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Smith P 2009: FAUNA Paraguay Handbook of the Mammals of Paraguay Vol 1: Marsupialia FAUNA PARAGUAY HANDBOOK OF THE MAMMALS OF PARAGUAY VOL 1: MARSUPIALIA 2009 EDITION Smith P 2009: FAUNA Paraguay Handbook of the Mammals of Paraguay Vol 1: Marsupialia FAUNA PARAGUAY HANDBOOK OF THE MAMMALS OF PARAGUAY VOL 1: MARSUPIALIA 2009 EDITION by Paul Smith Interactive version available online via the links on: www.faunaparaguay.com/listmammals.html www.faunaparaguay.com/imagesmammals.html Photographs provided by : Paul Smith, Sylvia Qu, Philip Myers, Alberto Esquivel, Teatske Nieuborg, José Luis Cartes, Flavia Netto and ECOSARA Biodiversity Database. © FAUNA Paraguay 2009 No part of this work may be reproduced in any way, shape or form without prior written permission from the copyright holder. FAUNA Paraguay believes in freedom of information and permission will be granted for works of a non profit making nature provided appropriate accreditation is given. Recommended citation: Smith P 2009 — FAUNA Paraguay Handbook of the Mammals of Paraguay, Volume 1: Marsupialia: Insert Species name p X-XX. Accessed online at www.faunaparaguay.com on Insert Date. 2 Smith P 2009: FAUNA Paraguay Handbook of the Mammals of Paraguay Vol 1: Marsupialia CONTENTS 1a Introduction to the Paraguayan Marsupialia……………….……………………………………....4 1b Taxonomy of the Didelphimorphia……………………….………………………..……………..5 2 Family Didelphidae: Opossums…………………………….………………………………...…….6 3 Key to the Adult Opossums of Paraguay…………………………………………………….……..7 4 Subfamily Caluromyinae……………………………………………………………………………9 5 Brown-eared Woolly Opossum Caluromys lanatus…………………………………………….……10 6 Subfamily Didelphinae……………………………………………………………………………15 7 Genus Chironectes ……………………………………………………………………………...……16 8 Water Opossum Chironectes minimus ………………………………………………………………17 9 Genus Didelphis ……………………………………………………………………………………25 10 White-eared Opossum Didelphis albiventris …………………………………………………...……26 11 Southern Black-eared Opossum Didelphis aurita ……………………………………………..……35 12 Genus Lutreolina …………………………………………………………………………………43 13 Thick-tailed Opossum Lutreolina crassicaudata …………………………………………………..…44 14 Genus Philander ……………………………………………………………………………..……50 15 Southeastern Four-eyed Opossum Philander frenatus ……………………….…………………...…51 16 Genus Metachirus …………………………………………………………………………………60 17 Brown Four-eyed Opossum Metachirus nudicaudatus…………………………………………….... 61 18 Genus Cryptonanus …………………………………………………………………………..……67 19 Chaco Mouse Opossum Cryptonanus chacoensis……………………………………………………68 20 Genus Gracilinanus …………………………………………………………………………….…72 21 Agile Mouse Opossum Gracilinanus agilis …………………………………………………………73 22 Genus Micoureus …………………………………………………………………………….……80 23 Long-furred Woolly Mouse Opossum Micoureus paraguayanus ……………………………….……82 24 Genus Thylamys …………………………………………………………………………….……90 25 Long-tailed Fat-tailed Opossum Thylamys macrurus ………………………………………….……92 26 Chaco Fat-tailed Opossum Thylamys pusillus………………………………………………...……98 27 Genus Monodelphis………………………………………………………………………………104 28 Grey Short-tailed Opossum Monodelphis domestica ………………………………………..……106 29 Pygmy Short-tailed Opossum Monodelphis kunsi…………………………………………………111 30 Red-sided Short-tailed Opossum Monodelphis sorex………………………….……………...……114 31 Acknowledgements………………………………………………………………………..……119 32 Complete Bibliography…………………………………………………………………………120 3 Smith P 2009: FAUNA Paraguay Handbook of the Mammals of Paraguay Vol 1: Marsupialia 1a Introduction to Paraguayan Marsupialia The word marsupial, to the uninitiated, conjours up images of “primitive” mammals with a belly pouch in which they rear their young – their limited distribution across the globe indicative of the inferiority of their reproductive system when compared to the “higher” mammals. But that would do them a great disservice. Firstly not all marsupials even possess pouches, in fact more than half the species living Paraguay do not! Secondly pouch-breeding did not evolve by accident and is in no way inferior to “womb-breeding” when it comes to an effective strategy for self-perpetuation. In fact it has several distinct advantages. By raising the young outside of the womb from an early stage, breeding can be easily aborted if conditions later become too harsh to permit its success and at much lower cost to the parent (in fact the newly-born young can be converted quickly back into much-needed nutrients by the mother!). Secondly it allows for a faster breeding cycle with larger litter sizes than is possible in most other mammals. Thirdly the mother can remain mobile throughout her pregnancy, the young simply hanging on to her as she goes about her business. Marsupials are not inferior; they have just managed to find a different answer to the same question of how to propagate themselves effectively. South America was once home to a great diversity of marsupials on a par with those of modern-day Australia – with the “sabre-toothed tiger-alike” Thylacosmilus occupying first place in the food web hierarchy, right down to the tiny shrew-like Palaeothentes somewhere down near the bottom, marsupials evolved to fill every available niche. Today only three surviving Neotropical orders remain – the Didelphimorphia, the Paucituberculata and the Microbiotheria - with all Paraguayan species belonging to the former and the sole family Didelphidae, commonly known as “opossums” (which should not be confused with the unrelated Australian “possums”). A total of 15 species of opossum occur in Paraguay, from the large and adaptable White-eared Opossum Didelphis albiventris which has no problem living alongside man, right down to the tiny Dwarf Short-tailed Opossum Monodelphis kunsi the smallest member of the family and so tiny that its presence in Paraguay has been overlooked until very recently! Though principally forest dwellers, opossums have evolved to fill every niche imaginable, both humid and dry, and are present in all the major ecosystems in modern day Paraguay. The Brown Four-eyed Opossum Metachirus nudicaudatus is largely terrestrial; the ponderous Brown-eared Woolly Opossum Caluromys lanatus scarcely ever descends to the ground; whilst a host of other species fill every space in between, with tiny mouse-like arboreal species making use of vines and bamboo tangles ( Gracilinanus, Micoureus etc); the nimble Southeastern Four-eyed Opossum Philander frenatus as at home on the ground as he is in the trees. The aim of this volume is to summarise the current knowledge of the biology and ecology of the Paraguayan species of Marsupialia and present it in an accessible and readable form that I hope will be of interest to amateurs and of utility to professionals who work with this fascinating and ancient group of mammals. 4 Smith P 2009: FAUNA Paraguay Handbook of the Mammals of Paraguay Vol 1: Marsupialia 1b Taxonomy of the Didelphimorphia, Gill 1872 The higher level taxonomy of the Didelphimorphia has undergone considerable changes over recent years with wider use of new molecular and genetic techniques for determining relationships radically re-shaping our traditional understanding of the group and the species limits. That said much work still needs to be done, especially to clarify the species limits in the genera Gracilinanus, Cryptonanus, Marmosa, Marmosops, Monodelphis and Thylamys amongst others. The taxonomy used in this volume follows Gardner (2007). As currently recognised the Didelphimorphia forms an Order within the Cohort Marsupialia, a more wide-ranging group containing two other extant Neotropical orders and a host of more distantly related orders in Australasia. The latest review of the group splits the family Didelphidae into two subfamilies, the Caluromyinae (for the Woolly Opossums) and the Didelphinae (for the True Opossums). The Didelphinae are further separated into three tribes, the Didelphini (the Pouched Opossums), the Metachirini (the Brown Four-eyed Opossum) and the Monodelphini (the Pouchless Opossums). The Didelphimorphia in their current form are entirely New World in distribution, with the great majority of species in the Neotropical region. (Gardner 2007). The previous review of the group by Hershkovitz (1992) was controversial in splitting the Didelphidae into four separate families based largely on morphological grounds. The arrangement failed to gain widespread following and with the advent of DNA analysis was rapidly abandoned. See below for a comparison of the most recent classifications: Hershkovitz (1992) Gardner (2007) INFRACLASS MARSUPIALIA COHORT MARSUPIALIA ORDER DIDELPHIDIA ORDER DIDELPHIMORPHIA Family Caluromyidae Subfamily Caluromyinae – Caluromys Family Didelphidae Subfamily Caluromysopsinae – Caluromysiops Subfamily Caluromyinae - Caluromys, Caluromysiops, Family Marmosidae Glironia Subfamily Marmosinae – Micoureus, Marmosa, Subfamily Didelphinae Marmosops, Gracilinanus Tribe Didelphini - Chironectes, Didelphis, Lutreolina, Subfamily Thylaminae – Thylamys Philander Subfamily Lestodelphynae - Lestodelphys Tribe Metachirini - Metachirus Subfamily Monodelphinae - Monodelphis Tribe Monodelphini - Chacodelphys , Cryptonanus, Subfamily Metachirinae – Metachirus Gracilinanus, Hyladelphys, Lestadelphys, Marmosa, Family Glironidae – Glironia Marmosops, Micoureus, Monodelphis, Thylamys Family Didelphidae – Didelphis, Chironectes, Philander, Lutreolina 5 Smith P 2009: FAUNA Paraguay Handbook of the Mammals of Paraguay Vol 1: Marsupialia 2 Family Didelphidae: Opossums General characteristics: Fifteen species, the only Paraguayan representatives of the order Marsupialia. Most species are nocturnal