Pangolins, often dubbed "scaly anteaters," are among the world's most trafficked mammals. Their populations have drastically declined due to their perceived economic and medicinal value in certain regions. Conserving these unique creatures, especially through ex situ breeding programs, necessitates a deep understanding of their nutritional needs and dietary habits. This article delves into the dietary aspects of pangolins, comparing their natural diet to that of captive pangolins, highlighting key factors for successful ex situ care, and exploring strategies to enhance their conservation both in animal care centers and in the wild.
Pangolins: An Overview
Pangolins belong to the genus Manis, order Pholidota, and family Manidae. There are eight species of pangolins, with four found in Asia and four in Africa. These toothless mammals primarily feed on ants and termites, capturing them with their remarkably long tongues. An adult pangolin can consume over 70 million insects annually, playing a crucial role in controlling forest termite populations.
The economic benefits derived from pangolins, stemming from their assumed medicinal and gastronomic value, have fueled illegal trade, leading to a significant decline in their wild populations. To combat this, the Chinese government has upgraded all pangolin species to national Grade I protected wildlife. While policy changes offer better protection, ex situ breeding is considered a more effective conservation method.
However, transitioning pangolins from a wild diet of ants and termites to artificial food under human care poses significant challenges. A lack of comprehensive understanding of their nutritional needs remains a major obstacle to successful ex situ breeding. Studies have linked pangolin health to nutrition and parasite infection, with some pangolins suffering from gastrointestinal diseases and malnutrition due to unsuitable artificial diets.
Natural Diet of Pangolins
In the wild, pangolins primarily consume termites and ants. Field studies have revealed that their diet may also include insect larvae, bee pupae, flies, earthworms, crickets, and other arthropods, along with occasional ingestion of sand, small grains, and grass. The diet composition varies depending on latitude and season.
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While pangolins have a specialized diet, they may not exhibit a strong preference for specific ant species. Research indicates that they feed on various ants and termites without an obvious preference. However, some studies have found that certain ant species are unacceptable to pangolins, suggesting that nutritional composition, palatability, and safety are important factors in their food selection.
Nutritional Composition of Natural Food
The nutrient profile of different ant species, and even within the same species, varies significantly. For instance, protein, fat, and mineral content differ between ant castes (queens, soldiers, workers). Ants generally have a high crude protein content compared to other foods like eggs, milk, and common cat food. They also boast higher mineral and vitamin concentrations than many common food items.
The ratio of non-protein energy to protein energy (NPE/PE) in ants ranges between 0.48:1 and 1.2:1. Ants are rich in crude protein, with varying levels of fat, minor amounts of carbohydrates, and varying levels of ash (minerals).
It's important to note that crude protein determination doesn't distinguish between real protein and non-protein nitrogen fractions. In insects with a large exoskeleton proportion, chitin can constitute a considerable part of the crude protein fraction. Therefore, crude protein concentrations in ants and termites should not be taken as an indicator of real protein requirements in pangolins.
The varying ash content likely reflects the insects' lifestyle, with some species consuming soil and loading their guts with ash.
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In addition to basic nutrients, ants are rich in formic acid, which they use for defense, trace marking, and antibacterial action.
Ex Situ Feeding of Pangolins: Challenges and Solutions
Maintaining pangolins in captivity presents several challenges, primarily related to their specialized diet and the difficulty of replicating it in a controlled environment.
Limitations of Artificial Diets
The requirement of ant breeding is strict on temperature and humidity, and the breeding time is from March to October, so the availability of ants is reduced at other times. For larger-scale care of pangolins, there are not enough natural ant resources to meet their nutritional needs, which implies insufficient food supply for pangolins under human care and will affect the display of natural behavior.
Compared to their natural diet, artificial diets often contain fewer insects and vitamins (such as vitamin E, vitamin A, and vitamin B2) and more carbohydrates and non-protein substances. Although many successful dietary formulae have been developed, the pangolin’s nutritional needs are still less well studied. A diet with the nutrient concentrations observed in the wild may add to successful ex situ conservation.
Successful Dietary Formulas
Based on the natural food ingredients of pangolins in the wild, many recipes have been developed for pangolin husbandry, including eggs, meat (ground beef, horse meat, fish), milk, milk powder, orchid leaves, carrots, yeast, multivitamins, and insects. Taipei Zoo has been very successful in raising and breeding pangolins, which is largely related to the gradual development of a suitable diet. Their pangolin diet formula was developed from 1989 to 1995; the researchers optimized a diet for pangolins, consisting of 100 g of mixed silkworm powder (silkworm powder, yeast powder, coconut powder, ratio of 10:2:1), 100 g of bee larvae, 50 g of mealworms, 1 egg yolk, a quarter of an apple, and 0.5 mL infant multivitamin solution.
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Other successful artificial diets have included ingredients like milk, porridge, Crematogaster rogenhoferi Mayr, Polyrhachis lamellidens Smith, locust leaf powder, a multivitamin mixture, glucose, and egg yolk. Some formulas incorporate fresh milk, ant powder, minerals, and vitamin supplements.
Variability in Dietary Practices
Due to differences in geographical environment and biological abundance, the types of food and nutritional composition in different pangolin protection agencies show great differences. Diets range in their levels of invertebrates (ants, red weaver ants, green weaver ants, weaver ant eggs, red ants, bee larvae, silk worms, and/or mealworms), vertebrates (beef meat, eggs, and/or egg yolks), plant matter (coconut husk, apples, corn flour, and/or soya beans), concentrates (cat kibbles, hedgehog pellets, and/or insectivore pellets), dairy (yoghurt), and supplements (clay, chitin powder, calcium lactate, vitamin B, vitamin A, vitamin K, choline chloride, and/or olive oil) and water. There is a high variability in the nutrient content of diets across institutions: crude fat, crude protein, acid detergent fiber (ADF), neutral detergent fiber (NDF), Ca, P, and water soluble carbohydrates (WSCs) vary significantly.
Key Considerations for Ex Situ Pangolin Feeding
For most pangolins that move from the wild to captivity, it is important to provide a diet that allows a smooth adaptation to the new environment. The diet under human care contains fewer insects, with …
Mimicking the Natural Diet
The main difference between diets in the wild and in human care of pangolins is that the latter contains fewer insects and vitamins, such as vitamin E, vitamin A, and vitamin B2, and more carbohydrates and non-protein substances than the former. A diet with the nutrient concentrations observed in the wild may add to successful ex situ conservation.
Nutritional Needs
The nutritional needs of many wildlife species are still largely unknown and how they are fed is often based on a “model” species for which there is already an understanding of their nutritional needs. The giant anteater (Myrmecophaga tridactyla) serves as a “model” species of the pangolin because it has a similar feeding ecology.
Pangolin Conservation: Beyond Diet
While proper nutrition is crucial, pangolin conservation requires a multifaceted approach.
Combating Illegal Trade
All pangolins face declining populations because of illegal trade. In fact, they’re believed to be the world’s most trafficked non-human mammal. Their scales, like rhino horns, have no proven medicinal value, yet they’re used in traditional Chinese medicine to help with health problems such as arthritis. The scales are typically dried and ground up into powder, which are sometimes turned into pills. Tens of thousands of pangolins are poached for their scales each year, as well as for their meat.
Government officials, conservationists, and investigative journalists in Asia and Africa are working together to protect these shy, harmless animals.
Habitat Preservation
Pangolins are also losing habitat due to human encroachment, with forestry being turned into agricultural tracts.
Community Engagement
Community education and outreach programs in villages and towns across Asia advise against the hunting and poaching of pangolins, as well as providing the tools necessary for sustainable agriculture as an alternative source of food and income. Wildlife authorities patrolling protected areas are increasingly trained in investigating and apprehending poachers. Various rescue centres have been established across Asia for the protection and rehabilitation of live pangolins seized by police.