Animal behavior

Question 1

Ethology

Answer 1

The scientific study of non-human animal behavior, usually with a focus on behavior under natural conditions, and viewing behavior as an evolutionarily adaptive trait.

Ethology looks at the phenotype and has a comparative approach.

Question 2

Behaviorism

Answer 2

also describes the scientific and objective study of animal behavior, usually referring to measured responses to stimuli or to trained behavioral responses in a laboratory context, without a particular emphasis on evolutionary adaptivity.

It dominated mainstream American academic psychology from the 1920s for four or five decades and It emerged slowly under Watson.

Question 3

The founding fathers of Ethology

Answer 3

In 1973 the Nobel Prize for Physiology or Medicine was awarded to three pioneer practitioners of ethology: Austrians, Karl von Frisch and Konrad Lorenz, and Dutch-born British researcher Nikolaas (Niko) Tinbergen. All three were acute observers who, through extensive field experience, sought to determine patterns and motivations in the behavior of animals.

Question 4

Konrad Lorenz

Answer 4

Austrian 1903-1989: wrote Civilized man’s eight deadly sins (1973)

these eight are:
overpopulation
devastation of the environment
humankind competing against itself
emotional entropy
genetic decay
the break with tradition
indoctrinability
nuclear weapons

Question 5

Tinbergen

Answer 5

was a zoologist, he studied animal behavior in the field, and for him the goal of ethology is to understand the real life of animals, how they live. Observation, description and experimentation on animal behavior with a comparative, evolutionary approach. The four questions by Tinbergen:

What is it for? Biological function, survival (adaptative) value. Remote causation, evolution shapes the behavior in relation to the environment
How did it develop? Ontogeny, innate and learning factors
How did it evolve? Phylogeny and comparative approach, comparison among the species we are observing and the others around it
How does it work? Physiological mechanisms. Proximate causation, the causes are close

Question 6

Classical ethology

Answer 6

the study of instinct, learning processes, dichotomy instinct vs learning, development and interaction between learning and innate patterns, animal communication (ritualisation: the signals are the results of an evolutionary process that ritualizes behavior).

In classical ethology, the starting point is the ethogram, which aims at observing and assessing the behavioral repertoire of animal species. An ethogram is a catalog or inventory of behaviors or actions exhibited by an animal. The premise is that there is an animal repertoire that is instinctual.

Question 7

Modern disciplines derived from ethology

Answer 7

behavioral ecology and sociobiology (study of the structure of animal societies), cognitive ethology (the understanding of the self in the environment), neuroethology

Question 8

Skinner box

Answer 8

a chamber that isolates the subject from the external environment and has a behavior indicator such as a lever or a button.

When the animal pushes the button or lever, the box is able to deliver a positive reinforcement of the behavior (such as food) or a punishment (such as noise) or a token conditioner (such as a light) that is correlated with either the positive reinforcement or punishment.

Skinner introduced a new term into the Law of Effect - Reinforcement. behavior which is reinforced tends to be repeated (i.e., strengthened); behavior which is not reinforced tends to die out-or be extinguished (i.e., weakened).

The idea is that animal instincts are a tabula rasa that then learn behavior: according to this idea, everything is learnt, acquired. This idea was unacceptable for ethologists such as Lorenz, who believed that the organisms have inner information (instinct) deriving from evolution.

Question 9

Animal communication

Answer 9

this is another important chapter of animal ethology. Animals communicate by means of signals using sensory channels. Signals travel across the environment, so the information gets from a sender to a receiver, who will elaborate the info and send a response. Communication means that a part of the behavioral repertoire is evolved through the communicative function, it travels through communication.

Question 10

Animal ritualization

Answer 10

a behavior that occurs typically in a member of a given species in a highly stereotyped fashion and independent of any direct physiological significance. Ritualization means that the behavior is shaped to send/receive information.

Question 11

Behavioral ecology

Answer 11

It investigates the relationship between behavior and the ecological context.

Example: birds removing eggs’ fragments from the nest: among the hypotheses on the reason for this behavior, the bright color of the interior of the egg reflects light and makes the nest more visible for predators.

Question 12

Main topics of behavioral ecology

Answer 12

Foraging, territoriality, habitat use, food resources, dispersion and migration: natural selection would favor the most efficient foraging and feeding behaviors, animals defend areas to increase their reproductive success acquiring resources, animal species exhibit an active selection for optimal habitats.

Sexual selection and reproductive behavior: parental care, secondary sexual traits and mating systems are correlated, and evolve to maximize reproductive success in relation to environmental challenges.

Social behavior: social systems evolved cooperation and altruism in many animal groups. Social learning. → sociobiology: Wilson wrote a book about it, and it was criticized, especially by left-winged people, because of the idea of innate patterns in humans justifying even bad behaviors.

Question 13

Optimal foraging theory

Answer 13

predicts that animals will either attempt to maximize energy gained or minimize time spent to obtain a fixed amount of energy. A time-minimizing approach implies that an animal is attempting to maximize time spent in other behaviors such as reproduction or to minimize its exposure to temperature extremes, predators, or some other factor in the environment while foraging.

Question 14

Territoriality

Answer 14

competition for space. Territory size in birds is adjusted according to the number of competitors. In ethology, territory is the sociographical area that an animal consistently defends against conspecific competition (or, occasionally, against animals of other species) using agonistic behaviors or (less commonly) real physical aggression. Animals that actively defend territories in this way are referred to as being territorial or displaying territorialism.

Territorial behavior, in zoology, the methods by which an animal, or group of animals, protects its territory from incursions by others of its species. Territorial boundaries may be marked by sounds such as bird song, or scents such as pheromones secreted by the skin glands of many mammals.

Question 15

Home range

Answer 15

an individual or a group of animals occupies an area that it habitually uses but does not necessarily defend; this is called its home range. The home ranges of different groups of animals often overlap, and in these overlap areas the groups tend to avoid each other rather than seeking to confront and expel each other. Within the home range there may be a core area that no other individual group uses, but, again, this is as a result of avoidance.

Question 16

Territoriality and paternity

Answer 16

example of monogamous birds, having a stable bound. Extra-pairs fertilizations occur when a bird exceeds its own strict territory: this maintains high levels of genetic diversity. The chicks could have more than one father. Genetic tests are used to determine paternity. Most of birds are monogamous, more than mammals. The reason is that fitness would decrease if bird-parents were alone. Some bird monogamies are very stable, others are less stable. → The organization of the mating system is strongly influenced by the environment.

Question 17

What is a lek?

Answer 17

an aggregation of male animals gathered to engage in competitive displays and courtship rituals, known as lekking, to entice visiting females which are surveying prospective partners with which to mate.

A lek can also indicate an available plot of space able to be utilized by displaying males to defend their own share of territory for the breeding season.

A lekking species is characterized by male displays, strong female mate choice, and the conferring of indirect benefits to males and reduced costs to females. The complicated aspect is due to the arena in which mating happens: they need to find the right arena to do it, but what if they don’t find it? These kinds of arenas are under threat because of human disturbance, e.g. tourism. Moreover, hunters kill more males than females.

Question 18

Applications of animal behavior

Answer 18

Wellfare and conservation

Question 19

Human impacts and animal behavior

Answer 19

habitat modification, hunting, fragmentation, corridor construction, reduced resource quality, resource variation.

These impacts affect individual behavior, therefore there is an expanding effect on the population.

mating system, social plasticity, migration, dispersal, mate choice…

Every individual in a population interacts with the environment through behavior, which is a phenotypic feature that acts both actively and passively on the environment. Therefore, behavior is a sort of mediation between the individual and the environment.

Question 20

Home range and dispersion

Answer 20

rea where animal spends its time and gets resources (trophic resources and other kinds). Carnivorous animals search for their prey in their home range. The larger the home range, the more critical it is: it is a complex system. Reserve borders may contain various home ranges, which may have different sizes.

The larger the home range, the higher the vulnerability. There also is a relationship between the mean species body mass and the mean species home range area (m²): the home range is wider for species composed of bigger (in terms of mass) individuals. Animals that are able to move more may have an even larger home range → carnivorous birds like eagles have the largest home range (up to 500 km 2). Fishes and lizards have the smallest home ranges.

Competition for food and other resources influences how animals are distributed in space. Even when animals do not interact, clumped resources may cause individuals to aggregate.

Question 21

Migration

Answer 21

the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. A particular form of dispersion.

Migration is affected by Climate Change → human pressures can have important effects on the roots of animal dispersal and migration, leading to the alteration of a species distribution.

Migration is a costly strategy: it takes high costs in terms of dangers and energy spent in the travel, but is beneficial. Some of these migrating species were resident, but then evolved the use of migration.

Question 22

Example of Blackcaps

Answer 22

Species may also shift from migrating to being resident, and even in this case anthropic climate change is involved.

Before 1940, in England, cold winters and lack of food supplies necessitated migration to the Mediterranean region for winter. Currently, supplemental feeding, possibly coupled with slightly warmer winters, fosters successful wintering in England. Blackcaps have become fully resident, they do not migrate anymore.

Question 23

Mismatch/decoupling

Answer 23

Anthropogenic impacts on breeding: most northern temperate birds start to lay eggs earlier in a warm spring than in a cold spring independent of any global climate change. Two examples:

Tachycineta bicolor, tree shallow: North America, from 1959 to 1991 → Egg laying advanced up to 9 days.
Aphelocoma ultramarina, Mexican jays: Arizona from 1971 to 1998 → The mean date of first nest occurred earlier in the spring by 10-11 days.

Mismatches/decoupling between food availability and avian annual cycles: if a species arrives earlier in a breeding area, the peak of resources for the chicks may not be early as well. If there was not a synchronization between bird cycle and resource peak availability, a mismatching occurs, causing the species’ vulnerability.

Question 24

Phenology

Answer 24

the study of periodic events in biological life cycles and how these are influenced by seasonal and interannual variations in climate, as well as habitat factors.

Question 25

Example of the Cuckoos

Answer 25

Cuckoo uses a sneaky strategy to raise its babies. First, a female cuckoo finds a nest built by a bird of a different species. For example, it might be a great reed warbler. Then, she sneaks into the warblers’ nest, lays an egg and flies away. The warblers often accept the new egg. Indeed, they take care of it along with their own eggs.

The cuckoo chick hatches before the warbler chicks. And it wants all the food from the warbler parents for itself. So the young cuckoo pushes the warbler eggs onto its back, one by one. It braces its feet on the sides of the nest and rolls each egg over the edge. Smash!

We investigated changes in timing of spring arrival of the cuckoo and its hosts throughout Europe over six decades, and found that short-distance, but not long-distance, migratory hosts have advanced their arrival more than the cuckoo. Hence, cuckoos may keep track of phenological changes of long-distance, but not short-distance migrant hosts, with potential consequences for breeding of both cuckoos and hosts. The mismatch to some of the important hosts may contribute to the decline of cuckoo populations and explain some of the observed local changes in parasitism rates of migratory hosts.