Young animals grow up If the zygote can grow in and interact with a suitable environment, it contains all the information required to create a new organism. It stands to reason that some aspects of embryology must be considered when studying the development of behaviour. For instance, the way the nervous system's fundamental structure is built, but we must go much further than this. Young animals grow up It is entirely possible to argue that in some animals, behavioural development continues throughout life. Long after an animal is independent, its behaviour may still change. Learning could therefore be seen as a form of development, and young animals occasionally learn a lot as they grow. But in this section, we'll focus on other behavioural changes that frequently occur early in life, often quickly and dramatically. It is important to understand that young animals must always be fully functional creatures capable of acting appropriately in their own worlds. They cannot simply be incomplete creatures or inadequate stages on the path to adulthood. Some animals are protected during their early development by an eggshell or uterus or by watchful parents, but others are free-living and must care for themselves completely. Young animals may develop into miniature adults as they grow in size over time, but in order to keep up, their behavioural responses must also adapt. Although young cuttlefish (Sepia) start out and continue to be carnivores, at first, they can only kill tiny crustacea that are disregarded as prey once the cuttlefish has grown. As they grow closer to adult size, they move on to food that is bigger and bigger, which requires a change in the behaviour patterns used to find and catch prey. Even more drastic behavioural and morphological changes may occur in some cases because some young animals live entirely different lives than do adults. Tadpoles are herbivores that swim and breathe like fish before changing into land-dwelling carnivorous frogs or toads. Eristalis tenax, an aquatic filter-feeding rat-tailed maggot that breathes through a long snorkel tube at its back, transforms into a flower-feeding hoverfly (see Fig. 2). Young and adult require almost entirely different behavioural repertoires for these life histories. Rat-tailed maggot | Flower-feeding hoverfly These alterations mean that development frequently has to produce patterns that only function for a portion of an animal's life before disappearing. The specific coordinated movements that cockroaches use to emerge from their individual eggshells as well as the protective case that bundles a group of eggs together were both described by Provine in 1976. These movements, which are only observed on this one occasion, consist of a series of reversed waves of contraction along the body from the tail to the head. They appear at the exact right time, at the end of the egg stage's development, and are used to propel the young cockroach nymph into the following growth

1. Young animals grow up
If the zygote can grow in and interact with a suitable environment, it contains all the information
required to create a new organism. It stands to reason that some aspects of embryology must be
considered when studying the development of behaviour. For instance, the way the nervous
system's fundamental structure is built, but we must go much further than this.
It is entirely possible to argue that in some animals, behavioural development continues
throughout life. Long after an animal is independent, its behaviour may still change. Learning
could therefore be seen as a form of development, and young animals occasionally learn a lot as
they grow. But in this section, we'll focus on other behavioural changes that frequently occur
early in life, often quickly and dramatically.
It is important to understand that young animals must always be fully functional creatures
capable of acting appropriately in their own worlds. They cannot simply be incomplete creatures
or inadequate stages on the path to adulthood.
Some animals are protected during their early development by an eggshell or uterus or by
watchful parents, but others are free-living and must care for themselves completely. Young
animals may develop into miniature adults as they grow in size over time, but in order to keep up,
their behavioural responses must also adapt.
Although young cuttlefish (Sepia) start out and continue to be carnivores, at first, they can only
kill tiny crustacea that are disregarded as prey once the cuttlefish has grown. As they grow closer
to adult size, they move on to food that is bigger and bigger, which requires a change in the
behaviour patterns used to find and catch prey.

2. Even more drastic behavioural and morphological changes may occur in some cases because
some young animals live entirely different lives than do adults. Tadpoles are herbivores that
swim and breathe like fish before changing into land-dwelling carnivorous frogs or toads.
Eristalis tenax, an aquatic filter-feeding rat-tailed maggot that breathes through a long snorkel
tube at its back, transforms into a flower-feeding hoverfly (see Fig. 2). Young and adult require
almost entirely different behavioural repertoires for these life histories.

3. These alterations mean that development frequently has to produce patterns that only function
for a portion of an animal's life before disappearing. The specific coordinated movements that
cockroaches use to emerge from their individual eggshells as well as the protective case that
bundles a group of eggs together were both described by Provine in 1976. These movements,
which are only observed on this one occasion, consist of a series of reversed waves of
contraction along the body from the tail to the head.
They appear at the exact right time, at the end of the egg stage's development, and are used to
propel the young cockroach nymph into the following growth stage. Once this is done, they are
never again elicited. The aquatic hoverfly larvae's feeding behaviour patterns, which were just
mentioned, must have a lifespan somewhat longer than this because they must support the larva
through its entire growth phase until it pupates, after which they vanish like the cockroach
hatching behaviours.
Complete metamorphosis requires an animal to, in essence, be able to manage two separate
lives, carry two sets of genes that manage two developmental programmes, and interact with
two distinct environments. Sometimes, the two life stages can overlap.
Within a colony of weaver ants, Figure 3 depicts a nice example of "cooperation" between
juveniles and adults (Oecophylla sp.). Worker ants bring together the two opposing edges of a
leaf to form a protected nest space within it by employing adult behavioural patterns and clinging
on with jaws and clawed feet.
The edges are then sealed by raising larvae and forcing them to spin silk across the opening in a
pattern that the larvae had to develop in order to spin their cocoons before pupating. There are
numerous other instances of how young and adult animals lead very different lives. An excellent
review of these facets of behavioural development is given by Monaghan et al. (2008).
● Instinct and Learning Behavior
● Methods of capturing animals
● How many zoos does Pakistan have? and where?
Baby meerkats (an African mongoose, Suricata suricatta), when grabbed by an adult by the scruff
of the neck, go limp and exhibit passive behaviour. This reflex makes it easier to move them

4. without hurting them. Similar relaxation occurs in adult female meerkats when the male seizes
them in a neck bite during copulation.
The neural underpinning of the reflex is still present in adults, and additional examples show that
some juvenile reflexes persist even if they are not used. Domestic chickens use a variety of
unusual movements to emerge from their eggs as they hatch, including beating their beaks
against the shell and making powerful leg thrusts that rotate the body. in a series of tasteful
tests.
Bekoff and Kauer (1984) demonstrated that if young chickens are gently pushed back into a
huge artificial eggshell and then placed in the posture of the chick at hatching, the same
movements will be performed again by the chickens several weeks after hatching.
The neural circuitry underlying this pattern has likely been retained due to the fact that some of
its components are involved in adult locomotor behaviour. We'll talk about more instances of this
kind of "neural recycling" in insects later.
The change from adolescence to adulthood, whether sudden or gradual, does not always occur
along a single path. In this chapter, we'll look at a variety of ways that behaviour can develop as
well as how far young animals can make up for deviations from the norm.
Few animals, though, reach a single conclusion or exhibit a consistent pattern of adult behaviour
in all of their members. Some animals develop into males, while others develop into females, and
their behavioural repertoires may differ greatly. While female grasshoppers of some species may
remain solitary or develop into swarming locusts, female honeybees (Apis mellifera) develop into
queens or workers.
In these circumstances, we are aware of definite genetic or environmental triggers that direct
subsequent development in one of two or more different directions. The sexual pathway of
mammals is determined by the presence or absence of a Y chromosome in the zygote, though as
we shall see, subsequent'sign posts along the pathway are not genetic.
Whether a honeybee larva develops into a queen or worker depends on how long it is given royal
jelly as it grows. The desert locust (Schistocerca gregaria) has two distinct forms, or "phases," as
they are known; it can be either a solitary, pale green grasshopper or a highly gregarious, black
and orange locust.
These two were classified into different genera when they were first described because their
behaviour and appearance are so utterly dissimilar! The change is triggered in part by behaviour
and in part by the quality of the eggs. When crowded together, solitary nymphs alter their
appearance and behaviour, whereas the eggs of crowded females, even if they had lived alone as
adults, give rise to gregarious nymphs (Roessingh et al. 1993; Islam et al. 1994; Fig. 3).

5. The grasshopper locust's gregarious (above) and solitary (below) phases (Schistocerca
gregaria)
Not every trigger is as obvious. Some vertebrate males engage in combat to protect territories
that attract females before mating with them. Other males might choose to behave as so-called
"satellite" males, hanging out submissively in another male's territory rather than engaging in
combat and defending their own territory.
Animals as diverse as sticklebacks (Fig. 2.4), ruffs (Philomachus pugnax), gelada baboons
(Theropithecus gelada), and white rhinoceroses exhibit this behaviour during the breeding season
(Ceratotherium simum).

6. For male ten-spined sticklebacks, there are two additional mating methods (Pungitius
pungitius).
Although satellites initially appear to be unsuccessful, close observations reveal that they
occasionally succeed in mating with females, frequently when a territory holder is focused on
fending off rival territorial males. Depending on the specifics, temporarily becoming a satellite
could be a useful adaptive tactic. There isn't always a single, predetermined developmental path
that leads to adulthood.
We now know of numerous instances in which newly independent young birds or mammals can
choose between two alternative reproductive strategies: they can disperse, find mates, and
reproduce on their own, or they can remain with their parents and assist them in raising new
generations of offspring.
Research is currently being done to determine the genetic or environmental factors that influence
how much development develops. For such life-history "decisions," ecological factors frequently
prove to be just as important as genetic and physiological factors.
Further change and development may be possible as ecological conditions permit, as animals
age, and as their individual experiences enable them to adapt, so they are not necessarily final
choices.