Mexico: Yucatan Peninsula (Jan 2019)

This last-minute 3-night visit with Juan Cruzado Cortes was arranged as a follow-up to a longer trip focusing on the peninsula’s mammals in March 2018. Both of us were less prepared than usual as we were originally intending to spend a week visiting sites in Oaxaca and Chiapas. Despite touch-and-go planning and numerous logistical issues, the trip was quite successful and we managed to find 27 mammal species, including most of the peninsula’s remaining key species and several real rarities.

Note that this report should be used in conjunction with my March 2018 report as a reference to this region. All bat IDs were by detector, using Juan’s personal library of calls from animals he has captured by mistnet as part of his project to catalogue echolocation calls of all relevant bat species of Mexico (not useless auto-ID features included in some detectors).

Cozumel:

3 hours (10AM-1PM) 12/31/18

+ Pygmy Raccoon just about guaranteed near Punta Norte, behind the Isla de Pasion boat launch site (20.5444, -86.8810), any time of day; 3 tame animals seen within 5 minutes of arrival at ~11AM

+ Cozumel Dwarf Coati is more difficult—2 seen on the track to the wasteland at (20.2997, -86.9741) after much searching; no current stakeouts with habituated animals

+ The ponds at (20.3279, -86.9272) are also good for Coatis and the endemic nanus ssp. of Collared Peccary; a friend of Juan’s saw both there the previous day

+ The island is a ghastly tourist trap—highly recommend spending the minimum time possible; I’d recommend taking the passenger ferry from Playa del Carmen (every hour) and leave your car in secure parking on the mainland—rent a car on the island, 4WD recommended for the raccoon site

+ Cozumel has a roadkill problem; we saw roadkills of both raccoon and coati in our short visit…

+ The endemic Reithrodontomys is extremely rare and the Urocyon form is likely extinct

Reserva Toh:

1 hour (4PM-5PM) 12/31/18

+ Central American Agouti and White-nosed Coati in the small clearing at the entrance

+ A small cenote nearby held Jamaican Fruit-eating and Lesser Doglike Bats

+ Gray Fox is also common; reports of brockets at the site are misidentified White-tailed Deer

Reserva de Xocen:

1 night 12/31/18-1/1/19

+ Visited as a last-minute alternative to wilder Reserva el Eden (closed for the holidays), this site has a fantastic mammal list but I didn’t have too much luck this time around

+ A 4-hour night drive + thermal imager only yielded a Common Opossum, 2 Big-eared Climbing Rats, and a Yucatan Deer Mouse; the best record was very rare/local Dwarf Bonneted Bat, identified by bat detector flying high over a small agricultural clearing

+ No captures in 40 traps, despite many presumed pocket mouse burrows nearby; 2 roadkill Gaumer’s Pocket Mice also seen on the Xocen-Chichimila road. We could only set traps at 10PM, so if this species is a priority, try setting them at nightfall when it is likely more active

+ Margay is resident ~3-4km down the road and tall forest past the gate holds Yucatan Brown Brocket and likely Yucatan Vesper Mouse; spotlighting was ruined by rain and a morning drive/walk here only yielded a Central American Agouti

+ See my March 2018 report for more details on bats and rodents (I targeted larger species this trip)

Reserva Biosfera Calakmul:

1 night 1/1/19-1/2/19

+ My favorite mammal watching site on the peninsula, which combines a great mammal list featuring several impressive and/or rare species with spectacular Mayan ruins and huge expanses of intact forest

+ The best place to stay is Campamento Yaax’che inside the park at (20.3279, -86.9272); located on the access road, you can do night drives of the first 20 km 24/7 after buying a permit

+ A 3-hour night drive on the first 20km yielded a fabulous Margay walking off the road as well as Gaumer’s Spiny Pocket Mouse, Common Opossum, and Big-eared Climbing Rat

+ It’s worth noting the first 20 km are ejido land (not park) so the best drive would be to leave the ruins as late as possible and drive the road back through the reserve at dusk/night where large mammals are more likely; I’d only use thermal imager however, not spotlight

+ Bat-detecting at the km11 aguada (ask the camp host) yielded Northern Yellow Bat, and detector-only (but close) Underwood’s Bonneted Bat, Black Mastiff Bat, and Broad-eared Bat plus many common species

+ A 2-hour night walk at Campamento Yaax’che yielded a Mexican Mouse Opossum; the resident troop of Yucatan Black Howlers were easy to hear the next morning

+ A slow early morning drive to km27 yielded a brocket sp. (possibly Central American Red Brocket, as in tall forest) as well as fabulous Ocellated Turkeys and Great Curassow

+ 1.5 hours walking around the aguada at km27 yielded a Yucatan Brown Brocket, White-tailed Deer, many Central American Spider Monkeys and Yucatan Black Howlers in a patch of fruiting trees, and fabulous Morelet’s Crocodiles; many Puma and Baird’s Tapir tracks also seen

+ See my March 2018 report for more details on bats; according to Juan’s friend who researches Chrotopterus auritus at Hormiguero, Yucatan Vesper Mouse and Wrinkle-faced Bat are reportedly quite common in forests surrounding the site

Merida:

1 hour 1/2/19

+ A fresh roadkill Tayra was notable N of Escarcega on the drive from Calakmul

+ There is a roost of Yucatan Yellow Bat and extremely local endemic Alvarez’s Mastiff Bat in the north of the city; contact Juan for details on the location

Progreso:

1 night 1/2/19-1/3/19

+ An interesting area for many endemic species of the arid zone of NW Yucatan, though mammals are a bit thin on the ground and the mosquitos are diabolical; pack insect repellant or prepare to suffer—Juan had over 30 bites, while I got ~50 in just a night and morning…

+ A 3-hour night drive on the road heading South from (21.2835, -89.6375) yielded Northern Raccoon in mangroves, fabulous Big-crested Mastiff Bats hunting over the wasteland at (21.2835, -89.6375), and Eastern Cottontail as well as abundant Davy’s Naked-backed Bat and distinctive Yucatan Yellow Bats in the thornscrub

+ 70 traps in the thornscrub got 5 Yucatan Deer Mice and a White-footed Mouse; we set traps at 10PM so I suspect, again, we were too late for Gaumer’s Spiny Pocket Mouse (reportedly common here)

+ Northern Tamandua, Greater Fishing Bat, and Gray Fox are also regularly seen on night drives; rare sightings include Yucatan Small-eared Shrew, Coyote (only recently discovered in the arid zone), White-tailed Deer, and Southern Yellow Bat (better to check streetlights near town)

+ Tayra and Jaguarundi are regularly seen crossing the road at dawn and dusk

+ There is also a roost of Alvarez’s Mastiff Bat at Santa Clara, 70 km to the East

–Venkat Sankar