Mortality in peregrine falcon nestlings due to the massive outbreak of black flies in the Canadian Arctic

Vincent Lamarre1,4 (lamarre_vincent@hotmail.com), Alastair Franke2, Erik Hedlin3, Joël Bêty1,4

Black flies: arctic troublemakers? Black flies: falcon serial killers

Monitoring the peregrine falcon Implications

Acknowledgments

• We provide the first observations of the direct effects of black flies on the survival of juveniles in an arctic-nesting bird species

• Arthropods are expected to be among the first animals to respond to global warming in the Arctic

• This response can be in the form of: • Earlier emergence • Increased abundance • Range shifts

• These changes can have cascading effects on local wildlife

• However, because their emergence can be episodic and detection

requires close monitoring, the effects of black flies (Diptera: Simuliidae) on wild animals remains poorly documented

• Here, we provide the first evidence of the effects of black flies on the reproductive success of a bird species nesting in the Canadian Arctic, the peregrine falcon

• Motion sensitive cameras deployed annually since 2008 to record breeding activities: • From egg-laying (early June) until fledging

(late August) • Set up : 1 picture/motion followed by a 3

second quiet period; 1 scheduled picture after 15 minutes of inactivity

• > 1 000 000 photos recorded annually

Fig. 1. Effects of black flies in a brood of 4 nestlings: a) female feeding the nestlings in apparent good condition prior to the infestation, b) first visible black flies on the nestlings (red arrows), c) appearance of first skin lesions (red arrows), d) female shielding the brood against ectoparasites, e) hematoma and large areas of denuded skin visible on apparently exhausted nestlings and f) female removing dead nestling from the nest.

Inland

a

f c

b e

d

Fig. 2: Proportion of nestlings killed by black flies at nests with confirmed (camera; n = 9) and probable (no camera; n = 21) presence of black flies on July 20, 2013.

Proportion of nestlings killed by black flies per nest

0% 25% 33% 50% 66% 100%

To summarize • Synchronized and ephemeral outbreak of black flies resulting

in the death of 34 nestlings (out of 96) at 15 nests on July 20 • Death potentially caused by body fluid losses and enhanced energetic expenditure

Black flies can kill falcon nestlings very rapidly (< 9hrs)

• Close monitoring of bird breeding cycles using automatic cameras will help understand the potential impacts of changes in arthropod populations on arctic wildlife

• However, we do not know if such infestations are rare events or a consequence of recent climate warming

1

4

3 2

© Erik Hedlin

© Erik Hedlin

© Erik Hedlin

Camera installation

% o

f to

tal m

ort

alit

y

• Black flies were by far the main cause of chick mortality in 2013

• Black fly oubtreak also observed in 2012 with similiar effect on nestling mortality

Fig. 4. Potential changes in the abundance and distribution of arthropods in the Arctic

Future Present

Fig.3. Causes of nestling mortality at Rankin Inlet in 2013