Biological Corridors Connecting Panama's Parks: CBM and CMAR

Why corridors exist at all

The case for corridors rests on a single ecological problem. When a forest is fragmented (split into isolated blocks separated by cleared land), the populations inside each block become cut off from one another, and isolated populations are vulnerable: they cannot recolonise after a local crash, they lose genetic diversity, and they cannot shift their range in response to climate change. A protected park, no matter how well-managed, becomes one of those isolated blocks if the land around it is converted. The corridor idea is to keep, or rebuild, the strips of habitat that connect the blocks, so that wildlife can move between them.

Panama is an unusually important place for this concept, for the simple reason that it is a narrow bridge. It is the land connection between North and South America, and its waters sit between the eastern Pacific and the Caribbean. Anything that moves on a continental scale, a jaguar, a migratory bird, a sea turtle, a whale, is liable to pass through Panama, which makes the country a bottleneck where connectivity either works or fails for an entire hemisphere. That is why two of the hemisphere’s major corridor initiatives converge here.

The terrestrial corridor: the Mesoamerican Biological Corridor (CBM)

The Corredor Biológico Mesoamericano (CBM) is the terrestrial initiative. In its classic, internationally documented form it is a vast planning framework spanning the Central American isthmus. The FAO’s description, the standard reference for the corridor’s foundational scope, puts the CBM at approximately 533,000 km², containing three biomes, 22 ecoregions, and more than 300 landscape types, with some 6,600 km of mangrove- and reef-lined coastline^[2].

The critical detail for Panama is where the corridor ends. MarViva’s marine-corridors work describes the CBM as running “from south-eastern Mexico to the central Caribbean region of Panama”, which places Panama’s Caribbean side at the south-eastern terminus of the whole Mesoamerican chain^[1]. That terminus position is not cosmetic. It means the forests of central Caribbean Panama (the Chagres highlands, the Guna Yala and Darién Caribbean slopes) are the last link in a chain that starts in Mexico; if that link is broken, the corridor stops at the Colombian border rather than connecting through.

One honesty caveat that matters here: the FAO description of the CBM dates to 1998^[2]. The 533,000 km² figure is a foundational-scope number, not a current measurement of how much functional habitat the corridor actually retains today, nearly three decades later. The CBM concept has evolved substantially since the late 1990s (through changing national policies, ongoing deforestation, and the rise of indigenous-territory and private-reserve contributions to connectivity), so the 1998 reference is best read as the original framework, supplemented by more current Panama-specific material like the MarViva work for the marine side. Treat the headline area as historical context, not as a live status report.

The marine corridor: the Eastern Tropical Pacific Marine Corridor (CMAR)

If the CBM is the terrestrial chain, the Corredor Marino de América Central (the Eastern Tropical Pacific Marine Corridor, or CMAR) is the marine one, and it is the corridor where Panama’s role is most concrete. MarViva describes the CMAR as linking Coiba’s Special Zone of Marine Protection to a series of oceanic islands across the eastern tropical Pacific: Costa Rica’s Isla del Coco, Colombia’s Isla Malpelo and Gorgona, and Ecuador’s Galápagos^[1].

The logic is the same as on land, but the medium is open ocean. Pelagic species (sharks, sea turtles, whales, large fish) move across enormous distances, and no single marine protected area, however large, can cover the full route. The CMAR responds by stringing protected nodes, each a national marine park or reserve around one of these remote islands, into a connected pathway that follows the species’ actual movements. Coiba, as Panama’s largest and most internationally recognised marine site, is one of those nodes; the marine-protected-areas page covers the size of Panama’s protected waters, and the coiba-island geography page covers the island itself.

This is where the Banco Volcán expansion of 2023 (also on the marine-protected-areas page) and the CMAR connect. Expanding Panama’s protected waters was, among other things, an act of strengthening the Panamanian node of a transnational corridor, making the country’s piece of the chain more resilient so that the marine pathway as a whole functions better.

How corridors actually play out in Panama

Strip away the international planning language and the corridor concept shows up in Panama as a few practical realities:

• Terrestrial connectivity runs along the Caribbean watershed. The chain of protected areas on Panama’s Caribbean side (the Chagres and Soberanía highlands, running toward the Darién) is the physical expression of the CBM’s south-eastern terminus. Keeping forest continuous along this spine is what “maintaining the corridor” means on the ground.
• Marine connectivity runs through Coiba and the Gulf of Chiriquí. Coiba and its surrounding protected zone are the Panamanian anchor of the CMAR; the strength of protection there determines how well the marine corridor serves the migratory species that use it.
• Wetlands and private reserves are the stitching. The Ramsar wetlands (see wetlands-and-ramsar) and the private reserves (see private-reserves) often sit in the gaps between the big state parks, exactly the places where connectivity is most fragile and most important.

The recurring theme on the terrestrial side is deforestation. The deforestation page covers the long arc of forest loss on the Pacific slope; from a corridor perspective, that loss is significant precisely because it severs connections. A corridor that exists on a map but whose intervening forest has been cleared is not a functioning corridor. It is a diagram of what used to be connected.

The gap between map and function

The most important thing to understand about biological corridors, in Panama or anywhere, is that designating one is not the same as having one. A corridor is a hypothesis about connectivity: planners draw a chain of habitats and assert that wildlife will move along it. Whether the wildlife actually does so depends on whether the habitat in between is intact, whether the protected nodes are enforced, and whether the species’ behaviour matches the assumed route. The CBM’s 1998 founding scope and the CMAR’s island-chain design are both planning frameworks whose ecological effectiveness has to be measured on the ground (and in the water), not assumed from the planning documents.

That is why the most useful question to ask about any corridor is not “how big is it?” but “how connected is it in practice?” For Panama’s terrestrial corridor, that means asking how much Caribbean-slope forest remains between the protected cores. For the marine corridor, it means asking whether the protection at Coiba and Banco Volcán is enforced well enough for the migratory species to benefit. The corridor concept is only as good as the answers to those questions.

Using the corridor frame

For most readers, the corridor concept is a lens rather than a destination. You do not “visit” a biological corridor the way you visit a park. What the frame gives you is a way to understand why Panama’s individual protected areas matter beyond their own boundaries. Campana, Coiba, the Chagres highlands, the Ramsar wetlands, and the private reserves each look different when you see them as nodes in connected chains rather than as standalone sites. For anyone planning research, advocacy, or conservation investment in Panama, the corridor perspective is the one that matches how the wildlife itself actually uses the landscape: not in isolated blocks, but along connected routes that cross park boundaries, provincial lines, and national borders.

Why fragmentation severs a corridor

The mechanism by which a corridor fails is worth understanding, because it explains why a corridor that looks intact on a regional map can be functionally broken. A corridor works only if the habitat connecting two protected core areas is itself usable to the species that need to move through it. “Usable” means different things for different species: a forest-interior bird may need continuous closed canopy; a medium-sized mammal may cross narrow clearings but not wide ones; a large cat may need substantial cover and will not cross open country at all. When the connecting habitat is degraded (thinned, fragmented into pieces separated by cleared gaps, or narrowed to a strip too thin to use), the species that need it stop moving through, and the corridor ceases to function even if a green line still appears to connect the two cores on a satellite image.

That is the distinction between a notional corridor and a functional one, and it is the central challenge of corridor conservation. Declaring a corridor, drawing the connecting line on a planning map, is the easy part; keeping the intervening habitat usable enough for the target species to actually move through it is the hard part, because that habitat is often on private land, under development pressure, or already partially cleared. The FAO’s 1998 framing of the Mesoamerican corridor as a ~533,000 km² planning framework described the ambition; the actual ecological condition of that framework, nearly three decades of deforestation later, is a separate and harder question that has to be measured on the ground rather than assumed from the planning document.

Two corridors, two kinds of connectivity

It helps to keep the terrestrial and marine corridors distinct, because they work by different connectivity logics and fail in different ways. The terrestrial CBM is about land habitat, continuous forest that lets ground-dwelling and forest-interior species move between protected areas. Its failure mode is the classic one: forest cleared for agriculture or ranching, leaving gaps that forest-dependent species will not cross. The marine CMAR is about open water, a chain of protected nodes around oceanic islands that pelagic species move between across hundreds of kilometres of open ocean. Its failure mode is different: the “habitat” between the nodes is open sea that the species can physically traverse, so the question is not whether they can move but whether they survive the passage, which depends on fishing pressure and bycatch in the waters between the protected nodes.

Panama sits at the junction of both, which is why the country’s corridor story is unusually rich. On land, the Caribbean-slope forests are the south-eastern terminus of the Mesoamerican chain, where continental-scale terrestrial connectivity either holds or breaks. At sea, Coiba is a key node of the Eastern Tropical Pacific chain, connecting to Costa Rica, Colombia, and Ecuador across open ocean. The two corridors share the same underlying principle, connected protected areas serve wildlife better than isolated ones, but they require different conservation responses: forest protection and reforestation for the terrestrial corridor, large offshore marine protected areas and fishing regulation for the marine one. Panama is one of the few countries where both responses are being pursued at scale simultaneously, which is part of why its corridor profile, despite the deforestation pressures on the Pacific slope, is regionally significant.

Quick reference

Last reviewed: 2026-07-03