer them first. There is a strong argument for ad lib feeding at this time, even if it is not the norm where they are growing up. Whereas chicks are tolerated by adults at feed bowls, juveniles are not; they are pecked by all adults, to make them wait their turn, which is last.
The pecking order is the flock hierarchy. Subordinate birds give way to those above them, and may get the beak equivalent of one or many clips round the ear while they are learning where they fit in the hierarchy. It is most obvious and most acute at feeding time and at roosting time. Having multiple feed bowls spaced apart can alleviate the situation, but some low ranking birds, especially juveniles, may opt to just wait their turn in the wings, and end up with slim pickings after all their superiors have gone through, or if their desire to avoid a bully exceeds their desire to eat.
Figure 6: Independent juveniles cannot easily eat with adults
The earlier a broody hen leaves her chicks to their own devices, the sooner they are exposed to this harsh reality; at or around six weeks old is often cited on BYC as a typical time for a hen to leave her chicks. The transition from chicks to juveniles is about 12 weeks here, ordinarily, though recently we had an 8-week exception.
Figure 7: Broodies here normally serve for 12+ weeks
For this summer I have seen contrasting behaviours from 3 young and novice broodies, who all turned 1 just days before or after their clutches hatched, and I have been able to compare their behaviours close in time. Fez’s chicks hatched in June, and co-broodies I and R’s chicks hatched in August.
The June brood were left by their broody Fez when they were 8 weeks old, which is shorter than any other in recent years here except for Fez herself. Her broody Polka was a young novice, who started sitting on a single egg on a secret nest in a neglected old planter just after we left on holiday, and the chick hatched shortly after we got home. They lived out together for 6 weeks until I finally persuaded Polka to go back to a coop to roost, with Fez in tow. Then when Fez was between 8 and 9 weeks old, her broody just stopped responding to her cheeps, and Fez found herself basically on her own; but as a solo, and a familial (although Polka roosted out with her for the first 6 weeks after she hatched, the flock knew perfectly well that the chick was one of their own) she seems to have been accepted into the main flock more or less immediately, fortunately. So, when Fez abandoned her brood at 8 weeks, she was just repeating what had happened to her. Now she has separated from her chicks when they were 8 weeks old, it remains to be seen how many of them will survive to maturity, and to reproductive status themselves – as she did. And although independence at 8 weeks is short by our standards, Fez joined the breeding population and raised a clutch (the one shown in Figure 6) herself, so her mother Polka scored on this metric as a fully successful broody (see #4 below).
Figure 8: Chicks learn from their broody
By contrast, the August broodies I and R had each been with their broodies (J and Pa respectively) until they were between 15 and 16 weeks old. I and R seem to be repeating the behaviour they experienced; while I write this, at 13 weeks both are still happy to play the broody role, but the little family is starting to drift apart, as is normal here, and Idris has just resumed laying. Time will tell how much longer they last as broodies, and whether, when they do go their separate ways, they go in sequence or concurrently, and whether they do it by not responding to their brood, or because their chicks just drift away from them and into independence, or a bit of both. Edited to add, I resumed laying before R, and these chicks were fully fledged and going their own way by 15 weeks.
The impact that the timing of the separation has on the behaviour of their broods was well illustrated a couple of days ago, when I put out a bowl of goodies near to, and specifically for, the June juveniles as they were passing by (to try to ensure that they are getting enough to eat, besides the forage that is always available to them as free rangers). Although they know I am a friend and a source of food, and they are nearly adult size (18 weeks old at the time this happened), they approached nervously, and ate voraciously, staying as far from the bowl as they could, and ready to leap away at a moment’s notice. Then the August broodies spotted that something was afoot, and ran over with their brood in tow; their chicks dived straight into the bowl without hesitation, and the juveniles ran away. The chicks that were 7 weeks younger and a third of adult size were more confident than the chicks that are nearly adults, because the former are still under the guardianship and tutelage of their broodies, and the latter are on their own.
So, how soon a broody leaves her brood can make a significant difference to the youngsters’ confidence and well-being for the next few months, and that can have a lasting impact. It is the period during which they are developing into adults, their puberty, when their reproductive systems are maturing, and it ends with them firing, or spluttering, into mating or laying action. A good, varied diet is essential at this time. How well she taught them to forage in whatever time they were together, and how much forage they can find once on their own, are obviously important factors too, and the environment and weather at each time will impact this as well. In a temperate climate such as here, what forage is available in autumn when they are juveniles is not exactly the same as the forage that was available in summer when they were chicks and they were being taught what’s what by their broody. Generally autumn is a time of plenty, but it is soon succeeded by winter and a time of hardship.
Measure 4: Sustaining the flock
A further (and for the purpose of this article, final) way of evaluating a broody is to count the number of her chicks that not only make it to maturity, but have offspring of their own, that is, the proportion that join the breeding population and help to sustain the flock. This is less pertinent when the keeper controls whose eggs and how many are set beneath the broody, as I do, but the numbers still cast an interesting light on different hens’ performances as broodies.
Analysing this data, I discovered that 5 of the clutches which fledged exceptionally well (suffering only 1 loss between all of them along the way) have been complete failures from a ‘sustaining the flock’ perspective. In addition, 4 clutches have delivered just 1, 2 clutches have delivered 2, 1 clutch has delivered 3, and the single most successful clutch to date delivered 4 of its 7 eggs to the breeding population. Turning from clutches to broodies, three broodies each got 4 chicks to the self-sustainability goal, one hen got 3 there, and one hen has got her first there to date; it is of course too soon to say for the younger hens how many they may raise to the sustainability level over their lifetimes. There is a broad but not complete correlation with the age of the hen – obviously, the older she is, the more time she has had to try to raise youngsters and gain experience. But it is still quite a revelation to discover that in a flock with (currently) 17 hens, of which 9 have raised broods, just 4 of them raised almost all of the adult breeding population of the current flock. About half the broodies fail on that measure. This is consistent with the results of the Collias et.al. 1994 study on the Red Jungle Fowl flocks that have been living wild in the grounds of San Diego Zoo, California, since 1942: a small number of hens were responsible for most of the flock’s population. However, contrary to the Collias study, one of the two most successful broodies here is not a dominant hen - and was barely a year old when she raised her most successful brood.
References
https://www.backyardchickens.com/th...hatch-a-long-and-informational-thread.457488/
https://www.backyardchickens.com/articles/guide-to-letting-broody-hens-hatch-and-raise-chicks.65989/
https://www.backyardchickens.com/ar...e-make-a-sitting-hens-job-so-difficult.74389/
Collias et.al. (1994) Dominant Red Junglefowl (Gallus Gallus) Hens in an Unconfined Flock Rear the Most Young over Their Lifetime The Auk 111: 863-872 Open access https://academic.oup.com/auk/article/111/4/863/5168263 https://doi.org/10.2307/4088818
This article focuses on the broody hen, and only incidentally on the chicks they raise. There are already a lot of good articles and threads on BYC about using broody hens to raise chicks, and links to three such articles can be found at the end of this article. What I want to do here is to consider how to assess whether a broody is actually any good at the job. There is very little proper published research on this topic, so this article is based largely on my own experience.
I have had 9 different broody hens raise chicks here since 2019, some of them sitting multiple times a year. As in other aspects of chicken life, they all do it differently, and beyond that, the same hen does it differently as she gains age and experience. In terms of growing the flock, I have gone from just pullets to a mixed flock, and from 3 to 29 (currently). Through that process I have come to consider having broodies as, without doubt, the best part of chicken-keeping; there are few things in life more enjoyable than watching a broody raise her chicks. And yet, this growth and this joy has been accompanied by some failure and sadness.
It is common for keepers with broodies to share their emotional rollercoaster ride on BYC threads, often accompanied by fear or anxiety that some person or broody hen did or might do something wrong. Given that both we and our broodies are usually novices first time round, and we are still learning on the Nth time of going through it, mistakes will surely be made, both by us and by our broodies. I don’t think it helps to remonstrate over it (unless we do not learn from them, and we repeat the same mistakes). Such thinking prompted me to investigate how we might evaluate the success, or otherwise, of broody hens. For just because a hen goes broody, it does not follow that she will make a good job of it, and it can cause real heartache, or financial loss, if she fails badly.
The discussion and statistics that follow omit hidden nests, predated nests and abandoned nests, a few of which I discovered and even photographed, but for which I made and kept no records.
Measure 1: Hatching
The first obvious metric we could examine is: what proportion of eggs that were set under a broody successfully hatched? This is easy to count. However, failure to hatch is often the result of the eggs being infertile, or old, or shaken, or deficient in some essential nutrient, or a host of other reasons, none of which is necessarily or even likely to be the broody’s fault, so it does not seem rational to judge her on that. Over the years the hatch rate here has improved significantly, most of it attributable to my actions rather than the broodies’ actions, I am sure; I now expect all home-grown eggs to hatch when I set them, and am disappointed if any does not. Purchased hatching eggs are still a lottery, and I am pleased if any of them hatch. Edited to add that I have added a page to this article with the hatching rate statistics against the name, age and breed of the broody, for whatever light it may shed on the topic.
What else might we use as a measure of the broody’s abilities?
Measure 2: Fledging
So, we might also ask: what proportion of the chicks that hatched, fledged? That is to say, how many of those that hatched survived to independence? For we might reasonably attribute the chicks’ survival rate, while she is raising them, to her capabilities, or lack thereof.
If we do this, there should be some allowance for brood size: it is a lot easier to look after 2 chicks than it is to look after 10 chicks, for example. On the whole, my broodies have done well by this metric. I typically set between 4 and 8 eggs, and in 10 out of 16 such clutches, all the chicks that hatched, fledged.
The 6 other broods lost 1 chick along the way in 5 cases, and 3 along the way in 1 case – a goshawk was probably responsible for at least 2 of the losses in that case, and the broody was a novice.
Here broodies incubate eggs and raise their chicks within the flock; the chicks are on grass as soon as the broody brings them off the nest; and they are free-ranging in a garden of about 1 acre size, from a few days old. My practice has changed in this regard over the years. My first broodies were not separated at all from the flock and the chicks were free-ranging from day 1. I do not know if those first broodies were themselves raised by broody, or by no-one, effectively, in a brooder, since I had acquired them as pullets.
For the last couple of years, just for the last few days of incubation, I have temporarily fenced off the area around the coop that the broody is in (I have 4 small mobile coops) with scaffolding netting, to prevent other birds disturbing the broody during the hatch. Without that, other hens are liable to come in and drive the broody off, if she’s in their favourite nest box and she’s junior to them, or lay their egg among the clutch if she happens to be off the nest for whatever reason. The temporary netting around the coop stays up until the chicks have learned to climb the ramp to get back into the coop at night, because the alternative is a frantic broody torn between staying with the ones that got up the ramp, or leaving them (and them following her out again) to guide in the ones that haven’t made it yet; it also involves me having to try to shoo tiny chicks out of the shrubbery at dusk, which is difficult and stressful for all concerned. As soon as I’ve seen that all the chicks can get up the ramp, the netting comes down and everyone is allowed access everywhere again.
In this free-ranging dawn-dusk environment, the principal lessons that the broody has to teach the young before they fledge are: how to find food in, on, and near the ground; what is and is not edible; what is and is not dangerous; and how to behave with other flock members. I recently observed such a lesson, when a broody spotted a toad crossing the lawn and called the family over to observe and register that this is not for eating (these toads are toxic).
As can be seen from the photo, in this case there are 2 broodies co-brooding. These broodies have done well so far, despite both being young and novices; they were raised by different broodies a month apart last year. So these 4 chicks are getting instruction and care from two heads rather than one; it remains to be seen whether this will turn out also noticeably better than having one. For fledging is not the final assessment of a broody’s abilities.
Measure 3: Surviving Independence to maturity
The ‘how many fledged’ metric has one obvious drawback: early fledging can give a false impression of a broody’s success rate, because this metric shifts the responsibility for survival from the broody, to her chicks, sooner. Thus, a broody that dumps her chicks when they are 3 weeks old may appear to have done better than a broody who stayed longer with her chicks, because the broody is then held responsible for any loss over that extra time.
And while their survival after fledging is reasonably considered the chicks’ own responsibility, rather than their broody’s, “the evolutionary success of individuals must ultimately be evaluated in terms of their lifetime contribution of mature young to the breeding population” (Collias et.al. 1994, emphasis added). Thus, in order better to gauge a broody’s success, we need to look beyond the chicks’ fledging, at whatever age that happens; we need to look as far as the chicks’ maturing into breeding adults themselves. We may find that fewer chicks that fledged sooner survived to maturity than those that fledged later, potentially inverting the impression of the broody’s abilities that was given by the fledging metric.
Survival through the ‘teen’ months, between fledging and breeding maturity, is not a given. Juveniles are young and inexperienced, and generally are more likely to meet with an accident or fall prey to a predator as a fledgling than they were when they had a broody to look out for them, or will be when they are older and more experienced. Those risks apart, their biggest certain problem is their position in the flock.
Juveniles are at the bottom of the pecking order. They get last dibs of whatever’s going. If there are nutritional shortages, they will suffer them first. There is a strong argument for ad lib feeding at this time, even if it is not the norm where they are growing up. Whereas chicks are tolerated by adults at feed bowls, juveniles are not; they are pecked by all adults, to make them wait their turn, which is last.
The pecking order is the flock hierarchy. Subordinate birds give way to those above them, and may get the beak equivalent of one or many clips round the ear while they are learning where they fit in the hierarchy. It is most obvious and most acute at feeding time and at roosting time. Having multiple feed bowls spaced apart can alleviate the situation, but some low ranking birds, especially juveniles, may opt to just wait their turn in the wings, and end up with slim pickings after all their superiors have gone through, or if their desire to avoid a bully exceeds their desire to eat.
The earlier a broody hen leaves her chicks to their own devices, the sooner they are exposed to this harsh reality; at or around six weeks old is often cited on BYC as a typical time for a hen to leave her chicks. The transition from chicks to juveniles is about 12 weeks here, ordinarily, though recently we had an 8-week exception.
For this summer I have seen contrasting behaviours from 3 young and novice broodies, who all turned 1 just days before or after their clutches hatched, and I have been able to compare their behaviours close in time. Fez’s chicks hatched in June, and co-broodies I and R’s chicks hatched in August.
The June brood were left by their broody Fez when they were 8 weeks old, which is shorter than any other in recent years here except for Fez herself. Her broody Polka was a young novice, who started sitting on a single egg on a secret nest in a neglected old planter just after we left on holiday, and the chick hatched shortly after we got home. They lived out together for 6 weeks until I finally persuaded Polka to go back to a coop to roost, with Fez in tow. Then when Fez was between 8 and 9 weeks old, her broody just stopped responding to her cheeps, and Fez found herself basically on her own; but as a solo, and a familial (although Polka roosted out with her for the first 6 weeks after she hatched, the flock knew perfectly well that the chick was one of their own) she seems to have been accepted into the main flock more or less immediately, fortunately. So, when Fez abandoned her brood at 8 weeks, she was just repeating what had happened to her. Now she has separated from her chicks when they were 8 weeks old, it remains to be seen how many of them will survive to maturity, and to reproductive status themselves – as she did. And although independence at 8 weeks is short by our standards, Fez joined the breeding population and raised a clutch (the one shown in Figure 6) herself, so her mother Polka scored on this metric as a fully successful broody (see #4 below).
By contrast, the August broodies I and R had each been with their broodies (J and Pa respectively) until they were between 15 and 16 weeks old. I and R seem to be repeating the behaviour they experienced; while I write this, at 13 weeks both are still happy to play the broody role, but the little family is starting to drift apart, as is normal here, and Idris has just resumed laying. Time will tell how much longer they last as broodies, and whether, when they do go their separate ways, they go in sequence or concurrently, and whether they do it by not responding to their brood, or because their chicks just drift away from them and into independence, or a bit of both. Edited to add, I resumed laying before R, and these chicks were fully fledged and going their own way by 15 weeks.
The impact that the timing of the separation has on the behaviour of their broods was well illustrated a couple of days ago, when I put out a bowl of goodies near to, and specifically for, the June juveniles as they were passing by (to try to ensure that they are getting enough to eat, besides the forage that is always available to them as free rangers). Although they know I am a friend and a source of food, and they are nearly adult size (18 weeks old at the time this happened), they approached nervously, and ate voraciously, staying as far from the bowl as they could, and ready to leap away at a moment’s notice. Then the August broodies spotted that something was afoot, and ran over with their brood in tow; their chicks dived straight into the bowl without hesitation, and the juveniles ran away. The chicks that were 7 weeks younger and a third of adult size were more confident than the chicks that are nearly adults, because the former are still under the guardianship and tutelage of their broodies, and the latter are on their own.
So, how soon a broody leaves her brood can make a significant difference to the youngsters’ confidence and well-being for the next few months, and that can have a lasting impact. It is the period during which they are developing into adults, their puberty, when their reproductive systems are maturing, and it ends with them firing, or spluttering, into mating or laying action. A good, varied diet is essential at this time. How well she taught them to forage in whatever time they were together, and how much forage they can find once on their own, are obviously important factors too, and the environment and weather at each time will impact this as well. In a temperate climate such as here, what forage is available in autumn when they are juveniles is not exactly the same as the forage that was available in summer when they were chicks and they were being taught what’s what by their broody. Generally autumn is a time of plenty, but it is soon succeeded by winter and a time of hardship.
Measure 4: Sustaining the flock
A further (and for the purpose of this article, final) way of evaluating a broody is to count the number of her chicks that not only make it to maturity, but have offspring of their own, that is, the proportion that join the breeding population and help to sustain the flock. This is less pertinent when the keeper controls whose eggs and how many are set beneath the broody, as I do, but the numbers still cast an interesting light on different hens’ performances as broodies.
Analysing this data, I discovered that 5 of the clutches which fledged exceptionally well (suffering only 1 loss between all of them along the way) have been complete failures from a ‘sustaining the flock’ perspective. In addition, 4 clutches have delivered just 1, 2 clutches have delivered 2, 1 clutch has delivered 3, and the single most successful clutch to date delivered 4 of its 7 eggs to the breeding population. Turning from clutches to broodies, three broodies each got 4 chicks to the self-sustainability goal, one hen got 3 there, and one hen has got her first there to date; it is of course too soon to say for the younger hens how many they may raise to the sustainability level over their lifetimes. There is a broad but not complete correlation with the age of the hen – obviously, the older she is, the more time she has had to try to raise youngsters and gain experience. But it is still quite a revelation to discover that in a flock with (currently) 17 hens, of which 9 have raised broods, just 4 of them raised almost all of the adult breeding population of the current flock. About half the broodies fail on that measure. This is consistent with the results of the Collias et.al. 1994 study on the Red Jungle Fowl flocks that have been living wild in the grounds of San Diego Zoo, California, since 1942: a small number of hens were responsible for most of the flock’s population. However, contrary to the Collias study, one of the two most successful broodies here is not a dominant hen - and was barely a year old when she raised her most successful brood.
References
https://www.backyardchickens.com/th...hatch-a-long-and-informational-thread.457488/
https://www.backyardchickens.com/articles/guide-to-letting-broody-hens-hatch-and-raise-chicks.65989/
https://www.backyardchickens.com/ar...e-make-a-sitting-hens-job-so-difficult.74389/
Collias et.al. (1994) Dominant Red Junglefowl (Gallus Gallus) Hens in an Unconfined Flock Rear the Most Young over Their Lifetime The Auk 111: 863-872 Open access https://academic.oup.com/auk/article/111/4/863/5168263 https://doi.org/10.2307/4088818
Hatch statistics
It has been suggested that it might be interesting to have the hatch statistics, even if it is difficult to extract any valid conclusions about broodies' abilities from them because of all the extraneous factors at play before and during incubation of the eggs. So I add them here; readers are welcome to share any impressions that they form from these statistics in the comments section of the article.
Breed acronyms: A = Araucana; H = hybrid; NG = Norfolk Grey; P = Penedesenca; RIR = Rhode Island Red; W = Welsummer. All the birds in the flock are large fowl.
Notes acronyms:
| Name, age, breed | Date | No. eggs set | No. eggs hatched | Notes |
| Dorothy 2 RIR | 2019 | 4 | 3 | 1 NR |
| Eve 1 NG | 2019 | 4 | 2 | 1 EB; 1 EED |
| Eve | 2019 | 7 | 4 | 1 I; 1 DIS; 1 DPE |
| Eve 2 | 2020 | 10 | 4 | 1 DIN; 1 DIS; 1 EB; 1 I; 2 NR |
| Eve | 2020 | 4 | 2 | 1 EB; 1 removed from coop by broody – it was going rotten |
| Eve 4 | 2022 | 8 | 3 | 4/6 bought eggs and 1/2 home grown eggs infertile |
| Maria 3 A | 2020 | 8 | 3 | 5/6 bought eggs infertile |
| Maria 4 | 2021 | 7 | 6 | 1 EED |
| Maria 5 | 2022 | 6 | 2 | 3 I; 1 LED |
| Janeka 2 W | 2021 | 10 | 9 | 1 I |
| Janeka 4 | 2023 | 8 | 4 | 1 knocked out of nest day 5; 1 EB day 7; 1 DIN; 1 DIS while hatching |
| Paprika 1 P | 2022 | 8 | 7 | 1 DIS after partial unzip |
| Paprika 2 | 2023 | 6 | 6 | |
| Polka 2 P | 2023 | 1 | 1 | Unplanned |
| Fez 1 H | 2024 | 6 | 6 | |
| Idris n Rhondda 1 H | 2024 | 5 | 5 | 1 DIN |
Notes acronyms:
- DIN = hatched but dead in nest, no injury; presumed dehydrated, suffocated or trampled
- DIS = dead in shell
- DPE = disappeared, presumed eaten
- EB = egg broke during incubation
- EED = early embryo death
- I = infertile
- LED = late embryo death
- NR = no record found to explain the failed egg
