Amazing! This bird's beak changes color during the breeding season

The arrival of spring is always accompanied by the breath of revival and vitality of all things. As the spring breeze blows through the branches, flowers bloom quietly, and the breeding season of birds also arrives as scheduled~

The American scarlet ibis, which is very popular in the bird world, will not miss the call of nature. They follow the rhythm of nature and start to build their love nests in the spring when the flowers bloom, preparing for a new round of reproduction. In order to ensure the smooth progress of this process, our breeders started the intensive and orderly preparation work early.

1. Intensive preparations before breeding

The American scarlet ibis usually builds its nests in trees and prefers to nest in groups. This is a biological adaptation to avoid enemies and improve reproductive survival rates.

Scarlet Ibis usually build their nests in trees and prefer to build nests in groups.

Therefore, in March every year, our keepers will select natural trees with many branches and easy nesting as nesting trees, and place fresh branches in the venue for the scarlet ibis to use for nesting.

Their nests are usually made of twigs, grass and plant materials and are bowl-shaped. Male and female birds participate in the nest-building process together. In addition to feeding and resting, they spend most of their time building nests with branches in their mouths. They will continue to add materials to the nest until they are satisfied.

The nest built by the scarlet ibis

In addition to providing the scarlet ibis with suitable nesting trees and abundant nesting materials, we also give in-depth consideration to the configuration of the litter in the museum.

We chose to use branches trimmed from the garden to crush into sawdust and spread it in the venue. The thickness of the mat is about 35-40cm.

Compared with straw, wooden litter is more effective when laid under trees. On the one hand, wood chips are softer, which is not only good for the feet of the scarlet ibis, but also can act as a buffer if the young birds fall from the nest. On the other hand, it is also a recycling of resources in the park.

Use tree branches cut from the garden to crush them into sawdust as litter

In addition, for the American Scarlet Ibis during the breeding season, we will also adjust its diet, increase the proportion of vitamin-rich foods, and supplement calcium.

Vitamin E is an essential vitamin for bird reproduction. It can not only improve the fertilization rate and hatching rate of breeding eggs, but also improve the reproductive performance of birds. Since young malt is rich in vitamin E, we cultivate young malt ourselves. This can not only enrich the food diversity of the American scarlet ibis, ensure that the scarlet ibis has sufficient nutrition, but also help to improve the reproduction rate of the scarlet ibis, and also reduce the heat stress response of the scarlet ibis in summer.

Young malt grown by breeders themselves

According to our observations and records, after the American Scarlet Ibis enters the breeding season, the color of its beaks changes from pink to black for both female and male birds.

This is a dynamic process, and after the breeding season, the black keratin of the beak will gradually fall off, revealing the pink beak. It has been observed that the beak color of sub-adults does not show this phenomenon during the breeding season.

Subadult Scarlet Ibis

Adult birds during breeding season

Adult birds during non-breeding season

Since there is no relevant literature on the cause of the color change of the scarlet ibis's beak, the specific cause remains to be verified. However, based on our breeding experience, we speculate that this physiological phenomenon may contain an important reproductive adaptation strategy.

Black beaks may have a higher visual appeal to chicks, making it easier for chicks to identify and touch their parents' beaks to ask for food. Black is more eye-catching against the background, which helps chicks locate in complex environments, thereby improving foraging efficiency and survival rate. This hypothesis is consistent with the behavioral pattern of many birds using obvious physical characteristic signals to guide and educate their offspring.

Of course, the specific biological function of this phenomenon still needs to be verified by further scientific research, but it undoubtedly adds an interesting perspective to our understanding of the reproductive ecology of the American scarlet ibis, and also provides a reference for us to provide better management and care plans during the breeding season: by continuing to pay attention to and study these special behaviors and physiological changes, we can more specifically create environmental conditions for the scarlet ibis that are closer to nature and conducive to successful reproduction.

2. Great progress in breeding work

In the conservation work of the rare species Scarlet Ibis, we have always paid great attention to the reproduction problem. However, in the past few years, we have found that although Scarlet Ibis can reproduce under natural conditions, the survival rate of naturally raised chicks is not ideal due to various reasons. We need to further explore and improve the breeding behavior of Scarlet Ibis and the artificial raising technology.

Our breeding work for the American Scarlet Ibis covers two core aspects: feeding management and artificial chick rearing.

First, at the breeding and management level, we solved the problem of individual identification of the American Scarlet Ibis and determined the sex of the animals through the color combination of the left and right leg rings. We also observed the reproductive capacity of each individual and provided a theoretical basis for adjusting the group structure.

Through three years of observation of the selection of nesting sites by scarlet ibis, we have discovered the characteristics of the trees that scarlet ibis prefer to choose for nesting, which provide us with a reference for building nesting trees, such as the type and height of the trees, the distance between the trees, and the planting location of the trees to ensure their safety and privacy, which is one of the prerequisites for successful reproduction.

At the same time, we made many scientific adjustments to the diet of the red ibis, and we experienced many twists and turns and failures in the process.

At first, we found that when young birds grow to a certain age, they will have some unhealthy symptoms, such as being unable to lift their necks or deformed leg bones and unable to stand. We realized that we might need to adjust the diet of adult and young birds. We added loach, shrimp, milk powder, mealworms, egg yolks, carrots and other foods to the feed formula for young scarlet ibises. By adjusting the consistency of the feed, we can increase the absorption rate of nutrients by scarlet ibises, solving the problem of low nutrient intake in the past.

This method has shown initial results. After continuous adjustments to the diet of adult and young birds, the physical condition of both adult and young birds has greatly improved, and their survival rate has also increased significantly.

Secondly, in terms of chick rearing, we observed that under natural conditions, scarlet ibis parents are limited by their own feeding capacity and resource allocation strategy, and can only focus on feeding one or a few chicks, resulting in other chicks not being able to survive due to insufficient care. To overcome this low survival rate caused by natural selection, we developed an artificial chick rearing program.

When the chicks are about ten days old, we will help the parents feed 1-2 of them. Through this strategy, the survival rate of the chicks in the entire population is greatly improved.

Through the comprehensive approach of these two main lines, we have made significant progress in the breeding of scarlet ibis, with the survival rate of chicks increasing from 6.9% to 62.5%.

This series of growth numbers not only represents an increase in the number of American scarlet ibis, but also accumulates valuable experience for the development of wildlife protection and breeding technology.

During this long research journey, our keepers and scientific research team have put in tremendous effort and time. In addition to their daily work, they have devoted themselves to in-depth research on the breeding behavior records of the American Scarlet Ibis and its artificial chick-rearing techniques, and have overcome one breeding problem after another.

In the future, we will continue to sum up our experience and explore more advanced and scientific feeding and breeding methods in the hope of going further on the road of protecting the American Scarlet Ibis and other rare species.