Beginning with Emlen (1966) and MacArthur and Pianka (1966) and extending through the last ten years, several authors have sought to predict the foraging behavior of animals by means of mathematical models. These models are very similar,in that they all assume that the fitness of a foraging animal is a function of the efficiency of foraging measured in terms of some "currency" (Schoener, 1971) -usually energy- and that natural selection has resulted in animals that forage so as to maximize this fitness. As a result of these similarities, the models have become known as "optimal foraging models"; and the theory that embodies them, "optimal foraging theory." The situations to which optimal foraging theory has been applied, with the exception of a few recent studies, can be divided into the following four categories: (1) choice by an animal of which food types to eat (i.e., optimal diet); (2) choice of which patch type to feed in (i.e., optimal patch choice); (3) optimal allocation of time to different patches; and (4) optimal patterns and speed of movements. In this review we discuss each of these categories separately, dealing with both the theoretical developments and the data that permit tests of the predictions. The review is selective in the sense that we emphasize studies that either develop testable predictions or that attempt to test predictions in a precise quantitative manner. We also discuss what we see to be some of the future developments in the area of optimal foraging theory and how this theory can be related to other areas of biology. Our general conclusion is that the simple models so far formulated are supported are supported reasonably well by available data and that we are optimistic about the value both now and in the future of optimal foraging theory. We argue, however, that these simple models will requre much modification, espicially to deal with situations that either cannot easily be put into one or another of the above four categories or entail currencies more complicated that just energy.

Citation classic - optimal foraging - a selective review of theory and tests

The principles of classification and a classification of mammals. Bulletin of the AMNH ; v. 85

Neotropical Rainforest Mammals. A Field Guide, Louise H. Emmons. University of Chicago Press, Chicago (1990), xiv, Illustrations by François Feer, +281. Price $45·00 hardback, $19·95 paperback

The hard ticks of the world (Acari: Ixodida: Ixodidae)

Bats are abundant and effective seed dispersers inside the forest, but what happens when a forest is fragmented and transformed into pasture? The landscape at Los Tuxtlas, Mexico, originally rainforest, is greatly fragmented and covered with pastures. We analyzed the seed rains produced by frugivorous bats and birds under isolated trees in pastures in the fragmented landscape and the contribution of this process to vegetational recovery. We surveyed bats and obtained fecal samples under isolated trees in pastures. We also collected seed rain below the canopy of 10 isolated Ficus trees, separating nocturnally dispersed seeds from diurnally dispersed seeds. We caught 652 bats of 20 species; 83% of captures were frugivores. The most abundant species were Sturnira lilium (48%), Artibeus jamaicensis (18%), Carollia perspicillata (12%), and Dermanura tolteca (11%). Fecal samples contained seeds of 19 species in several families: Piperaceae (50%), Moraceae (25%), Solanaceae (12%), Cecropiaceae (10%), and others (3%). Sturnira lilium was the most important disperser bat in pastures. Seed rain was dominated by zoochorous species (89%). We found seed diversity between day and night seed captures to be comparable, but we found a significant interaction of disperser type (  bird or bat) with season. Seven plant species accounted for 79% of the seed rain: Piper auritum (23%), Ficus (  hemiepiphytic-strangler tree) spp. (17%), Cecropia obtusifolia (10%), P. amalago (10%), Ficus (  free-standing tree) spp. (8%), P. yzabalanum (6%), and Solanum rudepanum (5%). Bats and birds are important seed dispersers in pastures because they disperse seeds of pioneer and primary species (trees, shrubs, herbs, and epiphytes), connect forest fragments, and maintain plant diversity. Consequently, they might contribute to the recovery of woody vegetation in disturbed areas in tropical humid forests.




Resumen: Los murcielagos son abundantes y efectivos dispersores de semillas en la selva humeda alta. Pero, ?que sucede cuando la selva es fragmentada y convertida en pastizales? El paisaje en Los Tuxtlas, Mexico, cuya vegetacion original era la de bosque lluvioso, esta fuertemente fragmentado y dominado por pastizales. Analizamos la lluvia de semillas producida por murcielagos y aves frugivoras bajo arboles aislados en pastizales del paisaje fragmentado, y la contribucion de este proceso a la recuperacion de la vegetacion. Capturamos murcielagos y obtuvimos muestras fecales bajo arboles aislados en pastizales. Colectamos la lluvia de semillas bajo 10 Ficus aislados, separando las semillas “nocturnas” de las “diurnas.” Capturamos 652 murcielagos de 20 especies, el 83% de ellos fueron frugivoros. Las especies dominantes fueron: Sturnira lilium (48%), Artibeus jamaicensis (18%), Carollia perspicillata (12%), y Dermanura tolteca (11%). Las muestras fecales contenian semillas de 19 especies de varias familias: Piperaceae (50%), Moraceae (25%), Solanacea (12%), Cecropiaceae (10%), y otras (3%). Sturnira lilium resulto ser el murcielago dispersor mas importante del pastizal. En la lluvia de semillas el 89% de las especies fueron zoocoras. No se encontro diferencia en la diversidad de semillas depositadas en la noche o en el dia; sin embargo, hubo una interaccion significativa del tipo de dispersor (ave o murcielago) con la epoca del ano. Siete especies dominaron el 79% del total de la lluvia: Piper auritum (23%), Ficus ( hemiepifito-matapalo; 17%), Cecropia obtusifolia (10%), P. amalago (10%), Ficus (terrestre; 8%), P. yzabalanum (6%) y Solanum rudepanum (5%). Los murcielagos y las aves son importantes dispersores en pastizales ya que dispersan semillas de especies pioneras y primarias (arboles, arbustos, hierbas y epifitas); conectan remanentes de selva y mantienen la diversidad vegetal. Consecuentemente pueden promover la recuperacion de la vegetacion lenosa en areas perturbadas de regiones tropicales humedas.

/pdf/bat-and-bird-generated-seed-rains-at-isolated-trees-in-3dpu1dheh1.pdf

Bat- and Bird-Generated Seed Rains at Isolated Trees in Pastures in a Tropical Rainforest

Lista taxonómica de los mammiferos terrestres de México

We present a molecular phylogeny of North American species of long-tailed shrews of the genus Sorex. Our focus is on Mexican and Guatemalan species to begin understanding their evolutionary relationships and to test the validity of nominal species. Seventy-seven sequences of the mitochondrial cytochrome b gene were analyzed, including 19 specimens representing nine Mexican and one Guatemalan species. Phylogenetic analyses using parsimony, maximum likelihood and Bayesian approaches revealed two major clades of North American species, all within the subgenus Otisorex. The first major clade includes S. trowbridgii and southern species (S. macrodon from Oaxaca; S. veraecrucis from Nuevo Leon, Michoacan, Chiapas, S. saussurei from Jalisco and Guatemala; S. veraepacis from Guerrero and Guatemala). Relatively deep branches among taxa characterize this clade and suggest that their early divergence from other North American shrews was soon after arrival of the ancestral stock from the Beringian region. The other major clade includes all other North American species of Sorex we examined, with two Mexican species, S. milleri and S. emarginatus, grouped in a subclade with the S. cinereus complex. Sorex veraecrucis is not, however, a monophyletic taxon because specimens of this nominal species were included in both the major clades. The Isthmus of Tehuantepec has likely played a role as a biogeographic barrier in the evolutionary history of Mexican shrews. This study of mitochondrial variation in southern North American shrews of the genus Sorex indicates there is substantial, previously undetected diversity that necessitates a revision of the taxonomy of S. veraecrucis and S. veraepacis.

/pdf/molecular-phylogeny-of-long-tailed-shrews-genus-sorex-from-41ge197rhw.pdf

Molecular phylogeny of long-tailed shrews (genus Sorex) from México and Guatemala

We studied the home-range and core-area size and overlap of Tehuantepec jackrabbits (Lepus flavigularis) by radiotracking 32 individuals between May 2001 and April 2003 in savanna habitat in the Isthmus of Tehuantepec, Oaxaca, Mexico. Annual home-range and core-area sizes averaged 55 ha 6 8 SE and 8 6 1 ha for 10 adults of both sexes using the 95% and 50% fixed-kernel isopleths, respectively. Seasonal home ranges varied widely for adults, from 15 to 111 ha for females and from 24 to 166 ha for males. Juvenile males had larger seasonal home ranges than did juvenile females (X ¼ 80 and 24 ha). For adult jackrabbits, seasonal home ranges were larger during the 1st year compared to those of the 2nd year of study (X ¼ 87 and 49 ha), particularly for females. Home ranges and core areas of Tehuantepec jackrabbits were comparable in size and overlapped between active periods (nocturnal and crepuscular hours) and inactive periods (diurnal hours). Adults overlapped their home ranges with 1–10 individuals. Home-range overlap among females was greater than among males. Females shared portions of their ranges with other females more frequently than did males with other males. Home-range and overlap analysis suggests that Tehuantepec jackrabbits have polygamous mating behavior and nonterritorial social organization.

https://www.jstor.org/stable/pdfplus/4094602.pdf

Home range and social behavior of the endangered tehuantepec jackrabbit (lepus flavigularis) in oaxaca, mexico

The phylogenetic position of southern relictual species of Microtus (Muridae: Rodentia) in North America

Home range size, daily travel distances, and diel activity patterns are important characteristics of how an animal uses its home range area. In species, such as the bobcat (Lynx rufus), with large geographical ranges, it is necessary to gather data on diverse populations across the range to better understand what might be factors influencing these home range parameters. Although there are many studies of bobcats in more northern areas of its range in the United States, few data exist from its extensive southern range in Mexico. To fill this gap in information, we collected data on home range size, daily travel distances, and diel activity patterns of bobcats from the center of the Chihuahuan Desert in Mexico. We compared our findings with available data from more northern studies and tested for any latitudinal trends in home range size. We trapped eight adult bobcats (four females and four males) between 2006 and 2008 at the Mapimi Biosphere Reserve in the Chihuahuan Desert. Each bobcat was equip...

https://bioone.org/journals/the-american-midland-naturalist/volume-168/issue-2/0003-0031-168.2.247/Home-Range-Size-and-Activity-Patterns-of-Bobcats-Lynx-rufus/10.1674/0003-0031-168.2.247.pdf

Fernando A. Cervantes

Papers

Lista taxonómica de los mammiferos terrestres de México

Molecular phylogeny of long-tailed shrews (genus Sorex) from México and Guatemala

Home range and social behavior of the endangered tehuantepec jackrabbit (lepus flavigularis) in oaxaca, mexico

The phylogenetic position of southern relictual species of Microtus (Muridae: Rodentia) in North America

Home Range Size and Activity Patterns of Bobcats (Lynx rufus) in the Southern Part of their Range in the Chihuahuan Desert, Mexico