Distribution of the parental care in the Iberian magpie Cyanopica cooki: worker males but lazy helpers?

Abstract In many species of cooperative breeding birds, breeders and helpers participate in the parental care with different food provision rules. Normally, helpers feed nestlings less frequently and with smaller quantities of food than breeders. But studies analysing the reaction of feeders to nestling demand are scarce and rarely measure the quantity of food that is actually delivered. In this study, we analysed the provisioning effort of breeders and helpers in the Iberian Magpie, Cyanopica cooki, and how this effort varies with brood demand. We did so by measuring the nestling feeding rate and the biomass supply of each individual. In this way, we obtained a more accurate measurement of the investment assumed by each individual belonging to each status. We found that breeding males visited the nest more often than both breeding females and helpers (mean = 2.24; 0.85 and 1.58, respectively). Furthermore, breeding males delivered more biomass in each feeding visit to the nest than those from other statuses. Breeders, both male and female, increased their parental effort (i.e., provisioning rate and biomass) when brood demand was higher (i.e., more siblings and older nestlings), whereas helpers contributed differently to the nest, but depending on the two types of helpers occurring in this species. Differences in the possible benefits obtained by breeders and helpers may explain these different strategies. In addition, male and female breeders (but not helpers) reduce the feeding rate throughout the breeding season. Thus, in the Iberian magpie, breeders and helpers reveal different patterns of investment depending on nestling food demand.

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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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Prolactin and the regulation of parental care and helping behavior in cooperatively breeding white-browed sparrow weaver societies

10.1101/2021.09.22.461403 ◽

2021 ◽

Author(s):

Lindsay A Walker ◽

Linda Tschirren ◽

Jennifer E York ◽

Peter J Sharp ◽

Simone L Meddle ◽

...

Keyword(s):

Parental Care ◽

Cooperative Breeding ◽

Natural Variation ◽

Underlying Mechanism ◽

Helping Behavior ◽

Fine Scale ◽

Physiological Mechanisms ◽

Nestling Provisioning ◽

Cooperatively Breeding ◽

Nestling Feeding

In many cooperatively breeding societies non-breeding individuals help to rear the offspring of breeders. The physiological mechanisms that regulate such cooperative helping behavior are poorly understood, but may have been co-opted, during the evolution of cooperative breeding, from pre-existing mechanisms that regulated parental care. Key among these may be a role for prolactin. Here we investigate whether natural variation in circulating prolactin levels predicts both parental and helper contributions to nestling provisioning in cooperatively breeding white-browed sparrow weavers, Plocepasser mahali. In sparrow weaver groups, a single dominant pair monopolize reproduction and non-breeding subordinates help with nestling feeding. We show that: (i) among parents, dominant females feed nestlings at higher rates, make longer provisioning visits and have higher prolactin levels than dominant males; and (ii) among subordinates, engaged in cooperative helping behavior, those within their natal groups feed nestlings at higher rates and have higher prolactin levels than immigrants. Moreover, continuous variation in prolactin levels positively predicts nestling-provisioning rates and mean provisioning visit durations when all bird classes are combined. These relationships are principally driven by differences among bird classes in both circulating prolactin levels and provisioning traits; the more limited within-class variation in prolactin and provisioning traits were not evidently correlated, highlighting a likely role for additional mechanisms in the fine-scale regulation of care. Our findings broadly support the hypothesis that parental care and cooperative helping behavior are regulated by a common underlying mechanism and highlight the need for experimentation to now establish the causality of any role for prolactin.

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Behavioural Differences Between Zebrafinch and Bengalese Finch (Foster) Parents Raising Zebrafinch Offspring

Behaviour ◽

10.1163/156853982x00139 ◽

1982 ◽

Vol 81 (2-4) ◽

pp. 152-172 ◽

Cited By ~ 59

Author(s):

Carel TEN CATE

Keyword(s):

Parental Care ◽

Sexual Behaviour ◽

Foster Parents ◽

Species Differences ◽

Sexual Preference ◽

Male And Female ◽

Bengalese Finch ◽

Parental Behaviour ◽

The Moment ◽

Sexually Mature

AbstractSexually mature zebrafinch males show a sexual preference for the species which has raised them. IMMELMANN (1972 a, b) stated that such a preference develops more readily if zebrafinch males were exposed to their own species than to Bengalese finches. The explanation for this phenomenon has been the supposition that an initial bias for the own species exists which is independent of post hatch experience. This hypothesis presupposes the absence of differences in behaviour between zebrafinch and Bengalese finch parents raising zebrafinch offspring. To investigate this supposition, the parental behaviour of zebrafinch and Bengalese finch (foster)parents raising zebrafinch offspring was observed. This was done in pure pairs (male and female of the same species) as well as in mixed pairs (male and female of different species). Differences between both species were found in parental care, and in clumping, allopreening, aggressive and sexual behaviour directed to zebrafinch young; most clearly in mixed, but often in pure pairs too. These differences were present from a few days after hatching till the moment of separating parents and young at about day 57. The kind of differences gradually changed during this period. Zebrafinch young are thus not exposed to equivalent experience with zebrafinch and Bengalese finch parents. The observed differences in experience may underly the more readily developing preference for zebrafinch than for Bengalese finch. This alternative should be explored more thorougly before the initial bias hypothesis is accepted.

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Fledgling care and male parental effort in the Hooded Warbler (Wilsonia citrina)

Canadian Journal of Zoology ◽

10.1139/z97-071 ◽

1997 ◽

Vol 75 (4) ◽

pp. 576-581 ◽

Cited By ~ 29

Author(s):

Lesley J. Evans Ogden ◽

Bridget J. M. Stutchbury

Keyword(s):

Parental Care ◽

Parental Effort ◽

Feeding Rates ◽

Male And Female ◽

Wilsonia Citrina ◽

Parental Feeding ◽

Nestling Period ◽

Brood Division ◽

Hooded Warblers ◽

Care Period

We followed family groups of Hooded Warblers (Wilsonia citrina) from hatching through to fledgling independence to determine (i) the duration and extent of parental care of fledglings, (ii) the extent of brood division, and (iii) whether male parental effort in caring for nestlings predicts male effort in caring for fledglings. The 9-day nestling period of Hooded Warblers was followed by 4 – 6 weeks of further parental care of fledged young. Parental feeding rates increased from hatching to when the young fledged from the nest, and males fed nestlings significantly more than females did. At the fledgling stage feeding rates to fledglings were significantly higher than at the nestling stage, but there was no difference in feeding rates between the parents. Parents usually divided the brood of fledglings equally, so that each parent assumed full and exclusive care of a subset of the brood. However, many females (45%) initiated a second brood and the male assumed care of the entire first brood at the time when his mate began incubating. The proportion of feeding trips to nestlings made by the male was not predictive of his subsequent effort in the care of fledglings. Exclusion of the fledgling care period in studies of parental investment may give a biased picture of overall investment on the part of both male and female parents.

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

Current Zoology ◽

10.1093/cz/zoab010 ◽

2021 ◽

Author(s):

Pascual LÓPEZ-LÓPEZ ◽

Arturo M PERONA ◽

Olga EGEA-CASAS ◽

Jon ETXEBARRIA MORANT ◽

Vicente URIOS

Keyword(s):

Energy Expenditure ◽

Parental Care ◽

Breeding Season ◽

Video Recording ◽

Experimental Manipulation ◽

Biparental Care ◽

Breeding Ecology ◽

Parental Effort ◽

Ecological Data ◽

Movement Trajectories

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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Sex, Coalitions, and Politics in Preindustrial Societies

Politics and the Life Sciences ◽

10.1017/s0730938400017214 ◽

1992 ◽

Vol 11 (1) ◽

pp. 63-80 ◽

Cited By ~ 31

Author(s):

Bobbi S. Low

Keyword(s):

Sex Differences ◽

Cross Cultural ◽

Resource Acquisition ◽

Political Activity ◽

Mating Effort ◽

Parental Effort ◽

Male And Female

Broadly defined, political activity normally involves some form of coalition, usually centering upon resource acquisition, and is not restricted to humans. Male and female mammals appear to have evolved to seek and use resources differently—males to get mates (mating effort) and females to raise healthy, successful offspring (parental effort). Because the return curves for these two types of effort differ in shape, several predictions follow about sex differences in political activity. These predictions are tested using the 93 odd-numbered societies of the Standard Cross-Cultural Sample. Results offer insights into current patterns of male and female political activity in Western societies.

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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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Annual Reproductive Yield in the Cooperative Pygmy Nuthatch (Sitta pygmaea)

The Auk ◽

10.1093/auk/105.1.70 ◽

1988 ◽

Vol 105 (1) ◽

pp. 70-77 ◽

Cited By ~ 8

Author(s):

William J. Sydeman ◽

Marcel Güntert ◽

Russell P. Balda

Keyword(s):

Reproductive Success ◽

Cooperative Breeding ◽

Reproductive Output ◽

Breeding Birds ◽

Overwinter Survival ◽

Northern Arizona ◽

Floral Diversity ◽

Indirect Fitness ◽

The Difference ◽

The Relationship

Abstract We studied cooperative-breeding Pygmy Nuthatches (Sitta pygmaea) for 4 yr in northern Arizona. Breeding units contained 2-5 birds. Helpers were found at about 30% of all nests. All helpers that later bred on the study area were male. Helpers were mostly yearlings, and offspring or siblings of the birds that they aided, but often aided at least one unrelated breeder. Breeding units with helpers produced significantly more young than those without helpers. Breeding units in habitats with the greatest floral diversity and structural maturity fledged significantly more young than those in other habitats. Habitat did not influence the effect of helpers. Year effects increased the strength of the relationship between helpers and annual reproductive output. Previous breeding experience and pair-bond duration were not related to reproductive success. Total brood loss, although rare, was responsible for the difference in reproductive output among pairs with and without helpers and between habitats. Breeding birds with helpers benefit by an increase in direct fitness. The advantage to the helpers is not clear but may be an increase in indirect fitness associated with aiding relatives. Helpers may benefit directly, however, by sharing roosting cavities on a group territory thereby enhancing overwinter survival.

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Nest Building is an Indicator of Parental Quality in the Monogamous Neotropical Buff-Breasted Wren (Thryothorus Leucotis)

The Auk ◽

10.1093/auk/122.4.1169 ◽

2005 ◽

Vol 122 (4) ◽

pp. 1169-1181 ◽

Cited By ~ 1

Author(s):

Sharon A. Gill ◽

Bridget J. M. Stutchbury

Keyword(s):

Mate Preferences ◽

Nest Building ◽

Nest Construction ◽

Dual Roles ◽

Male And Female ◽

Nestling Provisioning ◽

Feeding Effort ◽

Nestling Feeding ◽

Thryothorus Leucotis ◽

Parental Ability

Abstract In species with long-term partnerships, optimal mate preferences may differ from actual mate choice, and pair displays that advertise individual quality may be expected. We examined the relationship between nest-building and nestling-provisioning effort in Neotropical Buff-breasted Wrens (Thryothorus leucotis) to determine whether male or female expenditure during nest construction was used as an indicator of subsequent parental ability. Buff-breasted Wrens build two nest types: breeding nests used for raising offspring, and “dormitory“ nests built year-round and used by pairs for roosting overnight. The building effort of males was greater than that of their mates for dormitory nests, whereas male and female effort were similar during breeding-nest construction and nestling provisioning. Despite large within-sex variation in building and provisioning efforts, male and female effort within pairs were significantly positively correlated for construction of both nest types and for nestling feeding. Effort expended by males during dormitory-nest construction was positively correlated with nestling-provisioning effort, whereas female building effort was not. No relationship existed between effort in breeding-nest construction and nestling provisioning in either sex. These results suggest that effort in dormitory-nest construction was an indicator of male Buff- breasted Wren parental ability. Females that survived to the year following observation built dormitory nests at a lower rate than those that disappeared, which suggests that nest building may be costly and that by building more than females, males may increase the survival prospects of their partners. Dormitory-nest building by males may play dual roles throughout the year, indicating parental ability and investment in the partnership. La Construcción de Nidos es un Indicador de la Calidad de los Padres en la Especie Neotropical Monógama Thryothorus leucotis

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