Resource pulses shape seasonal and individual variation in the diet of an omnivorous carnivore

Ecology and Evolution, Journal Year: 2024, Volume and Issue: 14(7)

Published: July 1, 2024

Abstract Resource pulses are ecologically important phenomenon that occur in most ecosystems globally. Following optimal foraging theory, many consumers switch to pulsatile foods when available, examples of which include fruit mast and vulnerable young prey. Yet how the availability resource shapes ecology predators is still an emerging area research; much individual variation there response not well understood. We hypothesized would lead dietary convergence our population, we tested by tracking both population‐level coyote diets for 3 years South Carolina, USA. (1) described seasonal shifts relation pulses; (2) compared male female across seasons; (3) this hypothesis quantifying within periods were available. found white‐tailed deer fawns blackberries composed over half diet summer, persimmon fruits component fall. Male coyotes generally had similar diets, but males consumed more fall, perhaps driven scavenging more. support hypothesis, where individuals during a non‐pulse period. also happened before peak availability, suggesting non‐symmetric pulse availability. show nearly all eat fawns, targeted efforts remove “fawn killers” be vain. Instead, given quickly collectively converge on pulses, findings could potentially used managers alter behavior apex predators. More broadly, open new line inquiry into decisions scales up shape effects ecological communities.

Language: Английский

---

Adaptive divergence in diets between the sexes in a tropical snake (Stegonotus australis, Colubridae)

Oecologia, Journal Year: 2025, Volume and Issue: 207(3)

Published: March 1, 2025

Males and females within a population may differ in dietary composition either as non-adaptive consequence of sexual dimorphism, or because specific food types enhance fitness more one sex than the other. To test between those two explanations, we can ask whether consumption type (a) is constrained by sexually dimorphic traits such body size, (b) differentially benefits that consumes frequently. A 23-year field study Slatey-Grey Snakes (Stegonotus australis) tropical Australia provided data on 663 meals, which 130 were reptile eggs (primarily from Keelback (Tropidonophis mairii)). Over same range snake SVLs, consumed often female male (25.8 versus 15.2% records), but was independent size. Female not common active males during nesting periods, they likely to be captured vicinity oviposition sites males. In years with higher availability eggs, had clutch sizes masses (plausibly reflecting nutritional eating provision eggs). combination, our results suggest an adaptive basis sex-based divergence Snakes.

Language: Английский

---

Can diet niche partitioning enhance sexual dimorphism?

Ecology and Evolution, Journal Year: 2022, Volume and Issue: 12(12)

Published: Dec. 1, 2022

Classic evolutionary theory suggests that sexual dimorphism evolves primarily via and fecundity selection. However, evidence are beginning to accumulate suggesting resource competition can drive the evolution of dimorphism, ecological character displacement between sexes. A key prediction this hypothesis is extent divergence sexes will be associated with dimorphism. As stable isotope ratios animal tissues provide a quantitative measure various aspects ecology, we carried out meta-analysis examining associations isotopic body size Our models demonstrate large amounts between-study variation in (ecological) nonrandom may traits study subjects. We, therefore, completed meta-regressions examine whether We found modest but significantly positive across species differences sexes, increased strength when opportunity for dietary was greatest. results, further ecologically mediated selection, not directly related reproduction, contribute

Language: Английский

---

Diet variations and morphological changes of the rockcod Patagonotothen tessellata (Teleostei: Nototheniidae) in Chilean Central Patagonia

Environmental Biology of Fishes, Journal Year: 2023, Volume and Issue: 106(6), P. 1425 - 1442

Published: May 16, 2023

Language: Английский

---

Filling the gaps in ecology of tropical tiger beetles (Coleoptera: Cicindelidae): first quantitative data of sexual dimorphism in semi-arboreal Therates from the Philippine biodiversity hotspot

PeerJ, Journal Year: 2024, Volume and Issue: 12, P. e16956 - e16956

Published: March 13, 2024

Background Sexual dimorphism, driven by sexual selection, leads to varied morphological distinctions in male and female insects, providing insights into selection pressures across species. However, research on the morphometric variability within specific taxa of tiger beetles (Coleoptera: Cicindelidae), particularly arboreal semi-arboreal species, remains very limited. Methods We investigate dimorphism six Therates beetle from Philippines, focusing traits. employed measurements multivariate analyses reveal patterns between sexes taxa. Results Our results indicate significant elytra width, with females consistently displaying broader elytra, potentially enhancing fecundity. Notable size was observed fulvipennis bidentatus T. coracinus , suggesting heightened body size. Ecological factors, mating behavior, mate choice might contribute variation. These findings emphasize need for further studies comprehend dynamics, choice, ecological influences variations beetles.

Language: Английский

---

Sharks Violate Rensch's Rule for Sexual Size Dimorphism

Integrative Organismal Biology, Journal Year: 2024, Volume and Issue: 6(1)

Published: Jan. 1, 2024

Systematic trends in body size variation exist a multitude of vertebrate radiations, however their underlying ecological and evolutionary causes remain poorly understood. Rensch's rule describes one such trend-in which the scaling sexual dimorphism (SSD) depends on sex is larger. Where SSD male-biased, should scale hyperallometrically, as opposed to hypoallometrically where female-biased. The evidence for mixed, comes from small subset total diversity. We conducted first empirical test sharks, seeking confirm or refute long-hypothesied trend. find that sharks violate rule, magnitude increases with despite predominantly exhibiting female-biased SSD. This adds growing literature clades appear not follow suggesting absence single, conserved trend amongst vertebrates. It likely selection associated fecundity results "inverse rule" observed although additional studies will be required fully reveal factors this clade.

Language: Английский

---

Breeding Diet of the Australian Red Goshawk and its Implications for Understanding the Species’ Trophic Niche and Decline

Journal of Raptor Research, Journal Year: 2024, Volume and Issue: 58(4)

Published: Sept. 5, 2024

ABSTRACT The Red Goshawk (Erythrotriorchis radiatus) is one of Australia’s least encountered birds, poorly known, and under serious threat following its recent extinction in one-third historical breeding range, population decline another that range. species now confined to the tropical savannas northern Australia as a resident yet our understanding diet trophic niche within these environments limited. Using comprehensive dataset prey records, we found Goshawks are specialized avian predators targeting specific such Rainbow Lorikeet (Trichoglossus moluccanus), Red-collared rubritorquis), Blue-winged Kookaburra (Dacelo leachii), Sulphur-crested Cockatoo (Cacatua galerita). These bird-eating habits likely require extensive home ranges may explain why exhibits extreme levels reverse sexual size dimorphism. We females hunted larger than males, increased throughout season due female hunting later season. composition appeared be influenced by habitat, with riparian areas apparently supporting higher diversity including waterbirds. Prey selection not proportional relative availability birds environment. Fledgling sex did determine delivered nests despite significant discrepancy between male young. also most depend upon remain abundant Goshawks’ former range areas. Consequently, loss populations appear account for species’ decline, although habitat change inhibit capacity hunt items.

Language: Английский

---

The Sexually Dichromatic Use of Chromatophores for Cryptic Coloration in the Shrimp Neopontonides beaufortensis

Biological Bulletin, Journal Year: 2023, Volume and Issue: 245(3), P. 120 - 128

Published: Dec. 1, 2023

AbstractSexual dimorphism typically arises as a result of sexual selection or sex-specific natural selection. Species that exhibit cryptic coloration provide an excellent system for studying dichromatism. In this study, we examined the sexually dichromatic use chromatophores in seawhip shrimp,

Language: Английский

---