Killdeer are a type of plover bird found throughout much of North America. As ground nesting birds, their eggs and young are vulnerable to predators and weather extremes. This means killdeer eggs require fairly precise incubation conditions in order to successfully hatch.
Incubation Temperature Range for Killdeer Eggs
The incubation temperature range needed for killdeer eggs to hatch is generally accepted to be between 99-102°F (37-39°C). This relatively high and narrow temperature range is critical for proper embryo development and successful hatching.
If killdeer eggs become too cold, the embryos will stop developing and die. If the eggs become too hot, abnormalities and death can also occur. So maintaining proper incubation temperatures is essential.
Minimum Viable Temperature
Research indicates the minimum temperature killdeer embryos can withstand and still hatch is around 91°F (33°C). However, hatching success declines sharply at temperatures below 99°F (37°C).
In one study, killdeer eggs were incubated at various constant temperatures between 91-108°F (33-42°C). Eggs incubated at 91°F (33°C) had only a 3% hatching success rate. Hatch rates increased to 82% at 99°F (37°C).
This demonstrates that while killdeer eggs can survive brief cool periods, prolonged exposure to temperatures below 99°F will result in embryo death and hatching failure.
Maximum Survival Temperature
The maximum temperature killdeer embryos can withstand is around 104-108°F (40-42°C). However, temperatures above 102°F (39°C) result in decreased hatching success and an increase in abnormalities.
In the same incubation temperature study, eggs incubated at a constant 108°F (42°C) had a 63% hatching success rate. But many of the hatchlings showed physical abnormalities or died shortly after hatching.
This indicates that while short periods of 104-108°F may be tolerated, prolonged exposure to temperatures above 102°F can be detrimental to embryo survival and development.
Factors Influencing Incubation Temperature
In natural nests, several factors can influence the temperature killdeer eggs experience during incubation. Parents use various strategies to maintain nest temperatures within the optimal range.
Ambient Temperature
The ambient temperature of the environment impacts how much heating or cooling is required by the parents. In very hot climates, adults may need to provide shade or moisture to prevent overheating. In cool climates, incubation may be more challenging.
Nest Site
Killdeer often nest in open areas on gravel roads or bare ground. These exposed sites can lead to more temperature fluctuations. Nesting near water, under vegetation, or in sheltered sites helps buffer ambient extremes.
Incubation Behavior
To maintain proper egg temperatures, killdeer parents incubate in shifts. The non-incubating adult will sometimes shade eggs from the sun or expose them during cool periods. Egg turning and repositioning also helps distribute heat evenly.
Insulation
Killdeer nests contain little insulating material. The eggs rely primarily on contact incubation by the adult birds to stay warm. But some pairs may incorporate bits of gravel, shells or debris to help conserve heat when not incubating.
Incubation Temperature in Artificial Incubators
When using artificial incubators to hatch killdeer eggs, the same 99-102°F (37-39°C) range should be maintained. Some minor fluctuations above or below are acceptable, but extremes can be harmful.
Incubators allow very precise temperature control compared to natural incubation. But improper settings, malfunctions, or power outages can still have severe consequences if temperatures move outside the optimal range for too long.
Recommended Incubator Temperatures
For incubating killdeer eggs, maintaining a constant temperature between 99.5-100.5°F (37.5-38°C) is recommended. 100°F (37.8°C) is ideal.
Some minor adjustments above or below may improve hatch rates for a given incubator or batch of eggs. But in general, sticking close to 100°F provides the best results.
Incubator Temperature Recommendations for Killdeer Eggs |
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Minimum: 99°F (37°C) |
Optimal: 100°F (37.8°C) |
Maximum: 102°F (39°C) |
Maintaining Stable Temperatures
Fluctuations above or below the ideal temperature range should be avoided. Frequent changes or prolonged highs/lows of even a few degrees can negatively impact hatch rates.
Use incubators with reliable, accurate thermostats and humidity control. Do not place in areas with large temperature swings or direct sunlight. Monitor temperatures closely and adjust as needed to maintain a stable level.
Conclusion
For successful hatching, killdeer eggs require very precise incubation temperatures between 99-102°F (37-39°C). Ambient conditions, nest sites, egg positioning, and parental behavior all influence natural nest temperatures. Artificial incubators can also hatch killdeer eggs when maintained at 100°F (37.8°C). Stability is key – frequent fluctuations or prolonged extremes above or below this range reduce hatching success.