May 16, 2017 by Species Ecology
Small Mammal Conservation: The Genus Martes as Case Study
Mega vertebrates from mammalian guild often receive wholesale package of conservation attention both from socio-political and ecological spectrum. This is largely due to the human perspective based on our ecological and conservation prejudice stem from ‘ramshackle and ill-conceived’ mindset that large species are worth putting effort to preserve. Considerable funding and ecological research has been carried out focusing mega-mammalian fauna across the globe. For example, the most ambitious conservation project focusing tigers of India is a testimony to our efforts to conserve the charismatic mega carnivore. Similar examples come from mountain lion conservation in North America and jaguar conservation in South America. Carnivores are often the epicenter of ecological study by many wildlife biologists due to their conservation significance that encompass heterogeneous mosaic of broad landscapes including protected areas, reserve forests, biological hotspots and world heritage sites. The mammalian order carnivores show varying degree of ecological resiliency due to their diversity across terrestrial, semi-aquatic, aquatic and marine ecosystems across the planet. There are roughly 300 species of carnivores (including their sub species that are frequently subject to taxonomical and phylogenetic debate) and the family Mustelidae is the largest. Mustelidae comprises over 67 species (including the subspecies) representing 22% of the total carnivores. Despite their sheer proportion and species diversity across the bio-geographical realm much-needed study to understand their demographic and ecological parameters remain punishingly catholic. Martes is one of the neglected genus that hosts 13 species comprising roughly 20% of the total Mustelids. However, basic ecological and conservation information regarding this relatively miniature carnivores are sketchy and ‘anecdotal’. Species under Martes genus plays key role in maintaining ecological services including pollination of tropical and semi-tropical trees, plants, and shrubs that are in fact a cornucopia of invertebrates, arboreal mammals, reptilian fauna of high conservation importance and avian species including charismatic birds of paradise. If the numbers of Martes species decimate due to various subtle anthropogenic causes, these large diversity of other vertebrates and invertebrates that depends on martes will also diminish over time before we have the chance to study their vital role on sustaining healthy ecosystems and for providing intangible ecosystem services that we relies on for our own existence. Considering their importance on maintaining both temperate and tropical ecosystems across the globe there is a grave need to scientifically understand little over half a dozen of these species under Martes genus living under various deterministic threats that are yet to quantify. This article expects to fill this ’empty niche’ by providing statistically valid, ecologically sound and scientifically authoritative basic information about species under Martes genus in a brief generic form so that it can serve as a ‘first-ecological-notebook-to-pick-up’ for resource managers, carnivore biologists, students focusing their work on small mammal conservation, field staffs and forest officials working on protected area design in temperate and tropical landscapes.
The Martes genus is included in the Mustelidae family of the order Carnivora (Image 1). This genus includes a number of small carnivorous species and subspecies. Some of the notable species are Nilgiri Marten, European Pine Marten, Sable, American Marten and Japanese Marten. They live in a wide variety of habitats including forest, shrubland, grassland, rocky areas, and artificial landscapes (Image 2).
They are classified as carnivores because their diet consists primarily of small terrestrial vertebrates; however, they are predatory hunters capable of taking on prey the same size – or larger – than themselves. While a large part of their diet consists of small mammals such as mice and squirrels, some species have been known to eat birds, eggs, fish, and fruit. They are opportunistic feeders but will cache or store food for periods of poor weather conditions and low food availability.
They are generally agile tree climbers as well as good swimmers. They are solitary animals although they can sometimes be seen in mating pairs or as small family units (mother and kits). Their biggest threats are hunting/trapping by humans for their pelts and habitat loss; although they do have a number of natural predators such as predatory birds, wolves, foxes, lynx, and bobcats. However, even with these threats, their numbers are relatively healthy. They are all listed as species of Least Concern, with the exception of Martes gwatkinsii, the Nilgiri marten which is listed as Vulnerable by the IUCN.
I have carried out a simple ecological enumeration based on World Conservation Union (IUCN) species database (Version 1.0). I ran the database systematically under the following criterion index to gather qualitative data that we can suitably convert into mathematically viable data set in order to develop a quantitative framework. My aims were to address rudimentary ecological questions that are often faced by wildlife biologists: 1. What is the proportional richness and or diversity (notice we are not addressing the question of species evenness) of the species that are ecologically, taxonomically and phylogenetically represented under the genus Martes across its ecological biomes? 2. What is the proportional diversity and or richness of the Martes species across the broad geo-political landscapes? We believe answering these two questions are criticall if carnivore ecologists ought to advance Mustelid study in general but Martes study in particular under the chronic funding deficit and prevalent administrative and bureaucratic setbacks.
Six criteria that we pull together from IUCN database version 1.0 in order to construct our data framework:
4. Habitat Suitability
5. Conservation Status
6. Demographic Parameter
My results suggest that over one third of the species under the genus Martes inhabits and prefer temperate coniferous forest ecosystems. Despite the broad landscape of temperate ecosystems that we find in North America and Europe, our data suggest that 27% of the species are in fact living in North and Far East Asian coniferous ecosystems. 29% of the species lives in temperate broad-leaved and we found that majority of these species are associated with Europe representing 23% of the Martes diversity. 14% of the species under Martes prefers shrubland (also known as scrubland) and interestingly they are closely associated with South and South East Asian and North American shrublands comprising 15% each of these geo-political boundary across the continents. This has conservation implications and it challenges the average stereotype that ‘majority of the Martes species lives in North American and European temperate coniferous forests’. Our data clearly indicates that only 15% of the species are in fact associated with North American forest whereas collectively, 50% of the species lives in North/Far East Asia and Europe in temperate coniferous and temperate broad-leaved ecosystems respectively. We found 12% of the martes species are close associated with Russian temperate ecosystems of both broad-leaved, boreal taiga and coniferous in nature. Although 4% of the species lives in Africa and considering there is no Martes species in South America, our data statistically assumes that 11% of the species are living in tropical broad-leaved in which 80% are associated with South and South East Asian tropical forests where mammalian diversity is high. The remaining 20% may be linked with the 4% of the African tropics. Only small number of species are living in aquatic, boreal taiga and flooded grasslands representing 4% of the each biomes. Finally our data reveals that 4% of the species under Martes genus inhabits Middle East and Western Asia possibly associated with shrubland habitats.
I conclude from our result that conservation priority focusing large heterogeneous landscapes that harbors multitude species including Martes should be classes as keystone habitats to bring about over all biodiversity conservation. In this remit we feel conservation priority and statistically valid ecological research must focus on two of these large landscapes:
1. Temperate coniferous forest ecosystems of North and Far East Asia.
2. Temperate broad-leaved semi-natural woodlands of Europe.