Editing Grebe (section)

==Natural history==
===Habitat, distribution and migration===
Grebes are a nearly cosmopolitan clade of [[waterbirds]], found on every continent except [[Antarctica]]. They are absent from the [[Arctic Circle]] and arid environments. They have successfully colonized islands such as [[Madagascar]] and [[New Zealand]]. Some species such as the [[eared grebe]] (''Podiceps nigricollis'') and [[great crested grebe]] (''P.&nbsp;cristatus'') are found on multiple continents with regional subspecies or populations. A few species like the [[Junin grebe]] (''P.&nbsp;taczanowskii'') and the recently extinct [[Atitlán grebe]] (''Podilymbus gigas'') are lake endemics. During the warmer or breeding seasons, many species of grebes in the northern hemisphere reside in a variety of [[freshwater]] habitats like [[lake]]s and [[marsh]]es. Once winter arrives many will migrate to [[marine environment]]s along the coastlines. Grebes are most prevalent in the [[New World]] with almost half of the world's species native there.{{page needed|date=March 2023}}<ref name="Harrisonetal2021">{{cite book | last1 = Harrison | first1 =P. | last2 = Perrow | first2 =M. | last3 = Larsson | first3 =H. | year=2021 | title=Seabirds: The New Identification Guide. | publisher = Lynx Ediciones |location=Barcelona | isbn = 978-84-16728-41-1}}</ref>

===Feeding ecology===
The feeding ecology of grebes is diverse. Larger species such as those in the genus ''[[Aechmophorus]]'' have spear-like bills to catch mid-depth fish while smaller species such as those in the genera ''[[Tachybaptus]]'' and ''[[Podilymbus]]'' tend to be short and stout with a preference for catching small aquatic invertebrates. The majority of grebes predate on aquatic invertebrates, with only a handful of large-bodied [[piscivore]]s. The aforementioned ''Aechmophorus'' is the most piscivorous of the grebes. Closely related species that overlap in their range often avoid interspecific competition by having prey preferences and adaptations for it. In areas where there is just as a single species, they tend to have more generalized bills with more openness to different prey sources.<ref name="Johnsgard1987">{{cite book | last1 = Johnsgard | first1 =P. |year=1987 |title=Diving Birds of North America. | publisher=University of Nebraska Press | location=Nebraska | isbn = 9780803225664}}</ref>{{Rp|40–41}}
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| image1            = PodilymbusPodiceps 6798.JPG
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| caption1          = The [[pied-billed grebe]] (''Podilymbus podiceps'') is a small species of grebe that mostly hunts aquatic invertebrates. Here a parent feeds its chicks a crayfish.
| image2            = Dinner is Served (29844986194).jpg
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| caption2          = The [[Clark's grebe]] (''Aechmophorus clarkii'') is a large species of grebe that mostly hunts fish. Here a parent feeds its chick.
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===Breeding and reproduction===
Grebes are perhaps best known for their elaborate courtship displays. Most species perform a duet together and many have their own synchronized rituals. Some, like those species in the genus ''[[Podiceps]]'' do a "penguin dance" where the male and female stand upright, breast posturing out and run along the water's surface. A similar ritual in other species is the "weed dance" in which both partners hold pieces of aquatic vegetation in their bills and are positioned upright towards each other. There is also the "weed rush" in which partners swim towards each other, necks stretched out with weeds in their bill, and just before colliding position themselves upright and then swim in parallel.{{cn|date=April 2023}}

In the smaller and basal genera like ''Tachybaptus'' and ''Podilymbus,'' there is incorporation of aquatic vegetation in their courtship, but it is not as elaborate as the more derived and larger species. It has been hypothesized that such courtship displays between mates originated from intraspecific aggression that evolved in a way that strengthened pair bonds. Once these courtship rituals are completed, both partners solicit copulation towards each other and mount on floating platforms of vegetation.  Females lay two to seven eggs and incubation can last nearly a month. Chicks of the nest hatch asynchronously. Once the whole nest has hatched, the chicks begin to climb on one of their parent's backs. Both parents take care of rearing their young, and the duration of care is longer than those of other waterfowl. This enables a greater survival rate for the chicks. One parent dives for food, while the other watches the young on the surface.<ref name="Johnsgard1987" /><ref name="Ogilvie2002">{{cite book | last1 = Ogilvie | first1 = M. A. |year=2002 |title=Grebes of the World. | publisher=  Bruce Coleman Books | location= | isbn = 978-1872842035}}</ref>{{Rp|14–16}}<ref name="Fjeldså2004">{{cite book | last1 = Fjeldså | first1 =J. |year=2004 |title=The Grebes. | publisher=Oxford University Press | location=Oxford | isbn = 978-0198500643}}</ref>{{Rp|113–114}}

===Parasitology===
[[File:Theromyzon (YPM IZ 058099) 002.jpeg|thumb|The leech genus ''[[Theromyzon]]'' is an external parasite that has been found in the nasal cavities of grebes.]]

249 species of [[parasitic worm]]s have been known to parasitize the intestinal region of grebes. The [[Amabiliidae|amabiliid]]s are a family of [[Cyclophyllidea|cyclophyllid]] [[Cestoda|cestodes]] that are almost all grebe specialists. The life cycle of these tapeworms begins when eggs are passed through the feces, where they are picked by intermediate hosts, which include [[Corixidae|corixid]] [[Hemiptera|bug]]s and the nymphs of [[Odonata]]. These aquatic insects are eventually be consumed by grebes, where the lifecycle begins again. Another grebe specialist family of internal parasites are the [[Dioecocestidae]]. Other families such as [[Echinostomatidae]] and [[Hymenolepididae]] also contain several cestode species that are grebe specialists.<ref name="Storer2000">{{Cite journal |last1=Storer |first1=R. W. |year=2000 |title=The metazoan parasite fauna of grebes (Aves: Podicepediformes) and its relationship to the birds' biology. |journal=Miscellaneous Publications-Museum of Zoology, University of Michigan. |volume =  |issue = 188 |pages = 1–99}}</ref>

The prominent external parasites of grebes are the [[lice]] of the clade [[Ischnocera]]. One genus of these lice, ''[[Aquanirmus]],'' is the only one that is a grebe specialist. Another major group of parasites are the two [[mite]]s of the families [[Rhinonyssidae]] and [[Ereynetidae]]; these infect the nasal passages of grebes. The rhinonyssids move slowly in the mucous membranes, drinking blood, while the ereynetids live on the surface. Various lineages of feather mites of the clade [[Analgoidea]] have evolved to occupy different sections of the feather. ''[[Theromyzon]]'' ("duck leeches") tend to feed in the nasal cavities of waterbirds in general, including grebes.<ref name="Storer2000"/>