Deal et al., 2017 (cannibalistic gobies)

Question 1

Tradeoffs between … and … reproduction mean that factors that diminish a parent’s … prospects, such as increased … risk, are expected to increase investment in … …

Answer 1

current, future, survival, predation, current offspring

Question 2

Parental consumption of their own offspring is known as … …

Answer 2

filial cannibalism

Question 3

This study examined filial cannibalism and … … in a small fish with … egg care: the … …, both when exposed to a common predator of theirs: the …, and in the absence of predators.

Answer 3

nest characteristics, paternal, sand goby, perch

Question 4

Found that when males consumed some of their eggs (… filial cannibalism), the number of eggs eaten did not depend on … threat. This could indicate that…

Answer 4

partial, predation

partial clutch consumption is largely motivated by benefits to existing young.

Question 5

… filial cannibalism (whole clutch consumption) was marginally … common under predator exposure, while its strongest predictor was … … ….

This suggests that the return on parental investment has a greater influence on total filial cannibalism than the likelihood of … ….

Answer 5

Total, less, small clutch size, future breeding

Question 6

Regarding nest characteristics: males that consumed their entire brood after exposure to a predator built … … …, possibly to facilitate predator ….

Males that cared for at least part of their brood, however, maintained … … … regardless of … ….

Answer 6

larger nest openings, evasion

small nest entrances (leaves eggs less vulnerable), predation threat

Question 7

More … nests were NOT associated with … egg consumption, suggesting that filial cannibalism is not employed to sustain … ….

Answer 7

elaborate, greater, nest building.

Question 8

Parental care provides fitness benefits to parents via … … of young, though it can be … (e.g. time and energy could be spent foraging, it is energetically demanding itself, increased predation risk).

Answer 8

increased survival, costly

Question 9

A range of factors can alter the optimal balance of investment in current or future offspring. For example, parents may benefit by investing more into a current brood when…

However, if there are many opportunities to breed in the future, parents may be more inclined to … or even … investment into existing young to mitigate the costs of current reproduction.

Answer 9

chances of future reproduction are low (e.g. due to disease or predation risk)

reduce, terminate
- e.g. consuming young

Question 10

Consuming one’s own young not only prevents the … of parental care from negatively affecting future reproduction, but can also provide … and … to parents. … filial cannibalism could potentially provide parents with more resources and nutrients that can be used to support the parent in caring for … young, or could give the uneaten young a higher chance of survival due to reduced crowding within the nest and less individuals to share resources with.

Answer 10

costs, energy, nutrition, Partial, uneaten

Question 11

In acts of total filial cannibalism the motivation is likely to be solely…

Answer 11

an investment in future reproduction

Question 12

Therefore, parents are expected to commit more filial cannibalism when…

Answer 12

the potential for future reproduction is high

• not all empirical evidence supports this predictions, e.g. filial cannibalism is not more likely in the breeding season, despite increased prospects of future reproduction

Question 13

Individuals do not usually … to participate in multiple … ….

Answer 13

survive, breeding seasons

Question 14

Total filial cannibalism in sand gobies appears to be a facultative strategy employed when the costs of providing care to young are his hand the potential benefits low. However, certain factors that should promote future reproductive success, such as heightened access to gravid females, have…

Answer 14

not been found to be linked with higher rates of total filial cannibalism

Question 15

Larger males were selected as….

Answer 15

they are dominant and smaller males are often prevented from spawning or resort to sneak spawning tactics

Question 16

The plastic plant provided … for the male gobies in the … treatment, but was also added to the … treatment to ensure that all fish were subject to … stimuli.

Answer 16

refuge, predator, control, novel

Question 17

All males consumed at least some eggs (min = 12), and … of the 64 males in the final sample engaged in total filial cannibalism

Answer 17

18

Question 18

Males with small initial clutches were…

Answer 18

significantly more likely to engage in total filial cannibalism

Question 19

Exposure to a perch also tended to…

Answer 19

decrease the likelihood of a male engaging in total clutch cannibalism, occurring in 21% of perch-exposed males, compared to 33% of unexposed males - this effect was marginally nonsignificant - more research required

Question 20

With regards to partial filial cannibalism…

Answer 20

none of the potential predictors examined, including predation treatment, had significant effects on the numbers of eggs eaten.

Question 21

Total filial cannibals lost significantly … … than did partial filial cannibals

Answer 21

less weight

Question 22

The height and width of nest entrances was … to the predation treatment among partial filial cannibals, whereas among total filial cannibals, exposure to a perch was associated with…

Answer 22

unrelated (perhaps care-giving males do not compromise nest maintenance when confronted by a predator)

significantly taler and wider nest entrances

Question 23

For total filial cannibals only, consumption of … eggs was associated with piling less sand above the nest

Answer 23

more

(sand piling is thought to conceal the nest better - perhaps less important if you’ve eaten all your young)

• no evidence that energy from egg consumption is used for nest construction

Question 24

This study provides insufficient evidence that…

Answer 24

parental predation risk influences filial cannibalism

Question 25

It suggests that a threat of predation may have a more prominent effect on … … …

Answer 25

total filial cannibalism (rather than partial)

Question 26

Total filial cannibalism is thought to only be adaptive if parents can … to … again, which does depend on avoiding predation. Partial filial cannibalism, on the other hand, may be less influenced by predation risk as it can benefit parents in ways that do not depend on further reproduction, such as through…

Answer 26

survive, reproduce,

improved survival of existing young

Question 27

Neither form of filial cannibalism was related to male body condition - this goes against the idea that males in…

Answer 27

poor condition use filial cannibalism to replenish energy reserves

Question 28

The finding that males were more likely to engage in total filial cannibalism when clutch size was …, suggests that the benefits of TFC … the costs of offspring consumption when brood size is …

Answer 28

small, outweigh, small