This ecoregion is the only one of the continental United States or Canada that falls into the Neotropical biome rather than the Nearctic. Only found in south Florida, the ecoregion includes the entire length of the Keys and two small areas on the mainland which are higher elevation limestone outcroppings, distinct from the surrounding lower elevation coastal marshes or grasslands. One area is the strip of land from North Miami southward, just barely crossing into Everglades National Park. A second smaller area is in the Big Cypress National Preserve.
Adjacent ecoregions: the Everglades (NA0904), a grasslands ecoregion, entirely surrounds the South Florida Rocklands on the Florida mainland.
Description of the Ecoregion
A detailed description of the ecoregion can be found at WWF’s site (the map above is a screen shot from that Wildfinder site). There may also be additional information to be found on this ecoregion’s page at Wikipedia.
As noted by WWF, paraphrased here, the ecoregion is located on the Florida mainland on an extrusion of limestone known as the Miami Rock Ridge, and continues through the Florida Keys. Despite the thin soils of these outcroppings, they originally were covered with pinelands and tropical hardwood hammocks. Pine rocklands are fire-maintained forests, dominated by slash pine, Pinus elliottii, with a mixture of tropical and temperate understory plants. The associated hardwood hammocks contain a rare intrusion of tropical hardwoods more typical of the Bahamas and Greater Antilles than the adjacent southeastern conifer forests. WWF therefore places this ecoregion in the Tropical Moist Forest major habitat type, recognizing the extraordinary richness of its tropical hardwood flora.
This is one of North America’s most threatened ecoregions, with at most 2% of the original area remaining intact. South Florida humans have understandably clustered on this ecoregion’s limestone outcrops, rather than settling in lower swampy areas. The urban megalopolis of Miami now covers a good part of the mainland area of the ecoregion. The largest remaining natural tracts of this ecoregion are in Big Cypress Natural Preserve, Long Pine Key, and Big Pine Key.
Birds of the Ecoregion
Although floristically the ecoregion is most closely related to tropical Bahamian forests, the fauna is largely derived from southeastern temperate habitats. Thus the bird fauna in general is similar to that of the Southeastern Conifer Forests (NA0529) and the Everglades (NA0914). There are also a considerable number of bird specialties in this ecoregion because of its tropical nature, extreme southern location, and proximity to the Bahamas and West Indies. The following are the most interesting speciality groups of this ecoregion, a magnet for North American birders.
The Florida Keys (and particularly the outlying Dry Tortugas), because of their extreme southerly reach into the Gulf of Mexico, make this ecoregion the best place in the United States to see a range of nesting marine birds, rare further north. These include Magnificent Frigatebird, Masked Booby, Sooty Tern, and Brown Noddy (in the US, the latter two only nest on the Dry Tortugas). Brown Booby and Black Noddy are also occasionally recorded (neither on list below as very rare).
Terrestrial specialties that are endemic or near-endemic as concerns US distributions include Snail Kite, Short-tailed Hawk, White-crowned Pigeon, Mangrove Cuckoo, Antillean Nighthawk (Keys only), Black-whiskered Vireo, Cave Swallow (disjunct summering population in extreme southern Florida), and Bronzed Cowbird (disjunct resident population in extreme southern Florida).
Miami, part of which is in this ecoregion, is famous for its large number of exotic/introduced species. Those that are recognized by the ABA as having viable and countable populations include Nanday Parakeet, Monk Parakeet, White-winged Parakeet, Red-crowned Parrot, Red-whiskered Bulbul, Common Myna, and Spot-breasted Oriole.
West Indian vagrant species are not included on my list below as they are casual or accidental (Categories 4 or 5) but it is noteworthy that the Keys are the only likely place in the US to see most of these rarities. These include American Flamingo, La Sagra’s Flycatcher, Cuban Peewee, Loggerhead Kingbird, Bahama Swallow, Thick-billed Vireo, Bahama Mockingbird, Bananaquit, Western Spindalis, Yellow-faced Grassquit, and Black-faced Grassquit.
Finally, a few species are notable for having distinctive and identifiable sub-specific forms restricted to southern Florida: Osprey, Red-shouldered Hawk, Yellow Warbler (“Golden Warbler” of mangroves in the Keys), and Seaside Sparrow (“Cape Sable Sparrow”). The distinctive Caribbean form of Short-eared Owl is a rare visitor to the keys.
Resources for the Ecoregion Birder
I am not aware at this time (March 2017) of any resources specifically focussed on birds of the ecoregion.
List of Characteristic Bird Species of the Ecoregion
My list below of the “characteristic species” of the ecoregion (see an explanation on the About page) are those that are of regular occurrence and thus excludes very rare, or accidental species. The species are classed as residents (r), summer breeders (s), migrants (m), wintering (w), or peripheral (x), that is, occurring in the ecoregion but only on its periphery and more characteristic of an adjacent ecoregion. The peripheral species are not included in the ecoregion total.
The ecoregion total is 240 species, of which 94 are resident year round, 14 are summer breeding species, 38 are only to be found during migration, and 94 are wintering species. An additional 16 species are considered to be peripheral. The very low proportion of species that summer only and the high proportion of wintering species are striking for this ecoregion.
- Fulvous Whistling-Duck x
- Snow Goose x
- Brant x
- Wood Duck r
- Gadwall w
- American Wigeon w
- Mallard x
- Mottled Duck r
- Blue-winged Teal w
- Northern Shoveler w
- Northern Pintail w
- Ring-necked Duck w
- Lesser Scaup w
- Hooded Merganser w
- Red-breasted Merganser w
- Ruddy Duck w
- Northern Bobwhite r
- Common Loon w
- Pied-billed Grebe r
- Wood Stork r
- Magnificent Frigatebird r
- Masked Booby r
- Northern Gannet w
- Double-crested Cormorant r
- Anhinga r
- American White Pelican w
- Brown Pelican r
- American Bittern w
- Least Bittern r
- Great Blue Heron r
- Great Egret r
- Snowy Egret r
- Little Blue Heron r
- Tricolored Heron r
- Reddish Egret r
- Cattle Egret r
- Green Heron r
- Black-crowned Night-Heron r
- Yellow-crowned Night-Heron r
- White Ibis r
- Glossy Ibis r
- Roseate Spoonbill r
- Black Vulture r
- Turkey Vulture r
- Osprey r
- Swallow-tailed Kite s
- White-tailed Kite r
- Snail Kite r
- Bald Eagle r
- Northern Harrier w
- Sharp-shinned Hawk w
- Cooper’s Hawk r
- Red-shouldered Hawk r
- Broad-winged Hawk w
- Short-tailed Hawk w
- Swainson’s Hawk x
- Red-tailed Hawk r
- Black Rail x
- Clapper Rail r
- King Rail r
- Virginia Rail w
- Sora w
- Purple Swamphen x
- Purple Gallinule r
- Common Gallinule r
- American Coot r
- Limpkin r
- Sandhill Crane x
- Black-necked Stilt r
- American Avocet w
- Black-bellied Plover w
- American Golden-Plover m
- Wilson’s Plover r
- Semipalmated Plover w
- Piping Plover w
- Killdeer r
- Spotted Sandpiper w
- Solitary Sandpiper w
- Greater Yellowlegs w
- Willet w
- Lesser Yellowlegs w
- Upland Sandpiper m
- Whimbrel w
- Long-billed Curlew x
- Marbled Godwit w
- Ruddy Turnstone w
- Red Knot w
- Stilt Sandpiper w
- Sanderling w
- Dunlin w
- Least Sandpiper w
- White-rumped Sandpiper m
- Pectoral Sandpiper m
- Semipalmated Sandpiper m
- Western Sandpiper w
- Short-billed Dowitcher w
- Long-billed Dowitcher w
- Wilson’s Snipe w
- Wilson’s Phalarope m
- Bonaparte’s Gull w
- Laughing Gull r
- Ring-billed Gull w
- Herring Gull w
- Lesser Black-backed Gull w
- Sooty Tern s
- Least Tern s
- Gull-billed Tern w
- Caspian Tern w
- Black Tern m
- Roseate Tern s
- Common Tern m
- Forster’s Tern w
- Royal Tern r
- Sandwich Tern r
- Black Skimmer r
- Rock Pigeon r
- White-crowned Pigeon r
- Eurasian Collared-Dove r
- Common Ground-Dove r
- White-winged Dove r
- Mourning Dove r
- Yellow-billed Cuckoo s
- Mangrove Cuckoo r
- Barn Owl r
- Eastern Screech-Owl r
- Great Horned Owl r
- Burrowing Owl r
- Barred Owl r
- Common Nighthawk s
- Antillean Nighthawk s
- Chuck-will’s-widow r
- Eastern Whip-poor-will w
- Chimney Swift s
- Ruby-throated Hummingbird w
- Rufous Hummingbird x
- Belted Kingfisher w
- Red-bellied Woodpecker r
- Yellow-bellied Sapsucker w
- Downy Woodpecker w
- Hairy Woodpecker x
- Northern Flicker r
- Pileated Woodpecker r
- Crested Caracara x
- American Kestrel r
- Merlin w
- Peregrine Falcon w
- Monk Parakeet r
- Nanday Parakeet r
- White-winged Parakeet r
- Red-crowned Parrot r
- Eastern Wood-Pewee m
- Acadian Flycatcher m
- Least Flycatcher w
- Eastern Phoebe w
- Great Crested Flycatcher r
- Western Kingbird w
- Eastern Kingbird s
- Gray Kingbird s
- Scissor-tailed Flycatcher w
- Loggerhead Shrike r
- White-eyed Vireo r
- Yellow-throated Vireo m
- Blue-headed Vireo w
- Red-eyed Vireo m
- Black-whiskered Vireo s
- Blue Jay r
- American Crow r
- Fish Crow r
- Purple Martin s
- Tree Swallow w
- Northern Rough-winged Swallow w
- Bank Swallow m
- Cliff Swallow m
- Cave Swallow s
- Barn Swallow m
- Brown-headed Nuthatch r
- House Wren w
- Sedge Wren w
- Marsh Wren w
- Carolina Wren r
- Blue-gray Gnatcatcher r
- Red-whiskered Bulbul r
- Ruby-crowned Kinglet w
- Eastern Bluebird x
- Veery m
- Gray-cheeked Thrush m
- Bicknell’s Thrush x
- Swainson’s Thrush m
- Hermit Thrush x
- Wood Thrush m
- American Robin w
- Gray Catbird w
- Brown Thrasher r
- Northern Mockingbird r
- European Starling r
- Common Myna r
- American Pipit w
- Cedar Waxwing w
- Ovenbird w
- Worm-eating Warbler m
- Louisiana Waterthrush m
- Northern Waterthrush w
- Blue-winged Warbler m
- Black-and-white Warbler w
- Prothonotary Warbler m
- Swainson’s Warbler m
- Tennessee Warbler m
- Orange-crowned Warbler w
- Connecticut Warbler m
- Kentucky Warbler m
- Common Yellowthroat r
- Hooded Warbler m
- American Redstart w
- Cape May Warbler w
- Northern Parula w
- Magnolia Warbler w
- Bay-breasted Warbler m
- Blackburnian Warbler m
- Yellow Warbler s
- Chestnut-sided Warbler m
- Blackpoll Warbler m
- Black-throated Blue Warbler w
- Palm Warbler w
- Pine Warbler r
- Yellow-rumped Warbler w
- Yellow-throated Warbler w
- Prairie Warbler w
- Black-throated Green Warbler w
- Eastern Towhee r
- Chipping Sparrow w
- Savannah Sparrow w
- Grasshopper Sparrow w
- Seaside Sparrow r
- Lincoln’s Sparrow w
- Swamp Sparrow w
- Summer Tanager w
- Scarlet Tanager m
- Northern Cardinal r
- Rose-breasted Grosbeak m
- Blue Grosbeak m
- Indigo Bunting w
- Painted Bunting w
- Dickcissel m
- Bobolink m
- Red-winged Blackbird r
- Eastern Meadowlark r
- Common Grackle r
- Boat-tailed Grackle r
- Shiny Cowbird x
- Bronzed Cowbird r
- Brown-headed Cowbird r
- Orchard Oriole m
- Spot-breasted Oriole r
- Baltimore Oriole w
- American Goldfinch w
- House Sparrow r
Resident breeders (r) 94
Summer breeders (s) 14
Migrants (m) 38
Wintering (w) 94
Peripheral (x) [not in Total] 16
TOTAL 240
DJG: 95 spp. (April 2017)