scholarly journals Female breeding dispersal to higher quality habitats in a philopatric top predator

2021 ◽  
Author(s):  
Andreas Otterbeck ◽  
Andreas Lindén ◽  
Ruslan Gunko ◽  
Eeva Ylinen ◽  
Patrik Byholm
Keyword(s):  
Nest Site ◽  
Female Competition ◽  
Breeding Dispersal ◽  
Top Predator ◽  
Monogamous Species ◽  
Female Dispersal ◽  
Using Data ◽  
Breeding Seasons ◽  
Dispersal Events ◽  
Productive Landscapes

AbstractPhilopatry and monogamy are conventionally viewed as strategies for improving fitness. Many philopatric and monogamous species have, however, been shown to perform breeding dispersal—an exchange of territory (and often also partner) between two breeding seasons. The adaptiveness of breeding dispersal remains controversial, as data remain scarce and sporadic. For the Northern Goshawk, a typically highly philopatric and monogamous forest raptor, pairs breeding in barren forest landscapes produce fewer fledglings than pairs breeding in more productive landscapes. Using data on Finnish breeding female Goshawks (Accipiter gentilis) during 1999–2016, we tested the hypotheses that: (1) breeding dispersal is more likely at barren territories, (2) dispersing females move to less barren territories, and (3) breeding dispersal improves the survival of young. About 29% of the female Goshawks in our study performed breeding dispersal, which contrasts to philopatry and suggest that site and partner fidelities show large variation within the species’ breeding range. We found no evidence that territorial landscape barrenness (proxy on habitat quality) affects the probability of breeding dispersal. However, females that dispersed upgraded to less barren territories. Nevertheless, there were no subsequent effects of breeding dispersal on reproductive performance, suggesting no obvious difference in the capability of rearing young at either site. Although dispersal events were directed to less barren habitats, we suggest that female dispersal is not driven by the pursue for more prospersous habitats, rather that those females are forced to move, for whatever reason. In addition to other observed reasons such as female–female competition for mates and loss of the original mate, intense logging of mature forests lowering local food availability and restricting nest site availability were likely a partial cause of increased breeding dispersal.

Age, stucture, growth rates and movements of sea mullet, Mugil cephalus L., and Yellow-eye Mullet, Aldrichetta forsteri (Valenciennes), in the Swan-Avon river system, Western Australia

1981 ◽  
Vol 32 (4) ◽  
pp. 605 ◽  
Author(s):  
CF Chubb ◽  
IC Potter ◽  
CJ Grant ◽  
RCJ Lenanton ◽  
J Wallace
Keyword(s):  
Growth Rates ◽  
River System ◽  
First Year ◽  
Length Frequency ◽  
Frequency Distributions ◽  
Using Data ◽  
The Times ◽  
First Year Of Life ◽  
Breeding Seasons ◽  
System 1

The age structure, growth rates and movements of M. cephalus and A forsteri in the Swan-Avon river system have been investigated using data obtained from beach seining and gill netting carried out between February 1977 and June 1980. Length-frequency data and scale readings show that the populations of both species consist predominantly of 0+ and 1 + fish. From the times when the smallest fry (20-30 mm) were present in the lower part of the river system, and from the condition of the gonads of older fish, the breeding seasons of the sea and yellow-eye mullets have been estimated as extending from March to September and from March to August respectively. The bimodality or polymodality exhibited by the length-frequency distributions for the 0 + year classes suggest that in both species groups of individuals spawn at slightly different times. The range of mean total lengths and weights of animals caught in May near the end of the first year of life was 178-222 mm and 64-119 gin M. cephalus and 136-154 mm and 19-30 g in A. forsteri, which shows that the growth of each of these two species of mullet is relatively very rapid in the Swan-Avon river system. 1 + and 2 + fish tend to leave the estuary for varying periods. Although 0+ fish of both species utilized the shallow banks of the estuary throughout the year. the sea mullet moved further upstream and were not as consistently abundant in the lower estuary. Since 0+ yellow-eye mullet 40-100 mm long were also abundant in marine coastal waters between January and May. and sea mullet of comparable age were rarely observed in these regions, it would appear that M. cephalus is the more estuarine-dependent of the two species. Commercial catches of M. cephalus were greater than those of A. forsteri. This feature can be related in part to the much faster growth rate of M. cephalus, which results in a larger proportion of its youngest year classes reaching the minimum legal size for capture prior to the time when they leave the estuary in large numbers.

scholarly journals Social status, forest disturbance, and Barred Owls shape long-term trends in breeding dispersal distance of Northern Spotted Owls

The Condor ◽  
2019 ◽  
Vol 121 (4) ◽  
Author(s):  
Julianna M A Jenkins ◽  
Damon B Lesmeister ◽  
Eric D Forsman ◽  
Katie M Dugger ◽  
Steven H Ackers ◽  
...  
Keyword(s):  
Forest Disturbance ◽  
Dispersal Distance ◽  
Historical Study ◽  
Breeding Dispersal ◽  
Spotted Owls ◽  
Dispersal Distances ◽  
Dispersal Events ◽  
Northern Spotted Owls ◽  
Barred Owls ◽  
Over Time

Abstract Dispersal among breeding sites in territorial animals (i.e. breeding dispersal) is driven by numerous selection pressures, including competition and spatiotemporal variation in habitat quality. The scale and trend of dispersal movements over time may signal changing conditions within the population or on the landscape. We examined 2,158 breeding dispersal events from 694 male and 608 female individually marked Northern Spotted Owls (Strix occidentalis caurina) monitored over 28 yr on 7 study areas to assess the relative importance of individual (sex, experience), reproductive (annual productivity, mate availability), and environmental (forest alteration, presence of competitor) sources of variation in breeding dispersal distance. Median breeding dispersal distance was 3.17 km, with 99% of all breeding dispersal events <37 km. Mean annual dispersal distances increased by 2.43 km in Oregon and 9.40 km in Washington between 1990 and 2017, which coincided with increases in annual detections of nonnative Barred Owl (S. varia). Frequency of breeding dispersal events, both among and within individuals, also increased over time. Female owls moved farther than males (median of 3.26 and 3.10 km, respectively), and birds with less experience (territory tenure) moved farther than those with more experience. Owls that were single in the year prior to dispersal moved 13–31% farther than those paired prior to dispersal. The greatest environmental change occurring over the course of our study was the expansion of Barred Owl populations. Breeding dispersal distance was positively related to Barred Owls in the study area and disturbance within the originating territory. While it appears that social factors continue to be important drivers of breeding dispersal distance in Spotted Owls, increased competition from Barred Owls and habitat alteration have a contributing effect. Increased breeding dispersal distances should be of concern for conservation efforts and considered in population monitoring because changing dispersal behavior may lead to higher rates of mortality and/or emigration from historical study areas.

Nesting ecology of flatback sea turtles Natator depressus from Delambre Island, Western Australia

2020 ◽  
Vol 71 (4) ◽  
pp. 443 ◽  
Author(s):  
Michele Thums ◽  
Jason Rossendell ◽  
Rebecca Fisher ◽  
Michael L. Guinea
Keyword(s):  
Western Australia ◽  
Site Selection ◽  
Nest Site ◽  
Sea Turtle ◽  
Nest Site Selection ◽  
Coastal Development ◽  
Environmental Drivers ◽  
Nesting Ecology ◽  
Using Data ◽  
Natator Depressus

Nest site selection is likely to be important for the fitness of sea turtle populations, but data on the environmental drivers of nest site selection and other important parameters like nest site fidelity and inter-nesting and remigration intervals are limited. We address these questions using data on flipper tag resightings and track counts from flatback turtles (Natator depressus) from Delambre Island in Western Australia collected over 2–3 weeks each nesting season across six nesting seasons. The median inter-nesting interval was 13 days (range 9–17 days) and the mean±s.d. remigration interval was 1.99±0.95 years. Turtles had around 10% probability of returning to the same sector of the beach (150-m-long sections). The median distance between subsequent emergences (whether false crawls were included or not) was ~450m. The number of turtles both emerging and successfully nesting was higher when air temperature and humidity were lowest and emergences increased slightly with tide height. Sector of the beach was by far the strongest predictor of nest site, with turtles showing preference for the less exposed side of the island. The results of this study will assist with future monitoring of this population and the management of threats related to coastal development and activities.

scholarly journals Understanding resource driven female–female competition: ovary and liver size in sand gobies

2019 ◽  
Vol 6 (9) ◽  
pp. 190886 ◽  
Author(s):  
Aurora García-Berro ◽  
Johanna Yliportimo ◽  
Kai Lindström ◽  
Charlotta Kvarnemo
Keyword(s):  
Baltic Sea ◽  
North Sea ◽  
Nest Site ◽  
Operational Sex Ratio ◽  
Female Competition ◽  
The Baltic Sea ◽  
Nest Sites ◽  
The North ◽  
The North Sea ◽  
The Baltic

The operational sex ratio (OSR, ready-to-mate males to females) is a key factor determining mating competition. A shortage of a resource essential for reproduction of one sex can affect OSR and lead to competition within the opposite sex for resource-holding mates. In the sand goby ( Pomatoschistus minutus ), a fish with paternal care, male readiness to mate depends on acquiring a nest-site, whereas food abundance primarily impacts female egg production. Comparing body condition and gonadal investment of fish from two populations with different availability in resources (Baltic Sea: few nest-sites, more food; North Sea: many nest-sites, less food), we predicted females carrying more mature eggs in the Baltic Sea than in the North Sea. As predicted, ovaries were larger in Baltic Sea females, and so was the liver (storage of energy reserves and vitellogenic compounds) for both sexes, but particularly for females. More females were judged (based on roundness scores) to be ready to spawn in the Baltic Sea. Together with a nest colonization experiment confirming a previously documented difference between the two areas in nest-site availability, these results indicate a more female-biased OSR in the Baltic Sea population, compared to the North Sea, and generates a prediction that female–female competition for mating opportunities is stronger in the Baltic population. To our knowledge, this is the first time that female reproductive investment is discussed in relation to OSR using field data.

Influence on the variation in initiation of breeding in Peromyscus maniculatus

1991 ◽  
Vol 69 (3) ◽  
pp. 698-705 ◽  
Author(s):  
Sean T. Sharpe ◽  
J. S. Millar
Keyword(s):  
Reproductive Success ◽  
Peromyscus Maniculatus ◽  
Nest Site ◽  
Subalpine Forest ◽  
Stream Beds ◽  
Timing Of Initiation ◽  
Overwinter Mortality ◽  
Breeding Seasons ◽  
The Relationship ◽  
Forest Habitats

Correlates of the initiation of breeding by female Peromyscus maniculatus borealis (Mearns) were examined to test the hypotheses that asynchronous breeding was related to age, weight, matriline, and nest-site habitat. Life-history data were collected by mark–recapture techniques and by monitoring natal nests over two breeding seasons in 1985 and 1986. Timing of initiation of breeding was related significantly to nest-site habitat and age, but not to matriline or weight. At approximately the same altitude, females nesting in dry rocky stream beds bred first, followed by those in open rock fields, then shrub areas, and last in subalpine forest. Youngest animals bred first in all habitats, although the relationship between age and initiation date was weak. Habitat effects appeared to be primarily related to microclimatic effects. The influence of habitat on the timing of initiation of breeding also had consequences for reproductive success, total reproductive output, and survival. Reproductive success of first litters was greatest for females nesting in rocky stream beds in the spring and least for females nesting in shrub and forest habitats. The apparent advantages of early breeding in rocky stream beds were offset by greater overwinter mortality.

scholarly journals Female Dispersion Is Necessary, But Not Sufficient, For The Evolution of Monogamy in Mammals

2020 ◽  
Author(s):  
R.I.M. Dunbar
Keyword(s):  
Reproductive Success ◽  
Opportunity Cost ◽  
Selection Pressure ◽  
Mate Searching ◽  
Monogamous Species ◽  
Typical Day ◽  
Male Mate ◽  
Using Data

AbstractExplanations for the evolution of monogamy in mammals typically emphasise one of two possibilities: monogamy evolves when females are overdispersed (such that males cannot defend more than one female at a time) or when males provide a service to the female. However, the first claim has never been directly tested. I test it directly at three levels using data from primates and ungulates. First, I show that the females of monogamous genera do not have territories that are significantly larger, either absolutely or relatively, than those of polygamous genera. Second, using both the Mitani-Rodman and Lowen-Dunbar inequalities, I show that, given their typical day journey lengths, males of most monogamous species could easily defend an area large enough to allow them to monopolise as many as 5-10 females if these ranged solitarily. Finally, I use a model of male mate searching strategies to show that, unlike the males of socially-living polygamous species, the opportunity cost that monogamous males incur is typically more than five times the reproductive success they have by being obligately monogamous. This suggests that the selection pressure dissuading them from pursuing a roving male strategy must be very considerable.

scholarly journals Renesting Decisions and Annual Fecundity of Female Dickcissels (Spiza Americana) in Illinois

The Auk ◽  
2004 ◽  
Vol 121 (4) ◽  
pp. 1250-1261 ◽  
Author(s):  
Jeffery W. Walk ◽  
Kevin Wentworth ◽  
Eric L. Kershner ◽  
Eric K. Bollinger ◽  
Richard E. Warner
Keyword(s):  
Breeding Season ◽  
Nest Site ◽  
Demographic Information ◽  
Nest Failure ◽  
Spiza Americana ◽  
Nest Sites ◽  
Site Characteristics ◽  
Breeding Seasons

Abstract Renesting decisions and annual fecundity are crucial for interpreting other demographic information, yet are infrequently reported. We used radiotelemetry to monitor female Dickcissels (Spiza americana) throughout the 1999 and 2000 breeding seasons in southeastern Illinois. Overall fecundity (regardless of whether females remained in the study area throughout the breeding season) was 0.61 ± 0.13 female fledglings per year. Of females that remained within the study area, 94% fledged young (1.25 ± 0.15 female fledglings per year). Most females (62%) that experienced nest failure emigrated from the study area (moved >10 km) in 2.8 ± 0.6 days; others (36%) initiated subsequent nests in 8.5 ± 0.8 days. After fledging ≥1 young, 95% of females ceased breeding for the season. Successful and failed nest sites were indistinguishable on the basis of vegetative characteristics. Moreover, replacement nests had similar vegetative characteristics and were similar distances from habitat edges, compared with initial nests, which suggests that female Dickcissels do not or cannot “improve” nest-site characteristics in response to nest failure. We observed two behaviors unusual in female Dickcissels: one bird that fledged two broods in one season, and the return of five females banded in 1999 to the study site in 2000.

scholarly journals Breeding-Season Decisions, Renesting, and Annual Fecundity of Female Eastern Meadowlarks (Sturnella Magna) in Southeastern Illinois

The Auk ◽  
2004 ◽  
Vol 121 (3) ◽  
pp. 796-805 ◽  
Author(s):  
Eric L. Kershner ◽  
Jeffery W. Walk ◽  
Richard E. Warner
Keyword(s):  
Site Selection ◽  
Population Biology ◽  
Nest Site ◽  
Adult Survival ◽  
Demographic Parameter ◽  
Site Characteristics ◽  
Sturnella Magna ◽  
Double Brooding ◽  
Selection For ◽  
Breeding Seasons

Abstract Annual fecundity is a demographic parameter that is elemental to population biology, but accurate measures of fecundity are rarely obtained. We used radiotelemetry to follow female Eastern Meadowlarks (Sturnella magna) throughout the 1999-2000 breeding seasons in southeastern Illinois to estimate their annual fecundity and assess if the outcome of initial nesting attempts affected site selection for subsequent nests. Thirty-four females built 52 nests (1.53 ± 0.12 nests female−1), but only 21 females (62%) fledged young. Only 44% of females renested at the study site, and more females (53%) emigrated after successfully fledging young from an initial nest than after failing in their first attempt (21%). Nest-site characteristics were similar between successful and failed nests for both initial and subsequent attempts. Females that failed during first attempts did not change nest characteristics for renests. Given that few females were double-brooded and that unsuccessful females did not persistently renest, annual fecundity for females nesting at the study site was between 1.27 ± 0.38 and 1.36 ± 0.37 female young year−1. On the basis of our fecundity measure, we estimated that annual adult survival of 59–61% was necessary for maintenance of a stable population (λ = 1.0). Failure of most females to attempt to raise two broods suggests that double brooding carries substantial costs for meadowlarks.

Reproductive Ecology of Silver Gulls, Larus-Novaehollandiae Stephens, in South-Australia

1988 ◽  
Vol 15 (5) ◽  
pp. 541 ◽  
Author(s):  
JR Ottaway ◽  
R Carrick ◽  
MD Murray
Keyword(s):  
Nest Site ◽  
Reproductive Ecology ◽  
Spatial Relationship ◽  
South Australia ◽  
Spatial Separation ◽  
Nest Sites ◽  
The One ◽  
Breeding Seasons ◽  
Relationship Of ◽  
Do So

Aspects of the reproductive ecology of silver gulls, Larus novaehollandiae Stephens, were studied in South Australia during 1968-78. Some 15 950 pulli and 597 breeding adults were banded on 15 colonies, using numbered and coloured leg bands designed for identification of free-living individuals without the necessity of recapture. Nine colonies were on marine islands, four were on lacustrine islands, one was on a port breakwater, and one was on causeways in a saltworks complex. Fidelity to colony, mate and nest-site, and timing of breeding are considered in detail. The spatial relationship of adult and immature gulls, on the colony studied in greatest detail, and reproductive longevity of the gulls are also discussed. The gulls nested from June to December inclusive, although the commencement and length of breeding seasons varied between colonies and between years. There was a marked absence of 1-year-old gulls on breeding colonies. Of 3530 pulli banded on the major study colony, Penguin Island (37�30''S., 140�01''E.) at Beachport, in 1968, 950 were known to be alive in the 1970 breeding season. Almost 40% of these 2-year-olds were seen on breeding colonies, and mostly on the natal colony; however, only 0.3% were known to raise pulli, and a further 0.7% to produce eggs. Significant breeding activity therefore did not commence until the end of the third year, or later. The older, previously established breeders on Penguin Island were significantly more successful, and had significantly earlier laying dates, than younger birds. Potential reproductive longevity appears to be at least 11 breeding seasons. In this study, silver gulls showed considerably less fidelity to nest-sites and colonies than has been suggested previously. Significant shifts of nest-site, or change of colony, with or without the previous mate, were not uncommon. Of gulls banded on nests as established breeding aduls, 7-44% of gulls found breeding in subsequent years were at colonies other than the one where banded. In 1970, over 80% of 2-year-old gulls recorded present on any colony were only recorded on the natal one. Of the pulli banded on Penguin Island in 1968 and 1969 and later found actually nesting or breeding, 18% were recorded on other colonies. A small percentage of gulls were seen to have high fidelity to nest-site and to mate over 3 or 4 seasons, but it is suggested that, for some colonies, over 50% of silver gulls which eventually breed may do so at colonies other than natal. Significant spatial separation was found on Penguin Island between areas generally occupied by established breeders, which were known to be at least 4-year-olds, and by the 2-year-olds. The older birds may select and hold the territories most suitable for nesting, where vegetation or topography minimise intraspecific aggression which often leads to high mortality rates of eggs and pulli, and assist protection of eggs and pulli from extreme weather. Non-breeding gulls associating with the colonies occasionally move into the nesting areas, but are aggressively forced away and tend to congregate on the periphery of the colony or on exposed areas not suitable for successful breeding.

A test of the condition-bias hypothesis using Brown-headed Cowbirds trapped during the breeding season

1991 ◽  
Vol 69 (10) ◽  
pp. 2686-2692 ◽  
Author(s):  
Kevin W. Dufour ◽  
Patrick J. Weatherhead
Keyword(s):  
Breeding Season ◽  
Molothrus Ater ◽  
Foraging Strategies ◽  
Feeding Response ◽  
Poor Condition ◽  
Males And Females ◽  
Using Data ◽  
Breeding Seasons ◽  
Mist Net ◽  
Trap Bias

We examined trap bias relative to body condition, age, and sex using data collected from Brown-headed Cowbirds (Molothrus ater) decoy trapped during the 1987 and 1988 breeding seasons. A condition bias was evident, as decoy-trapped birds were in poor condition relative to those caught by mist net in an adjacent roost. This occurred in both sexes and independently of study year and male age. Paradoxically, however, males in better condition when first trapped were more likely to be recaptured in the same season, possibly reflecting more widespread movement, and hence fewer encounters with traps, by birds in poor condition. Hatching-year birds were more likely than adults to be recaptured in the same season. Trapped samples were strongly male biased, which probably reflects a difference in nutritional requirements, and thus foraging strategies, between males and females during the breeding season. This study indicates that biases among birds trapped by methods that rely on a feeding response are likely to be widespread and difficult to predict, suggesting that interpretation of data from such samples always requires caution.

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