When the average person hears the word ornament they think of Christams. The lights, smell of pine trees, with big red and silver globes hung from the branches, but ornaments aren’t just for the holidays. Organisms can possess ornate physical traits that are used for sexual selection. The males organisms of various species don’t have the advantage of having a mistletoe to kiss under, so they use ornamental traits and features to attract mates.

Ornamental features were defined by Darwin as dramatized traits used for the competitive behavior among mate acquisition. These traits often cause a cost to the physical resources of the organism and have no survival benefit. Females are thought of as passive, choosy, and coy while males get the reputation of being competitive and sexually indiscriminate. This theory of the contrast in sexual behaviors, although over simplified, gives a good representation of why male organisms possess these traits to attract females. However, females posses these ornamental traits as well for a whole different reason.

Unlike their male counterparts, females who display ornamental traits will utilize these traits for competing with other females when in comes to ecological resources instead of mate competition. These resources include those for reproductive fitness and materials needed to rear their young. The use of ornamental traits also has an impact on the social structure between females. In this aspect it is hard to differentiate which traits in females or males are due to social selection rather than more widely known and accepted sexual selection.

When the average person hears the word ornament they think of Christams. The lights, smell of pine trees, with big red and silver globes hung from the branches, but ornaments aren’t just for the holidays. Organisms can possess ornate physical traits that are used for sexual selection. The males organisms of various species don’t have the advantage of having a mistletoe to kiss under, so they use ornamental traits and features to attract mates.

Ornamental features were defined by Darwin as dramatized traits used for the competitive behavior among mate acquisition. These traits often cause a cost to the physical resources of the organism and have no survival benefit. Females are thought of as passive, choosy, and coy while males get the reputation of being competitive and sexually indiscriminate. This theory of the contrast in sexual behaviors, although over simplified, gives a good representation of why male organisms possess these traits to attract females. However, females posses these ornamental traits as well for a whole different reason.

Unlike their male counterparts, females who display ornamental traits will utilize these traits for competing with other females when in comes to ecological resources instead of mate competition. These resources include those for reproductive fitness and materials needed to rear their young. The use of ornamental traits also has an impact on the social structure between females. In this aspect it is hard to differentiate which traits in females or males are due to social selection rather than more widely known and accepted sexual selection.

There are five signal modalities that organisms use for communication including; visual, chemical, electrosensory, mechinosensory, and auditory. Using these signal modalities animals interact both intra- and inter-specifically to send prompts to other organisms that alter that individuals behavioral patterns. Animal vocalization is a signaling mechanism that every human has experiences. Think about being at the zoo and hearing chimpanzees with their high pitched wails or a lions roar. The physcial processes involved with vocalization is well known, but recently biologists have started to study what other conditions may efffect this form of communication. Scientists beleive that auditory or vocal communication may be driven by emotional and physiological states.

In a case study, conducted by Francesco Mazzini of the Department of Evolutionary and Functional Biology in Parma, Italy, researchers investigated the impact of social and physiological factors of wolf vocal communication. The functions of vocalization have been widely studied, but the mechanims had not been closely examined until this 2013 study on wolves. Mazzini and his colleagues beleived vocalization would be piloted by changes in the social-ecological environment and the animal’s understanding of its social world.

Results showed that animals may be capable of communicating with the same species in a flexible manner when using vocalization. Instead of the howls of individuals being produced due to stress hormones the study demonstrated that the signaler controled the flexibility of its vocalization for gathering other individuals in the pac. The production of vocalization is not necessarily a simple emotional response to environmental changes, but can also be used in a benefital way socially.

 

 

 

The human induced modification of shrub-steppe grasslands to farmland for forming crops in Washington has resulted in a negative inhabitance response from two native grouse species; Greater sage-grouse (Centrocercus urophasianus) and Columbian sharpe-tailed grouse (Tympanuchus phasianellus columbianus). The decline in grouse inhabitance is not only isolated to Washington, but there has been a 56% decline in North America and parts of Canada.

The disruption of grouse habitat selection is staggering because the various subspecies of grouse populations have actually been known to have no problem living in close proximate to humans. When the botanical make up of forests are kept in a juvenile state grouse populations thrive. In the spring grouse feed on leaves, fruits, and insects. Once winter arrives their main food source is flower buds. If plant life in the forests are left to mature the protective and food resources of grouse species dwindle. Small scale clear-cut logging and fires tend to be benefitial to grouse populations. The grouse would rather live in these constantly disturbed areas, than remote wilderness forests that are allowed to hit maturity.

The act of small scale clear-cutting is of no concern to these populations. What is concerning is the developmental practices being perpetuated in the United States when it comes to agricultural growth. Since certian sub-species of grouse are not protected under the Endangered Species Act it was easy for mining, energy, and farmining companies to continue development into the west. Consequently, the shrub-steppe communites have become among the most critically endangered ecosystem in North America.

The social behavior of grouse usually keep them in solitary conditions. The males express behavior that is aggressively territorial. Greater sage-grouse and Columbian sharpe-tailed grouse naturally inhabit both non-overlapping and overlaping geographic areas, but because of human development the two species overlap in less than 10% of the ranges they formally inhabit. Although weather trends may be attributed to the “cycle” of abundance between the species studies are showing that human development of agricultural land is having a devastating effect on these populations.  That is why it is important that research continues to study the life-histories of different species to effectively conserve these communities.

Since research is demonstrating the decline of grouse populations state and government agencies in the United States, such as the U.S. Department of the Interior Bureau of Land Management (BLM), have made efforts to restore and produce habitats for the reintroduction of grouse. The BLM has partnered with the U.S. Forest Service, the Fish and Wildlife Service, and the Natural Resources Conservation Services to conteract this development and support wildlife, ranching, and other traditional land use while conservine sagebrush habitats.

The subject of phenotypic plasticity is a relatively untouched area of biological study. The subject is comprised of a great deal of variables when it come to evolution that make defining the heritability of plasticity difficult. Phenotypic plasticity is the ability for a genotype to produce several phenotypes when the organism is subjected to different environmental factors. One subcategory of phenotypic plasticity involves genes expressing behavioral traits.

Behavioral traits are attributed to a combination of the organisms genes and its environment. Plasticity of a behavioral trait reveals different reaction norms, or a pattern of phenotypic expression, for the organism when exposed to different environmental stimuli. The environment causes either an up or down regulation of behavioral response as cues from the environment change. Individuals in a population can differ in the degree and directionality in which their behavior presents from the same stimuli. Even neighboring organisms of the same species may differ in both aspects. This phenomenon is able to occur because, just as genes can mutate and evolve, so can plasticity. The variation in degree and directionality is also due to the fact plasticiy evolves independenly from the gene which expresses the trait it effects.

 

 

Scientists are baffled by a recent phenomenon occuring in the oceans around the world, particularly in North Pacific Oceans. Humpback whales have been observed working in pairs to save various prey of orca whales including, sea lions, harbor seals, and grey whales. Is this an altruisitic behavior or is something deeper happening? Could the humpbacks have complex emotional processes such as what is seen in primates causing them to act with sentimental instinct? Then we must also consider the fact that humpback calves themselves are prey to the orca whale, and the Humpacks’ are acting under some internal instinctual parental behavior.

The number of recorded incidents of humpback whale interference with orca predation was recorded in a recent article by Robert L. Pitman published in July 2016. There was a documented 115 interactions between orcas and humpbacks collected between 1951-2012 . Overall in the 115 interactions 95% of them were with killer whales (orcas) attacking mammalian species. Of the mammalian species orcas attacked 95% of the cases were also prey to the humpback whales. Humpback could be exhibiting scavenging behavior, similar to interactions between hyennas and lions.The humpback’s could simply be trying to “catch a meal”, but the theory of altruism was introduced due to a radical behavior logged in the report of Pitman’s study.

In some instances, the study described a humpback whale putting a sea lion on its belly and using its flipper to keep them on their body until the pair reach a new icebarge for the sea lion to escape. Why would the whale bring them to safety if they wanted to catch a meal? The prey is now safetly on land away from their origional orca predator. Investigation of this interaction indicates that prey could not reciprocate any form of fitness to the humpback whales. So, this may be altruism or the whales must be gaining some kind of benefit from disrupting the foraging of orcas from another source.

The humpback whales could be displaying these actions in the evolution of parental care. Orca’s have been known to attack humpback whale calves for feeding upon. If the humpbacks prevent orcas from eating they could become weak and unable to attack their young. It could also cause the orcas to change feeding grounds, so the likelihood of an attack on a infant would decrease. The downfall to this theory of parental care is that orca whales only prey on humpback calves 11 percent of the time, and raises the question if that is sufficient reason to expose oneself to the costs of fighting an orca herd.

The complexity of animal behavior produces numerous hypothesis to why the humpback whales are displaying this response to orca attacks. Research is presently being conducted to explore the reasoning behind this behavior. Until further research is published the questions remains; is this altruism, parental care, territorialism, emotionally based, or a combination of these processes?

 

Navigation is a behavior necessary for species to travel from various daily activities to their homes. The diversity in the mechanisms and implementations of navigation techniques depend on the ecology, sensors, and actuators of the species. The regulation of genes plays an important role in navigation behavior of honey bees. In October 2016, seven species of honey bees native to Hawaii were added to the United States Federal list of endangered species. There are various reasons for their decline including habitat destruction and the introduction of nonnative plants species and predators, but the most interesting reason lies in a phenomenon called the Colony Collapse Disorder (CCD).

CCD occurs when the majority of worker bees disappear and leave behind a queen. While the cause of this disorder is unknown there are various stressors that have shown to have an effect on the worker bees’ homing behavior. Pesticides have been shown to cause uncharacteristic honeybee behaviors. Thiamethoxam, a seed treatment insecticide, damages the bees’ homing abilities. The bees are unable to navigate back to their hive, and the loss of these workers within a colony lead to devastation in the eusocial structure of the hive.

Bees have molecular mechanism that are the underlying cause for behavioral plasticity in navigation. Activity of a regulatory gene in the mushroom body increases in response to unfamiliar or changed environments. The disruption in the regulation of this gene is what hinders the individuals ability to pilot themselves home.

As part of the Earth, humans must take action to reverse and prevent furth devistations cause by our chemical usage if we want to maintain any hope on reviving these now endangered species. A number of different methods have been theorized for the restoration and reduction of the effect chemicals are having on honey bees including spraying pesticides at night, using different compounds or less toxic/rapidly degradeable formulas, and building apiaries (a place for bees to be kept) with proper help from beekeepers. The next step is putting these theories into action.

All individuals rely upon the same resources, such as; food, shelter and finding a mate. So, why do some decide to live in groups while others prefer to live their lives in solitude? The costs and benefits of each method would make either a viable option for an individual depending on their specific needs.

Solitary individuals are very territorial. They have to be in control of their domain in order to have enough resources to survive. If resources are abundant an individuals will only need to protect a small patch of land. However, if resources are scarce the individual will need to control a larger territory. Animals will “mark” their territory to warn others that the land is already claimed. Aggression can also be witness in organisms in defense of their territory. Robins in early spring will attack other robins who invade their territory. Individuals in the species will usually only come together for mating purposes. This is because otherwise they would be in constant competition for food and space. The energy put into protecting ones territory seems very costly, but if they are able to acheive this they reap the full benefits of all resources.

On the other hand species who live in social groups share their resources. Individuals can either be found in large or small colonies/groups. In this kind of social aspect the group can work together to to build their nest or collect food. They have the added benefit of being able to better defend each other against predators. The disadvantage to this is that now they have to compete with eachother in the social group for division of the reasources, such as food and mates. When picking a social group it all comes down to what advantages and disadvantages can you live with.

The theory of reciprocity, or reciprocal altruism, is a controversial topic when examining animal behavior. Reciprocity does not seem to fit into the theory of natural selection. The thought that reciprocity can evolve is further scrutinized when individuals in the species are observed to go against their reciprocal “debt.” Some scientists believe reciprocity could simply be categorized under other sectors of altruism such as kin selection, mutualism, or postponed cooperation.  The variety of generalized speculations to the underlying cause of this type of altruistic behavior has caused mass debate among biologists. In order to understand the contention reciprocity generates between scientists a definition of this term must first be constructed.

The simple definition of reciprocal altruism is developed by observing a series of events between two individuals. An individual who performs a beneficial act, the helper, for another, the receiver, is usually found to be later repaid by the receiver of the assistance (Alcock, 2013). The key factor that differentiates reciprocity from kin selection is that the two individuals are unrelated. Reciprocity persents itself in a variety of species including primates, pied flycatchers, and bats. Though there have been studies to support the theory of reciprocity, it can be difficult to determine if a case of reciprocity is pure altruistism, or instead a function of mutalism or postponed cooperation.

In a reciprocal relationship, the fitness of the individual who provided the help generally is not decreased in the long term. The initial fitness cost is later returned by the receiver. This returned fitness cost supplies evidence for the argument that reciporcity could simply be division of mutalism or postponed cooperation. However, “defectors”, or receivers who do not return a benefitial act, ruin this method for arguement. If the intital fitness cost to the helper is not returned by the receiver that helpers fitness will be reduced. This circumstance seems to cancel out the mutalism and postpone coppoeration theory. These “defectors” in the species also provide reason to why reciprocity is less likely to evolve. So, why has reciprocity evolved?

Though reciprocity and its direct payback behavior has evolved it is still a rare phenomenon in the animal kingdom. In theory, genes which code for the reciprocal behavior are passed to future generations unless they are selected against. Genetics are not the only element of this developing behavior. Environmental factors are always intertwined when it comes to the development of behavior. This behavior has simply not been selected against.

Upon examination of the different aspects of reciprocity we can begin to understand why there is such controversy in the biological field when classifing this theory.

Alcock, J. (2013). Animal behavior: An evolutionary approach. Sunderland, Mass: Sinauer Associates.