Week 12 Thursday - endangered species ams 111825

Learning Outcomes

  • Differences in African Elephants

    • Two types: African Savanna Elephants (Loxodonta africana) and African Forest Elephants (Loxodonta cyclotis)

    • Habitat:

      • African Savannahs for Savanna Elephants

      • Forests for Forest Elephants

    • Phenotypic Differences:

      • Savanna Elephants are larger with larger ears and tusks, while Forest Elephants are smaller with straighter tusks.

    • Reproductive Cycles:

      • Savanna Elephants reach reproductive maturity around 11 years; average age to give birth is 25 years.

      • Forest Elephants typically give birth later, around 31 years, with longer intervals between pregnancies (5-6 years).

  • Contribution of Elephants to Ecosystems

    • Elephants act as ecosystem engineers; they modify habitats that support various species.

    • Their feeding habits help control vegetation growth, fostering biodiversity by enabling other species to thrive.

    • Contribution to nutrient cycling through their dung, which fertilizes the ground and supports plant growth.

  • Orangutan Unique Characteristics

    • The name “Orangutan” means “person of the forest” from the Malay language.

    • All species of orangutans are found in Asian countries; three main species include:

    • Bornean Orangutan (Pongo pygmaeus)

    • Sumatran Orangutan (Pongo abelii)

    • Tapanuli Orangutan (Pongo tapanuliensis)

  • Sexual Dimorphism in Orangutans

    • Males are significantly larger than females (over 80 kg vs. 40 kg). Males develop large cheek pads (flanges) and a throat sac; females do not.

  • Habitat and Diet of Orangutans

    • Spend most of their time in trees (arboreal).

    • Diet:

    • Primarily fruits, also feeds on leaves, flowers, bark, insects, and birds’ eggs.

    • Lifespan: Average around 35-40 years in the wild.

  • Koalas

    • Capable of consuming eucalyptus leaves that contain toxins due to specialized digestion.

    • Nutrition from leaves impacts their sleep cycle and overall activity due to low caloric intake.

  • Marsupials vs Other Mammals

    • Marsupials have a unique gestation process where young are born underdeveloped and continue to develop in a pouch.

  • Monarch Butterfly Life Cycle

    • Stages: Egg, larva (caterpillar), pupa (chrysalis), and adult butterfly.

    • Survival rates as larvae vary, influenced by predation and environmental factors.

  • Monarch Breeding and Migration

    • Differences between breeding (summer) and migrating (fall) generations.

    • Total annual migration distance can exceed 3,000 miles from breeding grounds in North America to overwintering locations in Mexico.

    • Reproductive diapause allows monarchs to pause reproductive activity to survive adverse conditions during migration.

Conservation Status

  • Elephants:

    • Species: African Savanna Elephant (Loxodonta africana), African Forest Elephant (L. cyclotis)

    • Conservation Status: African elephants listed as Endangered (EN) and Critically Endangered (CR) by IUCN and Appendix I or II by CITES.

    • Population Decline: 60% in the last 50 years for African Savanna, 86% in 31 years for Forest Elephants.

    • Threats: Habitat loss, human-wildlife conflict, poaching.

  • Orangutans:

    • Conservation Status: Critically Endangered (CR) by IUCN, listed as Endangered (E) in the US.

    • Population Decline: Greater than 50% in the last 40 years, only about 800 Tapanuli left.

    • Threats: Deforestation, hunting, illegal trade, low genetic diversity.

  • Koalas: Conservation status needs specific mention regarding threats and decline.

  • Monarch Butterflies: Conservation status to be determined based on population data, threats, and decline.

CITES - Convention on International Trade in Endangered Species

  • Protects over 38,700 species globally, including 5,950 animal species.

  • An international agreement initiated in 1973 among 80 countries, now expanded to 184 parties.

    • Purpose: To limit international trade of endangered species.

    • Three Appendices:

    • Appendix I: Species threatened with extinction.

    • Appendix II: Species that are not necessarily threatened but require trade restrictions.

    • Appendix III: Species protected by at least one country.

Regulation of Endangered Species

  • Individuals involved: Department of the Interior, US Fish & Wildlife Service.

  • The Endangered Species Act indicates 2,054 species listed as endangered, 1,436 within the US.

  • Definitions:

    • Endangered: In danger of extinction throughout all or a significant portion of its range (exceptions for certain pest insects).

    • Threatened: At risk of becoming endangered in the foreseeable future.

    • Prohibitions: Taking (harassing, harming, pursuing, shooting, etc.) and trade of listed species without federal permits.

IUCN (International Union for Conservation of Nature)

  • Established in 1964 to share conservation information.

  • Over 147,517 species assessed, with categories including:

    • Extinct in the Wild, Endangered, Critically Endangered, Vulnerable, Near Threatened.

Elephant Population Dynamics and Data

  • Eastern Hellbender: Example of a locally endangered species in relation to the habitat described.

  • Tuition-related Considerations: The role of social dynamics within both African Savanna and Forest populations is underscored by genetic studies and behavior tracking across regions.

Tusks in Elephants

  • Definition: Tusks are permanently growing incisor teeth of the upper jaw, important for various survival functions.

  • Advantages/Disadvantages:

    • Assist in obtaining food, defense against predators, and competition for mates.

    • Recent trends show certain populations adapt to tusklessness, increasing survival rates in certain habitats.

    • Notably, in Zambia, tuskless females increased from 10.5% in 1969 to 38.2% in 1989.

    • In Addo Elephant National Park, nearly all elephants lack tusks.

Ecosystem Engineering by Elephants

  • Elephants play vital roles, such as:

    • Reducing competition among trees by foraging, promoting larger tree growth which sequesters more carbon.

    • Their dung contributes to nutrient cycling, aiding plant growth.

Conclusion and Further Exploration

  • Explore interactions between species and habitat configurations.

  • Continued assessment of conservation status and proactive measures against poaching and habitat loss is critical for long-term survival of elephants, orangutans, koalas, and Monarch butterflies.

  • Follow resources from various conservation organizations for updated information on species status.