Do hummingbirds come out when it’s really hot?

Hummingbirds are amazing little creatures that seem to defy physics with their ability to hover and fly backwards. Their rapid wing beats and high metabolisms enable them to be on the go from dawn to dusk in search of nectar. But what happens on extremely hot summer days when temperatures soar into the triple digits? Do hummingbirds stay active and buzzing about, or do they hunker down in the shade to wait out the worst of the heat?

How hummingbirds stay cool

Hummingbirds have adapted in several key ways to deal with heat:

• High body temperature – They have a high normal body temperature around 107°F. This allows them to thrive in hot environments that would cause hyperthermia in other birds.
• Rapid breathing – Hummingbirds take around 250 breaths per minute, even at rest. Increased breathing rate allows for evaporative cooling.
• Thermogenic muscle adaptation – Their flight muscles produce minimal heat during the downstroke, reducing heat generation.
• Small body size – With an average weight of 3-6 grams, their small body mass reduces heat absorption.
• Minimal insulation – Unlike other birds, they lack down feathers for insulation to facilitate heat dissipation.

These adaptations allow hummingbirds to function at high temperatures. However, even they have their limits when the mercury skyrockets.

Activity levels in extreme heat

Hummingbirds do continue to be active during hot summer days, but they may adjust their behavior to prevent overheating:

• Seeking shade – Hummingbirds rest in shady spots more often when it’s very hot out.
• Panting – They may pant to increase evaporative cooling.
• Wing drooping – Drooping and holding their wings away from their body dissipates excess heat.
• Perching – Perching for longer periods before flying reduces energy expenditure and heat generation.
• Adjusting feeding schedule – They may visit flowers more frequently in the cooler early morning and evening hours.

Studies monitoring hummingbird nests during heat waves reveal they maintain nearly constant incubation and have good breeding success on extremely hot days. This suggests hummingbirds are capable of adjusting their behavior to prevent overheating and population-level impacts.

When it’s dangerously hot

There are limits to what a hummingbird can endure. Here are some signs that temperatures have become dangerously high for them:

• Breathing rapidly with beak open
• Holding wings drooped or away from body
• Perching with feathers fluffed
• Reduced activity and lethargy

During periods of extreme heat, hummingbirds may rely on emergency survival mechanisms to cool down until temperatures become more tolerable:

• Hypothermic torpor – Dropping body temperature and entering a temporary hibernation-like state.
• Evaporative cooling – Using water sources like bird baths or wet foliage for cooling through evaporation.
• Heat exchange – Perching in shaded areas or against cooler surfaces to dissipate body heat.

Extreme heat waves well above 100°F, especially combined with drought conditions limiting nectar supplies, can overwhelm even hummingbirds’ remarkable heat adaptations. Providing clean water sources and ensuring adequate flowers and feeders are available will give them the resources they need to endure hot weather.

Conclusion

Hummingbirds are resilient in dealing with high temperatures thanks to evolutionary adaptations that help them offload excess heat. While they prefer cooler conditions, they continue to actively feed and go about their busy lives even during summer heat waves. However, extremely hot weather over 100°F can push the limits of their heat tolerance. At their most vulnerable, hummingbirds rely on emergency cooling behaviors and human support with clean water and ample food sources until the worst of the heat passes.

Hummingbird adaptations for heat

Here are some key ways hummingbirds have adapted to tolerate hot environments:

Behavioral adaptations

• Resting and perching more in shade
• Panting to increase evaporative cooling
• Drooping wings away from body to dissipate heat
• Adjusting feeding schedules to cooler times of day

Physiological adaptations

• High normal body temperature (107°F)
• Rapid breathing even at rest (250 breaths/min)
• Minimal heat production in flight muscles
• Small body size to minimize heat absorption
• Lack of insulating down feathers

Emergency responses to extreme heat

When temperatures climb well above 100°F into danger zones, hummingbirds rely on emergency measures to prevent overheating until conditions improve:

Hypothermic torpor

• Lowering body temperature
• Entering a temporary hibernation-like state
• Conserving energy and reducing heat production

Evaporative cooling

• Using bird baths and wet foliage as water sources
• Promoting cooling through water evaporation

Heat exchange

• Perching in shade or against cooler surfaces
• Losing excess body heat to environment

Signs of heat stress in hummingbirds

Here are some visible signs that indicate a hummingbird is getting dangerously overheated:

If hummingbirds at your feeders are showing these types of distress signals during a heat wave, it’s important to provide extra support with clean water sources for evaporative cooling and plenty of nectar to fuel their high metabolisms until conditions improve.