Transandinomys talamancae (J. A. Allen, 1891)

Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Cricetidae, Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona: Lynx Edicions, pp. 204-535 : 425-426

410.

Talamancan Rice Rat

Transandinomys talamancae

French: Oryzomys de Talamanca / German: Talamanca-Reisratte / Spanish: Rata arrocera de Talamanca

Other common names: Transandean Oryzomys

Taxonomy. Oryzomys talamancae J. A. Allen, 1891 , Talamanca, Limon, Costa Rica.

Transandinomys talamancae is the type species of the genus. Substantial variation in diploid numbers (2n = 34, 36, 40, 54) and fundamental numbers (FN = 64, 66, 67) suggests a potential species complex, clouded by morphological similarity. Additional taxonomic work needs to be done to calrify this. Monotypic.

Distribution. S Costa Rica through Panama to N & W Colombia, E to N Venezuela, and S to W Ecuador and extreme NW Peru.

Descriptive notes. Head-body 120-151 mm, tail 105-152 mm, ear 18-24 mm, hindfoot 28-32 mm; weight 47-74 g. The Talamancan Rice Rat resembles the Longwhiskered Rice Rat (7. bolivaris ) in general size but with tail longer and smaller hindfeet. Dorsum is orange to reddish brown; venter is whitish gray. Legs are long and narrow. Mystacial and superciliary vibrissae are long (more than 40 mm). Toes are thin, with long hairs extending over all claws, except on thumb. Soles offeet are scarcely covered with indistinct scales. Tail is thin and bicolored, often with tip slightly mottled; its length is equalto orslightly shorter than head-body length, naked in appearance but finely covered with small hairs.

Habitat. Evergreen, semideciduous, and deciduous tropical forests, including moist and dry associations and within primary or secondary growth from sea level to an elevation of 1385 m. The Talamancan Rice Rat adapts well to secondary vegetation and plantations, and it is tolerant of habitat disturbance.

Food and Feeding. Talamancan Rice Rats eat fruits, seeds, herbaceous vegetation, and insects.

Breeding. Breeding occurs year-round, with an apparent peak in October-November; juveniles and subadults were most common in wet season when population levels were highest; testes of adult males did not appear to vary significantly in size throughout the year. Average litter size is 3-9 young, and females produce an average of 6-1 litters/year. Several females were known to produce two litters in rapid succession, suggesting females undergo postpartum estrus. Combining rate oflitter production with averagelitter size, each female can produce an average of 23-7 young/year. Females become sexually mature at less than two months old; males 55-65 days old had large numbers of spermatozoa in epididymis. Maximum measured longevity in the field was c.9 months.

Activity patterns. Talamancan Rice Rats are nocturnal. They are terrestrial but are good climbers at low levels.

Movements, Home range and Social organization. Talamancan Rice Rats are most common in forested lowland, in areas of dense undergrowth, and around fallen logs. They seem to be alloresponsive because marked individuals were captured at a significantly faster rate than unmarked individuals. Densities in Panama peaked at 3-2 ind/ ha (rainy season; October). Juvenile mortality is high. Home ranges averaged 1-3 ha; male home ranges were larger than female home ranges. No seasonal differences in movements were found between sexes.

Status and Conservation. Classified as Least Concern on The IUCN Red List.

Bibliography. Allen (1891c¢), Anderson et al. (2008), Carleton (2015b), Emmons (1997), Fleming (1971), Garcia, Delgado-Jaramillo et al. (2012) , Linares (1998), Musser & Williams (1985), Musser, Carleton et al. (1998), Pérez-Zapata et al. (1986), Weksler et al. (2006).

Figures

353. Bogota Grass Mouse (Neomicroxus bogotensts), 354. Ecuadorean Grass Mouse (Neomucroxus latebricola), 355. Altiplano Chinchilla Mouse (Chinchillula sahamae), 356. Small Red-nosed Tree Mouse (Juliomys pictipes), 357. Delicate Red-nosed Tree Mouse (Juliomys ossitenuis), 358. Montane Red-rumped Tree Mouse (Juliomys rimofrons), 359. Araucaria Forest Tree Mouse (Juliomys ximenezi), 360. Ruschi’s Spiny Mouse (Abrawayaomys ruschii), 361. Chebez’s Spiny Mouse (Abrawayaomys chebezi), 362. Montane Atlantic Forest Rat (Delomys altimontanus), 363. Pallid Atlantic Forest Rat (Delomys sublineatus), 364. Striped Atlantic Forest Rat (Delomys dorsalis), 365. North-western Conyrat (Reithrodon caurinus), 366. Naked-soled Conyrat (Reithrodon typicus), 367. Hairy-soled Conyrat (Reithrodon awritus), 368. Short-tailed Cane Mouse (Zygodontomys brevicauda), 369. Colombian Cane Mouse (Zygodontomys brunneus), 370. Ucayali South American Spiny Mouse (Scolomys ucayalensts), 371. Gray South American Spiny Mouse (Scolomys melanops), 372. Boquete Rice Rat (Nephelomys devius), 373. Santa Marta Rice Rat (Nephelomys maculiventer), 374. Mount Pirre Rice Rat (Nephelomys pirrensis), 375. Western Colombian Rice Rat (Nephelomys pectoralis), 376. Coastal Cordilleran Rice Rat (Nephelomys caracolus), 377. Merida Rice Rat (Nephelomys meridensis), 378. Child’s Rice Rat (Nephelomys childi), 379. White-throated Rice Rat (Nephelomys albigularis), 380. Greater Golden-bellied Rice Rat (Nephelomys aurirventer), 381. Gray-bellied Rice Rat (Nephelomys moerex), 382. Lesser Golden-bellied Rice Rat (Nephelomys nimbosus), 383. Keays’s Rice Rat (Nephelomys keaysi), 384. Nimble-footed Rice Rat (Nephelomys levipes), 385. Hammond's Rice Rat (Mindomys hammondi), 386. White-bellied Arboreal Rice Rat (Oecomys bicolor), 387. Yellow Arboreal Rice Rat (Oecomys flavicans), 388. Savanna Arboreal Rice Rat (Oecomys speciosus), 389. Long-furred Arboreal Rice Rat (Oecomys trinitatis), 390. Robert's Arboreal Rice Rat (Oecomys robert), 391. Unicolored Arboreal Rice Rat (Oecomys concolor), 392. Guianan Arboreal Rice Rat (Oecomys awyantepui), 393. King Arboreal Rice Rat (Oecomys rex), 394. Red Arboreal Rice Rat (Oecomys rutilus), 395. Brazilian Arboreal Rice Rat (Oecomys paricola), 396. Foothill Arboreal Rice Rat (Oecomys superans), 397. Dusky Arboreal Rice Rat (Oecomys phaeotis), 398. Mamore Arboreal Rice Rat (Oecomys mamorae), 399. Anderson’s Arboreal Rice Rat (Oecomys sydandersoni), 400. Franciscos’ Arboreal Rice Rat (Oecomys franciscorum), 401. Atlantic Forest Arboreal Rice Rat (Oecomys catherinae), 402. Cleber’s Arboreal Rice Rat (Oecomys cleber), 403. McConnell’s Rice Rat (Euryoryzomys macconnelli), 404. Emmons’s Rice Rat (Euryoryzomys emmonsae), 405. Big-headed Rice Rat (Euryoryzomys legatus), 406. Russet Rice Rat (Euryoryzomys russatus), 407. Bufty-sided Rice Rat (Euryoryzomys lamia), 408. Elegant Rice Rat (Euryoryzomys nitidus), 409. Long-whiskered Rice Rat (Transandinomys bolivaris), 410. Talamancan Rice Rat (Transandinomys talamancae), 411. Long-nosed Rice Rat “ Handleyomys (™ rostratus), 412. Chapman’s Rice Rat “ Handleyomys (” chapman), 413. Black-eared Rice Rat “ Handleyomys (™ melanotis), 414. Guerrero Rice Rat “ Handleyomys (™ guerrerensis), 415. Cloud Forest Rice Rat “ Handleyomys (” saturatior), 416. Highland Rice Rat “ Handleyomys (” rhabdops), 417. Alfaro’s Rice Rat “ Handleyomys (” alfaroi), 418. Colombian Western Andes Cloud Forest Mouse (Handleyomys fuscatus), 419. Colombian Central Andes Cloud Forest Mouse (Handleyomys intectus)

Distribution. S Costa Rica through Panama to N & W Colombia, E to N Venezuela, and S to W Ecuador and extreme NW Peru.