Finches are small songbirds in the family Fringillidae. They are found worldwide, with the greatest diversity occurring in the Americas and Australasia. Finches build cup-shaped nests and lay between 2-6 eggs. The female incubates the eggs while the male brings food to the nest. But how long do finches actually sit on their eggs before they hatch? Let’s take a closer look.
Incubation Period
The incubation period is the amount of time it takes for finch eggs to hatch after being laid. This can vary slightly between finch species, but is generally 11-14 days.
Here are incubation times for some common finch species:
Finch Species | Incubation Period |
---|---|
Zebra Finch | 12-14 days |
House Finch | 12-14 days |
Purple Finch | 11-13 days |
Goldfinch | 11-14 days |
As you can see, incubation lasts for approximately 2 weeks for most finch species. The female finch develops a brood patch – a bare area of skin on her belly that transfers heat efficiently to the eggs. She sits tightly on the eggs, rarely leaving the nest, to keep them at the proper temperature for embryonic development.
Sitting Pattern
While the incubation period gives the total time finch eggs take to hatch, the actual amount of time a female spends sitting on the nest each day can vary.
Finches don’t necessarily sit constantly without breaks. The female may take occasional short breaks during the day to feed, drink, preen herself, or remove old eggshells from the nest. However, she needs to spend most of her time incubating so that the eggs stay warm enough.
Research on zebra finches found that females spent anywhere from 75-90% of daylight hours on the nest during incubation. On average, female zebra finches took about 1-2 breaks per hour lasting around 2-10 minutes each. Their husbands brought food to them either at the nest or at a nearby perch during breaks.
Sitting time tends to increase as the hatch date approaches, especially in the last 2-3 days when the embryos are most vulnerable. At night, the female may continue to brood the eggs to provide warmth. However, night incubation is optional and she may also sleep off the nest once the eggs have accumulated enough heat through the daytime.
Factors Influencing Sitting Time
Several factors can influence how much time a female finch spends incubating:
- Number of eggs – More eggs means greater heat requirements.
- Predation risk – Higher risk may limit time off nest.
- Weather – Cooler temperatures increase sitting needs.
- Food availability – Plentiful food allows more breaks.
- Stage of incubation – More time on nest closer to hatching.
- Individual bird – Some females sit more diligently than others.
Understanding these factors helps explain why incubation schedules can vary across finch nests. However, the primary aim is keeping the eggs adequately warm for normal embryo development.
Nest Attentiveness and Hatching Success
Researchers sometimes quantify “nest attentiveness” – the percentage of time a bird spends on the nest during incubation. This gives insight into incubation behavior and commitment.
Higher nest attentiveness generally equates to greater hatching success, meaning more eggs in the clutch hatch. For example, one study on tree swallows found:
Nest Attentiveness | Hatching Success |
---|---|
95-100% | 80-100% |
90-95% | 60-80% |
85-90% | 40-60% |
<85% | <40% |
Clearly, nests with lower female attentiveness had poorer hatching success. This pattern holds true for many bird species. Finches likely need 90% or higher nest attentiveness for maximum hatch rates. Females that take fewer, shorter breaks have more hatchlings.
However, occasional breaks are still important. Constant sitting prevents the female from meeting her own nutritional and self-maintenance needs. This can negatively impact her health and future reproduction. An optimal incubation schedule balances egg temperature needs with the female’s requirements.
Conclusion
To summarize key points:
- Finch eggs take 11-14 days to hatch after being laid.
- Females spend 75-90% of daylight hours incubating, with 1-2 short breaks per hour.
- Sitting time increases near hatching and during cooler weather.
- High nest attentiveness (>90%) is linked to better hatching success.
- Some breaks allow the female to feed and preen without compromising eggs.
Understanding incubation behavior helps provide insight into the reproductive strategy of finches. The female’s diligent sitting ensures eggs stay warm for proper embryonic development. At the same time, occasional breaks meet her own needs so she stays healthy. This balanced approach allows the greatest chance of hatching success, leading to healthy nestlings and eventual fledglings.