Runfan YangPaddington is a lovable bear who traveled from Peru and arrived at Paddington Station in London. Alongside his adoptive family, the Browns, he embarked on countless adventures. Created by British author Michael Bond, Paddington is cherished for his polite yet sometimes clumsy nature and his love for marmalade, especially in the form of a sandwich. The story of Paddington centered around the simple yet symbolic marmalade sandwich to convey themes of warmth, connection, and resilience. For Paddington the bear, this sweet and sticky spread is more than just a treat; it represents comfort and security. The marmalade sandwich acts as his magical elixir, sustaining him through every adventure and misstep — a constant reminder that he is loved and belongs.
In Paddington’s world, it is often said that “just one (marmalade) sandwich contains all the vitamins and minerals a bear needs for the whole day.” Made of ripe oranges, lemons, and sugar, would this cherished delicacy truly meet a bear’s dietary needs in the real world? And if not, what could be added to support Paddington’s growth and well-being?
The Andean Bear
Paddington is an Andean Bear (Tremarctos ornatus) — the only bear species native to South America. These bears inhabit the mountainous regions of the Andes, with a range stretching from western Venezuela through Colombia, Ecuador, Peru, and into Bolivia. Known for their distinctive light-colored rings of fur around their eyes, which contrast with their predominantly black or dark brown coats, they are affectionately called “spectacled bears.”
The Spectacled Bear Conservation has identified three distinct ecosystems that these bears call home, depending on elevation: the equatorial dry forest (around 250 meters), tropical cloud forest (around 900 meters), and high alpine grassland (up to 3,500 meters). Adapted to a range of latitudes and altitudes, Andean Bears adjust their diet composition based on the availability of vegetation, demonstrating remarkable flexibility in response to environmental cues.
Plenty of Greens, Just a Little Meat
Contrary to the common belief that bears are primarily meat-eaters, many bear species are omnivores, consuming both plants and animals. Andean Bears, in particular, have a remarkably diverse diet that includes over 300 types of plants and more than 20 types of animals. Their food choices depend on geographic region, availability, and seasonal changes. Despite these variables, Andean Bears are predominantly frugivorous, relying mainly on fruits and plant-based foods such as roots, shoots, nuts, and seeds.
According to the rehabilitation guidelines published by the Andean Bear Foundation in 2016, approximately 75% of the diet of wild Andean Bears in the tropical cloud forest consists of fibrous plants. The remaining 25% is largely made up of wild fruits, with only a small fraction dedicated to animal proteins. In high-altitude grassland ecosystems, up to 90% of their diet consists of fibrous plants.
With a diet predominantly consisting of plants, Andean Bears consume animal protein opportunistically, only when it is readily available. Their natural protein sources include insects, rodents, rabbits, reptiles, birds, fish, and eggs. In rehabilitation centers, rescued Andean Bears receive an elevated protein intake to support muscle growth and repair. Twice a week, their diet is supplemented with additional animal protein about 2-3% of their body weight in the form of small invertebrates, meat, eggs, and occasionally dog food.
A Heart for Fiber-Rich Plants and Sweet Fruits!
Andean Bears are of intermediate size among bear species. Adult males in the wild typically range from 1.37 to 1.88 meters (4.5 to 6.2 feet) in length, measured from the tip of the nose to the end of the tail, and weigh between 130 and 200 kilograms (286 to 440 pounds). Data from studies on 60 wild and captive Andean Bears indicate that males are 30–40% larger than females, who weigh between 35 and 70 kilograms (77 to 154 pounds), despite having similar body lengths (1.30 to 1.48 meters, or 4.3 to 4.9 feet). The reason for this size difference between the sexes remains unclear but is thought to be related to differences in gastrointestinal anatomy, behavior, and nutrient requirements.
High-calorie foods with balanced nutrients and vitamins are essential for the health and development of Andean Bears, providing the energy needed to maintain their size and strength. Based on nutritional studies, the rehabilitation program for Andean Bears prescribes a daily intake of 8% of body weight for captive bears to help maintain a healthy body mass in preparation for reintroduction to the wild. Over half of this daily intake consists of mixed fruits — primarily bananas, papayas, and seasonal staples. The remaining portion of the diet includes fibrous content and vitamin supplements. Before release, the bears are gradually reintroduced to native foods, guided by research on wild populations and consultations with local farmers.
Wild Andean Bears predominantly consume plant matter, with their most commonly eaten plants varying by region. In Ecuador, their diet often includes bamboo, bromeliads, palm hearts, and prayer plants. Among these, bromeliads (Bromeliaceae, the pineapple family) are a significant and favored component. Andean Bears in the wild exhibit a preference for both terrestrial and epiphytic bromeliads. Field studies conducted in Peru over 203 days of observation revealed that bromeliads accounted for 28% of recorded feeding instances — nearly 60% more frequent than their second-most common behavior, climbing trees for fruit (17% of recorded events).
Bromeliads, native to tropical and subtropical regions of North and South America, serve as a reliable year-round food source, especially when ripe fruit is scarce. Rich in soluble carbohydrates, fat, and protein, they provide a nutritious option for Andean Bears. These plants are typically well-defended with tough exteriors. For example, a pineapple’s hard shell and spiky leaves protect its sugary, sweet core. However, Andean Bears are well-adapted to access this core, thanks to their strong jaws and wide grinding molars, which allow them to break through the tough exterior and extract nutrients from the fibrous interior. Additionally, while mammals like Andean Bears lack the enzymes needed to break down fiber, it is believed that their gastrointestinal tract hosts cellulose-hydrolyzing microorganisms. These microorganisms likely form a symbiotic relationship with the bears, aiding in the breakdown of cellulose, hemicellulose, and lignocellulose. This adaptation enhances nutrient digestion and absorption, allowing Andean Bears to efficiently process their fibrous diet.
Ripe fruits and berries are another essential food source for Andean Bears. The specific types of fruits they consume vary seasonally and depend on the region within their ecosystem. In the wild, Andean Bears primarily eat fruits like wild fig and avocados in the cloud forest, and blueberries in the grassland ecosystem. In rehabilitation programs and zoos, fruits such as apples, oranges, and grapes are commonly provided to meet their nutritional needs. Notably, Andean Bears are the primary mammalian consumers of fruits and berries within their range, making them invaluable seed dispersers. Seeds that remain unharmed during digestion are excreted and dispersed as the bears travel, aiding in forest regeneration. Through these activities, Andean Bears play a critical role in maintaining the dynamics and structure of their ecosystems.
The Perfect Sandwich for Paddington!
What constitutes the perfect sandwich to support Paddington’s growth and daily activities in London? In the movie Paddington, he is estimated to be around 1.07 meters (3 feet 6 inches) tall, suggesting he has not yet reached adulthood. Assuming his weight is approximately 100 kg based on his height, he would need to consume about 8% of his body weight daily to maintain a healthy body mass. Since he is still maturing, an additional supplement of animal protein is required to help Paddington grow into a big bear. Based on published literatures and the dietary guidelines of the Andean Bear Foundation, the ideal sandwich for Paddington would include:
- Thick slices of bread (~1 kg): Multigrain bread offers a good balance of carbohydrates and fiber. Assorted cereal flakes can also be added as an excellent source of additional fiber.
- Mixed fruit (~5 kg): Marmalade would be a great choice, though its sugar concentration should be monitored to avoid obesity. Marmalade spread, supplemented with sliced apples, bananas, grapes, and seasonal berries, would provide a variety of food sources.
- Guava or other high-fiber sources (~1 kg): Guava, known for its high fiber content, would be an excellent addition to the sandwich.
- Wheatgerm (~0.5 kg): In the absence of terrestrial plants and fruits, Andean Bears have been observed enjoying occasional corn from local fields to meet their nutritional needs.
- Supplements: Mineralized salt and a powdered vitamin complex to ensure balanced nutrition.
- Animal protein (2-3 kg, twice a week): To support Paddington’s growth, animal protein should be added to the sandwich a couple of times a week. Eggs would likely be the most readily available form of animal protein in London, closely resembling the wild Andean Bear’s diet. However, other animal meats could also suffice in meeting his nutritional needs.
Bon appétit, Paddington!
Peer Editor: Anna Goddard