What time of year do birds start nesting?

What factors affect the timing of the avian breeding season?

Although not the only factors, assured food supplies and accompanying benign weather are by far the most common influences that affect the timing of the avian breeding seasons. To find examples of other factors, however, we must look outside of North America.

Do food resources mediate seasonal declines in reproductive performance of late-breeding individuals?

We show that reproductive success of late-breeding individuals was causally related to a seasonal decline in environmental quality and provide evidence that food resources mediate seasonal declines in reproductive performance.

Why do reproductive success rates decline seasonally?

The date hypothesis states that seasonally declining reproductive success is a response to a seasonal deterioration in environmental quality (Perrins, 1970; Verhulst & Nilsson, 2008 ).

Are early breeding pairs of chickens of higher quality?

Indeed, there is some evidence for fitness costs of early breeding (Nilsson 1994; Brown & Brown 2000). In a way, this indicates that early pairs are of higher quality, in the sense that they are better able to cope with the costs of laying early in the season.

Why do organisms in seasonal environments breed earlier in the season?

For organisms in seasonal environments, individuals that breed earlier in the season regularly attain higher fitness than their late-breeding counterparts.

What drives seasonal variation in reproductive success in plant species?

Decisions about timing of breeding have fitness consequences (Daan & Tinbergen, 1997) that are likely mediated by individual and environmental quality (Reed et al., 2009 ), these being the two primary hypotheses proposed to explain seasonal variation in reproductive success.

How does incubation affect reproductive success?

When incubation is costly in terms of fitness (de Heij et al.2006), and there is a linear decline in reproductive success, experimental effects are equally likely to be caused by the change in incubation effort as by the change in hatching date, as they are perfectly correlated.

What causes variation in reproductive success in animals?

‘Quality’ as a cause of variation in reproductive success, as used here, will refer to the phenotypic quality or condition of the breeding individuals, the quality of their territories or other aspects of the environment, or any combination of these.

Why does reproductive success decline during the season?

Reproductive success usually declines in the course of the season, which may be a direct effect of breeding time, an effect of quality (individuals with high phenotypic or environmental quality breeding early), or a combination of the two.

Why is it important to be selective when breeding chickens?

If you are breeding a specific breed, it is only right to be selective with the cock and hens you choose. Genetically, the parents’ traits are passed down to the progeny, so if you are breeding from inadequate quality stock, you will be increasing the number of low-quality birds.

What is chicken breeding and genetics?

Chicken breeding and genetics. Breeding chickens is the simple and easy practise of mating pairs or groups of chickens to producing chicks. Genetics is a hugely complicated subject, often made more so by the fact that it is rarely black or white, there are hundreds of shades of Gray or dominance in the middle.

Is there a breeding season for chickens in the US?

Breeding Season In fact poultry birds are prolific breeders and they bred in all seasons. Therefore, there is no specific breeding season for poultry unlike that of other livestock but fertility percentage may vary in different seasons. For that also only season may not be the sole cause for reduced fertility.

Does environmental quality affect reproductive success of late-breeding individuals?

Reduced reproductive success of late-breeding individuals was causally related to a seasonal decline in environmental quality.

How to differentiate between two families of chickens?

The makeup of each family should be made based on phenotype. Thus, all the hens in one family are similar in appearance while the hens in the other group are similar. I utilize colored leg bands to designate the two families.

Why is it important to be selective when breeding with hens?

If you are breeding a specific breed, it is only right to be selective with the cock and hens you choose. Genetically, the parents’ traits are passed down to the progeny, so if you are breeding from inadequate quality stock, you will be increasing the number of low-quality birds. Sadly, so many pure breeds become spoilt by poor breeding.

What is an example of timing relative to seasonal environment?

The classic example of timing relative to the seasonal environment is the timing of breeding seasons of great tits relative to the annual peak in caterpillar abundance (Perrins 1965; van Balen 1973; Verboven et al.2001).

Why do late-breeding tree swallows have less reproductive success?

We found that reduced reproductive success of late-breeding tree swallows was causally related to a seasonal decline in environmental quality.

How do we predict lifetime reproductive success of barn swallow offspring?

Longevity and lifetime reproductive success of barn swallow offspring are predicted by their hatching date and phenotypic quality. Journal of Animal Ecology, 81 ( 5 ), 1004 – 1012 .

What determines parental energy-expenditure during brood rearing in the great tit (Parus major)?

Parental energy-expenditure during brood rearing in the great tit ( Parus major) in relation to body-mass, temperature, food availability and clutch size. Functional Ecology, 8 ( 5 ), 563 – 572 .

What is the reproductive cycle of flowering plants?

The reproductive cycle of a flowering plant is the regular, usually seasonal, cycling back and forth from sporophyte to gametophyte. The flower produces two kinds of gametophytes, male and female. The female gametophyte arises from a cell within the ovule , a small structure within the ovary of the flower.

What factors influence reproductive success in mammals?

In mammals, amounts of protein, carbohydrates, and fats are seen to influence reproductive success. This was evaluated among 28 female black bears evaluated by measuring the number of cubs born.