Melanie A. Calicdan, MSc.Melanie A. Calicdan, MSc.PhD in Resource ManagementPhD in Resource Management

OUTLINEOUTLINEIntroductionMajor Threats: Real Threat of Endangerment and Extinction Anthropogenic Pressures

- Natural Events- Climate Change

Characteristics of Threatened/Endangered Species- Large Size- Dietary Specialist- Low Reproductive Output- Habitat Specialist- Small population size- Limited Geographic Distribution- Economic or commercial value

Extinction ProcessCause and Consequence of Endemicity and RarityEndangered and threatened Species in the PhilippinesIUCN Criteria for Endangered and Threatened Species

IntroductioIntroductionnPhilippines – treasure trove of biodiversity. One of the 17 mega diverse

countries

Host 70-80% world’s biodiversity.

2nd among 10 botanical hotspot areas in the tropics.4th in the world with highest number of threatened species5th in the number of plant species and maintains 5% of the world’s flora4th in bird endemism

Has more than 52,177 species (plants and animals) with 680 considered as threatened (IUCN).

Approximately 30-40% is endemic and no elsewhere can be found in the world.

Described not only “hotspot” but the “hottest of the hotspot” because of high levels of endemism , large number of threatened and endangered species and other human activities that threatens biodiversity.

Endangerment and Endangerment and ExtinctionExtinction

Biodiversity Loss: Biodiversity Loss: A Real ThreatA Real Threat

Anthropogenic PressuresAnthropogenic Pressures

• Habitat Loss/Forest Fragmentation Habitat Loss/Forest Fragmentation – a landscape –scale process involving both habitat loss and breaking apart of habitat. “ When habitats are fragmented, plants and animals in that habitat must in essence, re-learn how to survive. Food sources that were once there maybe gone, or homes maybe destroyed. The areas where young were or raised may be gone. This may cause many species to die of quickly, affecting the biodiversity or variation of life” – Enzor (2010)

• Introduction of Alien Species Introduction of Alien Species – when animals and plants from foreign place arrive into a new habitat displacing the native species, can prey on the native species and sometimes introducing diseases that the native species can not fight.

3 Common Pathways of Invasion3 Common Pathways of Invasion

1.1.Ballast water -(transport of organisms to a new habitat – between Ballast water -(transport of organisms to a new habitat – between islands or countries)islands or countries)2.2.Establishment and propagation of IAS in the new habitat – (either in Establishment and propagation of IAS in the new habitat – (either in natural or man-made habitats such as closures, artificial ponds, natural or man-made habitats such as closures, artificial ponds, reforestation areas and gardens)reforestation areas and gardens)3.3.Uncontrolled spread from initial population over large area - (either Uncontrolled spread from initial population over large area - (either through deliberate release or accidental escape).through deliberate release or accidental escape).

Pomacea canaliculata

Hypseleotris agilis Clarias batrachus Eichhornia crassipes

• “ “Kaingin” /Forest Fires (slash and burn farming) Kaingin” /Forest Fires (slash and burn farming) – resulted in extensive fragmentation of upland forests.

Factors that lead to the practice of increasing “kaingin”Factors that lead to the practice of increasing “kaingin”

1.Habitation by communities marginalized by development projects2.Rapid urbanization displacement due to natural events (landslides and flooding)3.Land clearing4.Increasing human settlements in close forest proximities

• Pollution/Habitat Development – Pollution/Habitat Development – one of the primary ways in which humans have cause drastic modifications of wildlife.

Other factors that destroy physical Other factors that destroy physical habitatshabitats

1.Draining and filling of swamps and marshes2.Damming of rivers be levelling of forest for residential and industrial developments3.Strip mining4.Oil spills 5.Water pollution

Development sites and housing projects in urban and semi-urban areas are major barriers to the movement of species between remaining forest patches.

• Over-hunting/Overharvesting Over-hunting/Overharvesting – animals are over hunted because their meat and other parts are very useful.

Problems of Overhunting (CBD 2002Problems of Overhunting (CBD 2002))

1.Animals are hunted for sports2.For products like furs and oils3.For their meat

Natural EventsNatural Events

• Climate Change - Climate Change - affect the distribution of marine species and to thought to represent threat to biodiversity. Biogeographically, distribution of species is largely determined by climate , as in the distribution of ecosystems and plant vegetation zones (biomes).

Examples : Examples :

1. Shorter periods of sea ice in the Artic endanger polar bears habitat and giving less time to hunt.2. El Nino Southern Oscillation affects coral reef3. Impacts on mountain ecosystem – some plant species in Alps migrate upwards by one to four meters per decade and some plants previously found on the mountain tops disappeared (CBD, 2007).

EXTINCTION PROCESS

It is estimated that more than 99.9% of all species of plants and animals that It is estimated that more than 99.9% of all species of plants and animals that have ever existed are now extinct .have ever existed are now extinct .

(American Society of Mammalogists)(American Society of Mammalogists)

Endangered species – Endangered species – number of species are reduced to such an extent that it is likely to become extinct in the near future.

Threatened species Threatened species – one whose numbers have been reduced to such an extent that any further decline in numbers will warrant its designation as an endangered species. are species which are vulnerable to endangerment in the near future. Threatened categories consist of 3 categories depending on which degree they are threatened (vulnerable, endangered, critically endangered) .

Extinct – Extinct – species that no longer exist in the wild or captivity.

ExtinctionExtinction – a natural phenomena or process that has been occurring since the earliest forms of live evolved. This may refer to the disappearance of a species from its entire range (global) or loss of species from a portion of its geographic range (regional or local).

Large deer (Irish elk) with huge antlers that were 3m across became globally globally extinct extinct at the end of the last glacial stage.

Wild horses became regionally extinct regionally extinct in N.A. but survived in Europe and Asia

The extinction of species provides opportunities for other species to take over the niche (s) or ecological role (s) of species that become extinct.

The extinction of Dinosaurs provided numerous opportunities for mammals which have been minor players on the evolutionary stage throughout the age of Reptiles. In the absence of dinosaurs, mammals were able to prosper and evolved to fulfil many of the ecological niches formerly occupied by dinosaurs.

Characteristics of Threatened and

Endangered Species

Threatened and endangered species possess certain characteristics. The species that possess these characteristics often are candidates not only for

threatened or endangered status but also for possible extinction.

• Large size - Large size - large mammals by virtue of their size alone require larger areas in which to obtain necessities of life (food, mates and cover) than do smaller animals.

“Not only do large mammals need large areas to live but also their total numbers are much smaller than those of small mammals”

• Dietary Specialist – Dietary Specialist – mammals have dietary needs such as carnivores and frugivores need to forage over much larger areas than dietary generalists such as herbivores and omnivores.

Footed ferret (predator) Prairie dog (prey)

• Low Reproductive Output – Low Reproductive Output – species of mammals have evolved reproductive strategies than in part reflect their probability of dying.

There is a balance between the probability of dying and a number of young a female must reproduce to help insure the survival of the species. When man alters the natural balance between birth and deaths by increasing mortality, populations decline.

Exemption to the general Exemption to the general rulerule (bats) (bats)

• Habitat Specialist – Habitat Specialist – species of mammals often become threatened if the specialized habitats they occupy are small in size and widely separated in space.

•Under such conditions, these species exist in small, isolated populations which can be affected by local catastrophic events.

Example:Example:

Loss of 300,000 Indiana bats when the cave in which they were hibernating flooded.

• Small population size – Small population size – species with small population have a greater probability of extinction than those with large populations.

There are species that appear to be naturally rare and may never have occurred in large numbers. Those are the species that are confined in distribution to isolated mountain tops.

Restricted in the Eastern and Southern Africa during Old World.

• Limited geographic distribution- Limited geographic distribution- mammals with limited geographic distribution risk of becoming extinct whenever their habitats is altered or destroyed.

• Economic or commercial value Economic or commercial value – mammals with economic value or commercial value are often subjected to higher mortality rates.

Endangered Endangered

Category CR EN VU Subtotal NT LR/CD DD LC TotalPlants 55 35 35 125 27 3 9 112 276Animals 38 81 339 458 302 5 257 928 1,950

Taxonomic GroupsTaxonomic Groups

Mammals Birds Reptiles** Amphibians Fishes** Molluscs**Other

inverts** Plants** Total**

Total # of Total # of threatened threatened speciesspecies 39 60 35** 48 63** 3* 210** 222** 680**

Source: IUCN Red List Data

Endemicity and

Rarity

Endemic species - refers to a taxon which is geographically restricted in distribution. Endemism refers to the occurrence of particular species only in a particular habitat and often represents unique step in the process of evolution. geological state of being unique to a particular geographic location such as specific island, habitat, nation or any other defined zones.

Rare Species - mostly simply based on its distribution and abundance (Lexicon of Conservation Biology)

- merely the current status of an extant organism which is restricted either in numbers or area to a level that is demonstrably less than the majority of other organisms of comparable taxonomic entities (Reveal, 1981).

Rare species - is a group of organisms that are very uncommon, scarce, or infrequently encountered. They are generally considered

threatened because a small population size is more likely to not recover from stochastic events (things that could happen) (www.wikipedia.org).

 

When the continent splits, two halves of the population are separated, and over many generations, they evolve into separate species. These species' distribution is the result of vicariance. Many different processes can cause vicariancevicariance — plate tectonics, the rise of mountain ranges, a shift in the course of a river, or just climate change that causes an unfavourable habitat to develop that ends up splitting a species' range into two. 

DispersalDispersal,, on the other hand, occurs when a species spreads or immigrates from one area to another. If part of a population moves to a new area, the two subpopulations may eventually evolve into separate species.

CCAAUUSSEE

EndemicityEndemicity

Example: Example:

One land masses splits sequentially into three separate islands.

A mountain range rises on one of these islands, effectively splitting it. If a group of organisms was widespread on the original land mass and was sequentially split along with the geologic changes, we'd expect the sequence of splits in the phylogeny to match the sequence of splits in the geography.

Additional tectonic action causes one more split. some members of species C disperse to the new island, and they evolve into a separate species.

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Endemic species of plants and animals remain poor in adaptation to direct types of environmental conditions (physical, climatic and biological factors).

Essentially affected to demographic pressure and introduction of exotic species because of their restricted habitats (Maiti and Maiti, 2011).

RarityRarity

Two Categories Two Categories

• Natural Causes Natural Causes – defined by species inherent biological or ecological characteristics.

• Anthropogenic Causes Anthropogenic Causes – defined by harmful human activities that have resulted in limited distribution and abundance, independently on their biology. (Partel et.al., 2005).

Factors lead to RarityFactors lead to Rarity

1.1.Habitat loss and degradationHabitat loss and degradation2.2.IASIAS3.3. PollutionPollution4.4.Overharvesting/OverhuntingOverharvesting/Overhunting5.5.Climate ChangeClimate Change

CCAAUUSSEE

RarityRarity

Rare species may have highly fragmented populations. This can limit the potential for reproductive exchange of genes between individuals and increase the possibility of problems resulting from inbreeding

The loss of even a few individuals can represent a substantial decrease in the total numbers of a rare species.

The common denominators of rarity of species are human land transformations leading to habitat loss and degradation; biotic mixing, stemming from the introduction of non indigenous species, direct human exploitation for control, subsistence, or collecting: and pollution through the alteration of biochemical cycles or the introduction of synthetic compounds.

1. Its population has been reduced by 70 percent in the last ten years.

2. It population has been reduced over 50 percent in the last ten years, where the cause of reduction has not been stopped or is determined to be irreversible.

3. Its population is suspected to be reduced by 50 percent in the next ten years or three generations, whichever is longer, up to a maximum of 100 years.

4. The species is known to exist in five or less geographic locations.

IUCN Criteria for IUCN Criteria for Endangered SpeciesEndangered Species

Al-jabber JM. 2003. Habitat fragmentation: Effects and Implications. American Society of Mammalogists. Undated. Why species Become Threatened or Endangered. A Mammalogists Perspective. Caugley, G. 1994. Directions in Conservation Biology. Journal of animal Ecology. 63:215-44.Ceballos, G. and Navarro, L. 1991. Diversity and Conservation of Mexican Mammals. Pp. 167-98 in Latin American Mammalogy: History, Biodiversity and Conservation.

Ehrlich, P.R. and Ehrlich, H.A., 1981. Extinction: The Causes and Consequences of the disappearance of species. Random House New York, New York . USA.

Enzor, L.. Undated. Pollution and Habitat Destruction: The Human Factors Contributing To Endangerment & Extinctionhttp://education-portal.com/academy/lesson/pollution-and-habitat-destruction-the-human-factors-contributing-to-endangerment-extinction.html#lesson. Fahrig, L. 2003. Effects of Habitat Fragmentation on Biodiversity.Annu. Rev. Ecol. Syst. p. 487-515.Gaston, K. J. 1994. Rarity. London. Chapman and Hall.

Hogan, M.C. 2010. Cause of extinction. Retrieved from http://www.oearth.org/view/article/150962.

International Union for Conservation Network Red List of Endangered Species. www.iucn.org. Jones, M.C. Dye, R.S., Fernandes, J.A., Fro¨licher, T.L., Pinnegar, J.K., Warren, R., Cheung, W.W.L. 2013. Predicting the Impact of Climate Change on Threatened Species in UK Waters. Maiti, P.K., and Maiti, P. 2011. Biodiversity: Perception Peril and Preservation. www.googlebooks.com.McGill, B. J. 2003. Does Mother Nature really prefer rare species or are log-off-left skwed SADs a sampling articraft? Ecology letters. 6:766-73.

Partel, M. R., Kalamees, U. Reier, E.L. Tuvi, E. Roosaluste, A. Vellak, and M. Zobel. 2005. Grouping and Prioritization of vascular plant species for conservation: Combining natural rarity and management need. Biological Conservation. 123:271-78.

Reveal, J.L. 1981. The concept of rarity and population threats in plant communities. Pp. 41-46 in Rare plant conservation, ed. L.E. Morse and M. S. Henefin. Bronx: New York Botanical Garden.

Rob. Brooker. 2010. Understanding the Causes and Consequences of Rarity In Scottish Plants. Ecosystem and Biodiversity. http://www.knowledgescotland.org/briefings.php?id=150.Venter, O., N. N., Brodeur, L. Nemiroff, B. Belland, I. J., Dolinsek, and J.W.A. Grant. 2006. Threats to endangered species in Canada. Bio Science. 56:903-10.