FOOD SUPPLY AND PARENTAL FEEDING RATES OF HOODED WARBLERS IN FOREST FRAGMENTS

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.

Download Full-text

SURVIVAL OF FLEDGLING HOODED WARBLERS (WILSONIA CITRINA) IN SMALL AND LARGE FOREST FRAGMENTS

The Auk ◽

10.1525/auk.2008.125.1.183 ◽

2008 ◽

Vol 125 (1) ◽

pp. 183-191 ◽

Cited By ~ 56

Author(s):

SCOTT A. RUSH ◽

BRIDGET J. M. STUTCHBURY

Keyword(s):

Forest Fragments ◽

Wilsonia Citrina ◽

Hooded Warblers

Download Full-text

Testing predictions of inclusive fitness theory in inbreeding relatives with biparental care

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.1933 ◽

2019 ◽

Vol 286 (1916) ◽

pp. 20191933 ◽

Cited By ~ 1

Author(s):

Elizabeth A. Gow ◽

Peter Arcese ◽

Danielle Dagenais ◽

Rebecca J. Sardell ◽

Scott Wilson ◽

...

Keyword(s):

Parental Care ◽

Mating System ◽

Feeding Rate ◽

Inclusive Fitness ◽

Empirical Studies ◽

Feeding Rates ◽

Extra Pair Paternity ◽

Inclusive Fitness Theory ◽

Parental Feeding ◽

Focal Male

Inclusive fitness theory predicts that parental care will vary with relatedness between potentially caring parents and offspring, potentially shaping mating system evolution. Systems with extra-pair paternity (EPP), and hence variable parent–brood relatedness, provide valuable opportunities to test this prediction. However, existing theoretical and empirical studies assume that a focal male is either an offspring's father with no inbreeding, or is completely unrelated. We highlight that this simple dichotomy does not hold given reproductive interactions among relatives, complicating the effect of EPP on parent–brood relatedness yet providing new opportunities to test inclusive fitness theory. Accordingly, we tested hierarchical hypotheses relating parental feeding rate to parent–brood relatedness, parent kinship and inbreeding, using song sparrows ( Melospiza melodia ) experiencing natural variation in relatedness. As predicted, male and female feeding rates increased with relatedness to a dependent brood, even controlling for brood size. Male feeding rate tended to decrease as paternity loss increased, and increased with increasing kinship and hence inbreeding between socially paired mates. We thereby demonstrate that variation in a key component of parental care concurs with subtle predictions from inclusive fitness theory. We additionally highlight that such effects can depend on the underlying social mating system, potentially generating status-specific costs of extra-pair reproduction.

Download Full-text

Prey selectivity and parental feeding rates of Blue Tits Cyanistes caeruleus in relation to nestling age

Bird Study ◽

10.1080/00063657.2012.662939 ◽

2012 ◽

Vol 59 (2) ◽

pp. 236-242 ◽

Cited By ~ 17

Author(s):

Vicente García-Navas ◽

Esperanza S. Ferrer ◽

Juan José Sanz

Keyword(s):

Prey Selectivity ◽

Feeding Rates ◽

Cyanistes Caeruleus ◽

Parental Feeding ◽

Blue Tits

Download Full-text

Influence of forest management on pre- and post-fledging productivity of a Neotropical migratory songbird in a highly fragmented landscape

Canadian Journal of Forest Research ◽

10.1139/x11-119 ◽

2011 ◽

Vol 41 (10) ◽

pp. 2009-2019 ◽

Cited By ~ 10

Author(s):

Margaret L. Eng ◽

Bridget J. M. Stutchbury ◽

Dawn M. Burke ◽

Ken A. Elliott

Keyword(s):

Forest Management ◽

Ecological Trap ◽

Cumulative Probability ◽

Fragmented Landscape ◽

Forest Fragments ◽

Reference Sites ◽

Partial Harvest ◽

Male Density ◽

Fledgling Survival ◽

Hooded Warblers

Little is known about the effects of forest management on fledgling survival in birds, despite the fact that this is a key determinant of overall productivity. In 2005–2006, we compared male density, nesting success, and fledgling survival of Hooded Warblers (Wilsonia citrina Boddaert, 1783) among forest fragments that were reference sites (n = 3; not logged in >21 years) or had received either a standard selection system harvest (n = 3) or a heavy cut (n = 5) within the past 6–10 years. Density tended to be higher in logged sites than reference sites, but cumulative probability of nest survival (0.22 ± 0.02; 21 days) did not differ among treatments. Brown-headed Cowbird (Molothrus ater (Boddaert, 1783)) parasitism was significantly higher in recently logged sites, and reference sites produced significantly more Hooded Warbler young per successful nest than standard selection harvest sites. Logging treatment did not have a strong negative effect on fledgling survival, and overall, 51% (33/65) of fledglings survived until three weeks after fledging. Standard selection harvest sites had the highest Hooded Warbler density (0.2 males/ha) but also the lowest seasonal productivity (0.84 independent fledglings/female), raising the possibility of an ecological trap. The estimated number of daughters produced per female per year that are expected to survive to breeding age was lower for all treatments (reference, 0.26; selection, 0.17; heavy cut, 0.32) than the expected annual mortality probability of adult females (0.4–0.6). Forest fragments in this region appear to be population sinks, regardless of extent of partial harvest within the fragment.

Download Full-text

Division of labour by song sparrows feeding fledged young

Canadian Journal of Zoology ◽

10.1139/z78-028 ◽

1978 ◽

Vol 56 (2) ◽

pp. 187-191 ◽

Cited By ~ 46

Author(s):

James N. M. Smith

Keyword(s):

Young Male ◽

Division Of Labour ◽

Feeding Rates ◽

Young Leave ◽

Male And Female ◽

Energy Demands ◽

Song Sparrows ◽

Breeding Territory ◽

Parental Feeding ◽

Family Division

Parental feeding of nestlings and fledglings is described in an individually marked population of song sparrows. Thirty-five broods of nestlings were observed in 1976 and 68 broods of fledglings in 1977. On leaving the nest, individual young dispersed to separate locations in the breeding territory where, at 13 days of age, a single parent fed each young. In broods with even numbers of young, male and female parents divided the young equally in most cases. With odd numbers of young, either male or female could feed the extra young, but females did so more often. Older young were more mobile and harder to observe, but there was some evidence that family division persisted. Male parents played a larger role in feeding older young than younger ones. Feeding rates of 13-day-old young were 44% higher than those of 7- to 8-day-old nestlings, suggesting that energy demands of young and investment of parents are maximal after young leave the nest. I suggest that division of labour helps parents to locate young and regulate their parental feeding efficiently.

Download Full-text

Environmental factors affecting growth and survival of juvenile western rock lobsters Panulirus longipes (Milne-Edwards)

Marine and Freshwater Research ◽

10.1071/mf9750177 ◽

1975 ◽

Vol 26 (2) ◽

pp. 177 ◽

Cited By ~ 96

Author(s):

RG Chittleborough

Keyword(s):

Growth Rate ◽

Food Supply ◽

Growth Increment ◽

Dominant Factor ◽

Feeding Rates ◽

Continuous Darkness ◽

Growth And Survival ◽

Factors Affecting ◽

In The Wild ◽

The Impact

The effects of temperature, photoperiod, oxygen, food supply, crowding, and autotomy of limbs have been measured under controlled conditions in aquaria. Growth rate increased with temperature to a maximum 26� C above which both growth rate and survival declined. Varying the length of photoperiod did not affect growth rate or survival, except that the growth rate was depressed significantly in continuous darkness. A mild deficiency of oxygen (60-67 % saturation) resulted in a smaller size increment at a moult; depression to 47-55 % saturation caused deaths at ecdysis. Daily feeding was necessary to maintain maximum rate of growth. The fist response to decreased food supply was a reduction in frequency of moulting. More severe shortage of food also depressed growth increment per moult. Feeding rates and conversion ratios have been measured. Frequency of moulting (and hence growth rate) was depressed markedly when juveniles were held in isolation. At a moult replacing two lost limbs, the growth rate was not affected; replacement of four limbs reduced that moult increment. Single loss of up to four limbs did not result in an earlier moult, but repetitive loss of two or more limbs at or immediately after each ecdysis led to precocious moulting. The impact of these and other components of the environment (shelter, salinity, turbidity, competitors and predators) upon juveniles during the 4 years spent on shallow coastal reefs is discussed. Food supply is emerging as the dominant factor determining growth and survival in the wild population.

Download Full-text

Intersexual variation and factors affecting parental care in Western Bluebirds: a comparison of nestling and fledgling periods

Canadian Journal of Zoology ◽

10.1139/z90-106 ◽

1990 ◽

Vol 68 (4) ◽

pp. 733-742 ◽

Cited By ~ 17

Author(s):

Kimberly A. With ◽

Russell P. Balda

Keyword(s):

Parental Care ◽

Close Association ◽

Feeding Rates ◽

Energetic Costs ◽

Factors Affecting ◽

Brooding Period ◽

Parental Feeding ◽

Nestling Period ◽

Brood Division ◽

Western Bluebirds

We compared factors affecting parental feeding rates in Western Bluebirds (Sialia mexicana) between the nestling and fledgling periods to evaluate intersexual variation in parental care. Parents did not adjust the frequency of feeding visits between modal (five young) and below-modal (four or less young) broods during the nestling period. The frequency of parental feeding visits also was not significantly affected by offspring age during the nestling period. Males and females exhibited no significant differences in provisioning offspring, although males maintained a constant level of care throughout the nestling period, whereas females increased feeding visits following the brooding period. During the fledgling period, offspring from below-modal broods were fed at higher rates with increasing age than offspring from modal broods. Broods remained together (siblings averaged 8 m apart) within 200 m of the nest box for a week after fledging. As fledglings became more mobile, they would pursue parents while parents were foraging; parental feeding rates thus tended to increase with fledgling age and distance moved from the nest. Offspring sex did not influence parental care during the fledgling period. Both adults fed fledglings, with males taking sole care of fledglings if females initiated a second clutch soon (7–10 days) after fledging of the first brood. Parental feeding rates increased by 60% during the fledgling period compared with the nestling period. No evidence for brood division during the fledgling period was found. Although brood division represents one way of reducing energetic costs attributable to feeding fledglings, Western Bluebirds exhibit an alternate behavior in which the energetics of raising a brood are shared equally between the parents throughout both the nestling and fledgling periods. This is further facilitated by a close association of young during the fledgling period that may reduce energetic costs related to locating and feeding young.

Download Full-text

The Effects of Parent and Offspring Gender On Food Allocation in Budgerigars

Behaviour ◽

10.1163/156853987x00422 ◽

1987 ◽

Vol 101 (1-3) ◽

pp. 177-199 ◽

Cited By ~ 51

Author(s):

Judy Stamps ◽

Anne Clark ◽

Barbara Kus ◽

Pat Arrowood

Keyword(s):

Reproductive Success ◽

Sex Ratios ◽

Negative Relationship ◽

Female Parent ◽

Feeding Rates ◽

Significant Relationships ◽

Parental Feeding ◽

Highly Correlated ◽

Offspring Gender ◽

Negative Relationships

AbstractParental feeding rates in relation to the sex of parents and offspring were studied in domesticated budgerigars in large flight cages at Davis, California. While neither the male nor the female parent preferentially fed offspring of either sex, paternal feeding rates were strongly related to the sex ratio of the brood. Fathers fed female-biased broods much more frequently than male-biased broods throughout the nest cycle, and male feeding rates were highly correlated with the sex ratios of the broods. Mothers exhibited a similar but much weaker tendency to feed female-biased broods more often, and only at the end of the nest cycle was there a barely significant relationship between sex bias and maternal feeding rate. As a result of the extra parental care, female-biased broods obtained nearly three times more regurgitations in the final pre-fledge period than male-biased broods. Brood sex ratios were unrelated to fledge weights, and male and female nestlings fledged at comparable weights. However, for all but the smallest broods, there was a strong negative relationship between the percent of females within the brood and the average age of fledging. Fledge age, in turn, was related to post-fledge activity rates. Females fledging at younger ages initiated more flights than those fledging at older ages. Conversely, in males, fledge age was either unrelated, or positively related to the rate of flights. There were also significant negative relationships between female fledge age and reproductive success (e.g. number of young fledged in the first breeding season), but no significant relationships between male fledge age and reproductive success. Hence, male parents may provide extra care to broods biased toward the offspring sex which most benefits from this extra care.

Download Full-text