Lecture 18

class: center, middle, inverse, title-slide

# Lecture 18
## Interspecific interactions: Predation
### <br/><br/><br/>WILD3810 (Spring 2020)

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## Readings

> ### Mills 142-153

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## Interspecific interactions

#### Interactions come in many different forms
<br/>

<table class="table table-striped" style="width: auto !important; margin-left: auto; margin-right: auto;">
 <thead>
  <tr>
   <th style="text-align:center;"> Species A </th>
   <th style="text-align:center;"> Species B </th>
   <th style="text-align:center;"> Interaction type </th>
  </tr>
 </thead>
<tbody>
  <tr>
   <td style="text-align:center;"> + </td>
   <td style="text-align:center;"> + </td>
   <td style="text-align:center;"> Mutualism </td>
  </tr>
  <tr>
   <td style="text-align:center;"> + </td>
   <td style="text-align:center;"> 0 </td>
   <td style="text-align:center;"> Commensalism </td>
  </tr>
  <tr>
   <td style="text-align:center;"> + </td>
   <td style="text-align:center;"> - </td>
   <td style="text-align:center;"> Contramensalism </td>
  </tr>
  <tr>
   <td style="text-align:center;"> 0 </td>
   <td style="text-align:center;"> - </td>
   <td style="text-align:center;"> Amensalism </td>
  </tr>
  <tr>
   <td style="text-align:center;"> - </td>
   <td style="text-align:center;"> - </td>
   <td style="text-align:center;"> Competition </td>
  </tr>
</tbody>
</table>

---
## Interspecific interactions

#### Interactions come in many different forms
<br/>

<table class="table table-striped" style="width: auto !important; margin-left: auto; margin-right: auto;">
 <thead>
  <tr>
   <th style="text-align:center;"> Species A </th>
   <th style="text-align:center;"> Species B </th>
   <th style="text-align:center;"> Interaction type </th>
  </tr>
 </thead>
<tbody>
  <tr>
   <td style="text-align:center;"> + </td>
   <td style="text-align:center;"> + </td>
   <td style="text-align:center;"> Mutualism </td>
  </tr>
  <tr>
   <td style="text-align:center;"> + </td>
   <td style="text-align:center;"> 0 </td>
   <td style="text-align:center;"> Commensalism </td>
  </tr>
  <tr>
   <td style="text-align:center;font-weight: bold;color: white;background-color: #446E9B;"> + </td>
   <td style="text-align:center;font-weight: bold;color: white;background-color: #446E9B;"> - </td>
   <td style="text-align:center;font-weight: bold;color: white;background-color: #446E9B;"> Contramensalism </td>
  </tr>
  <tr>
   <td style="text-align:center;"> 0 </td>
   <td style="text-align:center;"> - </td>
   <td style="text-align:center;"> Amensalism </td>
  </tr>
  <tr>
   <td style="text-align:center;"> - </td>
   <td style="text-align:center;"> - </td>
   <td style="text-align:center;"> Competition </td>
  </tr>
</tbody>
</table>

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class: middle, center, inverse

# Predation

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## Predation

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## Predation

#### Important, widespread effects on:

- Evolution of behavior, morphology, physiology

.pull-left[
**Semelparity**

- Synchronous and massive production of offspring

- Predators readily become full (satiated)

- Most offspring escape and survive
]

.pull-right[
<img src="https://upload.wikimedia.org/wikipedia/commons/3/3b/Agave_July_2011-1.jpg" width="75%" style="display: block; margin: auto;" />
]

???

Image courtesy of

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## Predation

#### Important, widespread effects on:

- Evolution of behavior, morphology, physiology

.pull-left[
**Behavior**

- Adult birds feign injury to lure predators away from nest

]

.pull-right[
<iframe width="560" height="315" src="https://www.youtube.com/embed/OUKieDNDWCs" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
]

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## Predation

#### Important, widespread effects on:

- Evolution of behavior, morphology, physiology

.pull-left[
**Behavior**

- Group hunting

]

.pull-right[
<iframe width="560" height="315" src="https://www.youtube.com/embed/Ai3eVjr0Pzg?start=17" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
]

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## Predation

#### Important, widespread effects on:

- Evolution of behavior, morphology, physiology

.pull-left[
**Physical defense**

<img src="https://upload.wikimedia.org/wikipedia/commons/7/76/Negev_Tortoise_Luxor.JPG" width="80%" style="display: block; margin: auto;" />
]

.pull-right[
<img src="figs/cactus.png" width="80%" style="display: block; margin: auto;" />
]

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## Predation

#### Important, widespread effects on:

- Evolution of behavior, morphology, physiology

.pull-left[
**Chemical defense**

]

.pull-right[
<br/>
<img src="figs/dart_frog.png" width="80%" style="display: block; margin: auto;" />
]

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## Predation

#### Important, widespread effects on:

- Evolution of behavior, morphology, physiology

.pull-left[
**Camouflage**

<img src="https://upload.wikimedia.org/wikipedia/commons/1/18/Crocodylus_acutus_camouflage.jpg" width="80%" style="display: block; margin: auto;" />
]

.pull-right[
<iframe width="560" height="315" src="https://www.youtube.com/embed/_gyHNYtLgWo" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
]

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## Predation

#### Important, widespread effects on:

- Evolution of behavior, morphology, physiology

.pull-left[
**Aposematic coloration**

<img src="https://upload.wikimedia.org/wikipedia/commons/c/cb/Micrurus_tener.jpg" width="80%" style="display: block; margin: auto;" />
]

.pull-right[
<img src="https://upload.wikimedia.org/wikipedia/commons/4/4a/Xystodesmid_Catoctin_Mountain_Park.jpg" width="80%" style="display: block; margin: auto;" />
]

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## Predation

#### Important, widespread effects on:

- Evolution of behavior, morphology, physiology

.pull-left[
**Mimicry**

- *Batesian* mimicry: harmless species mimic poisonous/unpalatable species
<img src="https://upload.wikimedia.org/wikipedia/commons/c/cb/Micrurus_tener.jpg" width="80%" style="display: block; margin: auto;" />
]

.pull-right[
<br/>
<br/>
<img src="https://upload.wikimedia.org/wikipedia/commons/a/aa/Red_milk_snake.JPG" width="70%" style="display: block; margin: auto;" />
]

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## Predation

#### Important, widespread effects on:

- Evolution of behavior, morphology, physiology

.pull-left[
**Mimicry**

- *Mullerian* mimicry: convergence of several harmful species on same pattern

]

.pull-right[
<img src="https://upload.wikimedia.org/wikipedia/commons/6/6e/M%C3%BCllerian_mimicry_%2832149192376%29.jpg" width="80%" style="display: block; margin: auto;" />
]

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## Predation

#### Important, widespread effects on:

- Evolution of behavior, morphology, physiology

.pull-left[
**Physiology**

]

.pull-right[
<img src="https://upload.wikimedia.org/wikipedia/commons/6/61/Falco_peregrinus_-Morro_Rock%2C_Morro_Bay%2C_California%2C_USA_-flying-8.jpg" width="80%" style="display: block; margin: auto;" />
]

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## Predation

#### Important, widespread effects on:

- Community structure
    + Picky predators can promote coexistence among competing prey species when the dominant competitor is the preferred prey (i.e. ‘competitive exclusion’ is prevented by predator)

--
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**The predator**

]

.pull-right[
**The prey**

<img src="https://upload.wikimedia.org/wikipedia/commons/2/23/Acorn_Barnacles_%28Balanus_perforatus%29_group%2C_Irvine.jpg" width="80%" style="display: block; margin: auto;" />
]

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## Predation

#### Important, widespread effects on:

- Community structure

.pull-left[
- In the presence of starfish, mussels and barnacles coexist

- If starfish are experimentally removed, competitive exclusion of barnacles
    + mussels are the dominant competitor but also the preferred prey

- *competitor-mediated coexistance*
]

.pull-right[

<img src="figs/cmc.png" width="80%" style="display: block; margin: auto;" />
]

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## Predation

#### Important, widespread effects on:

- Regulation of abundance and population dynamics of both predator and prey

--
#### Do predators control the abundance of their prey?

--
##### Yes

- Introduced rats, mongoose, and cats have caused the extinction of at least 43 bird species

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## Predation

#### Important, widespread effects on:

- Regulation of abundance and population dynamics of both predator and prey

#### Do predators control the abundance of their prey?

##### Yes

- Invasive brown tree snakes caused the extinction of 10 bird species on the island of Guam

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## Predation

#### Important, widespread effects on:

- Regulation of abundance and population dynamics of both predator and prey

#### Do predators control the abundance of their prey?

##### Yes

- Mesopredator release

.pull-left[
<img src="https://upload.wikimedia.org/wikipedia/commons/f/f5/Kojote2010.JPG" width="75%" style="display: block; margin: auto;" />
]

.pull-right[
<img src="https://upload.wikimedia.org/wikipedia/commons/6/69/Raccoons_eat_deer.png" width="75%" style="display: block; margin: auto;" />
]

---
## Predation

#### Important, widespread effects on:

- Regulation of abundance and population dynamics of both predator and prey

#### Do predators control the abundance of their prey?

#### Maybe?

.pull-left[
<img src="https://upload.wikimedia.org/wikipedia/commons/d/dc/Eurasian_wolf.JPG" width="75%" style="display: block; margin: auto;" />
]

.pull-right[
<img src="https://upload.wikimedia.org/wikipedia/commons/c/c9/Moose-Gustav.jpg" width="75%" style="display: block; margin: auto;" />
]

---
## Predation

#### Important, widespread effects on:

- Regulation of abundance and population dynamics of both predator and prey

#### Do predators control the abundance of their prey?

- On Island Royale, wolf/moose populations are linked but also influenced by vegetation and winter severity

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# How do predators impact prey population?

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## How do predators impact prey population?

#### Predation rate `$(\large P)$`

> Percentage of prey population killed per unit time

`$$\large P = \frac{\#\; prey\; killed}{Prey\; abundance} \times 100$$`

--
- Number of prey killed = numerical response `$\times$` functional response

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class: inverse, middle, center

# Numerical response

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## Numerical response

#### Change in number of predators as prey abundance changes

- Number of predators present at a given prey density

--
- Function of how prey influence `$B$` `$D$` of predator

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## Numerical response

#### Change in number of predators as prey abundance changes

- Number of predators present at a given prey density

- Function of how prey influence `$B$` `$D$` of predator

- Predators may also congregate at prey source: *aggregative response*

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## Numerical response

#### When introduced prey lead to large numerical response of predators, native prey can suffer

- high abundance of predators leads to unsustainable predation on native prey

-  **hyperpredation**

.pull-left[
<img src="https://upload.wikimedia.org/wikipedia/commons/9/9b/Wild_hog_%286887959199%29.jpg" width="80%" style="display: block; margin: auto;" />
]

.pull-left[
<img src="https://upload.wikimedia.org/wikipedia/commons/f/f4/Golden_eagle_at_ACES_%2811809%29.jpg" width="40%" style="display: block; margin: auto;" />

]

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class: inverse, middle, center

# Functional response

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## Functional response

#### Also known as the *kill rate*

> number of prey killed per predator per unit of time

- as number of prey increases, kills rate should change 
    + search time
    + handling time
    + satiation

--
#### Type II

---
## Functional response

#### Also known as the *kill rate*

> number of prey killed per predator per unit of time

- as number of prey increases, kills rate should change 
    + search time
    + handling time
    + satiation

#### Type III

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class: inverse, middle, center

# Total predation rate

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## Total predation rate

`$$\large P = \frac{Numerical\;response \times\;functional\;response}{Prey\; abundance} \times 100$$`
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<img src="Lecture18_files/figure-html/unnamed-chunk-33-1.png" style="display: block; margin: auto;" />

<img src="Lecture18_files/figure-html/unnamed-chunk-34-1.png" style="display: block; margin: auto;" />
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<br/>
<br/>

<img src="Lecture18_files/figure-html/unnamed-chunk-35-1.png" style="display: block; margin: auto;" />
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## Total predation rate

`$$\large P = \frac{Numerical\;response \times\;functional\;response}{Prey\; abundance} \times 100$$`

.pull-left[
As prey numbers increase:
- predation rate goes down

- survival rate increases

- prey population "escapes" regulation by predator

As prey numbers decrease:
- predation rate goes up

- survival rate decreases

- prey population declines (Allee effect)
]

.pull-right[
<br/>
<br/>

<img src="Lecture18_files/figure-html/unnamed-chunk-36-1.png" style="display: block; margin: auto;" />
]

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## Total predation rate

`$$\large P = \frac{Numerical\;response \times\;functional\;response}{Prey\; abundance} \times 100$$`

.pull-left[
<img src="Lecture18_files/figure-html/unnamed-chunk-37-1.png" style="display: block; margin: auto;" />

<img src="Lecture18_files/figure-html/unnamed-chunk-38-1.png" style="display: block; margin: auto;" />
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--
.pull-right[
<br/>
<br/>

<img src="Lecture18_files/figure-html/unnamed-chunk-39-1.png" style="display: block; margin: auto;" />
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## Predation

#### Other considerations

- Is increased predation compensated by higher fecundity?

- Which individuals are killed?

- Human dimensions