ArticlePublisher preview available

No effects of asynchrony between hatching and peak food availability on chick growth in Semipalmated Plovers (Charadrius semipalmatus) near Churchill, Manitoba

March 2019
Polar Biology 42(3):1-9

DOI:10.1007/s00300-019-02456-w

Authors:

C. Anne Corkery

Erica Nol

Trent University

Laura McKinnon

York University

Birds rely on consistent patterns of food availability on their breeding grounds to successfully complete their breeding cycle. Due to ongoing warming of the sub-Arctic, there is potential for a mismatch between the peak in available invertebrate biomass and the peak in food demand for shorebird chicks. During the summers of 2010 and 2011, we investigated the relationship between temperature and benthic and terrestrial invertebrate biomass, measured using three sampling techniques in Churchill, Manitoba. We also investigated the relationship between timing of breeding of Semipalmated Plovers (Charadrius semipalmatus) and timing of peaks in invertebrate biomass. In 2011, chick growth rates were also measured to examine whether hatching in synchrony with the peak in invertebrate biomass during the brood rearing period affected growth rates. In 2010, emergent and core invertebrate biomass were negatively related to soil degree days, whereas in 2011, core biomass increased with soil degree days and pitfall biomass increased with air temperature. Total invertebrate biomass (summed over trap types) peaked from 25 to 31 days before the median chick hatch date in 2010 and 10 days after the median chick hatch date in 2011. In 2011 we did not detect any effects of asynchrony on the growth of Semipalmated Plover chicks. These results may indicate that food resources in their environment remain adequate throughout the breeding season, despite inter-annual fluctuations in the timing of invertebrate peaks.

Map of the Churchill, Manitoba study site. Black stars indicate coastal sites and gray stars indicate inland sites. Dashed lines separate major habitat types in the Churchill region

…

Plot of the four-parameter logistic growth curve for all Semipalmated Plover (Charadrius semipalmatus) chicks that were measured in the 2011 breeding season near Churchill, Manitoba. Circles represent chicks that hatched within 5 days of the peak in invertebrate biomass, and triangles represent those that hatched greater than 5 days before or after the peak

…

Boxplots of hatch dates for Semipalmated Plovers (Charadrius semipalmatus), and mean daily invertebrate biomass between 29 May and 10 August in 2010 and 2011 near Churchill, Manitoba. Boxplots present the median, 10th, 25th, 75th, 90th percentiles, and all outliers

…

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Polar Biology (2019) 42:593–601

https://doi.org/10.1007/s00300-019-02456-w

ORIGINAL PAPER

No eects ofasynchrony betweenhatching andpeak food availability

onchick growth inSemipalmated Plovers (Charadrius semipalmatus)

nearChurchill, Manitoba

C.AnneCorkery1· EricaNol1· LauraMckinnon2

Received: 26 March 2018 / Revised: 4 January 2019 / Accepted: 5 January 2019 / Published online: 22 January 2019

Abstract

Birds rely on consistent patterns of food availability on their breeding grounds to successfully complete their breeding cycle.

Due to ongoing warming of the sub-Arctic, there is potential for a mismatch between the peak in available invertebrate

biomass and the peak in food demand for shorebird chicks. During the summers of 2010 and 2011, we investigated the rela-

tionship between temperature and benthic and terrestrial invertebrate biomass, measured using three sampling techniques in

Churchill, Manitoba. We also investigated the relationship between timing of breeding of Semipalmated Plovers (Charadrius

semipalmatus) and timing of peaks in invertebrate biomass. In 2011, chick growth rates were also measured to examine

whether hatching in synchrony with the peak in invertebrate biomass during the brood rearing period aﬀected growth rates.

In 2010, emergent and core invertebrate biomass were negatively related to soil degree days, whereas in 2011, core biomass

increased with soil degree days and pitfall biomass increased with air temperature. Total invertebrate biomass (summed over

trap types) peaked from 25 to 31days before the median chick hatch date in 2010 and 10days after the median chick hatch

date in 2011. In 2011 we did not detect any eﬀects of asynchrony on the growth of Semipalmated Plover chicks. These results

may indicate that food resources in their environment remain adequate throughout the breeding season, despite inter-annual

ﬂuctuations in the timing of invertebrate peaks.

Keywords Charadrius semipalmatus· Invertebrates· Shorebird· Chick growth· Phenology· Weather

Introduction

Migratory species time their movements in part to take

advantage of seasonal ﬂushes in food resources on their

breeding grounds (Johansson and Jonzen 2012). The phe-

nology of migration in many long-distance migrant birds

is primarily driven by day length, an environmental factor

that is not inﬂuenced by weather (Both and Visser 2005).

As climate change aﬀects northern latitudes at a more accel-

erated pace than southern latitudes, diﬀerential changes in

climate may outpace the ability of populations to adapt to

climate-induced changes in the timing of resource peaks

on their breeding grounds (Both and Visser 2001; Stenseth

and Mysterud 2002; Senner 2012). A delayed migratory

response to changes in climate on the breeding grounds

could result in a later start to breeding, lower breeding suc-

cess, and a subsequent decline in population size (Both and

Visser 2001; Drever etal. 2012).

Climate change induced gaps between the timing of hatch

and peaks in food availability on the breeding grounds, here-

after “mismatch” (Stenseth and Mysterud 2002), has been

noted as one the of the possible mechanisms driving popu-

lation declines in insectivorous Arctic-nesting shorebird

populations (Tulp and Schekkerman 2008). In the Arctic,

short peaks in invertebrate abundance during mid-summer

(MacLean and Pitelka 1971; McKinnon etal. 2012; Bolduc

etal. 2013) are driven largely by temperature (Hodkinson

etal. 1998; Danks 2004). Short summer and weather-related

resource availability translates into a small window during

which there is adequate food available for reproduction and

the growth and survival of young. As such, birds breeding

* Laura Mckinnon

lmck@glendon.yorku.ca

1 Environmental andLife Sciences Graduate Program,

Trent University, 2140 East Bank Drive, Peterborough,

ONK9J7B8, Canada

2 Department ofMultidisciplinary Studies, York University

Glendon Campus, 2275 Bayview Avenue, Toronto,

ONM4N3M6, Canada

Content courtesy of Springer Nature, terms of use apply. Rights reserved.

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