How would human activities affect the migration of animals like the Christmas crabs in Australia?

Answers

Answer 1

Answer:

Most of Christmas Island's adult red crabs begin their breeding migration to the sea as soon as the wet season rains have established. But we can never be sure when the wet season is going to begin!

The crabs' breeding timetable is fixed around the phases of the moon. Spawning (the dropping of their eggs into the sea) must occur before sunrise on spring tides during the last quarter of the moon, regardless of any other factor. The timing of spawning is the only certain and predictable part of the whole migration; all other stages of the migration will vary with the prevailing weather.

The crabs will start their migration if there is enough time for them to complete their downward migration, mate and develop eggs before the next suitable spawning date.

The red crab breeding migration comprises a series of separate actions on the crabs' part that follow on from one to the other in a programmed sequence. These separate actions in combination make up the breeding migration and one action will not occur unless the preceding action is accomplished. If there isn't enough time for them to be able to do all of these things before the next spawning opportunity, they will delay the start of their migration and attempt to meet the following month's spawning date.

The first action that occurs is movement of crabs to the sea. The largest mass movement of crabs takes place in this first downward migration. Males farthest inland start this movement and are progressively joined by more and more crabs (both males and females) as the movement progresses toward the sea.

When the crabs arrive at the shoreline, they dip in the sea to replenish body moisture and salts. The male and female crabs then move back on to the shore terraces where the males dig burrows for mating. Mating takes place and then the males again dip in the sea and then they will start their return migration.

The females remain behind in the mating burrows to brood their eggs. This takes a couple of weeks. A day or two before the spawning date the females emerge from the breeding burrows with ripened eggs and move to the shoreline where they again dip in the sea and then retreat to shade.

Before the turn of the high tide and just before dawn the females will again move to the waterline and around the turn of the tide they will drop their eggs into the sea. After they have jettisoned their eggs the females commence their return migration.

The next phase of the breeding migration takes place in the sea. The eggs that the females drop into the sea hatch immediately into larvae. They grow through several larval stages into tiny prawn-like animals called megalops. After about four weeks the megalops emerge from the sea and they moult into baby crabs. The baby crabs then move inland and settle at suitable localities. The successful emergence of baby crabs is unpredictable but is incredible when large numbers emerge. Some years very few, or none, emerge. After about four years growth crabs will take part in the breeding migrations and the life cycle continues.

If the rains stop or peter out, the crabs will delay the start of their migration, or, if they have started migrating, they will stop moving and stay wherever they are until the rains begin again. It is rare that substantial rains will begin early enough in the year for a spawn during the last lunar quarter in October - but it has happened! Spawning in November or December are the more usual, which means that rain must commence in the preceding month and continue.

All phases of the crabs' breeding migration involve colossal numbers of crabs and usually occur all over the island. If the rains continue, there is usually a second, and sometimes even a third, smaller, downward migration by crabs that did not join in the first migration. When this happens it is possible to see crabs on return journeys mingling with the crabs on their downward migration. It can become confusing for all concerned! We are sorry that we can not be more explicit about the timing of the start of the red crab migrations, but the weather as you know cannot be accurately predicted. The best advice we can give is to be at Christmas Island during the last quarter of the moon in either November or December for the best chance of seeing something interesting happening in the annual red crab migration. If you are able to arrive earlier and to stay longer the more parts of the migration sequence you will be able to experience.

Explanation:


Related Questions

East Asia is home to approximately what percentage of the world's population?
A.15%
B.50%
C.25%
D.30%

Answers

The answer would be C.25 percent

The Italian Renaissance stayed in Italy and never touched the rest of Europe. True or false

Answers

Answer:

i think the answer is -- False

:-))

1. What is the elevation of point "C"?

A. 170 m
B. 160 m
C. 130 m
D. 20 m
E. 50 m

2. Which side is steeper?
A. North
B. East
C. West

3. What is happening between points "F" and "D"?

A. going uphill
B. going downhill

Answers

Answer:

a 170 elevation of c

west is steeper

a going uphill

Explanation:

i love geology

i so good at topographic maps

Which statement is NOT true of the internal migration of African Americans in the United States since 1865?
O Most African Americans migrated out of the South along early major roadways. In the second half of the twentieth century, inner-city ghettos expanded to the outer city in major metropolitan areas.
O Industrial booms in Northern cities were pull factors for African Americans living in the South. O Some real-estate agents used blockbusting to push African Americans out of neighborhoods. O Today, African Americans are highly clustered in urban areas.​

Answers

Answer:

In the second half of the twentieth century, inner-city ghettos expanded to the outer city in major metropolitan areas.

Explanation:

I am taking the same test. The text says that in the early twentieth centure (early 1900's) African Americans moved from inner cities to outer city. I can't see if I got the answer right or wrong after I submit. If you can, please rate  this a 1 if it is incorrect and a 5 if it is correct

Answer:

D. Some real-estate agents used block busting to push African Americans out of neighborhoods.

Explanation:

Blockbusting is a business process in which U.S. real estate agents and building developers convince white property owners to sell their houses at low prices, which they do by telling house owners that racial minorities will soon move into their neighborhoods in order to instill fear in them.

Which of the following would also follow a similar pattern to pork consumption in the Middle East? А Coffee B Tea С C Alcohol D Soda​

Answers

Answer:

Alcohol

Explanation:

Predict the consequences that might occur if underground aquafers run out of water?

Answers

Answer:

Consequences of this would be lack of water in the area, earthquakes, and crumbling of surface crust, and creation of huge openings in it.

Explanation:

Aquifers are basically underground reservoirs of water. They can be found at different depths and their size varies greatly. Humans have their potential and started to use them, and it has been of great benefit. The problem is that the aquifers are often overexploited, meaning that more water is extracted from them than what they gain, so their water levels drop and eventually will dry out.

By drying out, the lack of aquifers, especially in regions where freshwater is rare, will cause huge problems. People will not have enough water for their needs, and agriculture will not be possible. The crust will destabilize, and as it adjusts there will be earthquakes. The crust that has been above the aquifer will crumble because of the empty space below it and the influence of gravity, meaning that huge openings will get created, and if there is any infrastructure in the area it will get fully destroyer.

Why did the US and USSR never declare war on one another?

Answers

Answer:

Neither country wanted to engage in a nuclear war that would lead to

worldwide destruction.

Explanation:

The US and the USSR were the two global powers between the end of the World War II and the beginning of the 1990s. Each of them was the leader of a block, with the US being the leader of the democratic and capitalist world, while the USSR being the leader of the communist and command economy world.

Despite all of the tensions between the two, and often engaging in wars in other territories on opposite sides, they never engaged in a direct war with each other. They had everything they needed to do so, being heavily militarized and with an abundance of nuclear weapons, but luckily they didn't fight directly. The explantion for this is simple, they were aware that if they entered a war with each other they would destroy the whole world, so everyone would have lost and there wouldn't have been any gain from it.

Which of the following definitions is the best way to describe local culture?
A a cultural trait that is accepted by the majority of the people and that can change quickly
Ba cultural region that focuses on only one cultural trait
Ca cultural group that exists only within a dominant culture
a cultural group that can be defined by a region or location
Please select the best answer from the choices provided

Answers

Answer: A I did the quiz

brainliest!!!!!!
how volcanism change into climate?

Answers

Gases and solids injected into the stratosphere circled the globe for three weeks. Volcanic eruptions of this magnitude can impact global climate, reducing the amount of solar radiation reaching the Earth's surface, lowering temperatures in the troposphere, and changing atmospheric circulation patterns.

Answer:

The gases and dust particles thrown into the atmosphere during volcanic eruptions have influences on climate. Most of the particles spewed from volcanoes cool the planet by shading incoming solar radiation. The cooling effect can last for months to years depending on the characteristics of the eruption.

The red circle on the map is marking what land form?

A) Jutland Peninsula
B) Iberian Peninsula
C) Icelandic Peninsula
D) Scandinavian Peninsula

Answers

Answer:

D) scandinavian peninsula

Explanation:

The red circle on the map is marking what landform Scandinavian Peninsula. option (D) is correct.

What is a map?

The term map is having been described as they have a scale in It's as we call the longitude and latitude as well as we see there are different types of things are being different things are also in it as we see there are different things are being there in it as we see the oceans are there the roads and in it.

The Scandinavian Peninsula is a peninsula in Northern Europe that roughly consists of the mainlands of Finland's northwestern region, Sweden, and Norway. The word "Scandinavia," which refers to the cultural area that includes Denmark, Norway, and Sweden, is where the peninsula gets its name.

Therefore, option (D) is correct.

Learn more about the map here:

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what is one main characteristics of rainforest trees​

Answers

The tropical rainforest is a biome with a constant temperature and a high rainfall. The level of humidity and density of the vegetation give the ecosystem a unique water and nutrient cycle. Rainforests around the world are threatened by human expansion.

Answer:

Nutrient poor soil

Explanation:

I thinkkkk


Which part of the South American continent is suitable for the
practice of agriculture? Why?

Answers

Brazil

Explanation:

They have abundant land and a significant labour force

The fastest flow is on the inside of a meander bend. True or false

Answers

Answer:

True.

Explanation:

Because when the water flows faster it has more power to erode the outside bank. The outside bend of the meander becomes deeper, reducing friction and allowing for even faster flow of water, which in turn means more erosion. On the inside bend of the meander the river is flowing much slower.

What happens at a divergent boundary?
A. Two tectonic plates slide past each other.
B. One tectonic plate slides under another.
C. Two tectonic plates move away from each other.
D. Two tectonic plates move toward each other.

Answers

Two tectonic plates move away from each other at a divergent boundary. Thus, option C is correct.

What is the tectonic plates?

A tectonic plate is also known as a lithospheric plate, is a substantial slab of solid rock with an uneven shape that is typically made up of both continental and oceanic lithosphere.

The Pacific and Antarctic Plates are among the largest plates, but they can range in size from a few hundred to thousands of kilometres broad. People can't survive underwater, therefore it created the continents on which we now reside.

Volcanoes are produced when plates clash and subduct (when one plate slides under another). Peoples believe that this procedure, repeated numerous times, is what created the continents.

Therefore, option C is correct, that the At a diverging border, two tectonic plates advance apart.

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Please help i don't get it.
Which image matches the Topographic Map Shown?
Also, please explain how your answer is the correct answer. Why is your answer correct?

Answers

Answer:

the map matches C.

Explanation:

the map shows an elevated land with a flat top, also known as a plateau. image C shows a plateau, therefore the map matches C.

hope this helps

Answer:

Devil's Tower

Explanation:

Evaluate the different approaches used to manage the threats facing deciduous woodlands in a named region.

Answers

Traditional management techniques include pollarding . This technique encourages new growth, and maintains the trees for future generations. It is a form of sustainable management in the woodland. Pollarding also encourages birds to nest.

What two oceans surround this area of the world?

Pacific and Indian
Atlantic and Pacific
Atlantic and Indian
Indian and Arctic

Answers

In the west, the Atlantic, east, Atlantic is connected to the pacific, and the Arctic is in the both and south. I hope it somewhat helped. Sorry if I didn’t :)

Answer:

Atlantic and Pacific

Explanation:

Atlantic ocean surrounds on east and Pacific ocean on west

What is the manager of

Answers

Answer:

The manager of.........

✨karen✨

is.........

✨Donald Trump✨

Heat Flow Inside Earth Activity

Answers

Answer:

1- Explosive situation

As it said in the lesson the tectonic plates allow magma to build up over time and then it goes up into the volcano when it finally goes up it explodes in a volcano

What you should say- Tectonic plates allowing magma to build up so our local volcanoes in mount tambora can explode?

2- Shake rattle and roll

Umm yeah... The lesson said it occurs when the tectonic plates collide pull apart or or slide pass each other creating the earthquake.

What you should say- Earthquake caused in the indian ocean because of our tectonic plates passing each other.

3- Ocean expansion

as it says in the lesson ocean expansion (or ocean basin) are caused when the tectonic plates and uplift the new rocky crust causing the ocean to form.

What you should say- Tectonic plates causing our oceans to form because of otectonic plates uplifing new rocky crust in the pacific!

4- island popping up everywhere (or as i like to call it island games)

it says in the lesson when rocks uplift from the bottom of the ocean it causes a island

What you should say- Tectonic plates uplifting rocks from the sea to create oceans in the Caribean?

Explanation:

Rly hope this helps! Pls give brainliest  

The earth heat flow is 80% by mantel convection and 1% by volcanic activity.

What is heat flow of earth ?

The heat flow of the earth is regulated by two factors such as the external that is sun and the internal factors such as geothermal heat.

Due to the volcanic activity of the earth the heat is released from the mantel of the earth in the form of lava. While 99% of the earth's heat is lost by the conduction by crust.

The movement of the heat from the earth's core to the mantle and then to the crust is caused by the convective current coming from below and this leads to the formation of volcanic activity, formation of mounting, and leads to earthquakes.

Find out more information about the Earth Activity.

brainly.com/question/8973293.

On a piece of paper, graph y< -2/5x + 1. Then determine which answer choice
matches the graph you drew.
A
B
D
(-5,3)
(-5,3)
(0, 1)
(-5,3)
(0, 1)
(-5,3)
(0, 1)
(0, 1)
-5
A. Graph A
B. Graph B
C. Graph C
D. Graph D

Answers

The graph D is matched by graph y -2/5x + 1. Option (D) is right as a result.

What does a graph mean?

A graph shows the correlation between two variables that are typically assessed along one axis of a pair at right angles.

A graph in discrete mathematics is made up of vertices a group of point and edges the lines bridging those vertices.

There are many different kinds of graphs, including connected and unconnected graphs, weighted graphs, bipartite graphs, directed and undirected graphs, and simple graphs.

Because they make information accessible and simple to comprehend, graphs and charts are effective visual aides.

Graphs are therefore often used in print and electronic media, which is not surprising. Sometimes, data can be better understood when it is presented as a chart.

Learn more about graph, from :

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What I can do/ plan to do to 'green' my life

Answers

I think you mean make your life more eco-friendly by “green”.

- don’t use so much water ( try to close the tap when brushing teeth - it saves water! )
- eat less meat (Being careful with what you’re consuming is at the heart of being more eco-friendly, and cutting down on the amount of meat you eat can have a huge impact)
- recycle ( Chances are that if you’re thinking about taking on a more eco-friendly lifestyle then you’ll already be recycling. Lol)
- try to cut out plastic (Plastic seems to have found its way into every single aspect of our lives. However, giving it up isn’t as difficult as you might think – bring a canvas bag with you when you go shopping, buy your fruit and veg loose and stop buying bottled water.)
I been thinking about this too lately

What is the thermocline?
beneath 200 meters, ocean water cools at a constant rate of 1°C per 100 meters depth
the ocean area near the polar regions where water temperatures cool
where magma is forced up through the ocean floor along mid-ocean ridges
the area off the continental shelf that declines to the ocean floor

Answers

Answer:

Beneath 200 meters, ocean water cools at a constant rate of 1°C per 100 meters depth.

Explanation:

The water in the oceans across the globe changes its characteristics from one area to another area, or from depth to depth. There are multiple factors that contribute to changes in the properties of the water, but the most important one, that tends to heavily influence all other factors, is the temperature of the water.

The oceans, in-depth, by temperature, have a surface zone, thermocline, and deep ocean division. The surface zone is the warmest of the zones, and it is the one where waters with different characteristics mix. The zone below it, the thermocline, is the zone where the water is not mixing anymore. In this zone, the temperature sharply changes between the depth of 200 and 1,000 meters, with every 100 meters of depth meaning 1 degree Celsius less. The deep ocean is the zone that has the biggest depth range, but there isn't much of a change in the temperature and characteristics of the water in it.

Random Answers Will Get Reported. Also If I Can Figure Out How To Give Someone Brainliest, Then I'll Give It To Them.

1. Which river is NOT found in South Asia, Southeast Asia, or East Asia?

A. Yellow
B. Yangtze
C. Mekong
D. Ob

2. Which mountain range can NOT be found in the Asian region?

A. Alps
B. Eastern Ghats
C. Western Ghats
D. Himalayas

3. What body of water is EAST of India?

A. Bay of Bengal
B. Indian Sea
C. Arabian Sea
D. Sea Of Japan

4. Which of the following is an Asian archipelago?

A. Korea
B. Philippines
C. Singapore
D. Cambodia

5. What climate belt is the Asian region found in? (not counting Russia)

A. Low-Middle
B. Middle to High
C. Middle-Middle
D. Low, Middle & High

6. Fine rich soil in the East Asian region?

A. Arable
B. Chernozem
C. Loess
D. Sand

7. River that is holy to Hindus in India is?

A. Yellow
B. Indus
C. Brahmaputra
D. Ganges

8. Area of increased seismic activity is? (volcanoes & earth quakes)

A. Ring of Fire
B. Ring of Volcano
C. Tectonic Plate
D. Ridge

9. The Gobi Desert has a dry or __________ climate

A. Semi-Arid
B. Arid
C. Tropical
D. Humid Continental

10. What Blocks moisture from the Indian Ocean into China and Mongolia?

A. Himalayan Mountains
B. Gobi Desert
C. Eastern Ghats
D. Western Ghats

Answers

Answer:

C. MekongD. HimalayasA. Bay of BengalB. PhilippinesB. Middle to HighC. LoessD. GangesA. Ring of FireA. Semi-AridA. Ring of FireB. Gobi Desert

Explanation:

hope this helps

opinions of climate change​

Answers

Answer:

It's getting way colder

Explanation:

I live in Wisconsin

Answer:

I believe it does exist, the Earth is getting warmer, but I think those progressives and left-wing people are exaggerating it.

GH and IJ are chords in F. Given GH I FK.
JI 1 FL and FN – FM.
Let GH = 29, FN 10, How long is JP
*the figure is not drawn to scale
OH
N
G
Your Answer:
Answer

Answers

Answer:

srry

Explanation:

A meander is the name given to a ________in a river. They are found in the ___________ course of the river, where the slope levels out and the land either side becomes wider and_________. This is called a_______________.
Middle,bend,floodplain, flatter

Answers

Answer:

A meander is the name given to a _bend_in a river. They are found in the _middle_ course of the river, where the slope levels out and the land either side becomes wider and_flatter_. This is called a_floodplain_.

Which mountain range is located in South America?
A. Cascade Range
B. Andes Mountains
C. Rocky Mountains
D. Appalachian Mountains

Answers

B. The Andes Mountains

Answer:

B. The Andes Mountain ranger

Explanation:

toto Andy is running along South America's western side is among the world's longest mountain ranges. it's a very terrain encompasses glaciers volcanoes grassland desert lakes and forests the mountains pre-shot her Colombian archaeological sites and wildlife including chinchillas and condors. From Venezuela in the north the range pastures passes through Columbia, Ecuador Peru, Bolivia, Argentina, and Chile.

Which answer best describes the continental shelf?
thick deposits of sediments carried out from land
area of land that drops toward deep ocean basins
75-mile shallow flat area just off coastlines
the surf area along coastlines

Answers

I think the answer is (B)

PLEASE HELP!!!
I need help answering these questions, I watched videos and still don’t know.

Answers

Answer: the closer a planet is to the sun, the stronger the sun's gravity

Explanation:

Which statements describe cultural influences?

Forests are cleared to provide space for cattle grazing.
Birthdays are celebrated on January 1st.
Florida is bordered by water on three sides.
French is spoken in parts of Louisiana.
Male children are encouraged to attend the university.
The longest river on the continent is located here.
Per capita income of northern Buckland is more than $100,000.

Answers

Answer:

forests are cleared to provide space for cattle grazing.

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