Today: Grizzly Bears

We are only one of millionsofspeciesonearth.

Ecological Interconnections

Grizzly Bears

Grizzly bears are big.

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 28

How are bears related to each other?

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 15

12,000 years ago: the grizzly ancestor short-faced bear

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 17 and 23

Short-faced vs grizzly bears

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 78

Grizzly bears live most of their lives alone

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 78

Grizzly bears live most of their lives alone.

What do they do?

… mostly eat

What do grizzly bears eat?

Ray deLucia and the Grizzly Bear Fight AMNH photo # 296899 Courtesy of the American Museum of Natural History Library Services

Different mouth and teeth structures can tell about an animal’s diet

Fig 41.18

Grizzly bear teeth

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 54

cat

dog

grizzly

panda

Different teeth and diets

Carnivores have a short digestive system

Herbivores have a long digestive system

Fig41.19

HumansBears

Both humans and grizzly bears are omnivores.Our digestive systems can tell us about our ancestors.

Fig 41.19

About 75% of their diet is plants

They also eat carrion.

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 85

Some grizzlies are excellent predators, but most eat carrion.

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 186

Grizzlies constant search for food can lead to conflicts with humans.

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 215

Grizzlies constant search for food can lead to conflicts with humans.

There is not much to eat in winter...

Bears from temperate climates sleep over the winter in a den.(not hibernation)

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 62 and 63

Grizzlies have an amazing ability to gain and lose weight.

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 59

Grizzly reproduction

winter

fall

summer

spring

youngborn

den w/motherjuveniles

on own

Female Grizzly Bear reproductive cycle

Females are not fertile when caring for offspring

fertiliz-ation

Spring Summer Fall Winter(in den)

Birthyear

copulation delayed implantation gestation birth

Juvenileyear 1

Offspring with mom(lactation)

Offspring with mom(lactation)

Offspring with mom(lactation)

Offspring den with mom(lactation)

Juvenileyear 2

Offspring with mom(lactation)

Offspring with mom(lactation)

Offspring with mom(lactation)

Offspring den with mom(lactation)

Adolescentyear

Offspring with mom(lactation)

Offspring on own

Grizzly Bear Reproduction

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 58

Grizzly cubs are born in the den and are very small (~1 lb)

winter

fall

summer

spring

youngborn

den w/motherjuveniles

on own

Female Grizzly Bear reproductive cycle

Females are not fertile when caring for offspring

fertiliz-ation

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 76

Female bears are very protective of their young

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 77

Infanticide: males will try to kill young so that mother will become fertile

Historical Grizzly Bear range

Current Grizzly

Bear range

Habitat destruction and hunting have severely decreased grizzly populations in the U.S.

63 mi

54 mi

•466 mi of roads •950 mi of backcountry trails•97 trailheads•287 backcountry campsites

Yellowstone NP

Yellowstone Grizzly Bear population increases

Yellowstone NP is not big enough to support a viable grizzly bear population

Where do grizzly bears fit?

Are they important?

How much of our resources should we share with grizzly bears?

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 231

Animal behavior is unpredictable and inexplicable

Experiment Written Report:Title- Concisely describe your experiment.AuthorAbstract- Summarize your work. Do not exceed 250 words.Introduction-Results-Discussion-Materials and Methods-References- include: author name(s), article title, journal or book title, volume and page number, and year of publication

Staple your approved proposal to the back of your written report.

What is a reliable source?

xkcd.com

Building Blocks of Scientific Literature

peer review

What is peer review?

In a peer reviewed journal each article is looked at by an editor, and then it is then sent to two anonymous reviewers.

These reviewers send comments back to the editor.

After each article is sent to the editor, it is then sent to two anonymous reviewers.

These reviewers send comments back to the editor.

They give suggestions for improvement as well as an opinion about whether it should be published or not.

The editor then has three choices:

Accept paper as is. (rare)

Accept paper and ask for some changes.

Reject paper. (20-80% rejection rate in physical sciences*)

*Scholarly Consensus and Journal Rejection Rates. Lowell L. Hargens (Feb., 1988) American Sociological Review 53: 139-151andBang for Your Buck: Rejection Rates and Impact Factors in Ecological Journals. The Open Ecology Journal (2008) L.W. Aarssen, T. Tregenza, A.E. Budden, C.J. Lortie, J. Koricheva and R. Leimu 1: 14-19

Who reviews papers?

Other researchers knowledgeable in the field.

What is a reliable source?

xkcd.com

What is a reliable source?

What is a reliable source?

Can be a great source of sources...

What is a reliable source?

Who was the author(s)?Why was it written?Where was it published?Who checked/reviewed the article?

xkcd.com