land's end

the yellow Earth with rifts, ridges, rims
painted by an evening sun
watered by a scattered rain
orange bison calves beckon to motherly grunts
their long limbs stiff from sleep
it's time to move.
ahead, the people gather predicting the grizzly's path
as her golden-tinged cubs wrestle and roll toward thick blue-green sage, almost camouflaged
and still ahead a gray wolf abandons an elk carcass
goldeneyes display on a quiet lake
whose water is tilled in V-shape
as a young beaver glides to pause at a log most distant from land's end
where for a moment
pausing is
  the only thing to do.

Facultative species turn into obligate in forested wetlands

Facultative species in wetland habitat are not strictly confined to the wetland (i.e. are not obligate) until perhaps they are endangered by habitat loss in the surrounding landscape such as the Florida panther or the Bengal tiger, or the threatened species in forested peat swamps in SE Asia: orangutans, sun bears and clouded leopards. Perhaps these species become obligate out of necessity (their survival depends on it). According to Stoneman (1997), several mammal species in peat forest occur outside their previously known ranges including the marbled cat and slender tree shrew. For how many species is such a habitat shift actual, rather than an artifact of survey effort (i.e. how many species' distribution maps actually include wetland areas such as mangroves, which are so difficult to survey)? And how do species previously occuring only in terrestrial ecosystems adapt to successfully exploit the wetland (e.g. do they 'follow the tides')? I thought that these are questions which we'd have more time to pursue being that forested wetlands support old growth more than do adjacent upland forests (according to Aram Calhoun, author of Forested Wetlands in Maintaining biodiversity in forest ecosystems) as they are relatively difficult to access and log and to convert to agriculture. But the IUCN has just recently issued a press release on the state of the world's mangroves, and their future is bleak- even more bleak than peat swamp? These wetland habitats are still refugia for some threatened upland species, and the time to figure this into our valuation of these ecosystems is NOW.

Elephants are ecotonal species where humans aren’t a threat

Elephants are considered to be well-adapted to the ecotone. They have been described as ‘edge species’ with a liking for the ecotone between forest and disturbed area, at least where fresh water is available.  Although their former use of a greater variety of habitats is acknowledged, they are still described by some as favoring ecotones with an "interdigitation of grass, low woody plants, and forest” over continuous forest, where they are thought to live at low densities. 

While this certainly appears to be the case in general, the exception may be where human poaching threat is high and elephants take refuge in forested areas where they appear to feel equally at home in high canopy forest as in a habitat mosaic. The ecology of savanna elephants in Afro-montane forest is little studied in E. Africa, and while some populations move between open and closed habitats, others are resident in closed forest year-round. So how does an ecotonal species successfully exploit undisturbed forest? The old networks of elephant trails, and their intersections, in forests may provide some good clues. 
Until we know more, generalizations should not be made when describing elephants' effects on sympatric species. Likely, the cascade effects that ensue a local extinction of elephants will be more detrimental to biodiversity than the community-level changes that take place after elephants have modified vegetation where they are compressed into small reserves. Linking local populations is key; here are two of the best papers on the subject: van Aarde & Jackson 2007 and Gillson and Lindsay 2003. 
For more on elephants' need for refugia see Graham et al. 2009.

Ecotones as refuges

In a recent Opinion piece in TREE entitled 'Agroforestry: a refuge for tropical biodiversity?', Bhagwat from the Oxford University Centre for the Environment and colleagues combine two ideas that have appeared on this blog: ecotones and refuges. They discuss the value of unprotected areas, specifically agroforestry systems- where trees and shrubs are grown in combination with crops- to the conservation of wildlife in human-dominated landscapes. Farms with trees can provide wildlife habitat outside of formally protected areas as well as connect reserves. As discussed in an earlier post, farms that attract wildlife could be viewed as having potential for agro-tourism and, if converting to agro-forestry would also mean decreasing crop losses, then such a scheme could be advantageous to farmers. What we need to learn is if the costs to farmers of having e.g. howling monkeys in their coffee plantations do not outweigh the benefits accrued from agroforestry, agrotourism and conservation. Ideas on how to evaluate such situations are needed, so post one here if you have one!

Habitat shifts and refuges

Animals world over are being affected by climate change and human disturbance. Many shift habitats and ranges for food, shelter, and reproduction. If they are unable to exploit an alternative habitat or one is unavailable, they may not survive. Habitats not easily accessed by humans and therefore not easily converted to agriculture may be particularly important now and in the future as 'refuges' for wildlife whose historical ranges and preferred habitats are threatened. I think there exist two such habitat types which make particularly good refuges for primates: mangroves and peat swamp forest. The use of mangrove has been called a 'survival adaptation' for the Senegal red colobus by researchers Galat-Luong and Galat (2005) and an upcoming article by Quinten and colleagues (from the Siberut Conservation Programme) reports high primate densities in peat swamp forest. Adapting to these wetland habitats must be challenging for primates: diets may be salty or high in tannins, locomotion can be tricky along mangrove prop roots, and tide levels change. But that even the 'specialist' colobines can exploit mangroves in Africa and peat swamp in SE Asia lends some hope that these relatively more extinction-vulnerable species will persist.

Why flexible 'specialists' can't be indicator species too

The capacity to shift habitat and diet by such supposed 'specialists' as red colobus makes me question the use of red colobus as indicators of forest health in some regions of Africa. Some primatologists claim that these behavioral adjustments of red colobus are temporary and that what we are seeing is a time lag between response and ultimate population crash. However, in some cases, extinction has long been forecasted and species persist. Many of them persist in altered landscapes - human-induced ecotones. The Zanzibar red colobus is one such species - an exceptional example of a species that ticks many of the vulnerability traits predisposing it to extinction (island endemism, fragmented habitat, persecution, specialized morphology) and yet adapts through innovative, flexible and opportunistic behavior.

Ego Fluidity

Maybe there IS something to Mr. Hyde. Could he be our id, as suggested here?

Permit into Nature

Restless

Mesmerized at the view which summons

Which tears at fibres of a soul which yes! is at the essence of me

I jerk at the trumpeter’s boastful call and face the mountain,

is it hazy or are my eyes inoperative from idleness, from deskbound futility

The green evokes a rush of reminiscing tears, and for a moment I am engaged with the only landscape able to make me feel

My insides rebel and scream, but my body stays still like an institutionalized automa

While even the parched blades of red grass are roused

by fluttering bronze manikins

Allow me a moment of misery as I am denied revival

as I grudgingly turn my stiff back on the rapture of arching trees

and deposit my spirit back into fetters out of sunlight’s caress

Wanting nothing more than a passport into, no! a residence permit, in Nature.

Why I must see mankind about this, I will never understand.

Should I be like the bushpig which left its foot in the snare to be free?

Some benefits and drawbacks of fluidity

Behavior is the most flexible component of our phenotype. It can readily change on cue. This change can and often is reversible.

Ways by which human beings can enhance their behavioral flexibility include role-play and improvisation. Both can help an individual to evade becoming and staying ‘habit-bound’. Or so goes Peter Lovatt’s hypothesis.

At one end of the spectrum, therefore, we can expect habit-bound individuals who are unable and/or unwilling to improvise or engage in role-play and may, as a result, become ineffective communicators. On the other end are those whose entire identity, in perpetual flux, relies on improvisation and the taking on of roles (a process which in itself can become habit) – maintaining such a behavioral range can be costly and incompatible with pair-bonding (see Robin Dunbar's new research). Mostly, human beings fall somewhere in the middle and e.g. employ improvisation upon assuming new roles, or, famously, when playing a piece of music.

Does improvisation necessarily require a departure from our so-called ‘behavioral’ or perhaps ‘cultural’ norm? Is role-play precluded by a penchant for pretense, deception, or Machiavellian intelligence? Will pantomiming sharpen our minds?

Are non-human primates capable of improvisation?

Frederick Ferre said that what distinguishes living systems from the non-living is that, ‘they are capable of novelty, improvisation, evolution, growth – in a word, creativity. This is their defining characteristic’ (Ferre, p. 331 in Being and Value: Toward a Constructive Postmodern Metaphysics). I think that the difference between human and other living beings is that the latter are superior in knowing when to employ their latent fluidity while the former have an under- or over-developed (Jekyll/Hyde syndrome) or misplaced fluidity within (or because of) their particular environmental (social, cultural) context.

Some researchers (Jablonka et al., 1995) maintain that in an especially stochastic environment, phenotypic carry-over effects or the persistence of a specific phenotype, despite changes in conditions, is adaptive. This may be synonymous with instances in which even our behavior is not fast enough in keeping up with environmental change and we adhere to an existing plan of action without regard to new, external cues (in extreme cases, 'learned helplessness', although this entails inaction rather than the persistence of previously reinforced courses of action/behavior). In choosing when to be flexible, discriminating between reliable and unreliable cues may be key.

Can hedgehogs and foxes coexist?

In nature

On a landscape scale, they can coexist. Both use suburban habitats (which provide refuge to the western European hedgehog (Erinaceus europaeus) from its predator, the Eurasian badger (Meles meles) (Young et al., 2006; J. of Zoology)). Foxes use urban areas where rich anthropogenic food resources sustain e.g. the red fox (Vulpes vulpes) (even though in sharing the human diet, the fox is exposed to food-borne contaminants and PCBs, see Dip et al. 2003). How far will a hedgehog disperse? Will it cross one or several ecotones as would a fox? If there aren’t badgers, then probably yes.
See this YouTube video.

In zoomorphic metaphor

Fox and hedgehog as co-workers has been tackled by Graham Sewell in his, of sorts, ‘natural history of workplace collusion’ (2008); collusion defined as the accommodation- up to a point- of the opposition upon seeing some merit in their position, be it monism in the case of a hedgehog or, in the case of a fox, pluralism. Sewell befittingly cites Lukes (2002): there can be more than one type of fox or hedgehog, including the fox that wishes he was a hedgehog (and probably vice versa). 

And so: In nature, they can coexist as opportunists in human suburbia – human food saves the fox a hunt and human megalopolitania shelters the hedgehog from the badger – and in metaphor, as collusionary complots in the human rat-race.

Foxy blogging isolatoes

Foxes are, I believe, synonymous with what blogger Steve Hardy calls ‘creative generalists’. They probably inhabit and seek to inhabit ecotones, as defined by blogger David Gessner (http://ecotoneblog.blogspot.com/), ‘places where borders are crossed, where both animals and humans live differently and more dangerously than on their own home turfs’. As the editor of Ecotone, Gessner admirably explores ecotones in human society and culture and describes those within them, often ‘isolatoes’ (citing Melville) who ‘pulse between retreat from and engagement with the world’.

Ecotone conservation

An ecotonal species can be defined as one significantly more frequent in ecotones than in either of the adjacent communities and as having a wide habitat range (based on Lloyd et al., 2000). Baker et al. (2002), studying avian communities in SE Australia, described birds as ecotone neutral, ecotone shy, and ecotone conspicuous. They found no evidence, however, of entirely ‘ecotonal species’. Species need to be more than just conspicuous at the edge, they warned, to be ‘ecotonal’.

The real function of areas that are increasingly ecotonal needs to be carefully evaluated. Ecotones may be a source of evolutionary novelty according to a 1997 article in Science by Smith et al. One example of morphological divergence between forest-ecotone populations includes longer wing length (for aerodynamic efficiency in an open area) in greenbuls in an ecotone. The conservation of ecotones would safeguard their role in generating behavioral diversity, morphological divergence, and ultimately, biodiversity. However, ecotonal regions are often considered unimportant as they are mosaics of 'pure' habitat types (Smith et al., 2005 in Tropical Rainforests: Past, Present and Future). How does a conservationist decide that a landscape is overly homogenous (without ecotones) or overly heterogeneous (with ecotones)? By the presence and abundance of 'fluid ecotypes'?