Welcome to Quarter 4! Do you need to go back to Quarter 1? Quarter 2? Quarter 3?

Day 136

1. The time it takes for eggs to hatch varies depending on the type of bird. Some birds, like passerines and woodpeckers, only take about 10 days to hatch, while albatrosses and kiwis can take up to 80 days. The size of the egg, how developed the bird is at birth, and the temperature outside can all affect how long the incubation period lasts.
2. Some birds are precocial. Precocial birds are born with their eyes open and feathers, and they are able to walk and even forage for food within hours or days of hatching. Examples of precocial birds include ducks, geese, and quail. In contrast, altricial birds are born naked, blind, and helpless, and they rely completely on their parents for food and protection. They develop their feathers and ability to walk and fly over a period of weeks or months. Examples of altricial birds include songbirds, pigeons, and raptors.
3. Watch the video about altricial vs. precocial strategies.

Day 137

1. Nest predation (predators attacking and eating eggs or chicks) can affect how birds take care of their eggs and chicks. Researchers have studied the behavior of 97 kinds of small birds and found that when there is a high risk of predators eating their eggs or chicks, birds may spend a long time sitting on the nest and take fewer trips to find food. But this means that the birds cannot feed their chicks often, which could make it harder for them to have more babies in the future. When there is a high risk of predators, birds may choose to have fewer chicks and nest for shorter times. This can make it easier for the birds to hide from predators and protect their young. But these choices can also limit how much time the mother bird has to find food. It’s a tricky balance!
2. During incubation, birds must balance caring for their embryos by staying on the nest with caring for themselves by leaving the nest to find food. When females are the sole incubators, males can help by feeding them on the nest. This is called incubation feeding. The male’s feeding can increase the amount of time the female spends on the nest, which is important for the embryos’ development. However, the male’s feeding can also attract nest predators, which can be dangerous for the eggs. Researchers studied birds that nest in cavities and birds that nest in the open to see how incubation feeding affects the birds’ behavior. They found that incubation feeding is higher among cavity-nesting birds and is negatively correlated with nest predation, meaning that male birds are less likely to feed females when there is a high risk of predators. The study also found that incubation feeding is positively correlated with nest attentiveness, which means that when males feed females during incubation, the females spend more time on the nest.
3. Watch the video of a bald eagle protecting its eggs from ravens attempting to eat them. The presence of a parent is the only reason that those eggs were not eaten.

Day 138

1. When a bird embryo is developing in its egg, the yolk and albumen provide the energy, protein, and water it needs to grow. The yolk has fats that give energy and the albumen has protein and water. The embryo grows and changes shape from a flat layer of cells on top of the yolk to a three-dimensional structure. This involves rearranging the cells into three layers that will become different parts of the bird’s body. Altricial birds, grow faster than others and focus more on developing organs that provide nutrition, like the digestive system. This means that when they hatch, they have smaller brains and weaker muscles than precocial birds that grow more slowly. Precocial birds need more calcium to grow strong skeletons, which mostly comes from the eggshell. Therefore, the eggshells of precocial birds have more calcium than those of altricial birds.
2. In precocial species, metabolic rates increase rapidly during most of the incubation period, but then level off or even decline when incubation is about 80% complete. In altricial species, on the other hand, metabolic rates of embryos increase continuously throughout the entire incubation period. Despite these differences, both types of embryos need the same amount of energy to grow. The difference between them lies in when they hatch during development and in the amount of energy their mothers invest in the eggs. Because altricial species hatch earlier and at an earlier stage of development, their mothers can invest less energy in the eggs than mothers of precocial species.
3. Watch the video about the development of a chicken in the egg.

Day 139

1. Birds make nests to keep their eggs and young safe from predators and bad weather. To avoid predators, birds might build their nests in places that are hard to reach, hidden, or that blend in with their surroundings. Nests can also help keep eggs and baby birds warm. There are several basic types of nests.

• scrape nests
• burrows
• cavity nests
• platform nests
• cupped nests

2. Watch the video about different types of nests.

Day 140

1. So scrape nests are a type of nest that is made by some birds by creating a simple depression in the ground or in the leaves. Some birds that use this type of nest include penguins, shorebirds, gulls, terns, nighthawks, and vultures.
2. Adélie penguins are one of the types of penguins that make scrape nests. They line their nest depression with stones. Watch the video about a penguin building his nest.
3. Turkey vultures are another example of a bird that lays its eggs in a scrape-style nest. Turkey vultures typically nest on the ground in sheltered areas, such as caves, rocky crevices, or under dense vegetation. They do not build nests, but instead, lay their eggs directly on the ground or on rocky ledges. Watch the video where they uncover the nesting site of a turkey vulture.
4. Continue your bird count! (If you are using the paper version and yours is full, you can print another copy of the tally sheet on day 5.) Go outside and count all birds you see or hear for 15 minutes. Try to identify the birds and count how many of each you notice. Save your count sheet (or if you are using the app, be sure you are logged in so your count will be saved.)

Day 141

1. A burrow nest is a type of bird nest that is dug into the ground or into a bank, creating a tunnel or cavity where the birds can lay their eggs and raise their young. These nests are typically used by birds that live in colonies, such as puffins and burrowing owls. The burrow provides protection from predators and harsh weather conditions, as well as a stable environment for incubation and rearing of offspring. Some bird species that typically nest in trees or shrubs, such as kingfishers or bee-eaters, may also dig burrows in sandbanks or soil to create their nests.
2. Watch the video about puffins and how they prepare and use burrows in nesting.
3. Watch the video about burrowing owls.

Day 142

1. Cavity nests are a type of bird nest that are made in cavities such as tree holes, abandoned woodpecker holes, or man-made nest boxes. These nests are used by a variety of bird species, including woodpeckers, bluebirds, chickadees, and swallows. Cavity nests offer protection from predators and harsh weather conditions, as well as providing a safe place for birds to lay their eggs and raise their young. Unlike open nests that are exposed to the elements, cavity nests are sheltered and can help keep the eggs and chicks warm and dry.
2. Birds that use cavity nests often have adaptations that allow them to enter and exit the cavity easily. For example, woodpeckers have strong bills that can chisel out cavities, and chickadees have small bodies that can easily fit inside small holes. However, cavity nests also have some potential drawbacks. They can become crowded with parasites. Additionally, if a cavity is too shallow or poorly constructed, it may not provide adequate protection from predators or weather.
3. Watch the video about cavity nests.

Day 143

1. Platform nests are typically built by raptors, or birds of prey, such as eagles and hawks. These nests are usually built high up on cliffs or in tall trees, and can take many months to build. Raptors often return to the same nest year after year, adding more branches and material each time, which can make the nests very large and heavy. In fact, a Bald Eagle’s nest can weigh as much as a ton, which is about the same as a small car.
2. Watch the video about eagles’ nests.
3. Some water birds, such as grebes and loons, also build platform nests, but they do so on the water’s surface. These nests are anchored to plants that are attached to the bottom of the body of water. Water birds build these nests on water because they aren’t as good at walking on land, and so they find shallow parts of the water to build their nests. When the babies are ready, they simply jump into the water and begin their aquatic life.
4. Watch the video about crested grebes nesting.

Day 144

1. Cup nests are a type of bird nest that is shaped like a smooth hemisphere with a deep depression in the center to hold the eggs. Many small bird species, like hummingbirds and swifts, and some larger birds, like certain flycatchers and warblers, build this type of nest. These nests are made of flexible materials like grass, although some are made of mud or saliva. Some birds use spider silk to construct their nests because it is strong and flexible, and helps the nest mold to the adult during incubation and stretch to accommodate growing nestlings.
2. Watch the video of the hummingbird building a nest.
3. Watch the video of a blackbird building a nest. How does the bird create the “cup” shape in the middle?

Day 145

1. Watch the video about 7 insane bird nests.
2. Continue your bird count! (If you are using the paper version and yours is full, you can print another copy of the tally sheet on day 5.) Go outside and count all birds you see or hear for 15 minutes. Try to identify the birds and count how many of each you notice. Save your count sheet (or if you are using the app, be sure you are logged in so your count will be saved.)

Day 146

1. Today watch the documentary Natural Architecture: The Bird’s Nest.

Day 147

1. Next, we are going to learn about the various ways that birds care for their young. Today watch the documentary “Born to Fly: Early Life of Birds.”

Day 148

1. After baby birds hatch from their eggs, their parents take care of them by keeping them warm, feeding them, and protecting them from predators. Most bird species have both the mother and father involved in taking care of their young. However, there are some species where only the mother takes care of the babies – typically species where one male mates with multiple females. On the other hand, there are about 30 species where only the father takes care of the babies, and this is seen in species where the females mate with multiple males.
2. The amount of care a baby bird needs after hatching depends on whether the birds are altricial or precocial (we talked about that already). The three main types of parental care a bird may give its chick include brooding, feeding, and protecting the young from predators.
3. Let’s talk about brooding. When altricial birds are born, they are not able to control their body temperature like adult birds can. They rely on their parents to keep them warm when it’s cold or cool them down when it’s too hot. This is called brooding. The parents cover the young birds to keep them warm or shield them from the sun or rain. The length of time they are brooded depends on a few factors. First, it takes some time for the young birds to develop the ability to control their own body temperature. This usually happens when they grow feathers. Second, the weather plays a role. If it’s cool or wet, the parents will brood the young birds for longer periods to keep them warm and dry. Third, the type of nest also matters. Birds that nest in cavities, like holes in trees, have more stable temperatures inside, so they don’t need to be brooded for as long as birds that nest in open areas. At the beginning, the young birds are brooded almost all the time, but as they grow, they are brooded less and less. Toward the end, they may only be brooded at night or during the day for nocturnal birds. And as they get ready to leave the nest, the parents stop brooding them altogether.
4. Chickens are an example of a precocial species that still provides parental care. Watch the video about how a chicken will care for her chicks from brooding the eggs through to weaning them away from parental care.

Day 149

1. Once baby birds hatch, their parents start feeding them (or showing them where to find food). This happens in species of birds that are altricial, semi-precocial, or subprecocial. In most species where parents take care of the young together or in some species where males have multiple mates, both parents help provide food for the young birds. There are different ways in which food is given to the young birds. Some birds carry food in their beaks and place it directly into the open mouths of the babies, which is common in most songbirds. Other birds swallow food and then regurgitate it, which means they bring it back up from their stomach and give it to the babies either by putting it directly in their mouths or in the nest where the babies can pick it up. Some birds like pelicans and cormorants open their mouths and let the young birds reach in and grab the food. In certain birds like pigeons and doves, they produce a special substance called “milk” in their crop, which they regurgitate and feed to the babies. Raptors, which are birds of prey, carry food in their talons and bring it back to the nest. Depending on the age of the young birds, the parents either tear the food into smaller pieces and feed them or give them the whole food item.
2. Watch the video of the robin feeding its chicks.
3. Watch the video about flamingo “milk.”
4. Watch the video about feeding and protecting young owls

Day 150

1. In the springtime, when you see baby birds in their nests, you may notice that they open their beaks wide and make a lot of noise to get their parents’ attention. Among Barn Swallows, this behavior is not just about getting food, but also a matter of life and death. Researchers found that parent swallows decide how much food to give to their nestlings based on how healthy they think the babies are. They judge their health by looking at the color of their wide-open beaks. If the beaks are not red, it means the baby bird might not be as healthy and they may not get enough food. The scientists did some experiments by dyeing the beaks of some baby birds red and found that those birds received more food from their parents. They also discovered that when they made the birds sick, the color of their beaks became dull and they were ignored by their parents. The color of the beaks is related to pigments called carotenoids, which also help with the birds’ immune system. So when birds are sick, they cannot spare these pigments to make their beaks bright. The researchers gave extra pigments to sick birds and their beaks turned red again, and they were fed just as well as their healthy siblings. This shows that parent Barn Swallows use the color of the beaks as a signal of how healthy their babies are and decide how much food to give them based on that. It’s a tough world out there for these birds!
2. Watch the video “Barn Swallow Feeding Chicks.”
3. Watch the video of the blackbird feeding its chicks. Whenever the parent returns to the nest, the chicks open their mouths and cheep in a behavior called “begging.” The parents use visual and audio clues to tell which chicks are healthy enough to feed.
4. Continue your bird count! (If you are using the paper version and yours is full, you can print another copy of the tally sheet on day 5.) Go outside and count all birds you see or hear for 15 minutes. Try to identify the birds and count how many of each you notice. Save your count sheet (or if you are using the app, be sure you are logged in so your count will be saved.)

Day 151

1. Some birds are what is called brood parasites. Instead of building their own nests and caring for their own young, brood parasites rely on other birds to raise their offspring. They sneakily lay their eggs in the nests of other birds, known as host species. Once the eggs hatch, the host parents unknowingly raise the chicks of the brood parasite as their own, often at the expense of their own chicks. The brood parasite chicks outcompete the host chicks for food and attention, sometimes even pushing them out of the nest. Common examples of brood parasites include the cuckoos and cowbirds.
2. Watch the documentary “Cuckoo – Spectacular Insight into the Life of a Con Artist.”

Day 152

1. Parasitic cuckoo chicks manipulate their host parents to receive more food and care. Cuckoos are birds that lay their eggs in the nests of other bird species, and once the cuckoo chick hatches, some species will push out the eggs or young of the host bird. Previous studies have shown that host birds feed a single cuckoo chick more and for a longer period than their own chicks. Researchers wanted to understand why this happens.
2. One suggestion was that the cuckoo chick’s large size, bright mouth, and intense begging make it seem like a superior and hungry offspring, so the host birds provide more care. However, experiments showed that the size alone was not enough to explain the increased care. When researchers replaced the host bird’s chicks with other chicks of similar size, the food delivery rate was similar to that of the host bird’s own chicks and lower than that of the cuckoo chick.
3. Further investigation revealed that the cuckoo chick’s begging call plays a crucial role. The cuckoo chick’s call sounds like the begging calls of a whole brood of the host bird’s chicks. On the other hand, other chicks like those of blackbirds and thrushes have a much lower calling rate and cannot elicit the same level of care. So, the cuckoo chick uses its vocal trickery to deceive its host parents by pretending to be a group of offspring rather than a single high-quality chick.
4. Watch the video of a cuckoo chick begging for more food.

Day 153
1. When baby birds beg for food from their parents, it involves making lots of noise, flapping, and opening their mouths wide. This behavior seems strange because it looks like it takes a lot of energy. Scientists have been studying why baby birds beg and what it means for them and their parents.
2. At first, people thought that baby birds begged to trick their parents into giving them extra food. But now we know that begging is a way for parents and babies to work out how much care the babies need. Sometimes, baby birds beg a lot and make a big fuss because they really need more food. The parents have to work hard to catch enough food to feed their babies, so they need to figure out how much food the babies really need.
3. As baby birds get older, their begging behavior changes. When they are very young, they might not do much begging because they are not as hungry. But as they get closer to being able to take care of themselves, they might beg more to get their parents’ attention. This can be a way for the babies to try to get their parents to take care of them for longer.
4. When baby birds beg for food, it can also attract predators. This means that other animals might come to the nest looking for a meal. The baby birds’ calls can give away their location. But the parents have ways to protect their babies. They give alarm calls to warn the babies about danger and might even call less themselves to keep the predators away.
5. Watch the video of chicks in a next box begging for food.
6. Watch the video showing how the chick of the cinerous mourner avoids being eaten by predators. What unusual strategy does it employ?

Day 154

1. Scientists have long known that nestlings call out to their parents for food. However, researchers have noticed that some owl chicks continue to vocalize even when their parents are not around. This led Alexandre Roulin and his team to wonder if these nestlings were actually communicating with each other. They conducted experiments with Barn Owl chicks to understand their communication patterns and feeding behavior.
2. In one experiment, the researchers randomly selected two siblings from a brood of barn owls. They provided one chick with dead mice to eat during the day while leaving the other chick hungry. The results showed that the hungry nestling cried more frequently during the following night compared to its well-fed sibling. Interestingly, once the hungry chick received its meal, the other sibling began begging more. This shows that the chicks adjust their vocalization based both on their hunger levels and the availability of food.
3. Another experiment revealed that as the number of siblings in a nest increased, the chicks called out less. This finding contradicted the idea that the chicks were simply trying to outshout each other for attention. The researchers propose that when the chances of obtaining food are low, chicks refrain from begging. Instead, they observe and respond to each other’s hunger levels through the intensity of their cries. When a nestling is more hungry, the value of food is higher for it, leading to physical competition for prey. As a result, less hungry chicks save their energy and wait for their turn to feed.
4. This study challenges the idea that nestlings communicate solely with their parents for food. The findings suggest that nestlings of other bird species might exhibit similar behaviors when it comes to communication and feeding dynamics. Further research is needed to explore communication patterns among nestlings in the absence of parental presence and their impact on feeding strategies.
5. Watch the video “Barn Owl Chicks Growing Up.”

Day 155

1. Parent birds play a crucial role in providing food to their young during the nesting period. They typically bring food that matches their own dietary preferences, such as insects, fish, seeds, or fruits. However, there are interesting variations in parental feeding behaviors among bird species that deserve exploration. Most parent birds feed their young the same food they eat themselves. However, seed-eating and fruit-eating species may also supplement their nestlings’ diet with insects, which are rich in protein. Additionally, parents adjust the size of food items according to the age and size of their nestlings. Smaller items are provided to young and small nestlings, while larger items are given to older and larger nestlings. The food provided by parents usually contains enough moisture, eliminating the need for them to bring water specifically for their young’s consumption. (Notable exceptions to this are certain birds like sandgrouse, where males have modified feathers with excellent water-holding capacity and can bring water to their young.)
2. Scientists have observed that some songbird species increase the amount of spiders they bring to their chicks as the chicks grow, but the reason for this behavior was not clear. In a study on Blue Tits, researchers found that the proportion of spiders in the chicks’ diet changed as the chicks got older, regardless of when they were born or how many spiders were available. By giving their chicks spiders, the parents provided them with a lot of a substance called taurine, which is very important for the development of mammals. The researchers also looked at how the taurine-rich spiders affected the chicks’ behavior. They found that the chicks who received more taurine when they were very young took more risks and performed better in tasks that involved learning about space. These findings suggest that what the chicks eat when they are young can affect how they behave later on, which could influence their ability to find food and compete with other birds.
3. Watch the video of Carlina wrens being fed.
4. Watch the video of the hummingbird being fed.
5. Continue your bird count! (If you are using the paper version and yours is full, you can print another copy of the tally sheet on day 5.) Go outside and count all birds you see or hear for 15 minutes. Try to identify the birds and count how many of each you notice. Save your count sheet (or if you are using the app, be sure you are logged in so your count will be saved.)

Da7 156

1. Today watch the video “I Put a Camera in a Chickadee Nest for 54 Days.”

Day 157

1. Now we’re going to talk about birding! Birding is also sometimes called birdwatching, and is the practice of observing, identifying, and studying birds in the wild.
2. Watch the video “Introduction to Birding.”
3. Read the article “How to Start Birding.”

Day 158*

1. Print the checklist of common backyard birds in North America.
2. Read the article “47 Common Backyard Birds in North America.” Follow along with your checklist and mark birds that you know how to identify. This is not a test. This is just to see how many North American backyard birds you can already recognize.

Day 159

1. Watch the video “How to Identify a Bird.”
2. Visit the bird guide. Search for a bird that you know well, and read the entry about it.
3. Here is the page about the American Robin. Click on “ID Info.” (There will be a small binocular icon.) Read about the “4 keys to ID” and learn what they are for robins.

Day 160

1. Watch the video Bird Songs & Sounds.
2. Continue your bird count! (If you are using the paper version and yours is full, you can print another copy of the tally sheet on day 5.) Go outside and count all birds you see or hear for 15 minutes. Try to identify the birds and count how many of each you notice. Save your count sheet (or if you are using the app, be sure you are logged in so your count will be saved.)

Day 161

1. Watch the video about the topography of birds.
2. Look through the bird topography flashcards. Be sure to flip them over to read the back.

Day 162

1. Today watch the video “Map of a Bird.”
2. Look through the bird topography flashcards again. Be sure to flip them over to read the back.

Day 163

1. Read “How to Identify a Bird.”
2. Watch the video “Inside Birding: Size and Shape.”

Day 164

1. Read about identifying birds by color pattern.
2. Watch the video “Inside Birding: Color Patterns.”

Day 165

1. Read about identifying birds by behavior.
2. Watch the video “Inside Birding: Behavior.”
3. Continue your bird count! (If you are using the paper version and yours is full, you can print another copy of the tally sheet on day 5.) Go outside and count all birds you see or hear for 15 minutes. Try to identify the birds and count how many of each you notice. Save your count sheet (or if you are using the app, be sure you are logged in so your count will be saved.)

Day 166

1. Read about identifying birds by habitat.
2. Watch the video “Inside Birding: Habitat.”

Day 167

1. Watch the video about the top 10 backyard birds. At the end, see how many you can identify.

Day 168

1. Today watch the documentary “Kings of the Sky: America’s Incredible Wild Birds.”

Day 169

1. Read the article “6 Unexpected Ways Birds Are Important for the Environment (and People).”
2. Watch the video “Protecting Birds is Protecting Our Future.”

Day 170

1. Today watch “Bird Conservation History.”
2. Birds are a vital part of the Earth’s biodiversity. They play key roles in various ecosystems as predators, prey, seed dispersers, and pollinators. Birds contribute to the overall balance and health of ecosystems, maintaining the diversity of plant and animal species. Birds are often considered indicator species because changes in their populations and distributions can reflect broader environmental changes. Monitoring bird populations can provide valuable insights into the health of ecosystems, the impacts of habitat loss and degradation, climate change, and pollution. Protecting birds can help safeguard entire ecosystems and the services they provide. Protecting birds is an essential component of environmental conservation and promoting a harmonious relationship between humans and the natural world.
3. Continue your bird count! (If you are using the paper version and yours is full, you can print another copy of the tally sheet on day 5.) Go outside and count all birds you see or hear for 15 minutes. Try to identify the birds and count how many of each you notice. Save your count sheet (or if you are using the app, be sure you are logged in so your count will be saved.)

Day 171

1. Watch the video “How to Save Birds.”
2. Which steps to help save birds do you think you can do?

Day 172

1. Watch the video “Pennsylvania Bald Eagles: Celebrating 30 Years of Recovery.”

Day 173

1. Today watch the documentary “The Condor’s Shadow.”

Day 174

1. Today watch the documentary “Saving Peru’s Parrots.”

Day 175

1. Today you will be doing your last bird count! (If you are using the paper version and yours is full, you can print another copy of the tally sheet on day 5.) Go outside and count all birds you see or hear for 15 minutes. Try to identify the birds and count how many of each you notice. Save your count sheet (or if you are using the app, be sure you are logged in so your count will be saved.)
2. Go back over the list of birds you have seen this year. How many kinds of birds have you identified?
3. For the rest of the semester you are going to make a bird book about the birds you have seen around you. (You can also make a slideshow or lapbook if you would prefer.) Create a new document and title it “Bird Observation Guide.” Create one page for each bird on your list. Each page will need to have the following about the bird:

• The name of the bird
• The scientific name of the bird
• The order of the bird
• A picture of the bird
• What time of year they live in your area
• The bird’s habitat
• The food they eat
• Where they nest
• Their behavior
• Their conservation level

You can find all of this information by searching the name of your bird at the Cornell Lab of Ornithology. They even have most of it in a convenient chart. (Here is an example of the chart for one type of bird.) For pictures, you may want to check Wikipedia.
4. You have until Day 180 to complete this assignment.

Day 176

1. Continue working on your Bird Observation Guide.

Day 177

1. Continue working on your Bird Observation Guide.

Day 178

1. Continue working on your Bird Observation Guide.

Day 179

1. Continue working on your Bird Observation Guide.

Day 180

1. Finish and present your Bird Observation Guide. Congratulations! You’ve completed the class!