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The study on eastern woodrats, Neotoma floridana, shows no sign of sex-biased maternal investment in response to nutritional stress for this species despite a strong effect on growth rates of offspring from nutritionally controlled litters compared with those from control groups. Stressed dams can rear a single young with slight or no decrease in growth rates of the young compared with those of unstressed dams by mobilizing body reserves but growth rates are reduced from larger litters.

Guidelines for use of wild mammal species in research are updated from Sikes et al. (2011). These guidelines cover current professional techniques and regulations involving the use of mammals in research and teaching; they also incorporate new resources, procedural summaries, and reporting requirements. Included are details on capturing, marking, housing, and humanely killing wild mammals. It is recommended that Institutional Animal Care and Use Committees (IACUCs), regulatory agencies, and investigators use these guidelines as a resource for protocols involving wild mammals, whether studied in the field or in captivity. These guidelines were prepared and approved by the American Society of Mammalogists (ASM), in consultation with professional veterinarians experienced in wildlife research and IACUCs, whose collective expertise provides a broad and comprehensive understanding of the biology of nondomesticated mammals. [ABSTRACT FROM AUTHOR]

The article discusses the body size and growth of the eastern collared lizard (Crotaphytus collaris) in central Arkansas. Topics discussed include Crotaphytus being a saxicolous species, habitat fragmentation and continued population of Crotaphytus, and lack of data on body size of C. collaris in Arkansas.

The Guide for the Care and Use of Laboratory Animals (NRC 2011) serves as the principal reference for the oversight of most vertebrate use in research and teaching in the United States. The Guide was developed as a reference for biomedical research. Beyond guiding ethical principles, the Guide contains little information useful for the oversight of research involving wild taxa. To fill this breach, and at the behest of the National Science Foundation, taxon-specific societies in the United States developed independent guidelines that held to the principles of ethical use of animals in research and that were specific to wildlife. Recognition of these taxon-specific guidelines by federal grantmaking agencies and the animal welfare community as appropriate standards for wildlife research will facilitate the required oversight of research involving wild taxa and the ethical use of wild animals in research and teaching. [ABSTRACT FROM AUTHOR]

Ecological restrictions of the subterranean environment have resulted in sensory adaptations in its inhabitants that limit communication below ground. Adaptations such as degenerate vision and reduced hearing capabilities influence the communicative methods employed by subterranean rodents. Due to the logistic difficulties of investigating life underground, little is known about subterranean rodent communication. Vocal repertoires have been examined in a limited number of subterranean species, but never in north American taxa. We examined vocal communication in Baird's Pocket Gopher Geomys breviceps, a species indigenous to south central north America. our results show that this species has a repertoire of 4 audible signals, 2 of which are only emitted during close-contact encounters. energy of signals was concentrated within the frequency range correlating with pocket gophers' greatest hearing sensitivity. Results are also consistent with the frequency requirements for efficient transmission in the subterranean environment. Corresponding behavioural contexts suggest that vocal communication is important for facilitating social interaction with G. breviceps. Because the Geomyidae extend the furthest into the fossil record and are exclusively solitary species, this group is of fundamental importance for considering evolution of communication in subterranean rodents. [ABSTRACT FROM AUTHOR]

Recent advances in understanding mammalian reproductive patterns mirror general developments in phylogenetic, physiological, and ecological research. We provide an overview of the diverse approaches used instudying mammalian litter size and discuss recent advances in evolutionary ecological theory and experimental data concerning reproductive patterns. Extensively documented natural history studies and breeding data from work in applied zoology and animal husbandry constitute a rich source of information for comparative studies. Such studies have helped identify fundamental differences in reproductive 'strategies' depending on whether taxa produce altricial or precocial young andwhether a given reproductive effort results in a single offspring ora litter. On the other hand, research on ecological and physiological correlates of litter size is providing new insights about reproductive energetics, the relationship between resource availability and litter size, and optimality in varying environments in general. Continuing experimental approaches are broadening our understanding of the mechanistic bases of patterns of mammalian litter size, but such studies, especially those involving manipulation of litter size, must carefully consider the potential biases introduced by experimentally induced non-congruence between pre- and postnatal litter sizes. For example, without accounting for the effects of placental hormones on mammogenesis and lactation, postnatal manipulations of litter size might be based on faulty assumptions implicit in such manipulations. To conclude, despite substantial advances in these diverse approaches, our degree of understanding of optimal litter size in mammals remains unclear because of inconsistencies in data often used in comparative studies and because of physiological and ecological constraints on littersize adjustments that hinder or bias experimental approaches. These areas should be addressed in future studies. [ABSTRACT FROM AUTHOR]