Tri-axial accelerometry shows differences in energy expenditure and parental effort throughout the breeding season in long-lived raptors

Abstract Cutting-edge technologies are extremely useful to develop new workflows in studying ecological data, particularly to understand animal behaviour and movement trajectories at the individual level. Although parental care is a well-studied phenomenon, most studies have been focused on direct observational or video recording data, as well as experimental manipulation. Therefore, what happens out of our sight still remains unknown. Using high-frequency GPS/GSM dataloggers and tri-axial accelerometers we monitored 25 Bonelli’s eagles (Aquila fasciata) during the breeding season to understand parental activities from a broader perspective. We used recursive data, measured as number of visits and residence time, to reveal nest attendance patterns of biparental care with role specialization between sexes. Accelerometry data interpreted as the Overall Dynamic Body Acceleration, a proxy of energy expenditure, showed strong differences in parental effort throughout the breeding season and between sexes. Thereby, males increased substantially their energetic requirements, due to the increased workload, while females spent most of the time on the nest. Furthermore, during critical phases of the breeding season, a low percentage of suitable hunting spots in eagles’ territories led them to increase their ranging behaviour in order to find food, with important consequences in energy consumption and mortality risk. Our results highlight the crucial role of males in raptor species exhibiting biparental care. Finally, we exemplify how biologging technologies are an adequate and objective method to study parental care in raptors as well as to get deeper insight into breeding ecology of birds in general.

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Energy Expenditure in Reproductive Effort of Male and Female Killdeer (Charadrius vociferus)

The Auk ◽

10.1093/auk/105.3.553 ◽

1988 ◽

Vol 105 (3) ◽

pp. 553-564 ◽

Cited By ~ 20

Author(s):

Dianne H. Brunton

Keyword(s):

Reproductive Success ◽

Energy Expenditure ◽

Parental Care ◽

Breeding Season ◽

Reproductive Effort ◽

Mating Effort ◽

Parental Effort ◽

Nest Failure ◽

Male And Female ◽

Charadrius Vociferus

Abstract The reproductive investment strategies of the sexes during the breeding season are detailed for Killdeer (Charadrius vociferus), a monogamous plover. I measured the energy investments of the sexes in reproductive, mating, and parental effort. As predicted, males expend more mating effort than females; however, the sexes expend equal amounts of parental effort. Total energy expenditure in reproductive effort (mating and parental effort) during a successful nesting attempt was also equal for the sexes. However, early parental effort expenditures by females, early mating effort expenditures by males, and high rates of nest failure combine to result in female reproductive energy expenditures being significantly higher over the breeding season. This suggests that energy expenditure alone is not adequate for accurate comparisons of the relative investments of the sexes. Studies investigating male and female investments need to consider the degree and pattern of nest failures along with patterns of energy expenditure. The advantages to male and female Killdeer of sharing parental care is demonstrated using adult removal experiments. In general, a deserted parent expends more energy in parental effort than a bi-parental parent and has significantly lower reproductive success. However, males are able to hatch chicks, whereas females lose or abandon their nests within a few days of mate removal. Thus, monogamy in Killdeer appears to result from high nest failure rates, the necessity of two parents for any reproductive success, and the generalizable nature of Killdeer parental care.

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Sharing the burden: on the division of parental care and vocalizations during incubation

Behavioral Ecology ◽

10.1093/beheco/arz049 ◽

2019 ◽

Vol 30 (4) ◽

pp. 1062-1068 ◽

Cited By ~ 4

Author(s):

Marwa M Kavelaars ◽

Luc Lens ◽

Wendt Müller

Keyword(s):

Reproductive Success ◽

Parental Care ◽

Reproductive Output ◽

Biparental Care ◽

Parental Effort ◽

Levels Of Care ◽

Incubation Behavior ◽

Evolutionary Conflict ◽

Larus Fuscus ◽

Nestling Period

Abstract In species with biparental care, individuals only have to pay the costs for their own parental investment, whereas the contribution of their partner comes for free. Each parent hence benefits if its partner works harder, creating an evolutionary conflict of interest. How parents resolve this conflict and how they achieve the optimal division of parental tasks often remains elusive. In this study, we investigated whether lesser black-backed gulls (Larus fuscus) divide parental care during incubation equally and whether this correlates with the extent of vocalizations between pair-members during incubation. We then investigated whether pairs showing more evenly distributed incubation behavior had a higher reproductive success. To this end, we recorded incubation behavior and vocalizations for 24-h time periods. Subsequently, we experimentally increased or decreased brood sizes in order to manipulate parental effort, and followed offspring development from hatching till fledging. Although incubation bouts were, on average, slightly longer in females, patterns varied strongly between pairs, ranging from primarily female incubation over equal sex contributions to male-biased incubation. Pairs contributing more equally to incubation vocalized more during nest relief and had a higher reproductive output when brood sizes were experimentally increased. Thus, vocalizations and a more equal division of parental care during incubation may facilitate higher levels of care during the nestling period, as suggested by a greater reproductive success when facing high brood demand, or they indicate pair quality.

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Male Parental Care and Extrapair Copulations in the Indigo Bunting

The Auk ◽

10.1093/auk/105.1.149 ◽

1988 ◽

Vol 105 (1) ◽

pp. 149-160 ◽

Cited By ~ 8

Author(s):

David F. Westneat

Keyword(s):

Parental Care ◽

Breeding Season ◽

Brood Size ◽

Current Theory ◽

Mating Effort ◽

Parental Effort ◽

Young Males ◽

Passerina Cyanea ◽

Male Care ◽

The Relationship

Abstract Levels of parental care by male Indigo Buntings (Passerina cyanea) were predicted to be lower and the tendency to pursue extrapair matings greater when (1) the opportunity of additional matings (extrapair copulations) was high, (2) the male was cuckolded, and (3) the clutch or brood size was small. Observations of male care revealed that approximately 10% of all males fed nestlings at least once, whereas more than 30% fed fledglings. Males in their first breeding season were never seen feeding young. Males made more trips off their territories when females were fertilizable on nearby territories, but other measures of parental care (feeding young and time spent within 10 m of nest) were not affected. Cuckolded males (known through genetic analyses of parents and offspring) tended to feed young less often, but forayed off their territories significantly less than apparently uncuckolded males. Finally, males with small clutches or broods gave slightly, but not significantly, less care than males with large clutches or broods. These results suggest that the relationship between mating effort and parental effort is complicated by the presence of extrapair copulations as a type of mating effort, and that factors not included in current theory on parental care might influence a male's parental care.

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Parental-care responses by yellow warblers (Dendroica petechia) to simultaneous manipulations of food abundance and brood size

Canadian Journal of Zoology ◽

10.1139/z98-011 ◽

1998 ◽

Vol 76 (5) ◽

pp. 916-924 ◽

Cited By ~ 4

Author(s):

G A Lozano ◽

R E Lemon

Keyword(s):

Parental Care ◽

Brood Size ◽

Theoretical Models ◽

Food Abundance ◽

Biparental Care ◽

Parental Effort ◽

Dendroica Petechia ◽

Supplemental Food ◽

Yellow Warblers ◽

Partial Compensation

Theoretical models view biparental care as a state of equilibrium that can be maintained only when the amount of parental care provided by one parent depends on the amount provided by its mate. According to these models, biparental care results when a decrease in the contribution of one parent is partially, but not completely, compensated for by an increase in the contribution of the other parent. Furthermore, this equilibrium state can only be stable if any other external factor affects male and female effort equally. We used yellow warblers (Dendroica petechia) to examine whether changes in brood size and food abundance affect the parental contributions of the sexes equally. Supplemental food did not affect parental care by either sex, but brood size did. Both males and females provided more to larger broods, and in large broods only, their provisioning rates increased with nestling age. Parental effort per nestling was similar in the two sexes, being higher for smaller broods and increasing with nestling age. Based on brood biomass, parental effort was greater for smaller broods, and decreased with nestling age in females only. Therefore, in agreement with current models of the maintenance of biparental care, the effects of brood size and nestling age on parental care did not differ significantly between the sexes. Nonetheless, data from other species and theory indicate that the costs and benefits of providing parental care differ between the sexes, so it is unlikely that biparental care can be maintained solely by a partial compensation response.

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Sex Roles in the American Oystercatcher

Behaviour ◽

10.1163/156853985x00145 ◽

1985 ◽

Vol 95 (3-4) ◽

pp. 232-260 ◽

Cited By ~ 14

Author(s):

Erica Nol

Keyword(s):

Energy Expenditure ◽

Parental Care ◽

Breeding Season ◽

Sex Roles ◽

Breeding Stage ◽

American Oystercatcher ◽

Males And Females

AbstractAmerican oystercatchers have extensive parental care. As a result sex roles are similar and highly complementary. During the pre-laying period the roles of males and females, except during copulation, are indistinguishable. During the laying period the roles diverge slightly with males spending more time chasing conspecifics. Presumably the similarity during pre-laying, and the differences during laying, function to prevent the male from being cuckolded. Males begin assisting in incubation as soon as the females begin incubating and then consistently perform the same proportion of incubation throughout this breeding stage. During incubation, females incubate more often than males, and consequently rest less, preen less and fly less than males. During chick-rearing males are involved in more chases than females and take more foraging trips to provision young but wait longer between successive trips. The pattern of foraging by each sex is complementary. Breeding season energy expenditure is approximately equal in both sexes. There is no evidence for conflict between the sexes over the contributions to parental care. Where sex roles diverge the differences in behaviour can be partly explained by the relative energetic efficiencies of each sex performing different tasks.

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New Nesting Records and Breeding Ecology Observations of Rufous-legged Owls in the Mediterranean Temperate Forest of Central Chile

Journal of Raptor Research ◽

10.3356/jrr-20-116 ◽

2021 ◽

Author(s):

Martín A. H. Escobar ◽

M. Angélica Vukasovic ◽

Jorge A. Tomasevic ◽

Sandra V. Uribe ◽

Ana M. Venegas ◽

...

Keyword(s):

Clutch Size ◽

Temperate Forest ◽

Breeding Ecology ◽

Ecological Data ◽

Central Chile ◽

Monterey Pine ◽

Nestling Diet ◽

Nestling Period ◽

Nothofagus Forests ◽

Southern Beech

ABSTRACT The Rufous-legged Owl (Strix rufipes) is the southernmost Strix owl species and its breeding ecology remains little known. We report new observations on the species' breeding ecology, including clutch size, egg size, duration of the incubation and nestling periods, and nestling diet. We conducted our observations on nests found during the summers of 1999 through 2004 in a forestry landscape of central Chile, dominated by Monterey pine (Pinus radiata) plantations with intermixed fragments of native southern beech (Nothofagus) forests. Clutch size was two eggs (n = 2 nests), with one egg larger than the other (mean = 48.8 × 40.1 mm). The incubation period was 30 d and the nestling period 34 d. We analyzed 10 pellets from nestling owls and identified 45 prey items, mostly dominated by large beetles, grasshoppers, and rodents (native and exotic). This information, though based on a limited number of nests, provides baseline ecological data that can inform future studies.

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Breeding ecology of the fairy martin

Australian Journal of Zoology ◽

10.1071/zo98041 ◽

1999 ◽

Vol 47 (5) ◽

pp. 463 ◽

Cited By ~ 10

Author(s):

Michael J. L. Magrath

Keyword(s):

Breeding Season ◽

Weather Conditions ◽

Adult Mortality ◽

First Year ◽

Breeding Ecology ◽

Adult Males ◽

Annual Productivity ◽

Adverse Weather ◽

Colony Site ◽

The One

The breeding biology of the fairy martin, Hirundo ariel, was studied over three years (1992–95) in the Yarra Valley, Victoria. Adult males and females in this population were morphologically similar, though only females acquired a brood patch during the breeding season. Colonies ranged in size from 8 to 29 nests. Birds arrived in the study area in September and usually commenced laying in October, though nesting activities were generally asynchronous both between and within colonies. Most colonies contained active nests until February. At least 16% of adults and 5% of fledglings, on average, returned to the study area in the following year. Returning adults generally nested at the same colony site as the previous year, while most first-year birds nested at sites other than their natal colony. Adult males were more likely to return than adult females. Clutch size ranged from 2 to 5, with a mean of 3.5, and declined over the season. The incubation period varied from 12 to 18 days with a mean of 13.7. A mean of 1.8 chicks fledged per completed clutch, while 60% of clutches produced at least one chick. The period from hatching to fledging varied from 17 to 32 days, with a mean of 22.1, and increased with brood size. Fledging success was highest during the middle of the breeding season. Adverse weather conditions, resulting in the abandonment of clutch and brood, were the most common cause of nest failure, and on several occasions also resulted in adult mortality. Almost half the breeding females produced at least two clutches in the one season. Pairs produced from 0 to 8 fledglings per season, with those that commenced nesting earlier in the season having higher annual productivity. These results are discussed in relation to the breeding ecology of other members of the Hirundinidae.

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Male parental investment reflects the level of partner contributions and brood value in tree swallows

10.1101/216119 ◽

2017 ◽

Author(s):

Ádám Z. Lendvai ◽

Çağlar Akçay ◽

Mark Stanback ◽

Mark F. Haussmann ◽

Ignacio T. Moore ◽

...

Keyword(s):

Parental Care ◽

Interesting Case ◽

Temporary Increase ◽

Southern Population ◽

Tree Swallows ◽

Parental Effort ◽

Northern Population ◽

Nestling Begging ◽

Two Populations ◽

Partial Compensation

AbstractBiparental care presents an interesting case of cooperation and conflict between unrelated individuals. Several models have been proposed to explain how parents should respond to changes in each other’s parental care to maximize their own fitness, predicting no change, partial compensation, or matching effort as a response. Here, we present an experiment in tree swallows (Tachycineta bicolor) in which we increased the parental care of females by presenting them, but not their mates, with additional nestling begging calls using automated playbacks. We performed this experiment in two populations differing in future breeding opportunities and thus the intensity of conflict over current parental care. We found that in response to a temporary increase in female parental effort, males in the northern population with lower sexual conflict matched the increased effort, whereas males in the southern population did not. We also found that increases in parental care during playbacks were driven by the females (i.e., females initiated the increased effort and their mates followed them) in the northern population but not the southern population. These results support the idea that with incomplete information about the brood value and need, cues or signals from the partner might become important in coordinating parental care.

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Description of the reproductive behavior of Symphysodon aequifasciatus (Cichlidae) in captivity

Acta Amazonica ◽

10.1590/1809-4392201600234 ◽

2016 ◽

Vol 46 (4) ◽

pp. 433-438 ◽

Cited By ~ 2

Author(s):

Douglas da Cruz MATTOS ◽

Rafaela SCRENCI-RIBEIRO ◽

Leonardo Demier CARDOSO ◽

Manuel Vazquez Vidal JUNIOR

Keyword(s):

Parental Care ◽

Reproductive Behavior ◽

Amazon Basin ◽

Color Change ◽

Biparental Care ◽

Reproductive Process ◽

Second Stage ◽

In Captivity ◽

Two Stages ◽

Couple Formation

ABSTRACT The blue discus (Symphysodon aequifasciatus) is often sold for ornamental purposes. It is a neotropical cichlid from South America, which is native to the rivers of the Amazon basin of Brazil, Peru and Colombia. The purpose of this study was to characterize the reproductive behavior of S. aequifasciatus and identify features that can later be used by breeders to facilitate the handling and reproduction of this species in captivity. The experiment was divided into two stages: the first dealt with partner selection and couple formation to observe the behaviors of territoriality, pursuing, fleeing, biting, stay, protecting and cleaning of the substrate. The second stage documented mating behavior, nesting and parental care, to observe vibration, spawning, permanence with the offspring, aeration of eggs, cleaning of spawning, color change and shift-taking in parental care. The results of the study allowed identifying disputes for and establishment of territory, as well as the selection and cleaning of the substrate for spawning performed by both sexes. The parental care was observed from spawning in the substrate until the care for the larvae. It was found that the reproductive success of this species is closely linked to biparental care observed during the entire reproductive process and early stages of the hatchings.

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Division of parental duties confirms a need for bi-parental care in a precocial bird, the mute swan Cygnus olor

Animal Biology ◽

10.1163/15707563-00002468 ◽

2015 ◽

Vol 65 (2) ◽

pp. 163-176 ◽

Cited By ~ 3

Author(s):

Radosław Włodarczyk ◽

Piotr Minias

Keyword(s):

Parental Care ◽

Breeding Season ◽

Time Budget ◽

Empirical Support ◽

European Population ◽

Mute Swan ◽

Cygnus Olor ◽

Territory Defence ◽

Male Activity ◽

Reproductive Activities

Parental investment is much reduced in precocial species when compared with altricial species, which may explain a predominance of uni-parental care in this group of birds. In precocial wildfowl, bi-parental care is mostly restricted to arctic-breeding species, where the short reproductive season forces mates to cooperate in caring for the young, but a temperate breeding mute swan Cygnus olor is one of the few notable exceptions. In order to explain a need for bi-parental care in this species, we collected data on the time-budget of eleven swan breeding pairs from a Central European population. We found sex-related differences in the mean time allocated to incubation, movement, feeding, resting and aggression. Others behaviours (nest maintenance, alert and comfort) changed along the breeding season, but did not differ between sexes. Females were primarily responsible for providing care to the brood, whereas male activity focused on territory defence and family guarding. Females were exclusively responsible for incubation and they covered 85% of the total time allocated by parents to feeding cygnets. Nearly constant incubation in females limited possibilities for other activities, including foraging. Males allocated significantly more time than females to aggressive interactions, directed mainly towards other breeding pairs and non-breeders. A clear division of parental duties between sexes gave empirical support for the presence of bi-parental care in the mute swan, despite the fact that reproductive activities of this species are not constrained by the short length of the breeding season, as in arctic-breeding wildfowl.

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