Zoology Commons^™

Chickens’ Brains, Like Ours, Are Lateralized, Lesley J. Rogers

Animal Sentience

This commentary draws attention to yet another attribute that has been instrumental in demonstrating the cognitive abilities of domestic chicks: lateralization of brain function. The discovery of lateralization in domestic chicks was part of the first evidence showing that humans are not unique in this respect. The effects on cognitive ability of sensory stimulation in critical stages of development have implications for the welfare of chicks, as well as other species.

Are Chicken Minds Special?, Rafael Freire, Susan J. Hazel

Animal Sentience

The number of publications on chicken cognition and emotion exceeds that on most birds and is comparable to the number of publications on some more “advanced” mammals. We argue that the chicken is an excellent model for this type of research because of (1) the presence of well-established fundamental mental processes in the chicken, (2) a challenging ethological environment and (3) social pressures that may have facilitated the evolution of cognitive abilities similar to those of some mammals. Marino’s (2017) review provides an excellent foundation for the continued study of complex mental abilities in this species.

In Memory Of Patrick Bateson, James A. Serpell

Animal Sentience

No abstract provided.

Chickening Out Of Change: Will Knowing More About Thinking Chickens Change Public Perceptions?, Ewan Bottomley, Steve Loughnan

Animal Sentience

This commentary examines the next step in Marino’s target article – changing people’s attitudes and beliefs about chickens. The scientific case seems clear: chickens are far more complex, psychologically and socially, than originally thought. Marino suggests we use this information to make people feel uncomfortable about their dietary choices in the hope of changing them. We review the psychological literature, examining how people maintain meat consumption despite the clash with their moral beliefs (the “meat paradox”). This work highlights the important gap between what science knows about animals and what people think about animals.

Evolutionary Continuity, Anne Benvenuti

Animal Sentience

The principle of evolutionary continuity states that all animal capacities and behaviors exist — with variations in degree — in continuity with other species. Rather than assuming discontinuity, we should ask why any behavior observed in humans would not be found in at least some other sentient animals under similar conditions. In the case of suicide, the more pertinent issue might be the ethical one: our human responsibility for creating conditions under which other animals might deliberately seek to end their own lives.

Non-Human Animal Suicide Could Be Tested, David Lester

Animal Sentience

Schaefer (1967) showed that mice can discriminate live from dead mice and lethal from nonlethal environments, and that they avoid a lethal environment; but the experiment lacked some controls. This might be a way to test whether mice would ever choose a lethal environment. Humans may also choose a potentially lethal environment unconsciously.

Animals Do Not Commit Suicide But Do Display Behaviors That Are Precursors Of Suicide In Humans, David Eilam

Animal Sentience

Although my commentary begins with a report about a monkey committing suicide, I agree with the target article's concluding statement that we cannot currently prove that any animal has committed suicide. The author’s proposed continuist approach is based on animal behaviors reminiscent of symptoms preceding suicide in humans (e.g., deep depression and grief). However, in both humans and nonhuman animals, these are just potential precursors of suicide, and dying as a result of grief is not necessarily suicide. In the absence of supporting evidence, the continuist hypothesis of animal suicide is not sustained.

Understanding Animal Suicide And Death Can Lead To Better End-Of-Life Care, Jessica Pierce

Animal Sentience

Peña-Guzmán’s target article on animal suicide will help inform end-of-life care for animals by emphasizing the need for a broad research focus on animal thanatology. Greater scientific understanding of the continuum of death-related awareness, experiences, and behaviors will help us improve veterinary care for animals at the end of life.

Complicated Grief, Teya Brooks Pribac

Animal Sentience

My commentary discusses complicated grief and the ensuing sense of helplessness that may lead to suicide. I close with a story about a pygmy pig.

Can Nonhuman Animals Commit Suicide?, David M. Peña-Guzmán

Animal Sentience

Many people believe that only humans have the cognitive and behavioral capacities needed for suicidal behavior, such as reflexive subjectivity, free will, intentionality, or awareness of death. Three counterarguments — based on (i) negative emotions and psychopathologies among nonhuman animals, (ii) the nature of self-destructive behavior, and (iii) the problem of model fidelity in suicide research — suggest that self-destructive and self-injurious behaviors among human and nonhuman animals vary along a continuum.

Tribute To Jaak Panksepp, Jonathan Balcombe

Animal Sentience

No abstract provided.

Histology Of Rathke’S Glands In The Razor-Backed Musk Turtle, Sternotherus Carinatus (Chelonia: Kinosternidae), With Comments On Lamellar Bodies, S. E. Trauth

Journal of the Arkansas Academy of Science

I examined the histology and ultrastructure of Rathke’s glands in two adult male razor-backed musk turtles (Sternotherus carinatus) collected in northeastern Arkansas. This species possesses two pairs of Rathke’s glands that are embedded beneath marginal bones and are named according to their anatomical location (i.e., axillary and inguinal). These integumentary glands are similar anatomically to one another. Each gland is comprised of a single, highly vascularized secretory lobule, which is surrounded by a thin tunic of asymmetrically arranged, striated muscle. Two types of large secretory vacuoles characterize most of the holocrine cells produced by a relatively thin secretory …

Getting To The Other Side, Debra Merskin

Animal Sentience

Marino’s comprehensive, detailed, and timely review provides clear evidence of the sentience of chickens and strong support for those wishing to challenge their exclusion from even the limited protections currently accorded to animals grown for food.

Sentience Does Not Require “Higher” Cognition, Giorgio Vallortigara

Animal Sentience

I agree with Marino (2017a,b) that the cognitive capacities of chickens are likely to be the same as those of many others vertebrates. Also, data collected in the young of this precocial species provide rich information about how much cognition can be pre-wired and predisposed in the brain. However, evidence of advanced cognition — in chickens or any other organism — says little about sentience (i.e., feeling). We do not deny sentience in human beings who, because of cognitive deficits, would be incapable of exhibiting some of the cognitive feats of chickens. Moreover, complex problem solving, such as transitive inference, …

Misperceiving And Underestimating The Ubiquitous Chicken, Carrie P. Freeman

Animal Sentience

Marino has provided an accurate and nuanced view about chickens’ complex capabilities as sentient individuals. I explore the implications of these findings for scholars as well as for activists in the protection of farmed animals.

Is Psychological Science Committing “Suicide” By Linguistic Muddling?, Roger K. Thomas

Animal Sentience

Beginning mainly with the “cognitive revolution” in psychology in the latter half of the 20^th century, psychological science has been committing “suicide” slowly via linguistic muddling. Peña-Guzmán’s target article is but one of thousands of cuts contributing to this death by “suicide.” Having said that, given the current state of affairs in animal cognition research, there is much to commend in Peña-Guzmán’s article. I leave that to others, however. This commentary explains how the suicide by muddling of psychological science is happening in general, with the understanding that it applies also to Peña-Guzmán’s target article.

On Assisted Suicide, Clark Glymour

Animal Sentience

What would be the moral implications of the capacity for suicide in nonhuman animals? Humans can be helped to end their lives if they no longer find them bearable. Should captive animals not be given the same possibility?

Geographic Distribution: Acrantophis Dumerili (Duméril’S Madagascan Ground Boa). Usa. Florida., Louis A. Somma, Kenneth L. Krysko, Laurence L. Conner

Papers in Herpetology

The geographic distribution of Acrantophis dumerili, a nonindigenous introduced species in Florida, with new records, is presented.

Acrantophis dumerili is indigenous to southern and southwestern Madagascar. We provide the first vouchers for Miami-Dade and Bay counties, which were likely escaped or released pets. Florida already has three established species of booid snakes (one boa, two pythons), all introduced through the pet trade pathway. Although there is no clear evidence for an established population of A. dumerili in Florida at this time, the Bay County individuals in a rural area in the Florida panhandle are a particular concern given that two …

The Status Of Two Species Of Nonindigenous Lizards In Florida, The Slender Chameleon, Chamaeleo Gracilis Hallowell 1842 And White-Lined Chameleon, Furcifer Lateralis (Gray 1831): A Corrigendum., Kenneth L. Krysko, Louis A. Somma

Papers in Herpetology

Krysko et al. (2016) recently published a summary of all known verified introductions of nonindigenous amphib­ians and reptiles in Florida, USA. Herein, we correct the iden­tity tity of one species and include an additional new record of a nonindigenous chameleon in Florida.

Krysko et al. (2016) reported the presence of a White-lined Chameleon, Furcifer lateralis (Gray 1831). In fact, this was a misidentified Slender Chameleon, Chamaeleo gracilis Hallowell 1842 (C. Anderson, pers. comm. 2016). Discussion and reference to F. lateralis in Krysko et al. (2016) and all associated data (UF voucher number, locality, collector, and collection date, including Table 1, …

Self, Death, And Suicide: Does An Animal Know Of These?, Carolyn A. Ristau

Animal Sentience

Peña-Guzmán makes a strong case, using examples from the media and scientific literature, that many captive animals suffer severely. In examining the possibility of animal suicide, he dismisses the need for “reflective self-subjectivity” and “intent” in suicidal behavior. He claims that at least some animals understand “death,” citing examples of behavior he deems to be death “rituals.” But these can be more simply interpreted. The possibility of animal suicide remains more dubious than Peña-Guzmán suggests.